Method for recycling metal from waste acid etching liquid

Abstract

The invention belongs to the field of copper-containing industrial waste resource comprehensive utilization and particularly relates to a method for recycling metal from waste acid etching liquid. The method includes the following steps of (1) mixed alkali neutralization and sedimentation, (2) suction filtration and elution for dechlorination, (3) leaching controlling, and (4) electro-deposition. Compared with existing waste acid etching liquid resource treatment technologies, the method has the advantages that alkali consumption is low, one-time construction investment cost is low, and the adaptability is wide; and a selective electro-deposition technology adopted at the end can adapt to high copper sulfate solution residual chlorine, the quality of produced products is stable, and operation is simple. Besides, no waste water is generated except that filtration concentrated saltwater is evaporated and independently treated in the whole treatment process; the adoption of selective electro-deposition equipment guarantees unified treatment of acid mist generated in the electro-deposition process, and harmless discharge is achieved; and no superfluous waste residues are generated in the whole process, printed circuit board (PCB) acid etching waste liquid treatment zero waste can be achieved, Cu and Cl in the acid waste liquid are fully recycled, and the environment can be effectively protected.

Description

technical field [0001] The invention belongs to the field of comprehensive resource utilization of copper-containing industrial waste, in particular to a method for recovering metal from waste acid etching solution. Background technique [0002] More specifically, the present invention relates to a method for producing industrial raw material metal copper from acidic time waste liquid of printed electronic circuit board (hereinafter referred to as PCB board), and preparing chloride ions in acidic waste liquid for industrial NaCl. [0003] The proportion of a country's raw material copper consumption directly reflects the development level of its manufacturing and information industries, while the proportion of recycled copper output in its refined copper directly reflects the development level of its country's renewable resource industry. In the past 10 years, my country has made considerable progress in the field of recycling and comprehensive utilization of scrap metal cop...

AI Technical Summary

Problems solved by technology

[0005] The domestic treatment of PCB acidic etching waste liquid usually produces copper-containing enrichments such as copper powder and copper oxide mud, and resells them; the former needs to consume a large amount of reduced iron powder, and also produces a huge amount of hydrogen; the latter produces copper oxide Difficult to filter mud and huge consumption of caustic soda

[0006] Among the comprehensive utilization technologies of PCB acidic etching waste liquid resources published in China, ion-exchange membrane electrodeposition, high-temperature spray cracking, boiling evaporation and other methods have certain technical foresight, but the corresponding industrial scale application is relatively rare. The cost and corresponding equipment are expensive and the promotion value is extremely low

[0007] For example, the publication number of a company’s patent application is 103803737 A, which adopts the method of reducing and replacing copper chloride in the waste acid etching solution to copper powder, and then rinses and roasts it to form copper oxide powder. The qualified rate of the product is relatively difficult. Control, the price of aluminum powder involved in the process is relatively expensive, and the audience for the output of copper oxide powder is also small, which does not have the value of large-scale industrial promotion

[0008] For example, the publication number of a company’s patent application is 101899665 A, which uses sulfuric acid to replace chloride ions to obtain a high-concentration copper sulfate solution and then finely purifies it to prepare copper sulfate crystals and copper oxide powder. The sulfuric acid replacement process involved requires extremely high reaction conditions, high temperature , High HCl corrosive atmosphere, although a relatively large number of market-oriented products can be obtained, the initial investment and follow-up maintenance costs of the equipment are high

[0009] For example, the publication number of a patent applied by a company is 102912375 A, which adopts ion membrane exchange electrodeposition to obtain cathode precipitation of copper. Its operation needs to first dilute the high-concentration waste acid etching solution to below 35g / L, and requires ion exchange membrane and Titanium-coated anodes can obtain national standard products with a wide audience, but the equipment investment is high at one time, and subsequent operations are also complicated due to the existence of ionic membranes

[0010] To sum up, the existing PCB acid etching waste liquid treatment process either has very strict requirements on the composition of the etching waste liquid, and cannot handle a wide spectrum of acid etching waste liquid with various complex components; or the comprehensive treatment cost is high, and the profit of the process is low or even only It can be handled at a loss; or the requirements for equipment and materials are extremely high, and a construction investment is huge

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