China Nonferrous Metallurgy

The antimony and mercury minerals contained in the antimony mercury coexisting ore cannot be obtained through mineral processing to obtain independent mercury concentrate or single antimony concentrate. However, in the case of mixed flotation, the sulfide minerals of antimony and mercury can enter the antimony-mercury composite concentrate with high recovery rate. The thermodynamics of separating antimony and mercury from antimony-mercury composite concentrate by volatilization roasting and the process conditions of selective oxidation volatilization roasting were studied. The results show that the heating-up is beneficial to the reaction, the main products are Sb₂S₃ and Hg0, and the roasting temperature should be less than 1323K；the saturated vapor pressure of various substances in antimony-mercury composite concentrate is different, and the volatilization order is Hg→HgS→Sb₂O₃→Sb₂S₃→Sb；the oxidation order of Sb₂S₃ is Sb₂S₃→Sb→Sb₂O₃→Sb₂O₄→Sb₂O₅; high temperature, high oxygen potential and low sulfur potential are beneficial to the oxidation of antimony, the optimal process conditions for selective oxidation volatilization roasting are as follows: the roasting temperature is 1273K, roasting time is 30mins, material layer thickness is 9cm, blast volume is 15L·min^-1, under these conditions, the volatilization rate of antimony is more than 96.87%, and the recovery rate of antimony oxide powder is more than 96%, volatilizaion rate of mercury is greater than 99.99%, and recovery rate of mercury is more than 98%. The study provides preliminary feasible experimental conditions for industrial production of antimony mercury separation.