Abstract
This paper presents the results of studies on the direct production of lead–antimony alloys from sodium antimonate and on the use of antimony obtained through carbothermic reduction for technical purposes. It was shown that during the carbothermic reduction of antimony from sodium antimonate onto a lead collector at 900 °C, antimony recovery into the lead–antimony alloy increased by 10.88–12.93% compared with the process performed without the addition of lead. The process proceeds without the addition of slag-forming components. A decrease in the Sb content in the lead–antimony alloy as a result of changes to the amount of metallic lead in the melt has practically no effect on the process performance. Examples of the production of lead–antimony alloy containing 25.58% and 11.52% antimony during the carbothermic smelting of sodium antimonate are given. It is shown that the alloy containing 25.58% Sb can be used in the technological process of lead refinement at the final bismuth removal stage. The alloy containing 11.52% antimony complies with the standard for the SSuYu grade of lead–antimony alloy (9.0–12.0% Sb), including the regulated impurities, except for iron. The iron content exceeds the specified limit by 0.045%, which will require minor additional purification or the use of this alloy for special purposes. Dilution of the antimony alloy by adding lead to reduce the antimony content to 4.0% Sb at 340–360 °C was also considered. The purpose of the latter is to reduce energy consumption in cases where a significant volume of metallic lead would otherwise need to be heated to the temperature of reduction smelting at 900 ± 20 °C. The proposed technical solutions can be integrated quite easily into the existing technological flowsheet of lead production.