How are pyrolysis techniques applied to printed circuit boards?

- Aug 02, 2017-

As the crushing size is usually larger. The energy consumption is low during the mechanical crushing process. Needless to say, this technology has a wider application prospect.

Pyrolysis technology, as an efficient waste treatment and resource recycling method, can play an important role in the recycling of waste printed circuit boards. With the further research on the basic theory of pyrolysis technology and the development of pyrolysis equipment, it will be one of the most important methods for the recycling of circuit boards in waste electrical appliances.

Although the existing research on measuring circuit board pyrolysis products containing bromine are limited to qualitative analysis or analysis of Total Bromine based on a specific bromine substance is also unable to achieve detection of accurate quantitative analysis, so it can not provide enough information to determine with complete conversion of brominated flame retardants and migration law of pyrolysis.

However, many researchers have carried out some attempts to remove bromine containing pollutants based on pyrolysis technology, and have made some breakthroughs.

If the technology and equipment of improper recycling on the circuit board, shielding of smoke, bromine and hydrogen bromide and brominated phenols, polybrominated biphenyls and dioxins / furans and other toxic and harmful substances generated in the combustion process of pyrolysis or more in. These substances not only cause incalculable serious harm to the environment, but also corrode the treatment equipment and reduce the quality of finished products. Therefore, whether it is safe or from the circuit board from the PCB recycling point of view, the need for circuit board pyrolysis of brominated flame retardant transformation and migration have a clear understanding, and the importance of the two pollution of waste pyrolysis processing circuit board control in the process and product of debromination problem.

The circuit board condenses the pyrolysis gas from the reactor. Condensable gas and liquid pyrolytic oil are obtained. Metals and glass fibers remain in the reactor to form solid residues, and then metal and nonmetal components are separated and removed by physical methods. The advantage of this process is that it prevents excessive crushing and heating, thus effectively avoiding the escape of poisonous and harmful gases.

At present, most of the circuit boards are recycled by fire, hydrometallurgy and other methods, focusing on the recovery of precious metals. The waste gas, waste water and waste residue produced in the treatment process are easy to cause serious two pollution. However, the resource and harmless treatment of non-metallic components, which account for over 50% of the total quality of the PCB, are relatively small. Besides a few used as fillers, they are mostly treated as landfills.

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