Printed circuit board manufacturing technology is a very complex, comprehensive high processing technology. Especially in the wet process, the need to use a lot of water, which has a variety of heavy metal wastewater and organic wastewater discharge, the composition of complex, more difficult to deal with. According to the printed circuit board copper foil utilization rate of 30% to 40% of the calculation, then the waste liquid, the copper content of waste water is considerable. According to 10,000 square meters of double-panel calculation (each side of the copper foil thickness of 35 microns), the waste liquid, waste water in the amount of copper is about 4,500 kilograms, and there are many other heavy metals and precious metals. These are present in the waste, the waste metal in the metal, such as untreated emissions, both caused by a waste and pollute the environment. Therefore, in the PCB production process of waste water treatment and copper and other metal recycling is very meaningful, is an indispensable part of the production of printed circuit boards.
As we all know, printed circuit board production process of wastewater, which is a lot of copper, a very small amount of lead, tin, gold, silver, fluoride, ammonia, organic matter and organic complexes.
As for the process of producing copper wastewater, there are: Shen copper, copper plating, copper plating, etching and a variety of printed circuit board pre-treatment process (chemical pretreatment, brush plate pretreatment, volcanic ash grinding plate pre-treatment, etc.).
The copper waste water produced by the above process can be divided into complex wastewater and non-complex wastewater according to its composition. In order to meet the national emission standards for waste water treatment, the maximum permissible emission concentration of copper and its compounds is 1 mg / l (according to copper), and different wastewater treatment methods must be adopted for different copper wastewater.