Black copper sludge recycling and harmless processing method

Abstract

The invention relates to a black copper sludge recycling and harmless processing method. The method comprises the steps of oxidation leaching, wherein normal-pressure hot acid oxidation leaching or pressurized oxidation leaching is adopted, if normal-pressure hot acid oxidation leaching is adopted, according to the liquid and solid ratio of 4 to 20, black copper sludge and sulfuric acid with the concentration of 20 to 200 g / L are adopted for size mixing, the reaction temperature is controlled, air is inflated, hydrogen peroxide is added according to 0.5 to 2 t / tblack copper sludge for the reaction, and leaching liquid and leaching slag are obtained; extraction-electrodeposition, wherein a specific organic phase is added into the diluted leaching liquid, the phase ratio and time are controlled, and a washed loaded organic phase is subjected to extraction-electrodeposition; and arsenic precipitating and solidifying, wherein alkali is added into a raffinate for neutralizing and deacidification, thickening is carried out, acidification dearsenification and washing are carried out, solution and gypsum residue are obtained, an iron-contained reagent and the hydrogen peroxide are added into the solution, iron and arsenic are oxidized into Fe3+ and As5+, scorodite seed crystals are added, pH value is controlled, during the reaction, arsenic solidifying, thickening, alkali adding for neutralizing, and liquid and solid separation are carried out, and precipitating arsenic slag is obtained and put into a landfill. The method has the advantages of efficiently recycling valuable metal like copper, arsenic open circuit and harmless processing can be achieved, process is simple, cost is low, the processing effect is good, the environment pollution risk is small, and the method is suitable for being applied to the non-ferrous metal metallurgy and environment protection.

Description

Technical field [0001] The invention relates to a method for treating black copper mud as a resource and harmless, which is suitable for non-ferrous metal smelting and environmental protection applications. Background technique [0002] The black copper sludge is the black sludge produced at the cathode during the copper electrolytic refining process, the electrolyte purification and copper removal process. The black copper mud contains 30-60% copper, 20-40% arsenic, and a small amount of antimony, bismuth, and lead. [0003] The traditional processing method of black copper mud is to return to the smelting system as an ingredient, which will cause arsenic to circulate and accumulate in the smelting system, which not only deteriorates the furnace condition and reduces the processing capacity of the smelting system, but also increases the output of smoke and dust and impurities such as arsenic, bismuth, and lead. It cannot be removed, and it accumulates cyclically during the smelti...

AI Technical Summary

Problems solved by technology

For example, Chinese patent CN 103290221A discloses a "method for oxidative leaching of black copper mud by sulfuric acid", in which air is introduced into the leaching process for oxidation, and the leaching solution is evaporated and crystallized to obtain copper sulfate, and the crystallization mother liquor is prepared by controlling the ratio of copper to arsenic and the pH value. To obtain copper arsenate, there is a small market demand for copper arsenate obtained in this method, unstable chemical properties, difficult follow-up treatment, and untreated liquid after precipitation of copper arsenate; as Chinese patent CN106148702A discloses a "from black copper mud Method for Separating Copper and Arsenic in China", which adopts normal pressure sulfuric acid oxidation to leaching black copper mud, adding hydrogen peroxide during the leaching process, the leaching solution is a copper and arsenic rich solution, and the copper and arsenic rich solution is evaporated and crystallized to obtain copper sulfate pentahydrate, and ferrous iron is added to the solution after crystallization Precipitation of arsenic, this method does not effectively recover the copper in the liquid after crystallization, the impact of copper on the subsequent iron salt precipitation of arsenic is not mentioned, how to deal with the liquid after iron salt precipitation of arsenic, whether the toxicity of the generated iron and arsenic slag meets the standard, etc. None of these problems are explained; Jiangxi Copper Co., Ltd. adopts a "staged pressurized oxidation acid leaching black copper mud and copper arsenic slag", and uses concentrated crystallization-arsenic reduction to obtain As 2 o 3 After the reduction, the liquid returns to the first-stage pressure leaching, the first-stage leaching residue is subjected to the second-stage pressure leaching, the leaching liquid returns to the first-stage pressure leaching, the leaching residue is removed by alkaline leaching, and then enters the antimony-bismuth recovery system, the leachate enters the arsenic reduction system, and the first-stage leaching Press leaching process control discloses copper arsenic slag: sulfuric acid = 1:0.1~0.3:1.4~1.8(w / w), temperature 100~130℃, total pressure 0.8~1.5Mpa, time ≥8h, sulfuric acid concentration ≤130g / L process conditions; as the patent of Chinese patent CN102851497B discloses a kind of " processing method of arsenic-containing material ", it is to carry out normal-pressure acid leaching to arsenic-containing material earlier, obtains the leaching solution that is rich in copper, arsenic, zinc, then will produce The atmospheric pressure leaching residue is further subjected to acidic oxygen-enriched leaching, the reaction temperature is controlled at 0-200°C, and the oxygen partial pressure is 0-500kPa. The leaching solution after stripping is produced by electrowinning to produce cathode copper, or evaporating and crystallizing to produce copper sulfate, and the raffinate is reduced by sulfur dioxide to produce arsenic trioxide. This process can solve the accumulation of arsenic in the system and produce arsenic trioxide with a purity of 99.9%. Two-stage acid leaching, there is a long process flow and As 2 o 3 Product sales difficulties and other issues

[0013] In short, the fire treatment process of black copper mud has problems such as poor working environment, low recovery rate, and easy to produce secondary pollution, etc., and is gradually being eliminated

At present, most enterprises tend to use wet process to process black copper mud, but among them As 2 o 3为 The wet treatment process of the product has problems such as high production cost, low recovery rate, small product market space, and difficult sales

The open circuit treatment of black copper mud is a difficult problem in nonferrous metallurgy. Many enterprises have made long-term efforts, but there has been a lack of an economical and environmentally friendly treatment method.

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