Application of Optimization Methods to Solid Phase Analysis of Combustion Gases Desulphurization Products
Abstract The variations in calcium and sulphur concentrations measured along cross-sections of limestone-lime sulphated particles in scanning electron microscope (EDS microanalysis) and the computation of the sum of oxides CaO+SO 3 , ( s ) and the molar ratio CaO/SO 3 , ( r ) are essential to identifying the compounds which could appear. A method of estimating the phase of sulphation limestone/lime products is presented in this paper. The aim of this method is to find such component proportions which minimize the differences between the measured and the calculated values of s and r . The method is developed using the software package CAMOS and enables one to calculate automatically the component proportions for the given system. In the paper the CaS–CaSO 4 –CaO–CaCO 3 and CaS–CaSO 4 –CaO–Ca(OH) 2 systems are considered. Some experimental examples are also shown.
Solid-gas reactions: Study of sulphation of limestone using thermogravimetry
Comparative data are presented on the absorption rate and capacity for SO2 capture by a natural Polish limestone with and without sodium chloride additive. Two sets of experiments were carried out, under dry and wet conditions during limestone calcination and sulphation.The presence of water vapour brought about a higher reactivity of the sorbent, probably as a result of an effect on the sintering of lime and through the influence of the CaSO4 layer. Further morphological investigations could provide confirmation of the present hypothesis.ZusammenfassungAbsorptionsgeschwindigkeit und -kapazität für SO2 an einem polnischen Kalkstein mit oder ohne NaCl-Zusatz werden verglichen. Zwei Reihen von Experimenten wurden in trockener bzw. wasserdampfhaltiger Atmosphäre bei der Calcination und Sulfatbildung durchgeführt. In Gegenwart von Wasserdampf wird die Reaktivität des Absorbens infolge Sinterung des Kalks und trotz des Einflusses der CaSO4-Schicht erhöht. Künftige morphologische Untersuchungen sollen diese Hypothese eventuel bestätigen.РезюмеПредставлены сравни тельные данные о скор ости и количестве поглоще ния двуокиси серы природным польс ким известняком в при сутствии добавки хлориастого натрия и без него. Обжиг и поглощение дв уокиси серы были пров едены в сухой и влажной атмос ферах. Присутствие паров во ды вызывает более выс окую реакционную способн ость сорбента, вероятно, вследствии спекания извести и вл ияния образующегося слоя с ульфата кальция. Дальнейшие морфолог ические исследовани я могут дать подтверждение выдви нутой гипотезе.
The distribution of 54-Mn in the enamel and dentine of the rat incisor.
Abstract The distribution of 54 Mn was studied in the lower incisors of rats. Autoradiograms show 54 Mn to be present in the enamel and dentine 5, 10 and 15 days after its administration. In the dentine, the radioisotope is first localized in a zone near to and encircling the pulp and later becomes more diffuse. Pre-existing as well as the newly formed enamel incorporates the isotope. In both enamel and dentine 54 Mn appears to be principally associated with the inorganic portion.