| The tin-bearing iron reserves large in China, and it is difficult to effective separate tin and iron in the ore. For this, the tin removal process with sulphuration volatilization was studied in this paper. Effects of sulfur contents in the coal on the tin removal rate were also studied.Firstly used sulfur in coal as curing agent studied the tin removal process.Based on the thermodynamic analysis, combination with chemical analysis and XRD analysis, the process of tin removal was studied. The results show that tin removal rate increases first with holding time lower than40min and then increases little with holding time raise further.TG-DSC analysis show that the temperature rise to about1423K liquid phase appeared, XRD analysis results show that the original iron phases of Fe2O3and Fe3O4are transformed into FeO and metallic iron after the sulphuration volatilization of pyrite, production of iron phase is realized. With the pyrite addition amounts lower than2g(iron concentrate of100g), the tin removal rate increase with the pyrite addition and then increasing little meanwhile precipitated matte phase. Tin removal rate follow coal addition amounts increases and then decreases, metallic tin and iron generate, and they combined forming hardhead, as a result of which the tin removal rate is reduced, controlling weak reducing atmosphere can promote the volatilization of tin. The kinetic analysis results show that the apparent activation energy of tin removal reaction is13.96kJ/mol, and the reaction limiting step the mass transfer of reactants.The tin can be removed effectively under the conditions of time of40min-50min, temperature of1273K-1373K, the pyrite addition amounts of1g-2g and the coal addition amounts of10g. The tin content is decreased to0.096%under the conditions of without pyrite, N2flow rate0.6L/min, temperature1273K, holding time40min, and sulfur-bearing coal (S content of0.62%) addition amount10g. This work supplies a new approach for the clean use of sulfur-bearing coal. |
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