Gas & Dust Treatment in the Process of Recycling and Dismantling of Waste PCBs
As a domestic professional manufacturer and supplier of waste circuit board recycling equipment, Zhengyang Machinery has made a preliminary exploration into the development prospects of various disposal methods, and has cleared about that the dry mechanical method is an effective way to realize the recycling of waste printed circuit boards (PCBs). Automatic dismantling of electronic components from PCBs is a key technology to implement this method, based on which we have optimized the existing treatment process of waste PCBs in China. On the analysis of the mechanical and physical properties of the waste PCBs as well as the connecting way of electronic components, Zhengyang Machinery proposed desoldering by heating is an essential premise to remove electronic components. Meanwhile, we analyzed different kinds of heating methods and put forward a new dismantling method, as shown in the following picture:
As shown in the above picture, the PCB Dismantling Machine and Gas & Dust Recovery System occupy very small space and have beautiful appearance. Heating is the general method to remove electronic components from waste PCBs. Under high temperature, the base plates, soldered dots and various components will release large amount of tail gases, which are irritant, hazardous, poisonous and even carcinogenic. If not handle them properly, it will cause serious secondary pollution. According to our research, when being heated, the waste PCBs produced phenol and some other kinds of organic compounds following the breaking of O-C, C-C, C-Br bonds in brominated epoxy resins, and also released a large amount of acid gases containing chemical elements such as S, N, Cl and Br. Moreover, heavy metals such as Sn, Pb, Sb, Hg, Cd and Cr escaped from PCBs and melting solder in the continuous tin fusion process. Therefor, gas and dust recovery system is very necessary in the process of PCBs dismantling. Now the capacity of PCB Dismantling Machine can reach 500kg/ph.