Method for treating microetching liquid waste and copper sulfate liquid waste

Abstract

The invention discloses a method for treating microetching liquid waste and copper sulfate liquid waste. The method is characterized in that usable materials in the microetching liquid waste and copper sulfate liquid waste are utilized, and the reasonable process conditions are controlled, so as to reach the purpose of treatment of wastes with processes of wastes against one another; in addition, the COD (Chemical Oxygen Demand) value in the mixed solution of the microetching liquid waste and copper sulfate liquid waste is greatly decreased, the copper-iron separation is effectively carried out, and as a result, copper ions in the microetching liquid waste and copper sulfate liquid waste can be further recycled. According to the method, the COD in the prepared mixed copper-containing liquid waste is decreased by more than 98.5%; under the control on the process conditions, the copper-containing acid liquid obtained by the method can be used for producing electroplating grade copper oxide or electroplating grade copper sulfate, and thus the waste is turned into wealth.

Description

technical field [0001] The invention belongs to the field of waste liquid recovery and utilization, and relates to a treatment method for micro-etching waste liquid and copper sulfate waste liquid, in particular to a new method for preparing electroplating-grade copper oxide or electroplating-grade copper sulfate by using micro-etching waste liquid and copper sulfate waste liquid method. Background technique [0002] In the process of PCB circuit board processing, effective micro-etching can not only make the use effect of the board good, And it can prolong the service life of the board. The traditional PCB micro-etching system is a peroxide system, mainly sulfuric acid-hydrogen peroxide system and sulfuric acid-sodium persulfate system. The micro-etching solution can clean fingerprints, oxides, and organic pollution on the board surface while micro-etching a certain amount of copper. Dirt, after treatment to form micro-etching waste liquid. The waste liquid has low coppe...

AI Technical Summary

Problems solved by technology

This method has a low recovery rate of copper, and the purity of the sponge copper obtained after the replacement is low, and there are still a large amount of sulfuric acid, COD and a certain amount of copper in the waste liquid, and direct discharge will cause secondary pollution to the environment;

[0006] ②Neutralization precipitation method: The neutralization precipitation method is to use alkali (caustic soda, sodium carbonate, etc.) to neutralize the sulfuric acid in the micro-etching waste liquid and precipitate copper into copper oxide or basic copper carbonate, etc. It contains a large amount of COD, directly adding alkali to precipitate it into copper salt, it is easy to cause COD in the micro-etching waste liquid to co-precipitate together, resulting in poor crystal form of copper salt and low copper content

Moreover, the micro-etching waste liquid after copper deposition still contains a relatively high concentration of COD. If it is not treated and discharged directly, it will cause serious pollution to the environment; Sodium and other strong oxidants affect the activity of microorganisms, resulting in difficult treatment; if the ultrafiltration membrane method is used for treatment, it will easily lead to membrane clogging, and the cost of consumables is high, and the intercepted macromolecular organic concentrate needs to be followed up; if the evaporation concentration is selected The method consumes too much energy;

[0007] ③Electrodeposition method: use the electrodeposition copper process to process the micro-etching waste liquid. Although electrolytic plate-shaped copper can be obtained, the energy consumption is high, and the micro-etch waste liquid is reduced by the cathode of the electrode to make sodium persulfate and hydrogen peroxide, etc. The reduction of oxidants not only causes waste of resources for these oxidants, but also the COD in the wastewater is still not removed and further treatment is still required

This method has a low recovery rate of copper, and the purity of the sponge copper obtained after replacement is low. There are still a large amount of sulfuric acid, COD and a certain amount of copper in the waste liquid, and direct discharge will cause secondary pollution to the environment.

[0010] ②Neutralization precipitation method: The neutralization precipitation method is to use alkali (caustic soda, sodium carbonate, etc.) to neutralize the sulfuric acid in the copper sulfate waste liquid and precipitate copper into copper oxide or basic copper carbonate, etc. It contains a large amount of COD, directly adding alkali to precipitate it into copper salt, which will easily lead to co-precipitation of COD in copper sulfate waste liquid, resulting in poor crystal form of copper salt and low copper content

Moreover, the copper sulfate waste liquid after copper precipitation still contains higher concentration of COD. If it is not treated and discharged directly, it will cause serious pollution to the environment; The high concentration of iron ions affects the activity of microorganisms, which makes the treatment difficult; if the ultrafiltration membrane method is used for treatment, it is easy to cause membrane clogging, and the cost of consumables is high, and the intercepted macromolecular organic concentrate needs to be followed up. If you choose evaporation Concentration methods consume too much energy

[0011] ③Electrodeposition method: use electrodeposition copper process to process copper sulfate waste liquid, although electrolytic plate-shaped copper can be obtained, but the energy consumption is high, and the COD in the waste liquid is still not removed after copper recovery, and further treatment is still needed

[0012] In summary, the existing methods for the treatment of micro-etching waste liquid and copper sulfate waste liquid all have problems such as high energy consumption and low efficiency.