Separation of arsenic from arsenic—antimony-bearing dust through selective oxidation—sulfidation roasting with CuS

Abstract

Abstract The feasibility of a new method for separating arsenic from arsenic—antimony-bearing dusts using CuS was put forward, in which Sb was transformed into Sb2O4 and Sb2S3 that stayed in the roasted calcine while As was volatilized in the form of As4O6. The factors such as roasting temperature and CuS addition amount were studied using XRD, EPMA and SEM—EDS. CuS has an active effect on the separation of arsenic due to the destruction of (Sb,As)2O3 structures in the original dust and the simultaneous release of As in the form of As4O6. At a roasting temperature of 400 °C and CuS addition amount of 130%, the volatilization rates of arsenic and antimony reach 97.80 wt.% and 8.29 wt.%, respectively. Further, the high As volatile matter can be used to prepare ferric arsenate after it is oxidized, with this treatment rendering the vapor harmlessness.