Method for producing bismuth and enriched silver from high-silver bismuth alloy

Abstract

A method for preparing bismuth and collecting silver from high silver bismuth alloy is provided. The high silver bismuth alloy is melted and is introduced with air, and oxidation reaction is carried out to remove most of stibium, arsenic and small amount of lead; an anode plate made of the bismuth alloy is electrolyzed in electrolyte of fluosilicic acid and bismuth fluorosilicate, so as to obtain electrolytic bismuth with small amount of impurity and anodic mud containing silver; sulfuric acid is added to remove lead from the electrolyte; then bismuth oxide is adopted to react with the electrolyte, so as to complement diluted bismuth ion in the electrolytic process; the electrolyte is melted and added with zinc to remove traces of cooper and silver from the bismuth, and metal aluminum is added to remove traces of arsenic and stibium from a bismuth melt and then chlorine is introduced to remove residual aluminum and micro-amount of lead. The method for preparing bismuth and collecting silver of the invention saves zinc, reduces entrainment of the bismuth when silver-zinc crust is formed, improves direct recovery rate of bismuth and reduce chlorine consumption when the traditional method is used for removing a great deal of lead.

Description

technical field [0001] The invention relates to the extraction and refining of bismuth in the field of metallurgy, in particular to a method for preparing high-purity bismuth from a high-silver-bismuth alloy and effectively enriching precious metals. Background technique [0002] Bismuth-containing materials are subjected to fire smelting to produce crude bismuth containing silver, lead, arsenic, antimony, tellurium, tin, copper and other metals. In order to obtain metallic bismuth products, the current processing methods for crude bismuth are fire refining and electrolysis. In the fire refining method, the crude bismuth is first melted, and sulfur is added to remove copper and a part of lead in the crude bismuth, and then air is passed into the bismuth melt to oxidize and remove arsenic and antimony, and the crude bismuth after removing arsenic and antimony Add alkali and sodium nitrate to remove tin, tellurium, arsenic and antimony by oxidation. The separation of silver ...

AI Technical Summary

Problems solved by technology

[0004] 1) In the fire refining process, different processes are used for various impurities, and the process flow is long. Especially for materials with high silver content, a large amount of zinc will be consumed by adding zinc to remove silver, and excessive zinc will also require In the process of lead removal, chlorine gas is introduced to remove lead together

[0005] 2) Bismuth pyro-refining adopts different methods for different impurities, and needs to adopt different heating temperatures according to different metal melting points, and the melting process is long and complicated

[0007] 4) These refining methods have high reagent consumption, large amount of slag return, and serious environmental pollution

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