Method for preparing bismuth electrolyte with bismuth oxide slag

Abstract

The invention provides a method for preparing bismuth electrolyte with bismuth oxide slag. The method is characterized by comprising the following steps: leaching fine-grained bismuth oxide slag in a fluosilicic acid system, and filtering; returning leaching slag back into a silver revolving furnace for blowing; adding lead powder into leach liquor to replace copper in a solution; adding sulfuric acid into the copper-removed solution to recover lead; precipitating lead in sulfuric acid for purifying to obtain a solution which is qualified bismuth electrolyte. By leaching through the fluosilicic acid system, separation of bismuth-lead-copper and silver is realized, piling of precious metals is reduced, and the metal leaching rate is high.

Description

technical field [0001] The invention relates to a hydrometallurgical process in the field of metallurgy, in particular to a hydrometallurgical method for effectively preparing bismuth electrolyte from bismuth oxide slag. Background technique [0002] The idea adopted in the pyroprocessing process of copper-lead anode slime is to use two processes of reduction smelting and oxidation refining to remove base metals, and to produce gold-silver alloys enriched with precious metals. The difficulty of metal oxidation is different, and it is oxidized in three stages. First, antimony, arsenic and lead are oxidized into the smoke dust, followed by blowing air to oxidize bismuth and lead to form bismuth oxide slag, and finally adding oxidants to make copper, selenium and tellurium Oxidation produces tellurium slag, which mainly contains bismuth, lead and copper, and a small amount of antimony and arsenic in the bismuth oxide slag. [0003] There are many studies on the methods of extr...

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Problems solved by technology

[0004] The pyromelting method is to mix the bismuth oxide slag with the flux and smelt it in a reverberatory furnace or a converter to directly produce crude bismuth. This method has been industrialized and has no waste water discharge, but it has low metal recovery rate, long process flow and processing Disadvantages such as low capacity, high cost and serious environmental pollution

The hydrochloric acid dissolution is to directly dissolve bismuth in the sulfuric acid and hydrochloric acid systems, lead and silver enter the leaching residue in the state of lead sulfate and silver chloride respectively, and the bismuth-containing solution is hydrolyzed to produce bismuth slag, which is then reduced and smelted to produce rough bismuth , this method can achieve comprehensive recovery of valuable metals, but there are still disadvantages such as low metal recovery rate, high treatment cost and large amount of wastewater.

[0005] The refining of crude bismuth mainly includes fire refining and electrolytic refining. The fire refining process mainly includes sulfur addition to remove copper, oxidation to remove arsenic and antimony, alkaline refining to remove tin, zinc to remove silver, and chloride to remove lead and zinc. Among them, the two processes that have the greatest impact on the entire process are the two processes of adding zinc to remove silver and chlorination to remove lead. These two processes not only take a long time, but also cause a significant reduction in metal recovery and environmental pollution.

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