A kind of method for recovering lead, silver and copper with precious lead as raw material

Abstract

The invention relates to a method for recovering lead, silver and copper by using precious lead as a raw material, and belongs to the technical field of combining fire method and wet method. Firstly, noble lead is separated from lead, antimony, bismuth and copper by vacuum distillation to produce high-bismuth lead and precious silver; the obtained high-bismuth lead is electrolyzed with high-bismuth lead to obtain precipitated lead, and the obtained precious silver is refined in a converter to produce Crude silver, and according to the length of converter refining time to obtain the early converter slag and converter late slag; the obtained coarse silver is electrolyzed with silver to obtain silver ingots, and the obtained converter early slag and converter late slag are respectively crushed to a particle size < 6mm, and then finely ground Converter slag fine powder is obtained by forming a powder with a particle size of less than 100 mesh, and then adding sulfuric acid solution to the converter slag fine powder for leaching, and obtaining leaching slag and copper sulfate solution after leaching is completed. The method improves the process flow for treating precious lead materials, and has the effects of refining and concise process flow, saving energy and reducing consumption, and optimizing the production environment.

Description

technical field [0001] The invention relates to a method for recovering lead, silver and copper by using precious lead as a raw material, and belongs to the technical field of combining fire method and wet method. Background technique [0002] At present, the existing technologies for recovering copper from silver converter slag, a by-product of precious lead, mainly include: (1) sulfuric acid is added to salt or hydrochloric acid for leaching and recovery. Then the copper and bismuth that enter the solution are replaced to obtain copper-bismuth slag, and then the copper is recovered. The process is to first crush the converter slag and grind it into powder below 100 mesh, and then divide it into a powder with a liquid-solid ratio of 5 to 6: 1 Put it into the solution of sulfuric acid and salt, stir it mechanically, keep the leaching temperature at 80-95°C for 2 hours, and use caustic soda or soda ash solution to neutralize and hydrolyze the leaching solution to remove bismu...

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Problems solved by technology

[0002] At present, the existing technologies for recovering copper from silver converter slag, a by-product of precious lead, mainly include: (1) sulfuric acid is added to salt or hydrochloric acid for leaching and recovery. Then the copper and bismuth that enter the solution are replaced to obtain copper-bismuth slag, and then the copper is recovered. The process is to first crush the converter slag and grind it into powder below 100 mesh, and then divide it into a powder with a liquid-solid ratio of 5 to 6: 1 Put it into the solution of sulfuric acid and salt, stir it mechanically, keep the leaching temperature at 80-95°C for 2 hours, and use caustic soda or soda ash solution to neutralize and hydrolyze the leaching solution to remove bismuth. After hydrolysis, replace copper with iron powder to obtain sponge copper. After the replacement, the liquid is sent to the sewage station for treatment, and the sponge copper is reduced and smelted to produce blister copper. The main defect of this method is the generation of waste water; (2) nitric acid leaching silver converter slag to recover copper, the principle is to remove all metals in the silver converter slag They are all dissolved in nitric acid solution, and then silver, lead, bismuth, copper and other metals are recovered respectively. The process is to crush and grind the converter slag into powder below 100 mesh, and then make it according to the liquid-solid ratio of 5-6: 1 Put it into the nitric acid solution with a nitric acid concentration of 460-480g / l, stir it mechanically, and keep the leaching temperature at 60-65°C for 2 hours to obtain the leaching solution, add common salt to chlorinate it to remove silver and lead, and remove lead and silver. Then add caustic soda or soda ash solution to neutralize and hydrolyze bismuth, and replace copper with iron powder after hydrolysis to obtain sponge copper; the disadvantage of this method is that waste water is generated, nitric acid is expensive and volatile; (3) soaking with ammonia— The method of extraction-electrowinning recovers copper from silver converter slag. The process is to first pass the silver converter through two countercurrent ammonia immersions, and the obtained ammonia immersion solution is subjected to two-stage extraction, and the obtained organic extract is washed and then subjected to one-stage reaction. The electrolytic copper product is obtained by electrolytic extraction and back extraction. The disadvantage of this method is that ammonia is volatile, the evaporation of the electrolyte is large during the electrowinning process, and the power consumption is high, resulting in high production costs and complicated processes.

[0003] The original process of the company's precious lead is to put the precious lead directly into the converter for blowing oxidation to form slag and add alkali to deep oxidize the slag to obtain silver converter slag and crude silver products, but the silver converter slag produced in the original process contains lead and bismuth Higher and high production cost disadvantages, it is necessary to smelt the silver converter slag into an alloy, and the step of alloy smelting to remove copper can further extract the copper in the silver converter slag; the obtained crude silver is electrolyzed to obtain silver products, and the silver The converter slag is directly put into the reverberatory furnace to smelt the high-bismuth alloy. When the high-bismuth alloy is melted and removed in the refining pot, copper enters the copper dross. After the refined high-bismuth alloy is electrolyzed, lead is precipitated. The by-product copper dross and the copper dross produced by the smelting of crude lead and copper removal are put into the reverberatory furnace to make ice copper to recover copper, but the defect of the method of recovering lead, silver and copper in the above-mentioned traditional process is that the recovery cost is high and the recovery The efficiency of copper is low, and the silver content in matte copper is high, resulting in incidental losses

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