Process for recovering bismuth from bismuth slag

Abstract

The invention belongs to the field of bismuth refining, and in particular, relates to a process for recovering bismuth from bismuth slag. Later slag (bismuth slag) of a dore furnace is crushed to feedin a ball mill to mill as powder; then, the powder is fed in a leaching tank with sulfuric acid, industrial salt and water solution for reaction by a period of time at a temperature of 80-90 DEG C; bismuth and copper are fed in the solution; and leaching liquid realizes liquid-solid separation through a plate frame filter press. Through neutralization, hydrolytic bismuth is precipitated in a slagform; copper in the solution is replaced by iron powder to finally prepare sponge copper; the bismuth slag is smelted by a pyrogenic reduction furnace to prepare crude bismuth; and the crude bismuthis refined and purified to obtain final products-refined bismuth. The process is convenient to operate, high in recovery rate of bismuth and low in energy consumption, and solves the difficulties of single recovered element, longer flow and low metal recovery rate in a traditional dore furnace later slag treatment method.

Description

technical field [0001] The invention belongs to the field of bismuth refining, in particular to a process for recovering bismuth from bismuth slag. Background technique [0002] With the continuous development of non-ferrous smelting, easy-to-handle minerals and raw materials are increasingly reduced and exhausted. Various difficult-to-handle ores and complex materials of valuable metals, such as waste generated during the smelting process, production by-product materials, etc., have gradually become valuable metal elements. recycled secondary resources. The late slag of the silver separation furnace is the late slag with complex composition obtained after the lead anode slime is smelted and blown for silver separation. It has become a valuable raw material for comprehensive recovery because it contains bismuth, lead, silver, antimony and other metals. [0003] Most smelters in China store the slag in the later stage for further processing or sell it as an intermediate prod...

AI Technical Summary

Problems solved by technology

[0003] Most smelters in China store the slag in the later stage for further processing or sell it as an intermediate product at a low price. At present, there are two traditional processing methods: fire method and wet method, reverberatory furnace and converter smelting, both of which tend to be single element or precious metals such as gold and silver. Recycling and extraction, so that other valuable metal elements cannot be completely recovered, resulting in waste of resources and environmental pollution

The properties of later-stage slag are complex, and the treatment methods of later-stage slag with different components are also different. For later-stage slag containing more rare and precious metals, gold and silver are concentrated and recovered through leaching; for late-stage slag with high heavy metal content, lead and copper are mainly recovered. Traditional The treatment method can only selectively recover metals, and cannot recover more valuable metals in the same process, which is likely to cause repeated smelting