The distribution of bismuth in the process of reductive smelting of lead agglomerate

Abstract

The world production of bismuth is largely supported by the pyro metallurgical processes of obtaining lead, where in this case bismuth is concentrated in gross lead around 94-98 %, from which elementary bismuth is exploited in the case of debismuthization. Bismuth production in the Trepça complex was based on its concentration in lead-zinc composite ores, with about 0.17 % Bi. While the concentration of bismuth in lead concentrates varies and ranges from 0.03-0.15 % Bi. Well, in addition to gross lead, bismuth is also concentrated in all other by-products of the process in which Pb is also concentrated. As a result of this, the recovery rate of bismuth in the case of bismuth enrichment is low and is around 65-78 % Bi. The rate of distribution of Bi in the products of the Pb refinery is as follows: 78 % of bismuth passes into refined bismuth; 6.62 % in Ca-Mg-Bi powder. Therefore, the purpose of this work is to intensify the debismuthization process by improving the recovery rate of Bi, where only the use of Ca as a reagent can reduce the content of Bi in Pb up to 0.04-0.005 %, while the use of only Mg as a reagent can to reduce the content of Bi in Pb up to 0.5 %. While the joint use of Ca and Mg, in a ratio of 1:2, can reduce the content of Bi in Pb to a value of 0.01 %. In cases where deep debismuthiation is required, then the amount of Sb in the molten lead is intervened and in this case the amount of bismuth in the lead is reduced to the values of 0.004 % Bi.