Forecasting of Perspective Flotation Reagents on the Base of Structure Based Virtual Screening
The molecular models of complexes of poorly studied mineral clusters and reagents in developing the principles of evaluation of forecasting in flotation reagent activity have been created and optimized by using Chem Bio 3D and ChemOffice2005 by Cambridge Soft with optimization by MM2. It is proposed to use structure based virtual screening (SBVS) and reduce enormous amount of chemical compounds to a more manageable number for synthesis and screening which could lead to potential flotation candidates. The metal tellurides and arsenic sulfides as poorly explored types of minerals have been investigated. HOMO, SOMO, LUMO and total energies, atomic charges and s, p, d-population were determined for the various compounds. The strategy of prognosis of collector activity evaluation (PCAE) has been proposed as a consistent approach to estimate the interaction between a collector and a mineral cluster to search the analogue of butyl xanthate. The relationship between PCAE and flotability has been established. Our results indicate that the lower PCAE the stronger the interaction between the collector and the mineral cluster. The binary complexes of various reagents on the mineral surface have been studied. It was shown that the lowest magnitude of PCAE was obtained for arsenopyrite with binary mixture of dibutyl dithiophosphoric acid and diethylaminoethyl xanthic acid that indicated the high chemical activity of the combination of reagents. Forecasting of perspective flotation reagents by screening of chemical compounds and theoretical results obtained from research can provide a basis for innovative technology in mineral processing.
Molecular Modeling as an Approach for Flotation Reagents Selection
In the present study computational modeling of minerals and reagents was performed using Chem Bio 3D and ChemOffice2005 by Cambridge Soft with optimization by MM2. The semi empirical calculations were provided by MOPAC. Molecular structures of antimony clusters were created. DTF approach was used to determine energies such as HOMO, LUMO and SOMO. Absolute hardness η and chemical potential χ by Pearson and Parr have been calculated. The strategy of prognosis of collector activity evaluation (PCAE) has been proposed as a consistent approach to estimate the interaction between a collector and a mineral cluster as a difference of total energy and sum of cluster energy and collector energy. To improve the separation of minerals the method of complex formation between collectors and mineral clusters was harnessed. The probable increasing collecting ability of sulfhydril collectors for stibnite follows the order as : butyl xanthic acid (BXA), dimethyldithiocarbamic acid (DMDTCA), piperidine dithiocarbamic acid (PDTCA),mixture of butyl xanthic acid and dithiocarbamic acid (BXA+DTCA), Bis(2-(dibutylamino)ethyl) dithiophosphonic acid (DBAEDTPA) and diethyl aminoethylxanthic acid (DEAEXA). Dialkylamino sulfhydryl collectors can be considered as prospective reagents for stibnite ore flotation. The results obtained were confirmed by experimental data in ore flotation.
Thermodynamics on the Carbochlorination of Titanium-bearing Ores
The equilibrium compositions of the multi-component, multi-phase and multi-reaction system of carbochlorination of titanium-bearing ores are calculated with HSC, a computational chemistry software. The thermodynamic equilibrium calculation of the reaction system shows that a complete conversion of titanium-bearing ores is feasible at a temperature near 200oC. At temperatures ranging from 800 to 1600oC, the products of the reaction system are all in gaseous phase. Thermodynamic analysis accords with the industrial practice. The simulated results provide reasonable scientific basis for improving suitable technological conditions of the carbochlorination reduction.