Separation and Recovery of Antimony from High Arsenic-bearing Flue Dusts through Selective Oxidation Using MnO₂

Abstract

The recovery of antimony from high arsenic-bearing flue dusts was carried out by a selective oxidation roasting process using MnO₂, in which the arsenic was removed through a volatilization and antimony was oxidized to Sb₂O₄ staying in the roasted products. In a certain range, the MnO₂ additive has an active effective on the arsenic volatilization for the reason that structures of some complicated As-Sb phases were destroyed after the Sb₂O₃ being oxidized to Sb₂O₄ and this part of arsenic continued to volatile. About 90.06% arsenic and only about 6.89% antimony went into smoke under the condition of roasting temperature of 723.0 K, MnO₂ amount of 20.5%, and roasting time of 90 min. The MnO₂ selective oxidation provided a good separation of arsenic from high arsenic-bearing flue dusts. The left antimony existing in the roasted products can be reclaimed through a process of reduction roasting and dust collection.