Precious Metal Etching Solution Regeneration Copper Recovery Equipment

Precious Metal Etching Solution Regeneration Copper Recovery Equipment
 
Copper Recovery Technology and Equipment for PCB Circuit Board
1: Copper etching waste liquid and Micro-etching waste liquid are abundant waste liquid in PCB plant, which not only cause pollution, but also have recycling value. Therefore, while developing PCB production, how to recycle wastewater treatment, recycle waste liquor, reduce pollution and pollution, maximize the reuse of useful resources, reduce pollution emissions, turn waste into treasure, and realize the harmonious development of waste by waste, increase production without pollution, create a harmonious development of human and nature, and take the road of sustainable development, is of great significance to the PCB industry. Of particular importance.
2: Treatment and Utilization of Etching Wastewater at Home and Abroad
Etching waste liquid contains 140-160 g/l of copper. At present, the common practice is to store them in PCB factories and put them in sealed pools or cans waiting for the outside units to pull them away. Outside units are generally qualified companies approved by the local environmental protection department to recycle. They pull back the waste liquor and use chemical methods (neutralization, electrolysis, replacement) to recover copper from the waste liquor or or copper sulphate products. These methods are backward in technology, incomplete recovery of copper, no obvious economic benefits of treatment, and secondary pollution pollutants are discharged. Especially alkaline etching, due to the presence of a large number of ammonia, once improperly treated and discharged, it will inevitably cause a great impact on the water ecosystem.
At present, there are many treatment methods for etching solution and low copper wastewater, one of the main pollutants in PCB production process. These methods not only make use of copper resources, but also have the shortcomings mentioned above. On the basis of summarizing the pros and cons of previous research results and aiming at the characteristics of etching process in PCB production, we efficiently utilize the residual useful components in etching waste liquid, extract the components that affect etching effect, form separation copper, electrolysis copper plate, so as to achieve the purpose of reducing pollution and recovering resources.
Technical Principle: In the process of PCB production, etching process is used to make the copper wall attached to the copper foil plate into the required circuit graphics. High-culvert copper waste liquor which loses etching function is produced by etching waste liquor in the process of etching. The technical scheme is based on adding special extractant to the super-high copper waste etching solution and separating copper selectively, so that the etching waste liquid can recover the etching function and recycle because of the reduction of copper concentration, and the separated copper liquid can be electrolyzed to form high purity copper plate, thus obtaining good economic benefits. The whole process adopts closed-circuit circulating system without secondary pollution and realizes zero emission of pollutants. The operation is also convenient and simple.
The main chemical reactions in the treatment process are as follows:
(1) Ao and adsorption: 2RH + Cu2+ = 2RCu + 2H + 2RCu + 2H = 2RH + Cu2+ - RH is an organic solvent.
This process mainly utilizes the adsorption capacity of organic solvents to selectively separate copper from waste liquor and make copper enter the acid electrolysis system. After this step, copper is separated from the waste liquid separately. When entering the acid system, copper salt exists in the solution in the form of copper salt, which is different from the waste liquid in the form of less impurities in the solution, which makes it possible to recover copper in a high purity way.
(2) Electrolytic part: Cu2++2e, Cu 2H2O-4e, 4H++O2
After the second step, the copper ion in acid can be transformed into simple copper. This step can sometimes be omitted according to the use of products. It is also feasible to produce high purity CuSO4 by crystallization method.
Composition comparison of etching solution before and after treatment:
By comparing the components of waste water and wastewater before and after treatment, it can be seen that there is no essential change in other components except copper concentration in etching solution or wastewater with low copper content. Among them, copper ion in etching effluent has been reduced more than twice after treatment, and the etching function can be completely restored after adjustment. In the treatment of low copper-containing wastewater, the copper content in wastewater has been reduced from 10-30 g/l to about 500 ppm by special adsorption electrolysis technology, and copper plate has been made to reduce pollution and pollution, thus greatly reducing the burden of wastewater treatment.

Contrast Table of Composition of Etching Solution and Wastewater Containing Low Copper before and after Treatment:
 

 
 
 
Equipment based on this technology
Based on the chelating adsorption electrolysis technology independently developed by the company, the company independently developed a special copper recovery equipment for adsorption electrolysis, namely, the recycling and recycling equipment for etching waste liquor and copper recovery equipment, which can selectively separate copper from waste liquor wastewater to achieve the purpose of reducing its copper ion concentration and recovering copper. After the treatment of the equipment, the copper concentration in the wastewater decreases to only several hundred ppm, which can be discharged to the standard with a little treatment, and no secondary pollution occurs during the treatment process.
Full set of recovery equipment is fully automatic control, easy to operate and no waste liquid discharged.