Process for the depyrophorization of pyrophoric metal catalysts and uses thereof
This is a division, of application Ser. No. 806,238, filed June 13, 1977, now U.S. Pat. No. 4,176,092. 
    
    
     The present invention relates to a process for the depyrophorisation of pyrophoric metal catalysts by reacting them with organic nitro or nitroso compounds. 
     Pyrophoric metal catalysts are to be understood as compositions which contain one or more metals in a very finely divided form and are used for catalytic purposes. Catalysts of this type are in use under the most diverse names, for example catalysts of the black type, such as platinum black and palladium black; also supported catalysts which contain metals, in particular noble metals, in a very finely divided form on a support, such as active charcoal, silicon dioxide, kieselguhr and aluminium oxide, for example platinum-on-active charcoal, palladium-on-active charcoal and nickel-on-kieselguhr, as well as catalysts of the Raney type. 
     The so-called Raney catalysts have acquired very particular importance as pyrophoric metal catalysts. Raney catalysts are obtained by dissolving out from an alloy of a catalytically active metal, in most cases nickel, with a catalytically inactive metal, for example aluminium, the aluminium being dissolved out using an alkali metal hydroxide solution under the influence of heat (U.S. Pat. No. 1,563,587). A metal sludge is obtained by this procedure, which possesses a severely fissured and porous structure and has a skeleton of metal crystals, for which reason these catalysts are also designated skeleton catalysts. The most frequently encountered representative of this type is Raney nickel, which is named after its inventor. Raney nickel consists essentially of aluminium, aluminium oxide constituents and hydrogen, in addition to the main component, nickel. The charging of the Raney catalysts with hydrogen in the course of their preparation is the basis of their use as hydrogenation catalysts and is responsible for their pyrophoric properties. 
     The pyrophoric character of these catalysts necessitates a number of instructions, which involve considerable expenditure, for their handling and storage and, in particular, also for their transportation. For example, it must be ensured that pyrophoric catalysts are never exposed to atmospheric oxygen, that is to say that the catalyst never dries out and is always covered with a layer of liquid, generally water. This condition can lead to considerable difficulties in the hydrogenation of compounds which can be reacted only in anhydrous solvents, since the catalyst must be washed free from water before its use. When the water is replaced by combustible organic solvents, for example benzene, working with these catalysts becomes particularly critical. The pyrophoric character of the metals must be taken into account also when carrying out the hydrogenation reactions. For example, the hydrogenation apparatus has to be carefully rinsed with an inert gas before being filled with the contact catalyst, in order to prevent the contact catalyst from igniting the organic solvent on the entry of air. 
     In the publication by J. Troger and G. Vollheim, Chemiker-Zeitung 99 (1975), page 446 to 452, it is thus stated (page 451, right-hand column, line 1 to 6): 
     &#34;Thus repeated attempts have been made to prepare a Raney nickel which is non-pyrophoric and yet has the same high activity as the pyrophoric type. Although many routes have been followed, no catalyst has hitherto been found with which this aim would have been achieved.&#34; 
     Of the many attempts which have been made to reduce or remove the adverse properties of the pyrophoric metal catalysts, the following measures, for example, for the treatment of pyrophoric metal catalysts have been proposed: treatment with carbon dioxide/oxygen mixtures (U.S. Pat. No. 2,677,668); with H 2  O/vapour at 150° C. (Chem. Techn. 15, 583 et seq. (1963)); with oxygen (Ind. Chim. belge 17, 581 (1952)) and with CO 2  at 200° C. (J. Sci. Res. Inst. (Tokio) 51, 168 (1957), and Japanese Patent 4325); with gelatine in the presence of Na 2  SO 4  solution, H 2  CO and other admixtures (Canadian Pat. No. 869,533); with Na 2  Cr 2  O 7  (U.S. Pat. No. 3,563,915 and with NaOCl or H 2  O 2  or KMnO 4  or K 2  Cr 2  O 7  (DAS (German Published Specification) No. 1,299,286); with CO 2  at 200° to 650° C. (U.S. Pat. No. 2,461,396); and with HNO 3  or NH 4  NO 2  or NaNO 3  or NaNO 2  (DAS (German Published Specification) No. 2,209,000) and with NaNO 2   (U.S. Pat. No. 2,810,666). 
     However, all these processes and the catalysts which are obtainable thereby have considerable disadvantages. In particular, the catalysts are brought into contact with foreign substances in the course of these processes, which can have the effect of catalyst poisons when the catalysts are charged with these foreign substances or even when only traces of these foreign substances enter into the catalysts treated in this manner. A further disadvantage of the proposed processes for the treatment of pyrophoric metal catalysts is that the catalysts thus obtained must be reactivated before their employment, so that a pre-treatment becomes necessary before the employment. 
     On the other hand, the modern chemical industry requires increasingly larger amounts of active catalysts which, with respect to their activity, should behave as pyrophoric contact catalysts, but, with regard to the continuously increasing requirements of transportation and use safety, should behave as non-pyrophoric catalysts in order to reduce or completely eliminate the danger of fire and explosion. 
     It has now been found that non-pyrophoric, highly active metal catalysts can be prepared from pyrophoric metal catalysts when a suspension of the pyrophoric metal catalyst in water and/or an organic solvent is treated with an organic nitro compound or a nitroso compound. 
     In general, the treatment with the nitro compound or the nitroso compound is carried out at temperatures of about 5° to about 250° C., preferably at 20° to 200° C. and particularly preferably at 40° to 150° C. This treatment can be carried out under normal pressure, under increased pressure or also under reduced pressure. Pressures of 1 to 30 bars are preferaly used. The treatment is particularly preferably carried out at pressures of 2 to 10 bars. In general, the ratio of nitro compound or nitroso compound to metal catalyst is 0.05 to 100 mols of nitro or nitroso group per 1 g atom of metal in the catalyst. The ratio of mols of nitro compound or nitroso compound to g atoms of metal catalyst is preferably 0.25 to 20:1, and particularly preferably 0.5 to 5:1. Very preferentially, this ratio is about 1:1. The time of the action of the nitro compound, which is added in the form of an aqueous, aqueous-alkaline or a non-aqueous solution to the aqueous or organic suspension of the metal catalyst, can be varied within wide limits and is 5 minutes to 10 hours, preferably 10 minutes to 5 hours. It can also be appropriate to use the nitro compound in the undiluted form, that is to say not dissolved in an organic solvent. 
     If the pyrophoric metal catalyst is employed as a suspension in an organic solvent alone or mixed with water or an aqueous-alkaline medium, the most diverse organic solvents which are inert towards the nitro or nitroso groups in the corresponding compounds can be used. It can sometimes be appropriate for the solvent used to form a homogeneous phase with the nitro or nitroso compound or the solution of the nitro or nitroso compounds, but this is in no way necessary for carrying out the process according to the invention. Solvents which can be used for the suspension of the pyrophoric metal catalyst to be employed are, for example: aliphatic, cycloaliphatic or aromatic as well as heterocyclic compounds, which can also be substituted. Suitable aliphatic hydrocarbons are straight-chain or branched hydrocarbons with 1-12, preferably with 5-8, hydrocarbon atoms. Cyclic hydrocarbons which can be used are those with 5-7, preferably with 6, carbon atoms in the ring system. Heterocyclic compounds which can be used are those with 5-7, preferably 6, atoms in the ring system. Suitable heterocyclic compounds are preferably 5-membered and 6-membered system which can contain oxygen and/or nitrogen as the hetero-atom. 
     The compounds employed as solvents can contain substituents, such as halogen atoms, for example fluorine, chlorine and bromine; hydroxyl, amino, sulphonic acid and carboxyl groups, as well as their esters; and C 1  -C 4  -alkoxy groups and C 1  -C 12  -alkyl radicals. Particularly preferred organic solvents which can be used are hydrocarbons, such as hexane, cyclohexane, benzene, toluene and xylene; alcohols, such as methanol, ethanol, propanol, isopropanol, butanol, amyl alcohol, ethylene glycol, glycerol and cyclohexanol; ethers, such as ethylene glycol monoethers and ethylene glycol diethers, ethylene glycol monotolyl ether and triethylglycol methyl ether; ketones, such as acetone; amines, such as ethylamine, cyclohexylamine and ethylenediamine; and phenols, such as phenol, 3-acetoxyphenol, resorcinol and pyrocatechol, as well as mixtures and blends of these compounds in the most diverse compositions. 
     Furthermore, solvents which can be used for the process according to the invention are aromatic and aliphatic hydrocarbons which contain small additions of water and additions of the compounds listed above, especially of alcohols. Thus, the following mixtures of alcohols with water have proved particularly suitable: isopropanol/water, methanol/water, ethanol/water, glycerol/water and ethylene glyol/water. The water contents can be chosen as desired and are, in general, 5-95, preferably 10-50%. Finally, solvents which can be used for the process according to the invention are water and aqueous solutions or suspensions of alkalis, such as, for example, the oxides, hydroxides, carbonates and bicarbonates of the alkali metals and alkaline earth metals, it being possible for the concentrations of these solutions to be chosen as desired. In general, they are 0.5-70, preferably 5-50 and very preferentially 10-40, % by weight. 
     Suitable organic nitro compounds or nitroso compounds with which the pyrophoric metal catalyst can be treated by the process according to the invention are the most diverse types of compounds. Both saturated, straight-chain or branched aliphatic, cycloaliphatic or aromatic systems and heterocyclic systems can be used which contain at least one nitro or nitroso group, it being possible for the compounds mentioned also to be substituted. Suitable aliphatic nitro or nitroso compounds are the appropriate straight-chain or branched compounds with 1 to 12, preferably 1 to 8, carbon atoms. Cycloaliphatic nitro or nitroso compounds which can be used are those with 5 to 7 carbon atoms, preferably those with 6 C atoms, in the ring system. In general, aromatic nitro and nitroso compounds which can be employed in the process according to the invention contain up to 14 carbon atoms, preferably 6 to 10 carbon atoms, in the aromatic nucleus. Suitable heterocyclic nitro or nitroso compounds are preferably 5-membered and 6-membered heterocyclic compounds which can contain oxygen and/or nitrogen as hetero-atoms. The heterocyclic compounds can also be fused once or twice with an optionally completely or partially hydrogenated aromatic ring. The nitro or nitroso compounds to be employed can contain 1 to 3 nitro groups or 1 to 3 nitroso groups in the molecule. Possible further substituents of the nitro and nitroso compounds mentioned are halogen atoms, such as fluorine, chlorine and bromine; hydroxylamino, sulphonic acid and carboxyl groups as well as their esters; and C 1  -C 4  -alkoxy groups, carbonyl groups and C 1  -C 12  -alkyl radicals. In general, nitroso compounds which can be used are all compounds of very different structure containing a nitroso group, for example also nitrosomethylurea. From the relevant technical literature it is known, with respect to the nitroso compounds, that they do not occur in large numbers as is the case with the corresponding nitro compounds since, in general, the nitroso compounds are classed as unstable substances. 
     In detail, the following nitro compounds are preferably suitable for use in the process according to the invention: nitrobenzenes and halogenonitrobenzenes, such as nitrobenzene, monochloronitrobenzenes, dichloronitrobenzenes, trichloronitrobenzenes, dinitrobenzenes and mono-, di and tri-chlorodinitrobenzenes, nitrotoluenes and halogenonitrotoluenes, such as nitrotoluene, mono-, di- and tri-chloronitrotoluenes, nitrobenzyl chlorides, 4-chloro-3-nitro-benzotrifluoride, dinitrotoluene, dinitrotoluene/toluylenediamine mixtures, nitroxylenes, 4-nitrobiphenyl, nitronaphthalenes, such as mono- and di-nitronaphthalene, mono- and di-nitronaphthalenesulphonic acids and their salts, nitrophenols, mono-, di- and tri-nitrophenols, mono- and di-nitroanisoles, nitrodiphenyl ethers, mono- and di-nitrophenetols, mono-, di- and tri-nitrochlorophenols, nitrochloroanisoles, chloronitrodiphenyl ethers, nitrosophenols, nitro derivatives of thiophenols, such as nitrodiphenyl sulphones and dinitrodiphenyl sulphides, nitrocresols, such as mono- and di-nitrocresols, nitroalkylanisoles, nitrobenzaldehydes, such as nitrobenzaldehyde and chloronitrobenzaldehydes, nitroacetophenones, nitrobenzoic acid derivatives, such as nitrobenzoic acid, nitrobenzoic acid esters, mono- and di-nitrochlorobenzoic acid and esters thereof, nitrotoluic acid and esters thereof and nitrohydroxybenzoic acid and esters thereof, nitrophenylsulphonic acids and their salts, such as nitrophenolsulphonic acids and the Na salt, and chloronitrophenolsulphonic acid and the Na salt, nitrophenylamines, such as mono- and di-nitroanilines, and N-alkyl-nitroanilines, nitrodiphenylamines, nitrochloroanilines, nitroalkanes, such as nitromethane and nitroethane, and 2-nitro-5-phenyl-thiomethoxyacetanilide. 
     In detail, nitroso compounds which can be used are: tert.-nitrosolentane, nitrosocyclohexane, nitrosodiethylaniline. nitrosodimethylamine, p-nitrosodimethylaniline, nitrosocresols, nitrosonaphthols, nitrosonaphthylamine, nitrosonitrotoluenes, nitrosophenols, nitrosopropionic acid, nitrosoresorcinol, nitrososalicylic acid and esters of nitrosalicylic acid, nitrosothymol, nitrosotoluidine, N-nitrosodiphenylamine, hydroxynitrosonaphthalenesulphonic acid, nitrobenzene, N-nitrosomethylurethane and N-nitrosomethylurea. 
     The organic nitro compounds or nitroso compounds can be treated in the most diverse forms with the pyrophoric metal catalysts. They can be employed either free from solvents and in the liquid or solid form or as solutions of any desired concentration in aqueous or non-aqueous solvents. Solvents which can be used are preferably all systems which are inert towards the nitro or nitroso groups in the corresponding compounds under the particular conditions of the process according to the invention. In general, the solvents used form a homogeneous phase with the nitro or nitroso compound. However, it is in no way necessary for the treatment according to the invention that the nitro or the nitroso compound homogeneously dissolves in the solvent. When water is used, for example, as a rule a two-phase system is formed with the nitro compound, which, however, is also suitable for the process according to the invention. Such two-phase systems can optionally also be used in the form of an emulsion, for example if a suitable emulsifier is added. 
     Solvents which can be used for the organic nitro or nitroso compounds are those solvents which have already been mentioned for the suspension of the pyrophoric metal catalyst to be employed in the process according to the invention. 
     The organic nitro or nitroso compounds can be metered into the initially introduced suspension of the pyrophoric metal catalyst, or vice versa. Preferably, the solution of the organic nitro or nitroso compound is metered into the suspension of the pyrophoric metal catalyst, this preferably being suspended in the same solvent which has served as a solvent for the organic nitro or nitroso compound. 
     Metal catalysts, the pyrophoric character of which arises from the surface or also from physically or chemically bonded hydrogen, such as are described, for example, in Chemiker-Zeitung, 99, (1975), page 447 to 448, can be used as pyrophoric metal catalysts, for the process according to the invention, which consist of one or more components and which can also contain one or more active metals. 
     For example, pyrophoric catalysts which contain metals of the groups IIa, IIIb, IVa, IVb, Vb, VIb, VIIb, VIII and Ib of th periodic system according to Mendeleev (a=main group elements, b=sub-group elements) and the rare earths can be employed in the process according to the invention. In detail, there may be mentioned, for example: thallium, vanadium, chromium, manganese, iron, cobalt, titanium, nickel, copper, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold and lead. Preferably Raney catalysts are employed in the process according to the invention. Nickel-containing or nickel- and iron-containing catalysts are very particularly employed. 
     The reaction can be carried out up to a maximum temperature of 250° C., preferably in the range from 20° to 200° C. It is appropriate to carry out the reaction with the addition of an inert gas under a slight excess pressure. If the pyrophoric metal catalyst is stored under water for reasons of safety, it can be advantageous to remove as much water as possible or, if the nitro or nitroso compound is employed as a solution, to replace the water by the solvent employed. The duration of the treatment with the nitro or nitroso compound by the process according to the invention is about 5 minutes to about 10 hours, preferably 10 minutes to 5 hours and particularly preferably 15 minutes to 2 hours. After the treatment with the nitro or nitroso compound, the catalyst, which is now depyrophorised, is separated off for working-up, which in general is effected by a filtration process which is accessible in industry. The catalyst is then washed and, if appropriate, dried. 
     The feasibility of carrying out the process industrially is illustrated with the aid of the depyrophorisation of Raney nickel. 
     After replacing the associated water by a suitable solvent, for example isopropanol, pyrophoric Raney nickel is initially introduced and treated with a solution of an organic nitro compound, for example dinitrotoluene in isopropanol, in the ratio of mols of NO 2  to g atoms of Ni of 0.1 to 20:1 at 30° to 70° C. After a reaction time of several hours, for example 4 hours, the catalyst is filtered off, washed, if necessary, with an organic solvent, for example isopropanol; and dried. The solutions obtained by this procedure can be either worked up by processes which are in themselves known or, after replacing the nitro compound consumed, by fresh nitro compound, re-employed in the process according to the invention. 
     The essential advantage of the process according to the invention compared with the process known hitherto for the preparation of completely or partially non-pyrophoric catalysts is that the depyrophorised catalysts thus obtained are not contaminated by contact catalyst poisons and start to function, without any pre-activation, at comparable, or only insignificantly elevated, temperatures to the pyrophoric catalysts on which they are based, that is to say that the catalytic activity of the catalysts depyrophorised by the process according to the invention is comparable to that of pyrophoric catalysts. When used repeatedly, the catalysts depyrophorised by the process according to the invention exhibit a very long life whilst the activity remains constant. 
     The process according to the invention can be carried out industrially in the sump phase, in the trickle phase or in the gas phase. The treatment of the Raney catalysts with nitro or nitroso compounds can be carried out discontinuously or continuously, for example in a cascade. 
     The main advantage of the non-pyrophoric catalysts prepared according to the invention is their completely problemfree handling, which makes possible transportation and storage without special restrictions and makes a more precise metering possible, compared with pyrophoric catalysts. 
     The despatch of the catalysts depyrophorised by the process according to the invention can be carried out in the dry form free from the transportation restrictions for dangerous goods, it being possible for the catalysts to be packed, stored and despatched in any desired packagings. Ballast substances, such as water, in which pyrophoric catalysts are as a rule suspended for despatch and storage, are dispensed with. Also, the danger of the ignition of organic solvents or other combustible substances on entry of air is eliminated in the case of the non-pyrophoric catalysts prepared according to the invention. 
     When pyrophoric Raney catalysts are employed in anhydrous media, the replacement of water by the required medium, for example benzene, is carried out before the actual catalytic reaction. When non-pyrophoric Raney catalysts, obtainable by the process according to the invention, are employed this not unhazardous process step is also avoided. 
     The present invention furthermore relates to the use of the non-pyrophoric metal catalysts for the most diverse hydrogenation processes. For example, all hydrogenation reactions, which are otherwise carried out with the corresponding pyrophoric catalysts, can be carried out with the nonpyrophoric metal catalysts prepared according to the invention, for example the Raney catalysts. In order to indicate, for example, the extent of the use possibilities of the non-pyrophoic Raney catalysts, the monograph by B. M. Bogoslowski and S. S. Kaskowa &#34;Skelettkatalysatoren in der organischem Chemie&#34; (&#34;Skeleton Catalysts in organic Chemistry&#34;), VEB Deutscher Verlag der Wissenschaften, Berlin 1960, chapter 3, &#34;Verwendung von Nickel-Skelettkatalysatoren in der organischen Chemie&#34; (Use of nickel skeleton catalysts in organic chemistry), page 40-124 is referred to. The catalysts according to the invention can be used for all the hydrogenation processes listed there. 
     Accordingly, for example, the metal catalysts prepared according to the invention can be employed for the hydrogenation of unsaturated hydrocarbons with an ethylenic and/or triple bond, or of diene systems, of aromatic compounds, such as, for example, benzene, naphthalene, diphenyl and their derivatives, or of anthraquinone and phenanthrene, of heterocyclic compounds with oxygen or sulphur atoms in the ring system, of carbonyl groups, of carboxyl groups or their esters, of carbon-nitrogen comounds, such as, for example, nitriles, acid amides, oximes and ketimines, of unsaturated compounds containing halogen, sulphur, nitroso and nitro groups, of azo and azoxy compounds, of hydrazines, Schiff&#39;s bases, imines and amines, of carbon-oxygen compounds, such as, for example, alcohols, ethers, ethylene oxides and organic peroxides and ozonides, of carbon-carbon compounds and of nitrogen-nitrogen compounds. 
     The metal catalysts prepared according to the invention are preferably used for the hydrogenation of nitroso and nitro compounds of aromatic hydrocarbons and of nitriles. 
     The use of the depyrophorised metal catalysts prepared by the process according to the invention is explained with the aid of the hydrogenation of a 2,4/2,6-dinitroltoluene mixture as follows. 
     The hydrogenation is carried out in a continuous sump phase hydrogenation apparatus, which consists of four reactors of customary construction connected in series, with the aid of which a hydrogen cycle is produced. 
     A catalyst depyrophorised by the process according to the invention, for example Raney nickel/iron, is suspended, in the hydrogenation apparatus, in an isopropanol/water mixture, for example with the composition 85% by weight of isopropanol and 15% by weight of water, as the solvent and, after adding a mixture of 65% by weight of 2,4-dinitrotoluene and 35% by weight of 2,6-dinitrotoluene, the treatment is then carried out at elevated pressure, for example 80-150 bars of nitrogen pressure, and at temperatures of 100°-200° C. The maximum throughput is about 5-6 tonnes of dinitrotoluene per hour. The consumption of catalyst is about 0.01-0.04% by weight of catalyst per kg of dinitrotoluene mixture. 
     The results achieved in the hydrogenation of a 2,4/2,6-dinitrotoluene mixture (65/35) are also to be observed for 2,4/2,6-dinitrotoluene (80/20) and for pure 2,4-dinitrotoluene. 
    
    
     EXAMPLES 
     Part A: Pyrophoric Catalysts Employed 
     Preparation of Raney catalysts from the corresponding aluminium alloys 
     The finely powdered Al alloy is added to initially introduced 20-25% strength cold sodium hydroxide solution in portions, whilst stirring and under an inert gas, whereupon the ratio of g atoms of Al to mols of NaOH should be between 1:3 to 1:4. The aluminium contained in the alloy dissolves as sodium aluminate, with vigorous evolution of hydrogen. During the dissolving process, in which, in general, at least 95% of the aluminium is dissolved out, the reaction temperature should not exceed 80° C. When the entire alloy has been added, the mixture is subsequently allowed to react at 80° C. for a further 1 to 2 hours and the crude catalyst is decanted off from the aluminate liquor. In order to remove adhering aluminate liquor, the crude catalyst is treated for a further 1 hour with 6-7 liters of 20% strength NaOH/kg of crude catalyst at 80° C. and the black metal sludge obtained after decanting is washed with water until the pH value of the wash water is pH 8. 
     The Raney catalysts employed for the depyrophorisation by the process according to the invention, according to the illustrative embodiments which follow, can be prepared by the above instructions. Wherever used herein, the term &#34;g atoms&#34; refers, of course, to &#34;gram atoms&#34;. 
     The composition of the individual Raney catalysts is shown in the following table. 
     
         __________________________________________________________________________
Composition of the Ra catalysts used                                      
Alloy              Ra catalysts                                           
__________________________________________________________________________
Al/Ni  70.00% by weight of Al                                             
                   Ra Ni  95.00% by weight of Ni.sup.1                    
       30.00% by weight of Ni                                             
                          5.00% by weight of Al                           
Al/Ni/Fe                                                                  
       60.00% by weight of Al                                             
                   Ra Ni-Fe                                               
                          82.00% by weight of Ni.sup.1                    
       34.00% by weight of Ni                                             
                          15.00% by weight of Fe                          
       6.00% by weight of Fe                                              
                          3.00% by weight of Al                           
Al/Ag  50.00% by weight of Al                                             
                   Ra Ag  95.00% by weight of Ag                          
       50.00% by weight of Ag                                             
                          5.00% by weight of Al                           
Al/Cu  70.00% by weight of Al                                             
                   Ra Cu  95.00% by weight of Cu                          
       30.00% by weight of Cu                                             
                          5.00% by weight of Al                           
Al/Co  70.00% by weight of Al                                             
                   Ra Co  95.00% by weight of Co.sup.1                    
       30.00% by weight of Co                                             
                          5.00% by weight of Al                           
Al/Co/Fe                                                                  
       60.00% by weight of Al                                             
                   Ra Co-Fe                                               
                          82.00% by weight of Co                          
       34.00% by weight of Co                                             
                          15.00% by weight of Fe                          
       6.00% by weight of Fe                                              
                          3.00% by weight of Al                           
Al/Co/Ni/Fe                                                               
       70.00% by weight of Al                                             
                   Ra Co-Ni-Fe                                            
                          91.50% by weight of Co                          
       28.30% by weight of Co                                             
                          3.65% by weight of Ni                           
       1.13% by weight of Ni                                              
                          1.84% by weight of Fe                           
       0.57% by weight of Fe                                              
                          3.00% by weight of Al                           
Al/Ni/Cu                                                                  
       70.00% by weight of Al                                             
                   Ra Ni-Cu                                               
                          87.30% by weight of Ni                          
       27.00% by weight of Ni                                             
                          9.70% by weight of Cu                           
       3.00% by weight of Cu                                              
                          3.00% by weight of Al                           
Al/Cu/Zn                                                                  
       50.00% by weight of Al                                             
                   Ra Cu-Zn                                               
                          64.00% by weight of Cu                          
       33.00% by weight of Cu                                             
                          33.00% by weight of Zn                          
       17.00% by weight of Zn                                             
                          3.00% by weight of Al                           
Al/Ni/Fe/Cr                                                               
       60.00% by weight of Al                                             
                   Ra Ni-Fe-Cr                                            
                          87.30% by weight of Ni                          
       36.00% by weight of Ni                                             
                          4.85% by weight of Fe                           
       2.00% by weight of Fe                                              
                          4.85% by weight of Cr                           
       2.00% by weight of Cr                                              
                          3.00% by weight of Al                           
__________________________________________________________________________
 .sup.1 The residual aluminium constituents were not taken into account   
 when calculating the experimental mixtures.                              
 
    
     
         __________________________________________________________________________
Alloy              Ra catalysts                                           
__________________________________________________________________________
Al/Ni/Fe/Ag                                                               
       59.00% by weight of Al                                             
                   Ra Ni-Fe-Ag                                            
                          75.70% by weight of Ni                          
       32.00% by weight of Ni                                             
                          18.90% by weight of Fe                          
       8.00% by weight of Fe                                              
                          2.40% by weight of Ag                           
       1.00% by weight of Ag                                              
                          3.00% by weight of Al                           
Al/Ni/Fe/Cu                                                               
       59.00% by weight of Al                                             
                   Ra Ni-Fe-Cu                                            
                          75.70% by weight of Ni                          
       32.00% by weight of Ni                                             
                          18.90% by weight of Fe                          
       8.00% by weight of Fe                                              
                          2.40% by weight of Cu                           
       1.00% by weight of Cu                                              
                          3.00% by weight of Al                           
Al/Ni/Fe/Ti                                                               
       59.00% by weight of Al                                             
                   Ra Ni-Fe-Ti                                            
                          75.70% by weight of Ni                          
       32.00% by weight of Ni                                             
                          18.90% by weight of Fe                          
       8.00% by weight of Fe                                              
                          2.40% by weight of Ti                           
       1.00% by weight of Ti                                              
                          3.00% by weight of Al                           
Al/Ni/Fe/V                                                                
       59.00% by weight of Al                                             
                   Ra Ni-Fe/V                                             
                          75.70% by weight of Ni                          
       32.00% by weight of Ni                                             
                          18.90% by weight of Fe                          
       8.00% by weight of Fe                                              
       1.00% by weight of V 40% by weight of V                            
                          3.00% by weight of Al                           
Al/Ni/Fe/Mo                                                               
       59.00% by weight of Al                                             
                   Ra Ni-Fe-Mo                                            
                          75.70% by weight of Ni                          
       32.00% by weight of Ni                                             
                          18.90% by weight of Fe                          
       8.00% by weight of Fe                                              
                          2.40% by weight of Mo                           
       1.00% by weight of Mo                                              
                          3.00% by weight of Al                           
Al/Ni/Fe/Pb                                                               
       59.00% by weight of Al                                             
                   Ra Ni-Fe-Pb                                            
                          75.70% by weight of Ni                          
       32.00% by weight of Ni                                             
                          18.90% by weight of Fe                          
       8.00% by weight of Fe                                              
                          2.40% by weight of Pb                           
       1.00% by weight of Pb                                              
                          3.00% by weight of Al                           
                   Ra Ni-Pt.sup.1                                         
                          92.00% by weight of Ni                          
                          5.00% by weight of Pt                           
                          3.00% by weight of Al                           
                   Ra Ni-Pd.sup.1                                         
                          92.00% by weight of Ni                          
                          5.00% by weight of Pd                           
                          3.00% by weight of Al                           
                   Ra Ni/Au.sup.1                                         
                          92.00% by weight of Ni                          
                          5.00% by weight of Au                           
                          3.00% by weight of Al                           
__________________________________________________________________________
 .sup.1 These Raney catalysts were prepared by subsequent treatment of    
 Raney nickel with the corresponding noble metal salts.                   
 
    
     Part B: Depyrophorised Catalysts, Illustrative Embodiments 
     Example 1 
     Depyrophorisation 
     Before the start of the experiment, all the air in a stirred glass apparatus, which is provided with a dropping funnel which can be heated, a gas inlet tube for inert gas and a vertical tube, is expelled by means of an inert gas. If a reaction is carried out at the boiling point of the reaction medium, the reaction apparatus must additionally be fitted with a reflux condenser. The pyrophoric Raney catalyst is now initially introduced as a suspension in a solvent, for example about 100 g of Raney nickel as an aqueous suspension corresponding to 50 g of 100% Raney nickel*), under an inert gas. In general, in the Raney catalyst/solvent suspension initially introduced, this solvent is then replaced by that solvent for the nitro compound, for example water by isopropanol. A solution containing the required amount of nitro compound, for example 773.5 g of dinitrotoluene 2,4/2,6-isomer mixture of the composition 80% by weight to 20% by weight (DNT 80/20) as a 10% strength by weight solution in isopropanol, corresponding to the ratio of g atoms of active metal to mols of nitro compound given above, is added dropwise to the Raney nickel/isopropanol suspension thus obtained, whilst stirring, starting at room temperature. In the present example, the ratio of g atoms of Ni to mols of DNT 80/20 is 1:5. 
    
     In order to prevent, if appropriate, the dissolved nitro compound from crystallising out, the solution of the nitro compound, for example in the form of the isopropanol solution, must be employed after warming to 40° C. This solution is added at such a rate that the reaction temperature of, for example, 50° C., is not exceeded. Since the reaction is weakly exothermic, external cooling with water is sufficient to maintain this reaction temperature. In order to bring the reaction to completion, the mixture is further stirred at this temperature until the total reaction time is 30 minutes. The Raney catalyst treated in this way is separated off from the mother liquor at 45°-50° C. on a heatable frit, washed with 50 ml of isopropanol, dried in a stream of inert gas and then discharged as a non-pyrophoric, dry powder. In general, the yield is 95-98%. In the present example, 49 g of non-pyrophoric Raney nickel, corresponding to 98% of theory, are obtained. The activity of the non-pyrophoric catalyst thus obtained is determined by the hydrogenation of DNT 80/20 under standard conditions. 
     Testing 
     80±0.1 g of solid dinitrotoluene (80/20) as well as 240±1 g of isopropanol and 10 g of the Raney catalyst to be tested are successively weighed out and filled into a 0.7 l V4A stirred autoclave. 
     The autoclave is flushed with H 2  and subjected to a pressure test at 100 bars of H 2  before the hydrogenation is started. During the reaction, the reaction temperature is registered with a temperature recorder. The reaction temperature reached after starting up is recorded. At the start of the hydrogenation, the stirrer is switched on, it being necessary to ensure that the stirring speed is always constant in all experiments. The reaction mixture becomes saturated with H 2 , the initial pressure of 100 bars falling a few bars to a constant value. The pressure is increased again to 100 bars and the mixture is stirred for 1-2 minutes. The mixture must be heated up, if appropriate by additional heating, until the start temperature is achieved. The amount of hydrogen consumed in the course of the hydrogenation is carefully replaced again, the heat liberated during the reaction determining the rate of the reaction, since the maximum hydrogenation temperature should be 100°±3° C. For this reason it is advisable to allow the initial pressure to fall from 100 bars to 10 bars and subsequently to carry out the reaction in the pressure range from 10-30 bars until no further absorption of H 2  can be detected and the reaction temperature slowly falls. The reaction has thus ended. This can also be recognised by the fact that an increase in pressure to 100 bars of H 2  causes no jump in temperature and no further decrease in pressure. The reaction mixture is allowed to react for a further 10 minutes under this pressure and at the temperature reached at the end of the reaction, whilst heating externally. If the hydrogenation described above has ended, the resulting reaction mixture is separated off from the catalyst by decanting and the latter is appropriately reemployed for further hydrogenation reactions. The constituents of the reaction mixture are subsequently analysed. If the hydrogenation reactions are carried out at higher pressures, so much heat of reaction is liberated that the maximum hydrogenation temperature given above of 100°±3° C. cannot be maintained. In order to make a more precise statement regarding the life, series of experiments must be carried out with repeated use of the catalyst to be investigated. 
     Examples 2-6 
     The depyrophorisation of Ra Ni 30/70 was carried out according to Example 1 with DNT 80/20 as a 10% strength by weight solution in isopropanol, but changing the ratios of g atoms of Ni to mols of DNT. 
     
         ______________________________________                                    
                       Ratio of                                           
                       g atoms                                            
              Ni g     of Ni to                                           
Ex-           of DNT   mols of                                            
ample g of Ra 80/20    DNT    Yield                                       
______________________________________                                    
2     41.36   128.1    1:1    40   g = 96.7% of theory                    
3     47.8    111      1:0.75 46   g = 96.2% of theory                    
4     40.58   62.8     1:0.5  40   g = 98.5% of theory                    
5     48.65   37.7     1:0.25 48   g = 98.6% of theory                    
6     32.0    12.4     1:0.125                                            
                              31.5 g = 98.4% of theory                    
______________________________________                                    
 
    
     The catalysts obtained gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
                            Running H.sub.2                               
       Use in hy-                                                         
                 Start temp-                                              
                            time [min-                                    
                                    consumption                           
Example                                                                   
       drogenation                                                        
                 erature [°C.]                                     
                            utes]   [bars]                                
______________________________________                                    
2      1st       55         33      225                                   
       2nd-6th   25-27      29-33   225                                   
3      1st       41         29      225                                   
       2nd-6th   25-27      27-34   225                                   
4      1st       58         31      230                                   
       2nd-6th   25-28      22-31   210-225                               
5      1st       52         31      225                                   
       2nd-15th  25-27      29-33   220-225                               
       16th-30th 28         33      220                                   
6      1st       36         33      220                                   
______________________________________                                    
 
    
     EXAMPLE 7 
     Example 1 was repeated, but 27.70 g of 100% Ra Ni were employed with 1.159 g of nitrobenzene without a solvent, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitrobenzene of 1:20. 
     27.2 g (98.1% of theory) of non-pyrophoric catalyst were obtained. 
     Example 8 
     Example 1 was repeated, but 8.45 g of 100% Ra Ni were employed with 1.770 g of nitrobenzene without a solvent, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitrobenzene of 1:100. 
     8.3 g (89.2% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  88° C. start                                              
                     230 bars H.sub.2                                     
                                 9 minutes                                
         temperature consumption hydrogenation                            
                                 time                                     
2nd-3rd use                                                               
         77-88° C.                                                 
                     230 bars H.sub.2                                     
                                 8-9 minutes                              
         start       consumption hydrogenation                            
         temperature             time                                     
______________________________________                                    
 
    
     Examples 9-12 
     The depyrophorisation of Ra Ni 30/70 was carried out according to Example 4 with DNT 80/20 as a 10% strength by weight solution in isopropanol, but changing the reaction time. 
     
         ______________________________________                                    
               Ni g     Reaction                                          
               of DNT   time                                              
Example                                                                   
       g of Ra 80/20    [hours]                                           
                               Yield                                      
______________________________________                                    
 9     37.47   58       0.5    37.1 g = 99% of theory                     
10     38.33   59.3     1      38   g = 99% of theory                     
11     29.47   45.5     2      29   g = 98.4% of theory                   
12     42.62   65.9     4      42.2 g = 99% of theory                     
______________________________________                                    
 
    
     Examples 13-17 
     The depyrophorisation of Ra Ni 30/70 was carried out according to Example 1, but using an isomer mixture of 2,4/2,6-dinitrotoluene 1 ) and 2,4/2,6-diaminotoluene 2 ) in the form of a 30% strength by weight solution in isopropanol, and changing the ratios of g atoms of Ni to mols of DNT. 
    
    
     
         ______________________________________                                    
                       Ratio of                                           
                       g atoms                                            
              Ni g of  of Ni to                                           
Ex-           isomer   mols of                                            
ample g of Ra mixture  DNT    Yield                                       
______________________________________                                    
13    46.49   431      1:1    46.1 g = 99% of theory                      
14    39.24   240.5    1:0.666                                            
                              38.9 g = 99.1% of theory                    
15    52.73   242.6    1:0.5  52.5 g = 98.9% of theory                    
16    22.82   52       1:0.25 22.3 g = 97.7% of theory                    
17    30.62   34.5     1:0.125                                            
                              30.3 g = 98.9% of theory                    
______________________________________                                    
 
    
     The resulting catalysts gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
                            Running H.sub.2                               
       Use in hy-                                                         
                 Start temp-                                              
                            time [min-                                    
                                    consumption                           
Example                                                                   
       drogenation                                                        
                 erature [°C.]                                     
                            utes]   [bars]                                
______________________________________                                    
14     1st       42         29      220                                   
       2nd-7th   25-28      26-28   220--225                              
15     1st       46         29      225                                   
       2nd-4th   24-26      27-31   225                                   
16     1st       68         38      230                                   
       2nd-4th   26-27      34-35   220-230                               
______________________________________                                    
 
    
     Example 18 
     Example 13 was repeated but 32.44 g of 100% Ra Ni-Fe were employed with 122.6 g of an isomer mixture of DNT/TDA, which corresponded to a ratio of g atoms of active metal (Ni+Fe) to mols of dinitrotoluene of 1:0.66. 
     32 g (98.6% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  103° C. start                                             
                     235 bars H.sub.2                                     
                                 67 minutes                               
         temperature consumption hydrogenation                            
                                 time                                     
2nd-4th use                                                               
         24-30° C. start                                           
                     220 bars H.sub.2                                     
                                 29-36 minutes                            
         temperature consumption hydrogenation                            
                                 time                                     
5th-7th use                                                               
         41-50° C. start                                           
                     220 bars H.sub.2                                     
                                 35-38 minutes                            
         temperature consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     Examples 19 to 23 
     The depyrophorisation of Ra Ni-Fe was carried out according to Example 1 with DNT 80/20 as a 10% strength by weight solution in isopropanol, but changing the ratios of g atoms of Ni-Fe to mols of DNT. 
     
         ______________________________________                                    
                       Ratio of                                           
                       g atoms                                            
                       of (Ni +                                           
                       Fe) to                                             
       g of Ra g of    mols of                                            
Example                                                                   
       Ni-fe   DNT     DNT    Yield                                       
______________________________________                                    
19     20.53   63.3    1:1    20.2 g = 98.4% of theory                    
20     37.8    87.5    1:0.75 37.1 g = 98.2% of theory                    
21     41.97   64.3    1:0.5  41.7 g = 99.3% of theory                    
22     39.54   30.3    1:0.25 39.2 g = 99.1% of theory                    
23     38.48   14.5    1:0.125                                            
                              38.2 g = 99.3% of theory                    
______________________________________                                    
 
    
     The resulting catalysts gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
                            Running H.sub.2                               
       Use in hy-                                                         
                 Start temp-                                              
                            time [min-                                    
                                    consumption                           
Example                                                                   
       drogenation                                                        
                 erature [°C.]                                     
                            utes]   [bars]                                
______________________________________                                    
19     1st       39         30      235                                   
       2nd-6th   25-27      36-40   215-220                               
20     1st       28         25      235                                   
       2nd-6th   26-40      29-31   210-230                               
21     1st       38         22      230                                   
       2nd-6th   24-26      23-29   220-230                               
22     1st       60         34      235                                   
       2nd-7th   24-26      28-35   215-225                               
23     1st       68         38      225                                   
       2nd-4th   22-24      31-36   210                                   
       5th-6th   52         29-30   205                                   
______________________________________                                    
 
    
     Examples 24 to 26 
     The depyrophorisation of Ra Ni 30/70 was carried out according to Example 1, but using DNT 65/35 in the form of solutions of various concentrations in isopropanol and changing the ratios of g atoms of Ni to mols of DNT. 
     
         ______________________________________                                    
                               Ratio of                                   
                               g atoms                                    
                               of Ni to                                   
Ex-   g of    g of     Solution in                                        
                               mols of                                    
                                      Yield (g = %                        
ample Ra Ni   DNT      isopropanol                                        
                               DNT    of theory)                          
______________________________________                                    
24    50      154.8    10% by  1:1    49.5 g = 99.0                       
                       weight                                             
25    41.87   64.7     20% by  1:0.5  41.5 g = 99.1                       
                       weight                                             
26    35.36   54.8     30% by  1:0.5  35  g = 98.9                        
                       weight                                             
______________________________________                                    
 
    
     The resulting catalysts gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
                            Running H.sub. 2                              
       Use in hy-                                                         
                 Start temp-                                              
                            time [min-                                    
                                    consumption                           
Example                                                                   
       drogenation                                                        
                 erature [°C.]                                     
                            utes]   [bars]                                
______________________________________                                    
24     1st       60         18      230                                   
       2nd-4th   24-30      17-19   235                                   
25     1st       62         18      225                                   
       2nd-3rd   46-48      16-18   220                                   
26     1st       62         14      235                                   
       2nd-3rd   52-56      10-12   220                                   
______________________________________                                    
 
    
     Example 27 
     Example 24 was repeated but 50 g of 100% Ra Ni-Fe were employed with 154.8 g of dinitrotoluene 65/35 as a 10% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni+Fe) to mols of dinitrotoluene of 1:1. 
     49.5 g (99% of theory) of non-pyrophoric catalysts were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  61° C. start                                              
                     235 bars H.sub.2                                     
                                 18 minutes                               
         temperature consumption hydrogenation                            
                                 time                                     
2nd-4th use                                                               
         28- 30°  C. start                                         
                     235 bars H.sub.2                                     
                                 17-20 minutes                            
         temperature consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     Example 28 
     Example 1 was repeated, but 20.16 g of 100% Ra Ni were employed with 105.1 g of 2-nitroanisole as a 30% strength by weight solution in amyl alcohol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2-nitroanisole of 1:2. 
     The reaction mixture was heated to 50° C. for 0.5 hour. 
     20 g (99.2% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  110° C. start                                             
                     240 bars H.sub.2                                     
                                 8 minutes                                
         temperature consumption hydrogenation                            
                                 time                                     
2nd-3rd use                                                               
         70- 72° C. start                                          
                     240 bars H.sub.2                                     
                                 7-8 minutes                              
         temperature consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     Example 29 
     Example 1 was repeated, but 9.18 g of 100% Ra Ni were employed with 233 g of the trisodium salt of 1-nitronaphthalene-3,6,8-trisulphonic acid as an 18% strength by weight solution in water, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitro compound of 1:3. 
     The reaction mixture was heated to 50° C. for 0.5 hour. 
     9.0 g (98.0% of theory) of non-pyrophoric catalyst were obtained. 
     Example 30 
     Example 1 was repeated, but 19.61 g of 100% Ra Ni were employed with 105.2 g of p-nitrochlorobenzene as a 10% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of p-nitrochlorobenzene of 1:2. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     19.4 g (98.9% of theory) of non-pyrophoric catalyst were obtained. 
     Example 31 
     Example 1 was repeated, but 10.63 g of 100% Ra Ni were employed with 77.8 g of 2-nitro-diphenyl ether (98.2% pure) as a 10% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2-nitro-diphenyl ether of 1:2. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     10.4 g (97.8% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  72° C. start                                              
                     300 bars H.sub.2                                     
                                 30 minutes                               
         temperature consumption hydrogenation                            
                                 time                                     
2nd-3rd use                                                               
         90- 104° C. start                                         
                     295 bars H.sub.2                                     
                                 8-9 minutes                              
         temperature consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     Example 32 
     Example 1 was repeated, but 10.8 g of 100% Ra Ni were employed with 55.9 g of 2-nitroanisole as a 10% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2-nitroanisole of 1:2. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     10.7 g (99.0% of theory) of non-pyrophoric catalyst were obtained. 
     Example 33 
     Example 1 was repeated, but 14.55 g of 100% Ra Ni were employed with 85.7 g of 4-chloro-2-nitrophenol as a 30% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 4-chloro-2-nitrophenol of 1:2. 
     The reaction mixture was heated to 50° C. for 0.5 hour. 
     14.4 g (98.9% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 34 
     Example 1 was repeated, but 16.16 g of 100% Ra Ni were employed with 101.3 g of 2,4-dinitrophenol as a 20% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2,4-dinitrophenol of 1:2. 
     The reaction mixture was heated to 60° C. for 0.5 hour. 
     16 g (99.0% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 35 
     Example 1 was repeated, but 14 g of 100% Ra Ni were employed with 65.2 g of 2-nitrotoluene without a solvent, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2-nitrotoluene of 1:2. 
     The reaction mixture was heated to 100° C. in a stirred autoclave under 1.5 bars for 0.5 hour. 
     13.8 g (98.5% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 36 
     Example 1 was repeated, but 15.23 g of 100% Ra Ni were employed with 31.6 g of nitromethane without a solvent, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitromethane of 1:2. 
     The reaction mixture was heated to 110° C. in a stirred autoclave under 3 bars for 0.5 hour. 
     15.0 g (98.4% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  124° C. start                                             
                     255 bars H.sub.2                                     
                                 7 minutes                                
         temperature consumption hydrogenation                            
                                 time                                     
2nd-4th use                                                               
         86- 94° C. start                                          
                     235-240 bars H.sub.2                                 
                                 8-9 minutes                              
         temperature consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     EXAMPLE 37 
     Example 1 was repeated, but 17.40 g of 100% Ra Ni were employed with 89.4 g of 2-nitro-1,4-dimethylbenzene without a solvent, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2-nitro-1,4-dimethylbenzene of 1:2. 
     The reaction mixture was heated to 100° C. in a stirred autoclave under 1.5 bars for 0.5 hour. 
     17.1 g (98.2% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  84° C. start                                              
                     255 bars H.sub.2                                     
                                 8 minutes                                
         temperature consumption hydrogenation                            
                                 time                                     
2nd-3rd use                                                               
         70- 66° C. start                                          
                     240-250 bars H.sub.2                                 
                                 7 minutes                                
         temperature consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     EXAMPLE 38 
     Example 1 was repeated, but 13.77 g of 100% Ra Ni were employed with 42.0 g of 2-nitropropane as a 50% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2-nitropropane of 1:2. 
     The reaction mixture was heated to 150° C. in a stirred autoclave under 1.5 bars for 0.5 hour. 
     13.4 g (97.3% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 39 
     Example 1 was repeated, but 24.69 g of 100% Ra Ni were employed with 161.3 g of 2,3-dichloronitrobenzene as a 30% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2,3-dichloronitrobenzene of 1:2. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     24.4 g (98.8% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  82° C. start                                              
                     250 bars H.sub.2                                     
                                 8 minutes                                
         temperature consumption hydrogenation                            
                                 time                                     
2nd-3rd use                                                               
         70-54° C. start                                           
                     250-240 bars H.sub.2                                 
                                 7 minutes                                
         temperature consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     EXAMPLE 40 
     Example 1 was repeated, but 8.36 g of 100% Ra Ni were employed with 65 g of 50% strength picric acid in H 2  O as a 10% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of picric acid of 1:1. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     8.3 g (99.2% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 41 
     Example 1 was repeated, but 7.88 g of 100% Ra Ni were employed with 30.5 g of pure picric acid as a 10% strength by weight solution in water, which corresponded to a ratio of g atoms of active metal (Ni) to mols of picric acid of 1:1. 
     The reaction mixture was heated to 80°-90° C. for 0.5 hour. 
     7.7 g (97.7% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  48° C. start                                              
                     245 bars H.sub.2                                     
                                7 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
2nd use  42° C. start                                              
                     235 bars H.sub.2                                     
                                7 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
3rd use  50° C. start                                              
                     235 bars H.sub.2                                     
                                7 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
______________________________________                                    
 
    
     EXAMPLE 42 
     Example 1 was repeated, but 14.51 g of 100% Ra Ni were employed with 77.8 g of 2-chloro-1-nitrobenzene as a 30% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2-chloro-1-nitrobenzene of 1:2. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     14.3 g (98.5% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  76° C. start                                              
                     230 bars H.sub.2                                     
                                 8 minutes                                
         temperature consumption hydrogenation                            
                                 time                                     
2nd-4th use                                                               
         66-82° C. start                                           
                     230 bars H.sub.2                                     
                                 8-10 minutes                             
         temperature consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     EXAMPLE 43 
     Example 1 was repeated, but 13.62 g of 100% Ra Ni were employed with 60.7 g of 2-nitro-diphenylsulphone as a 10% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2-nitro-diphenylsulphone of 1:1. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     13.5 g (99.1% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 44 
     Example 1 was repeated but 20.32 g of 100% Ra Ni were employed with 85.2 g of 4-nitroso-phenol as a 20% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 4-nitrosphenol of 1:2. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     20.2 g (99.4% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 45 
     Example 1 was repeated, but 35 g of 100% Ra Ni were employed with 118.1 g of 3,5-dinitro-2-hydroxytoluene as a 20% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 3,5-dinitro-2-2-hydroxytoluene of 1:1. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     34.9 g (99.7% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 46 
     Example 1 was repeated, but 23.40 g of 100% Ra Ni were employed with 78.80 g of 3,5-dinitro-2-hydroxytoluene as a 10% strength by weight solution in glycol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 3,5-dinitro-2-hydroxytoluene of 1:1. 
     The reaction mixture was heated to 90°-100° C. for 0.5 hour. 
     23.3 g (99.5% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  64° C. start                                              
                     230 bars H.sub.2                                     
                               8 minutes hydrogen-                        
         temperature consumption                                          
                               ation time                                 
2nd use  50° C. start                                              
                     230 bars H.sub.2                                     
                               7 minutes hydrogen-                        
         temperature consumption                                          
                               ation time                                 
3rd use  54° C. start                                              
                     230 bars H.sub.2                                     
                               7 minutes hydrogen-                        
         temperature consumption                                          
                               ation time                                 
______________________________________                                    
 
    
     EXAMPLE 47 
     Example 1 was repeated, but 16.65 g of 100% Ra Ni were employed with 56 g of 3,5-dinitro-2-hydroxytoluene as a 30% strength by weight solution in polyglycol P 400, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 3,5-dinitro-2-hydroxytoluene of 1:1. 
     The reaction mixture was heated to 90°-100° C. for 0.5 hour. 
     16.5 g (99.0% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  70° C. start                                              
                     235 bars H.sub.2                                     
                                8 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
2nd use  54° C. start                                              
                     235 bars H.sub.2                                     
                                8 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
3rd use  54° C. start                                              
                     235 bars H.sub.2                                     
                                8 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
______________________________________                                    
 
    
     EXAMPLE 48 
     Example 1 was repeated, but 26.62 g of 100% Ra Ni were employed with 89.8 g of 2,4-dinitroanisole as a 20% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2,4-dinitroanisole of 1:1. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     26.5 g (99.5% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 49 
     Example 1 was repeated, but 13.76 g of 100% Ra Ni were employed with 35.4 g of 2-nitro-benzaldehyde as a 10% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of 2-nitrobenzaldehyde of 1:1. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     13.5 g (98.1% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  94° C. start                                              
                     250 bars H.sub.2                                     
                                 9 minutes                                
         temperature consumption hydrogenation                            
                                 time                                     
2nd-3rd use                                                               
         65-70° C. start                                           
                     230-240 bars H.sub.2                                 
                                 8-9 minutes                              
         temperature consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     EXAMPLE 50 
     Example 1 was repeated, but 27.63 g of 100% Ra Ni were employed with 115.7 g of nitrobenzene as a 10% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitrobenzene of 1:2. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     27.4 g (99.1% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 51 
     Example 1 was repeated, but 24.76 g of 100% Ra Ni were employed with 51.8 g of nitrobenzene as a 30% strength by weight solution in ethylene glycol monotolyl ether, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitrobenzene of 1:1. 
     The reaction mixture was heated to 100° C. for 0.5 hour. 
     24.6 g (99.3% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  60° C. start                                              
                     210 bars H.sub.2                                     
                                7 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
2nd use  54° C. start                                              
                     200 bars H.sub.2                                     
                                8 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
3rd use  64° C. start                                              
                     210 bars H.sub.2                                     
                                8 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
______________________________________                                    
 
    
     EXAMPLE 52 
     Example 1 was repeated, but 20 g of 100% Ra Ni were employed with 41.9 of nitrobenzene as a 30% strength by weight solution in pyrocatechol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitrobenzene of 1:1. 
     The reaction mixture was heated to 100° C. for 0.5 hour. 
     19.7 g (98.5% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  64° C. start                                              
                     260 bars H.sub.2                                     
                                9 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
2nd use  72° C. start                                              
                     255 bars H.sub.2                                     
                                9 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
3rd use  76° C. start                                              
                     250 bars H.sub.2                                     
                                9 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
______________________________________                                    
 
    
     EXAMPLE 53 
     Example 1 was repeated, but 25.41 g of 100% Ra Ni were employed with 53.2 g of nitrobenzene as a 30% strength by weight solution in 3-acetoxy-phenol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitrobenzene of 1:1. 
     The reaction mixture was heated to 100° C. for 0.5 hour. 
     25.3 g (99.5% of theory) of non-pyrophoric catalyst were obtained: 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  54° C. start                                              
                     235 bars H.sub.2                                     
                                7 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
2nd use  60° C. start                                              
                     240 bars H.sub.2                                     
                                8 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
3rd use  68° C. start                                              
                     235 bars H.sub.2                                     
                                7 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
______________________________________                                    
 
    
     EXAMPLE 54 
     Example 1 was repeated, but 23.25 g of 100% Ra Ni were employed with 48.7 g of nitrobenzene as a 30% strength by weight solution in triethylene glycol dimethyl ether, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitrobenzene of 1:1. 
     The reaction mixture was heated to 100° C. for 0.5 hour. 
     23.0 g (98.9% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  66° C. start                                              
                     220 bars H.sub.2                                     
                                7 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
2nd use  58° C. start                                              
                     230 bars H.sub.2                                     
                                7 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
3rd use  70° C. start                                              
                     235 bars H.sub.2                                     
                                8 minutes hydro-                          
         temperature consumption                                          
                                genation time                             
______________________________________                                    
 
    
     
                                           Examples 55 to 70                       
__________________________________________________________________________
The depyrophorisation of Ra Ni 30/70 and Ra Ni-Fe was carried out         
according to Example 1, but                                               
using DNT 65/35 in the form of solutions in the different solvents in     
various concentrations.                                                   
              Ratio of                                                    
              g atoms of       Concentration                              
Ex- g of                                                                  
        g of DNT                                                          
              Ni/mols of                                                  
                    Solvent    of DNT solu-                               
                                       Reaction con-                      
ample                                                                     
    Ra Ni                                                                 
        65/35 DNT   [% by weight]                                         
                               tion    ditions Yield                      
__________________________________________________________________________
55  18.71                                                                 
        115.7 1:2   Benzene/water/                                        
                               30      0.5 hour 50° C.             
                                               18.2 g = 97.2%             
                    isopropanol                of theory                  
                    [59%:6%:35%]                                          
56  18.61                                                                 
        115   1:2   Cyclohexane/water/                                    
                               30      0.5 hour 50° C.             
                                               18.1 g = 97.2%             
                    isopropanol                of theory                  
                    [58%:6%:36%]                                          
57  23.13                                                                 
        71.5  1:1   Glycerol   30      0.5 hour 90° C.             
                                               23.0 g = 99.4%             
                                               of theory                  
58  19.49                                                                 
        60.2  1:1   1-Butanol/water                                       
                               30      0.5 hour 70° C.             
                                               19.1 g = 97.9%             
                    [90%:10%]                  of theory                  
65  32.30                                                                 
        100   1:1   Isopropanol/water                                     
                               10      0.5 hour 50° C.             
                                               32.0 g = 99.0%             
                    [80%:20%]                  of theory                  
59  22.15                                                                 
        68.6  1:1   Methanol/water                                        
                               10      0.5 hour 60° C.             
                                               22.0 g = 99.3%             
                    [80%:20%]                  of theory                  
60  26.46                                                                 
        81.9  1:1   Isopropanol/water                                     
                               10      0.5 hour boil-                     
                                               26.0 g = 98.2%             
                    [60%:40%]          ing point                          
                                               of theory                  
61  21.38                                                                 
        66.2  1:1   Ethanol/water                                         
                               30      0.5 hour 60° C.             
                                               21.1 g = 98.7%             
                    [90%:10%]                  of theory                  
64  22.68                                                                 
        70.2  1:1   Phenol     30      0.5 hour 100° C.            
                                               22.2 g = 97.8%             
                                               of theory                  
66  57.7                                                                  
        178.7 1:1   Isopropanol/water                                     
                               20      0.5 hour 50° C.             
                                               57.2 g = 99.1%             
                    [80%:20%]                  of theory                  
67  49  152   1:1   Isopropanol/water                                     
                               30      0.5 hour 55° C.             
                                               48.5 g = 98.9%             
                    [80%:20%]                  of theory                  
    g of      g atoms of                                                  
    Ra Ni-    (Ni + Fe)/                                                  
    Fe        mols of                                                     
              DNT                                                         
62  20  61.3  1:1   Benzene    30      0.5 hour 100° C.            
                                               19.8 g = 99.0%             
                                       2 bars  of theory                  
63  20  61.3  1:1   Cyclohexane                                           
                               30      0.5 hour 100° C.            
                                               19.6 g = 98.0%             
                                       2 bars  of theory                  
68  40.89                                                                 
        125.4 1:1   Isopropanol/water                                     
                               10      0.5 hour 50° C.             
                                               40.6 g = 99.3%             
                    [80%:20%]                  of theory                  
69  42.35                                                                 
        130   1:1   Isopropanol/water                                     
                               20      0.5 hour 50° C.             
                                               42.0 g = 99.1%             
                    [80%:20%]                  of theory                  
70  51  156.6 1:1   Isopropanol/water                                     
                               30      0.5 hour 55° C.             
                                               50.5 g = 99.0%             
                    [80%:20%]                  of theory                  
__________________________________________________________________________
 
    
     The resulting catalysts gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
      Use in    Start      Running                                        
Ex-   hydrogen- temperature                                               
                           time    H.sub.2 consumption                    
ample ation     [°C.]                                              
                           [minutes]                                      
                                   [bars]                                 
______________________________________                                    
55    1st       90         12      255                                    
      2nd-3rd   90-100     10-11   240                                    
57    1st       84         13      250                                    
      2nd-4th   74-76      9-11    245                                    
58    1st       96         14      250                                    
      2nd-4th   82-96      10-12   250                                    
65    1st       76         27      220                                    
      2nd -3rd  90-92      23      210                                    
59    1st       86         8       240                                    
      2nd-3rd   70         7-8     240                                    
60    1st       114        9       260                                    
      2nd       90         8       260                                    
      3rd       85         8       260                                    
61    1st       64         7       240                                    
      2nd-3rd   56-62      7       240                                    
64    1st       66         6       210                                    
      2nd-3rd   62-70      7-8     215                                    
66    1st       78         22      210                                    
      2nd-3rd   78-82      16-18   210                                    
67    1st       76         18      230                                    
      2nd-3rd   60-78      17-20   230                                    
      4th-5th   80-84      18      230                                    
62    1st       100        8       220                                    
      2nd-3rd   72-70      8       220                                    
68    1st       80         18      240                                    
      2nd-3rd   75-80      20-21   235                                    
69    1st       72         17      230                                    
      2nd-4th   66-74      15-17   230                                    
70    1st       74         17      230                                    
      2nd-3rd   66-72      15-17   225-235                                
      4th-6th   74-76      17-18   230                                    
______________________________________                                    
 
    
     EXAMPLES 71 to 75 
     The depyrophorisation of Ra Ni-Fe was carried out according to Example 1, but using other nitro compounds, which were employed as 30% strength by weight solutions in isopropanol, and heating the reaction mixture to the boiling point for 0.5 hour. 
     
         ______________________________________                                    
                            Ratio of                                      
                            g atoms                                       
                            (Ni + Fe)/                                    
                            mols of Yield                                 
Ex-   g of     g of nitro   nitro com-                                    
                                    (g = % of                             
ample Ra NiFe  compound     pound   theory)                               
______________________________________                                    
71    18.46    108 g of 4-chloro-                                         
                            1:2     18.1 g = 98                           
               2-nitrophenol                                              
72    19.63    114.7 g of 1-nitro-                                        
                            1:2     19.3 g = 98.3                         
               naphthalene                                                
73    25.64    130.5 g of 2-nitro-                                        
                            1:2     25.2 g = 98.3                         
               1,4-dimethyl-                                              
               benzene                                                    
74    16.1     49.8 g of 2,4-di-                                          
                            1:1     15.9 g = 98.7                         
               nitrophenol                                                
75    17.82    73.9 g of nitro-                                           
                            1:2     17.6 g = 98.8                         
               benzene                                                    
______________________________________                                    
 
    
     EXAMPLE 76 
     Example 1 was repeated, but 22.75 g of 100% Ra Co were employed with 95 g of nitrobenzene as a 30% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Co) to mols of nitrobenzene of 1:2. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     22.6 g (99.3% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 77 
     Example 1 was repeated, but 18.56 g of 100% Ra Co were employed with 57.2 g of dinitrotoluene 65/35 as a 30% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Co) to mols of dinitrotoluene of 1:1. 
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     18.4 g (99.1% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use                                                                   
       130° C. start                                               
                    280 bars H.sub.2                                      
                                32 minutes hydro-                         
       temperature  consumption genation time                             
2nd-3rd                                                                   
       124-128° C. start                                           
                    275-280 bars                                          
                                30-32 minutes                             
use    temperature  H.sub.2 consumption                                   
                                hydrogenation                             
                                time                                      
______________________________________                                    
 
    
     EXAMPLE 78 
     Example 1 was repeated, but 44.58 g of 100% Ra Ni 40/60 1 ) were employed with 691 g of dinitrotoluene 65/35 as a 30% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of dinitrotoluene of 1:5. 
    
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     44.4 g (99.5% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 79 
     Example 1 was repeated, but 38.1 g of 100% Ra Ni 50/50 2 ) were employed with 236 g of dinitrotoluene 65/35 as a 30% strength by weight solution in isopropanol, which corresponded to a ratio of g atoms of active metal (Ni) to mols of dinitrotoluene of 1:2. 
    
     The reaction mixture was heated to the boiling point for 0.5 hour. 
     37.7 g (98.9% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 80 
     As an example of the use of non-pyrophoric Raney nickel for the hydrogenation of aromatic compounds, 200 g of toluene were reacted with 10 g of Raney nickel, depyrophorised according to Example 1, in a 0.7 l stirred autoclave at a reaction temperature of 230°-240° C. and under a hydrogen pressure of 100 bars. The start temperature was 195° C. After a hydrogenation time of 15 minutes and a hydrogen consumption of 525 bars, the toluene had been quantitatively converted. The resulting methylcyclooctane had a purity of 99.99%. 
     EXAMPLE 81 
     As an example for the use of non-pyrophoric Raney nickel for the hydrogenation of aromatic compound, 200 g of benzene and 10 g of Raney nickel, depyrophorised according to Example 1, were reacted in a 0.7 l stirred autoclave at a reaction temperature of 220°-230° C. and under a hydrogen pressure of 100 bars. The start temperature was 182° C. After a hydrogenation time of 15 minutes and a hydrogen consumption of 600 bars, the benzene had been quantitatively converted. The resulting cyclooctane had a purity of 99.99%. 
     EXAMPLE 82 
     As an example for the use of non-pyrophoric Raney nickel for the hydrogenation of nitro compounds, 200 g of 2-nitrotoluene, 10 g of Raney nickel, depyrophorised according to Example 1, and 100 g of isopropanol as the solvent were reacted in a 0.7 l stirred autoclave at a maximum reaction temperature of 130°-140° C. and under a hydrogen pressure of 100 bars. The start temperature was 96° C. After a hydrogenation time of 16 minutes and a hydrogen consumption of 350 bars, the nitro-toluene had been quantitatively converted to toluidine. 
     EXAMPLE 83 
     Example 82 was repeated, but 200 g of nitrobenzene and 10 g of Ra Ni, depyrophorised according to Example 1, were employed. The reaction conditions were a hydrogen pressure of 100 bars and a maximum reaction temperature of 150°-160° C. The start temperature was 98° C. After a hydrogenation time of 15 minutes and a hydrogen consumption of 300 bars, the nitrobenzene had been quantitatively converted to aniline. 
     EXAMPLE 84 
     As an example for the use of non-pyrophoric Raney nickel for the hydrogenation of olefines, 200 g of cycloocta-1,5-diene were employed with 10 g of Raney nickel, depyrophorised according to Example 1, in a 0.7 l stirred autoclave at a reaction temperature of 190°-200° C. and under a hydrogen pressure of 100 bars. The start temperature was 142° C. After a hydrogenation time of 12 minutes and a hydrogen consumption of 265 bars, the cyclooctadiene had been quantitatively converted. The resulting cyclooctane had a purity of 98.4%. 
     EXAMPLE 85 
     Batches were run according to Example 1 with 2 kg of 100% fresh contact catalyst in a semi-industrial installation consisting of two 50 l kettles which were connected with a filter. In this procedure, one kettle was used as the reaction vessel and the second was used for the preparation of the required nitro solution. 
     The reaction was carried out as follows: 2 kg of 100% Raney nickel, corresponding to 4 kg of an aqueous suspension, were initially introduced into kettle 1. The water was replaced by isopropanol and the suspension was heated to 55°-60° C. 6.18 kg of DNT 65/35 were dissolved in 14.42 kg of isopropanol at 55°-60° C. in kettle 2. The 30% strength by weight solution prepared in kettle 2 was metered into the catalyst suspension initially introduced into kettle 1 according to the ratio of g atoms of Ni to mols of DNT 65/35 of 1:1. The total reaction time was set at 30 minutes. After the reaction had ended, the catalyst was freed from the adhering mother liquor in the filter, washed with isopropanol and blown dry with N 2 . 1.96 kg, corresponding to 98% of theory, of non-pyrophoric Raney nickel were obtained. 
     EXAMPLES 86 to 92 
     The depyrophorisation of Ra Ni and Ra Ni-Fe in a semi-industrial installation was carried out according to Example 85, but with other concentrations of the solution of DNT 65/35 in isopropanol. 
     
         ______________________________________                                    
Ex-                              Yield (g = %                             
ample g of Ra Ni                                                          
                g of DNT 65/35   of theory)                               
______________________________________                                    
86    2,000     6,180 as a 20% strength by                                
                                 1,970 g = 98.5                           
                weight solution in isopro-                                
                panol                                                     
87    2,000     6,180 as a 10% strength by                                
                                 1,980 g = 99.0                           
                weight solution in isopro-                                
                panol                                                     
88    2,000     6,180 as a 30% strength by                                
                                 1,950 g = 97.5                           
                weight solution in an iso-                                
                propanol/water (80%:20%)                                  
                mixture                                                   
      g of Ra                                                             
      Ni-Fe                                                               
89    2,000     6,124 as a 20% strength by                                
                                 1,950 g = 97.5                           
                weight solution in isopro-                                
                panol                                                     
90    2,000     6,124 as a 10% strength by                                
                                 1,970 g = 98.5                           
                weight solution in isopro-                                
                panol                                                     
91    2,000     6,124 as a 20% strength by                                
                                 1,960 g = 98.0                           
                weight solution in an iso-                                
                propanol/water (80%:20%)                                  
                mixture                                                   
92    2,000     6,124 as a 10% strength by                                
                                 1,980 g = 99.0                           
                weight solution in an iso-                                
                propanol/water (80%:20%)                                  
                mixture                                                   
______________________________________                                    
 
    
     The resulting catalysts gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
                 Start      Running                                       
Ex-   Use in hydro-                                                       
                 temperature                                              
                            time   H.sub.2 consumption                    
ample genation   [°C.]                                             
                            [minutes]                                     
                                   [bars]                                 
______________________________________                                    
86    1st        86         36     225                                    
      2nd-4th    76         33     220                                    
87    1st        66         20     240                                    
      2nd-4th    31         20     235                                    
88    1st        84         20     235                                    
      2nd-6th    84         20     220                                    
      7th-9th    94         50     220                                    
89    1st        68         13     250                                    
      2nd-10th   56-66      12-33  235                                    
      11th-14th  80-86      36-56  235                                    
91    1st        76         13     245                                    
      2nd-13th   72-96      13-56  235                                    
92    1st        64         17     245                                    
      2nd-10th   64-92      16-56  236                                    
______________________________________                                    
 
    
     EXAMPLE 93 
     Example 85 was repeated, but 2,000 g of 100% Ra Ni-Fe were employed with 6,124 g of dinitrotoluene 65/35 as a 30% strength by weight solution in an isopropanol/water (80%:20%) mixture, which corresponded to a ratio of g atoms of active metal (Ni+Fe) to mols of dinitrotoluene of 1:1. 
     1,980 g (99% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use  70° C. start                                              
                     240 bars H.sub.2                                     
                                 11 minutes hydro-                        
         temperature consumption genation time                            
2nd-10th use                                                              
         58-76° C. start                                           
                     230 bars H.sub.2                                     
                                 12-25 minutes                            
         temperature consumption hydrogenation time                       
11th-12th use                                                             
         82-90° C. start                                           
                     230-235 bars                                         
                                 31-52 minutes                            
         temperature H.sub.2 consumption                                  
                                 hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     In order to determine the influence of the storage time on the activity of the catalyst, activity tests were carried out again after 3 and 12 months. However, the maximum hydrogenation temperature of 100° C. indicated in Example 1 was exceeded here. 
     Activity after 3 months: 
     
         ______________________________________                                    
1st use 70° C. start                                               
                    245 bars H.sub.2                                      
                               16 minutes hydro-                          
        temperature consumption                                           
                               genation time                              
2nd-13th                                                                  
        68-92° C. start                                            
                    240 bars H.sub.2                                      
                               13-18 minutes                              
use     temperature consumption                                           
                               hydrogenation time                         
14th-35th                                                                 
        96-120° C. start                                           
                    240 bars H.sub.2                                      
                               13-19 minutes                              
use     temperature consumption                                           
                               hydrogenation time                         
______________________________________                                    
 
    
     Activity after 1 year: 
     
         ______________________________________                                    
1st use 84° C. start                                               
                     210 bars H.sub.2                                     
                                 22 minutes                               
        temperature  consumption hydrogenation                            
                                 time                                     
2nd-16th                                                                  
        72-98° C. start                                            
                     190-200 bars                                         
                                 12-17 minutes                            
use     temperature  H.sub.2 consumption                                  
                                 hydrogenation                            
                                 time                                     
17th-30th                                                                 
        106-124° C. start                                          
                     185-195 bars                                         
                                 12-14 minutes                            
use     temperature  H.sub.2 consumption                                  
                                 hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     EXAMPLE 94 
     Example 85 was repeated, but 2,000 g of 100% Ra Ni-Fe were employed with 6,124 g of dinitrotoluene 65/35 as a 30% strength by weight solution in an isopropanol/water (80%:20%) mixture, which corresponded to a ratio of g atoms of active metal (Ni+Fe) to mols of dinitrotoluene of 1:1. 
     1,980 g (99% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     The maximum hydrogenation temperature of 100° C. indicated in Example 1 was also exceeded here. 
     
         ______________________________________                                    
1st use 60° C. start                                               
                     265 bars H.sub.2                                     
                                 16 minutes                               
        temperature  consumption hydrogenation                            
                                 time                                     
2nd-16th                                                                  
        66-88° C. start                                            
                     240 bars H.sub.2                                     
                                 13-18 minutes                            
use     temperature  consumption hydrogenation                            
                                 time                                     
17th-45th                                                                 
        90-124° C. start                                           
                     245 bars H.sub.2                                     
                                 15-20 minutes                            
use     temperature  consumption hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     The influence of the storage time on the activity of the catalyst was also investigated. 
     After 3 months&#39; storage time: 
     
         ______________________________________                                    
1st use  80° C. start                                              
                      235 bars H.sub.2                                    
                                 17 minutes                               
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
2nd-10th use                                                              
         72-88° C. start                                           
                      220 bars H.sub.2                                    
                                 13-20 minutes                            
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
11th-30th use                                                             
         92-122° C. start                                          
                      220 bars H.sub.2                                    
                                 16-20 minutes                            
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     After 6 months&#39; storage time: 
     
         ______________________________________                                    
1st use  86° C. start                                              
                      230 bars H.sub.2                                    
                                 17 minutes                               
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
2nd-10th use                                                              
         70-98° C. start                                           
                      220 bars H.sub.2                                    
                                 15-21 minutes                            
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
11th-30th use                                                             
         100-120° C. start                                         
                      220 bars H.sub.2                                    
                                 13-17 minutes                            
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     EXAMPLE 95 
     Example 85 was repeated, but 2,026 g of 100% Ra Ni-Fe were employed with the organic reaction solution obtained analogously to Example 85 and increased to a 3,140 g DNT 65/35 content by adding fresh DNT 65/35, which corresponded to a ratio of g atoms of active metal (Ni+Fe) to mols of DNT of 1:0.5. 2,000 g (98.7% of theory) of non-pyrophoric catalyst were obtained. The resulting catalyst gave the following values with the activity test according to Example 1: however, in order to obtain as high a number of repeated uses as possible of one and the same catalyst, the maximum hydrogenation temperature of 100° C. indicated in Example 1 was exceeded. 
     
         ______________________________________                                    
1st use  90° C. start                                              
                      255 bars H.sub.2                                    
                                 15 minutes                               
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
2nd-6th use                                                               
         76-88° C. start                                           
                      250 bars H.sub.2                                    
                                 15 minutes                               
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
7th-43rd use                                                              
         96-122° C. start                                          
                      250 bars H.sub.2                                    
                                 15-21 minutes                            
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     EXAMPLE 96 
     Example 85 was repeated, but 2,009 g of 100% Ra Ni-Fe were employed with the organic reaction solution obtained analogously to Example 95 and increased to a DNT 65/35 content of 3,114 g by adding fresh DNT 65/35, which corresponded to a ratio of g atoms of active metal (Ni+Fe) to mols of DNT of 1:0.5. 1,998 g (99.4% of theory) of non-pyrophoric catalyst were obtained. The resulting catalyst gave the following values in the activity test according to Example 1: however, in order to obtain as high a number of repeated uses as possible with one and the same catalyst, the maximum hydrogenation temperature of 100° C. indicated in Example 1 was exceeded. 
     
         ______________________________________                                    
1st use  78° C. start                                              
                      230 bars H.sub.2                                    
                                 18 minutes                               
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
2nd-9th use                                                               
         68-90° C. start                                           
                      240 bars H.sub.2                                    
                                 18 minutes                               
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
10th-50th use                                                             
         104-132° C. start                                         
                      260 bars H.sub.2                                    
                                 20 minutes                               
         temperature  consumption                                         
                                 hydrogenation                            
                                 time                                     
______________________________________                                    
 
    
     EXAMPLE 97 
     Example 1 was repeated, but 24.94 g of 100% Ra Ni-Au were employed with 75.2 g of dinitrotoluene 65/35 as a 30% strength by weight solution in a mixture consisting of isopropanol/water (80:20% by weight), which corresponded to a ratio of g atoms of active metal (Ni+Au) to mols of dinitrotoluene of 1:1. 
     24.5 g (98.2% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st use                                                                   
      78° C. start temp-                                           
                    230 bars H.sub.2                                      
                               9 minutes hydrogen-                        
      erature       consumption                                           
                               ation time                                 
2nd use                                                                   
      66° C. start temp-                                           
                    230 bars H.sub.2                                      
                               8 minutes hydrogen-                        
      erature       consumption                                           
                               ation time                                 
3rd use                                                                   
      72° C. start temp-                                           
                    230 bars H.sub.2                                      
                               8 minutes hydrogen-                        
      erature       consumption                                           
                               ation time                                 
______________________________________                                    
 
    
     EXAMPLES 98-112 
     Example 97 was repeated, but the most diverse Raney catalysts were employed: 
     
         __________________________________________________________________________
                        Ratio of g                                        
                        atoms of                                          
                        active met-                                       
Ex-              g of DNT                                                 
                        als/mols of                                       
ample                                                                     
     g of Raney catalyst                                                  
                 65/35  DNT   Yield                                       
__________________________________________________________________________
 98  24.76 g of Ra CoFe                                                   
                 74.62  1:1   24.38 g = 98.5%                             
                              of theory                                   
 99  24.07 g of Ra NiFeCr                                                 
                 72.61  1:1   23.58 g = 98.0%                             
                              of theory                                   
100  23.09 g of Ra NiFeAg                                                 
                 69.16  1:1   22.85 g = 99.0%                             
                              of theory                                   
101  25.92 g of Ra NiFeCu                                                 
                 78.26  1:1   25.66 g = 99.0%                             
                              of theory                                   
102  20.47 g of Ra NiFeTi                                                 
                 62.24  1:1   20.10 g = 98.0%                             
                              of theory                                   
103  25.39 g of Ra NiFeV                                                  
                 76.98  1:1   24.88 g = 98.0%                             
                              of theory                                   
104  18.72 g of Ra NiFeMo                                                 
                 56.10  1:1   18.34 g = 98.0%                             
                              of theory                                   
105  21.68 g of Ra NiFePb                                                 
                 64.43  1:1   21.25 g = 98.0%                             
                              of theory                                   
106  24.78 g of Ra Ag                                                     
                 39.67  1:1   24.50 g = 98.0%                             
                              of theory                                   
107  20.43 g of Ra Cu                                                     
                 55.51  1:1   19.82 g = 97.0%                             
                              of theory                                   
108  21.23 g of Ra NiCu                                                   
                 63.15  1:1   21.00 g = 99.0%                             
                              of theory                                   
109  20.84 g of Ra ZnCu                                                   
                 57.15  1:1   20.20 g = 97.0%                             
                              of theory                                   
110  21.3 g of Ra CoNiFe                                                  
                 66.79  1:1   20.87 g = 98.0%                             
                              of theory                                   
111  26.67 g of Ra NiPd                                                   
                 78.10  1:1   26.40 g = 99.0%                             
                              of theory                                   
112  20.57 g of Ra NiPt                                                   
                 59.50  1:1   20.40 g = 99.0%                             
                              of theory                                   
__________________________________________________________________________
 
    
     The The resulting catalysts gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
                            Running                                       
Ex-   Use in hydro-                                                       
                 Start temp-                                              
                            time   H.sub.2 consumption                    
ample genation   erature [°C.]                                     
                            [minutes]                                     
                                   [bars]                                 
______________________________________                                    
 98   1st        120        33     310                                    
      2nd-3rd    102-94     27-31  300                                    
 99   1st        58         19     295                                    
      2nd-3rd    56-68      12-11  280                                    
100   1st        58         14     305                                    
      2nd-3rd    74-54      12     235                                    
101   1st        66         15     320                                    
      2nd-3rd    74-64      11-12  295-285                                
102   1st        110        12     265                                    
      2nd-3rd    50         11     250                                    
103   1st        106        14     260                                    
      2nd-3rd    62         9-11   240                                    
104   1st        94         11     250                                    
      2nd-3rd    70-58      11     250-240                                
105   1st        100        12     250                                    
      2nd-3rd    71-74      11-13  235                                    
111   1st        60         12     250                                    
______________________________________                                    
 
    
     EXAMPLE 113 
     Example 1 was repeated, but 40.4 g of 100% Ra Ni were employed in tablet form with 210 g of 100% pure nitromethane, which corresponded to a ratio of g atoms of active metal (Ni) to mols of nitromethane of 1:5. The reaction mixture was heated to the boiling point for 2.5 hours. 
     40 g (99% of theory) of non-pyrophoric catalyst were obtained. 
     The resulting catalyst gave the following values in the activity test according to Example 1: 
     
         ______________________________________                                    
1st   126° C. start                                                
                   240 bars H.sub.2                                       
                               8 minutes hydro-                           
use   temperature  consumption genation time                              
2nd   86° C. start                                                 
                   240 bars H.sub.2                                       
                               8 minutes hydro-                           
use   temperature  consumption genation time                              
3rd   80° C. start                                                 
                   240 bars H.sub.2                                       
                               12 minutes hydro-                          
use   temperature  consumption genation time                              
______________________________________                                    
 
    
     EXAMPLE 114 
     Example 1 was repeated, but 31.5 g of 100% Ra Ni were employed with 74.5 g of o-nitrophenol as a 26% strength by weight solution in a 10% strength by weight NaOH solution (corresponding to 21.44 g of 100% NaOH), which corresponded to a ratio of g atoms of active metal (Ni) to mols of o-nitrophenol to mols of NaOH of 1:1:1. 
     31 g (98.4% of theory) of non-pyrophoric catalyst were obtained. 
     EXAMPLE 115 
     As an example for the use of non-pyrophoric Raney nickel for the selective hydrogenation of nitro compounds, 151 g of 2-nitro-5-phenylthio-methoxyacetanilide, dissolved in 800 ml of chlorobenzene, were reacted with 32 g of Raney nickel, depyrophorised according to Example 1, in a 0.7 l stirred autoclave at a reaction temperature of 80°-85° C. and under a hydrogen pressure of 50-30 bars. The working-up of the reaction mixture gave 128 g=88% of theory of 2-amino-5-phenylthio-methoxy-acetanilide. 
     EXAMPLE 116 
     5,000 kg of DNT 65/35, corresponding to a isomer mixture of 65% by weight of 2,4-dinitrotoluene and 35% by weight of 2,6-dinitrotoluene, 4,960 kg of an isopropanol/water mixture (85% by weight of isopropanol and 15% by weight of water), 40 kg of a suspension in isopropanol and water of the catalyst prepared according to Example 94 (corresponding to 2 kg of 100% catalyst) and 5,000 kg of recycled catalyst suspension are fed in per hour into a continuous sump phase hydrogenation apparatus, which consists of four reactors connected in series, which are provided with cooling tubes to remove the heat of reaction, a product cooler, two separators and a gas circulation pump, and with the aid of which a circulation of hydrogen is produced, and are treated under a pressure of about 100 bars of H 2  and at at a temperature of 155°-170° C. The recycled catalyst is obtained during the filtration of the reaction mixture after the hydrogenation. It is re-employed as a suspension in the solution of the finished product.