Method for treating copper-containing etching waste solution

Abstract

The invention discloses a method for treating a copper-containing etching waste solution. The method comprises the steps of mixing an acid etching waste solution, a first pH regulator, hydrogen peroxide and a first flocculating agent, and filtering to obtain a copper chloride solution; mixing an alkaline etching waste solution, a second pH regulator, magnesium chloride and a second flocculating agent, and filtering to obtain an ammoniacal copper solution; mixing a part of copper chloride solution, a part of ammoniacal copper solution and ammonium hydroxide, filter pressing, washing, and filterpressing to obtain a third filter cake and a first post-filtration solution; pulping the third filter cake to obtain a fourth post-mixed solution; mixing concentrated sulfuric acid and the fourth post-mixed solution, and cooling to obtain a chalcanthite crystal; filtering and dewatering the chalcanthite crystal to obtain a copper sulfate product; mixing and dewatering the other part of copper chloride solution, the other part of ammoniacal copper solution and ammonium hydroxide so as to obtain water-containing copper chloride hydroxides and a second post-filtration solution; drying the water-containing copper chloride hydroxides to obtain copper chloride hydroxides; and mixing the first post-filtration solution, the second post-filtration solution and an alkaline liquor to obtain the alkaline etching solution.

Description

technical field [0001] The invention belongs to the field of chemical industry, in particular, the invention relates to a method for treating copper-containing etching waste liquid. Background technique [0002] Copper-containing etching waste liquid is produced after the etching process. As the etching process progresses, the amount of dissolved copper increases continuously, and the Cu in the etching solution + The ions are gradually transformed into Cu 2+ , the amount of dissolved copper in the etching solution is gradually approaching its maximum etching capacity. At this time, although the etching solution still has a certain etching ability, its etching speed has dropped sharply. It can meet the requirements of the etching process in industrial production. At this time, the etching solution becomes waste liquid and is discarded, and new etching solution must be replaced in the etching tank. The etching waste liquid contains a large amount of copper, Cl - , NH 4+ e...

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Problems solved by technology

[0003] At present, there are mainly five methods for the recovery and treatment of copper-containing etching solution: lime neutralization treatment method. The advantages of this treatment method are simple process, large treatment capacity, low equipment investment, low treatment cost, and discharge water up to standard. The disadvantage is that the operation technology The requirements are high, the product quality stability is poor, the mother liquor needs to be treated separately, the product is relatively single, and the purity is low; the iron filings replacement treatment method, the advantages of this treatment method are simple process, easy operation, low equipment investment, and the disadvantage is the discharge of waste water and waste gas The pollution is very high; the extraction electrowinning method can produce high value-added cathode copper products, but the extraction has high requirements on the composition of the feed liquid, and impurities must be removed before extraction, which requires a large amount of auxiliary raw materials. Larger consumption; adsorption method, the advantage of this treatment method is that the process is simple and easy to operate, but the enriched high-concentration copper eluate needs further treatment to realize resource recovery; acid-base neutralization-regeneration method, now In the prior art, on the one hand, this method has the disadvantages of producing a large amount of ammonia nitrogen wastewater that is difficult to handle, and the electrolytic copper current efficiency of the chlorination system is not high, and the electrolysis cost is high. On the one hand, there are high extraction agent costs, low extraction efficiency and Disadvantages that the generated waste water can only be discharged after subsequent treatment of impurities in the etching solution

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