Method for cooperatively removing copper, arsenic, tellurium and lead from crude bismuth

CN122105153AActive Publication Date: 2026-05-29SHANDONG HUMON SMELTING
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Patent Information

Authority / Receiving Office
CN Β· China
Patent Type
Applications(China)
Current Assignee / Owner
SHANDONG HUMON SMELTING
Filing Date
2026-04-30
Publication Date
2026-05-29

AI Technical Summary

Technical Problem

Existing crude bismuth refining processes are lengthy, cause serious environmental pollution, make it difficult to remove multiple impurities in a coordinated and deep manner, and result in low bismuth recovery rates. Traditional methods also have difficulty separating lead and bismuth, which have similar properties, leading to low comprehensive utilization of resources.

Method used

The method employs melting and pre-oxidation, synergistic slag formation and impurity removal, and vacuum distillation. It utilizes composite impurity removal agents such as iron powder, bismuth phosphate, and sodium sulfide to carry out pre-oxidation and slag formation reactions under an inert atmosphere to generate FeS heterogeneous crystal nuclei, simultaneously removing Cu, As, Te, and Pb impurities, and then further purifying them through vacuum distillation.

Benefits of technology

It achieves efficient and synergistic removal of copper, arsenic, tellurium, and lead, and effective recovery of silver, shortening the production cycle, improving the recovery rate and purity of bismuth, reducing environmental pollution, and meeting the requirements of the national standard Bi9995 grade.

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Abstract

The present application belongs to the technical field of non-ferrous metallurgy, and particularly relates to a method for cooperatively removing copper, arsenic, tellurium and lead in crude bismuth, which comprises the following steps: S1, obtaining molten bismuth liquid by melting, adding an oxidizing agent to the molten bismuth liquid, and performing a pre-oxidation reaction under stirring; S2, adding a composite removing agent and a fluxing agent to perform a reaction, and then removing surface dross; the composite removing agent comprises iron powder, bismuth phosphate and sodium sulfide; S3, adding the crude bismuth after step S2 to a vacuum rectification furnace, vacuum heat-insulating, and outputting refined bismuth. Through the cooperative design of pre-oxidation activation, in-situ sulfidation and phosphate slagging, the present application realizes the simultaneous and efficient removal of impurities such as Cu, As, Te and Pb, and the effective recovery of Ag. Subsequent vacuum distillation further removes residual lead in depth, and ensures that the refined bismuth product reaches a high standard.
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