System and method for improving regeneration and reuse rate of acid etching solutions

Abstract

The invention discloses a system for improving the regeneration and reuse rate of acid etching solutions. The system comprises an etching production line, an electrolyzation device, an adding device,a regeneration solution blending device and regeneration solution oxidation-reduction potential (ORP) lifting devices. The copper-rich acid etching liquid waste of the etching production line is electrolyzed into chlorine gas and copper-poor electrolyzation clear solutions through the electrolyzation device, the copper-poor electrolyzation clear solutions are mixed with low ORP acid etching solutions of the etching production line to form regenerated acid etching solutions, the regeneration solution ORP lifting devices carry out backflow injection on the acid etching solutions and collide withthe chlorine gas, and high ORP acid etching regeneration solutions are obtained and then returned to the etching production line. The invention further discloses a method for improving the regeneration and reuse rate of the acid etching solutions. By arranging the regeneration solution ORP lifting devices, the high ORP acid etching regeneration solutions are obtained and then returned to the etching production line so as to improve the ORP of the acid etching solutions on the etching production line, replace a mode of adding oxidizing agents and hydrochloric acids in a traditional etching production line, improve the regeneration and reuse rate of the etching liquid waste and reduce the use of chemical agents and discharge of waste water.

Description

technical field [0001] The invention relates to the technical field of waste liquid treatment, in particular to a system and method for improving the recycling rate of acidic etching liquid. Background technique [0002] PCB board is the support of electronic product components and the most basic hardware carrier in today's information society. The printed circuit board industry is the pillar industry of China's electronic information industry, and its growth rate is proportional to that of the electronic information industry. With the development of the industry, although the process of PCB board production has been greatly improved, the method of chemical potion etching is still used to draw the circuit diagram on the PCB board, especially the amount of acid etching solution is the largest. The main components of the acid etching solution are copper chloride, organic additives, hydrochloric acid, sodium chloride, etc. In order to maintain the etching performance of the ac...

AI Technical Summary

Problems solved by technology

However, in view of the disadvantages of traditional treatment methods, such as the need for centralized collection and disposal of acidic etching waste liquid, the risk of leakage and environmental pollution during transportation, and the difficulty of centralized disposal of waste water to meet the standards, in recent years, the industry has developed an online recycling of acidic etching waste liquid. For example, the Chinese patent with the authorized publication number CN202492581U provides a device for recycling acidic etching solution for printed circuit boards, and CN101768742B discloses a method and special device for regenerating acidic etching solution and recovering copper, Another example is CN101748430B which discloses a copper recovery system for acidic etching waste liquid of printed boards and a method for regeneration of etching liquid. The purpose of regenerating the acidic etching solution is achieved by mixing the jet with the etching solution of the printed circuit board production line

However, in the actual operation of the above-mentioned process, although the ejector can take chlorine gas out of the electrolytic cell, the mixing effect with the acid etching solution is very poor. The utilization rate of chlorine gas in the acid etching production line for printed circuit boards is less than 10%, of which 90% More than 100% of chlorine gas needs to enter the exhaust gas treatment system, and then use a large amount of liquid alkali for absorption treatment

The mixing effect of chlorine gas and acidic etching solution is poor, resulting in a low recycling rate of etching waste solution. The etching production line still needs to add a large amount of hydrochloric acid and oxidizing agent, such as sodium chloride, in order to keep the oxidation-reduction ratio of 500-550mv in the acidic etching solution Potential, it is also necessary to overflow a large amount of acidic etching waste liquid to keep the copper ion concentration in the acidic etching system of printed circuit boards at 120-140g / L, to avoid the crystallization of the etching liquid system, and the etching waste liquid still remains after the metal copper is recovered by electrolytic deposition. Containing 5-20g / L of copper and additives, such as thiourea and sodium chloride, these still need to be discharged to the comprehensive wastewater treatment station for treatment, which not only pollutes the environment, but also wastes limited water resources and is economical. Both economic and environmental benefits are poor

Images