METHOD FOR RECOVERING BISMUTH

摘要

PROBLEM TO BE SOLVED: To provide a method for refining and recovering bismuth, which can efficiently separate and refine bismuth from an acidic solution of hydrochloric acid and sulfuric acid produced in a copper smelting process to recover high-purity bismuth sulfate.

SOLUTION: The method for recovering the bismuth includes the steps of: subjecting the acidic solution containing bismuth ions to reduction treatment to produce reduced slag containing bismuth (reduction step); adding hot concentrated sulfuric acid to the reduced slag to leach bismuth therefrom (leaching step); cooling a solid-liquid separated filtrate to precipitate bismuth sulfate (cooling precipitation step); and solid-liquid separating the liquid to recover bismuth sulfate (recovering step). The method for recovering the bismuth also preferably includes a returning step of heating a filtrate (concentrated sulfuric acid) which has been obtained after having leached bismuth by adding the hot concentrated sulfuric acid that has been separated in the post-process to the reduced slag in the bismuth leaching step and having recovered bismuth sulfate in the recovering step, returning the heated filtrate to the bismuth leaching step, and using the filtrate for dissolving bismuth.

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