RESEARCH ON A NOVEL TECHNOLOGY OF INTERACTIVE ROAST OF COMPLEX LOW-GRADE BISMUTH SULFIDE ORE AND PYROLUSITE

摘要

A novel technology about interactive roast of complex bismuth sulfide ore with low grade and Pyrolusite was put forward using the low-grade bismuth sulfide ore and pyrolusite as raw materials. The predominance diagram of Bi-Mn-S-O system was drawn by thermodynamic calculations. Stable coexistence area of Bi_2O_3 and MnSO_4 and its control condition was obtained. The interactive roast conditions including roasting temperature、roasting time、the ratio of n(MnO_2)(S), ventilation rate and so on are investigated systematically. The results show that the sulfur-retained ratio reaches about 98%, in which formation rate of MnSO_4 was 94.04%, most of the residual sulfur in the ore exist in the form of Bi_(28)O_(32)(SO_4)_(10) in the roasting products The optimum roasting conditions were as follows: roasting temperature of 650℃, roasting time of 2h, 1.4 for n(MnO_2)(S) and 140L/h for ventilation rate.