Research of aluminothermic reduction of wolframite concentrates

Abstract

The paper describes the results of the study of aluminothermic reduction of wolframite with the ratio of FeO/MnO from 0.07 to 2.17 and with the content of WO₃ from 50 to 72 %. The restore sequence at different rates in the reaction layer of wolframite components is determined experimentally. It was established experimentally that the reduction of wolframite, (Fe, Mn)WO₄ proceeds in two steps. In the temperature range 1000–1300 °C the WO₃ is recovered to metal, the next stage is reduction of the remaining solid solution (FeO·MnO). The reduction of the solid solution occurs at higher temperature (1300–1500 °C). The reduction temperature of (FeO·MnO) in its turn is a function of the thermodynamic strength of solution which is determined by its composition. Wolframite is a solid solution of iron tungstenate FeWO₄ and manganese tungstenate MnWO₄ at constant content of WO₃. Thermodynamic strength in these solutions is determined mainly by the ratio of FeO / MnO which detects the temperature of reduction of residual solid solution (FeO·MnO). The values of orders of chemical reactions of reduction are determined. The order of WO₃ reduction changes from the first to the second, depending on the initial composition of wolframite.