Method for recycling copper from acid waste etching solution

Abstract

The invention discloses a method for recycling copper from an acid waste etching solution. The method is characterized by comprising the following steps that firstly, an organic phase and the acid waste etching solution are subjected to 1-5 levels of extraction according to the volume ratio of 1-30:1, and copper is extracted; secondly, the load organic phase obtained in the first step and purified water are subjected to 1-5 levels of washing according to the volume ratio of 0.1-10:1; thirdly, the load organic phase washed in the second step and a copper sulphate solution including sulfur acid of 130-250 g / L and copper ions of 1-50 g / L are subjected to 1-3 levels of back extraction according to the volume ratio of 1-10:1, the organic phase obtained through back extraction is returned to the first step to be repeatedly used, and a water phase is a copper sulphate solution; fourthly, metal stainless steel 304 or stainless steel 316 or metal titanium is used as a cathode, the copper sulphate solution obtained in the third step is electroplated under the current density of 50-400 A / m<2>, electroplated copper is obtained, and the copper sulphate solution obtained after the copper is electroplated is returned to the third step to be repeatedly used. According to the method for recycling copper from the acid waste etching solution, the copper can be separated selectively from the acid waste etching solution, the technology is simple, and the separation effect is good.

Description

technical field [0001] The invention relates to a method for recovering copper from acidic waste etching solution. Background technique [0002] The production process of printed circuit board (PCB) is long, and the etching process is the largest part of the PCB production process. In the etching process, when the etchant has too many dissolved substances and the etching index, including speed, side erosion coefficient, surface cleanliness, etc., is lower than the process requirements, it becomes a waste etchant. Etching liquids include acidic etching liquids, alkaline etching liquids and micro etching liquids. Acid etching is mainly used in the production of inner layer circuit patterns of multilayer circuit boards. Generally speaking, every 1m produced 2 The circuit board needs to consume 2~2.5L of etching solution, and correspondingly produce 2~2.5L of waste etching solution. The concentration of copper ions is very high, reaching 120g / L or higher. The main components o...

AI Technical Summary

Problems solved by technology

The grade of sponge copper obtained by the replacement method is not high, and the copper content in the tail liquid after copper recovery is high. Although the copper powder produced by the electrolysis method has high purity and is better than the copper powder produced by other methods, the efficiency of the copper powder produced by the electrolysis method is higher than that of copper powder produced by other methods. Relatively low, high power consumption, and the concentration of heavy metal ions in the waste liquid cannot be reduced very low, strict treatment must be carried out before discharge, and the electrolysis method is easy to produce chlorine gas; neutralization precipitation method to treat copper-containing waste liquid, the process Simple, low investment, but the copper content of the mother liquor after copper sulfate crystallization is high, which needs further treatment, and the inorganic and organic substances such as ammonium salt in the wastewater cannot be recycled, causing serious environmental pollution

At present, the extraction method has been carried out at home and abroad to recover copper in the etching solution. The extractant is mainly Lix series extractant or M5640 extractant; releases two molecules of H + ; if more copper is extracted, the released H + The more it is, the greater the acidity of the solution; while LIX? or M5640 extractant has a very low extraction rate of copper under acidic conditions

Moreover, LIX® or M5640 extractant for copper extraction belongs to oxime extractant, unlike phosphorus acidic extractant P204 and P507, which can use saponification to neutralize H in the extractant. + , so that it does not release H during extraction + , to keep the pH of the feed liquid stable; therefore, the current LIX? or M5640 extractant cannot be used in the extraction of high-copper feed liquid, especially in acidic systems