Method and system for treating copper-containing etching waste liquid

Abstract

The invention relates to the technical field of wastewater treatment, and provides a method and system for treating a copper-containing etching waste liquid. The method comprises the following steps:mixing an acidic etching waste liquid with an alkaline etching waste liquid to obtain a neutralized liquid; contacting the neutralized liquid with oxygen to obtain an oxidizing liquid; performing pressure filtration on the oxidizing liquid; beating the above obtained first filter cake, and carrying out pressure filtration on the above obtained first slurry; beating the obtained second filter cake,and reacting the obtained second slurry with concentrated sulfuric acid; and sequentially carrying out cooling crystallization and solid-liquid separation on the obtained copper sulfate-containing reaction liquid to obtain copper sulfate crystals and a copper sulfate mother liquor. The copper-containing acidic etching waste liquid is neutralized, then the neutralized liquid is aerated, cuprous ions in the neutralized liquid and chloride ions form a complex, cuprous ions are rapidly oxidized in an aeration state to form copper ions in order to form a basic copper chloride precipitate, and thebasic copper chloride precipitate is recovered by pressure filtration and used to prepare copper sulfate, so the copper concentration of the wastewater is reduced, and the copper recovery rate is increased.

Description

technical field [0001] The invention relates to the technical field of waste water treatment of printed circuit boards, in particular to a method and system for treating copper-containing etching waste liquid. Background technique [0002] In the manufacturing process of printed circuit boards, the total amount of copper in the copper etching waste liquid produced is more than 60,000 tons per month. The copper-containing etching waste liquid includes acid waste liquid and alkaline waste liquid. The main components of acid waste liquid are It is copper chloride and hydrochloric acid. The main components of alkaline waste liquid are cuproammonia liquid and ammonia water. Copper is a heavy metal element that exists in soil and human and animal bodies. The content in soil is generally about 0.2ppm. Excessive copper will interact with The enzymes in humans and animals undergo precipitation / complexation reactions, resulting in enzyme poisoning and loss of physiological functions. ...

AI Technical Summary

Problems solved by technology

Therefore, if a large amount of copper etching waste liquid produced in the manufacturing process of printed circuit boards is not promptly and effectively treated, it will undoubtedly cause serious pollution to the environment, especially the water resources and soil in the surrounding areas of printed circuit board factories.

[0003] In the prior art, the general treatment process of copper-containing acidic etching waste liquid is the neutralization precipitation method, and the concentration of copper in the treated waste water is relatively high

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