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How to solve the problem of waste printed circuit board pollution

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  Printed circuit boards are an important part of electronic and electrical products. Its components are disorderly, high hardness, strong resistance, contains a variety of valuable metals and a variety of harmful substances, and its resource has always been a problem in the field of electronic disposal of waste materials. In order to deal with the secondary pollution problem caused by the process of abandoning the printed circuit board, the DPC ceramics is invented. The invention includes a method of decontamination of exhaust gas and dust. A wet crushing method is used to break the printed circuit board by using water as a destroying medium. Low temperature fracture skills have also begun to be applied to the abandonment of printed circuit boards. Eddy current sorting is a method of sorting and discarding metal and non-metal parts of printed wiring boards.

DPC ceramic

  With the development of the economy and the advancement of science and technology, the number of discarded electronic products has risen in a straight line. The huge number of electronic products that abandon printed circuit boards are facing great damage to the environment, and on the other hand, they are ruining valuable resources, especially precious metals. This status quo has attracted the attention of governments, environmentalists and the business community around the world. Some countries and regions have taken useful measures to do a lot of work in laws and regulations, recovery of systems and recovery of skills research and development.

  From the current research level of DPC ceramics, the use of "mechanical physics separation + hydrometallurgical recovery" process to abandon printed circuit boards has the advantage of being able to complete industrial production in a short period of time, but the overall process optimization and The prevention and control of environmental pollution in the production process is still the main point of future research.

  The hydrometallurgical skills to recover the valuable metals in the discarded printed circuit boards are mainly the use of valuable metals in the circuit board to dissolve in the strong oxidizing medium such as nitric acid, aqua regia and into the liquid phase, so that most of the precious metals and Other metals enter the liquid phase and are separated from others, and then the various metals are withdrawn from the liquid phase. When using hydrometallurgical skills to recover metal from used printed circuit boards, it is necessary to disassemble, select (large visible metals, parts without precious metals), damage (usually metal and non-metal separation of the damaged powder), etc. Process, then chemically leaching precious metals or other valuable metals in between. Thus, hydrometallurgical skills can be used as a follow-up process to mechanically dispose of discarded boards.

  In addition, the principle of “whirlwind vortex separation” is used to independently develop “complete physical recovery equipment for waste printed circuit boards”, which is useful for completing the separation of metal and non-metal, and further materializing non-metallic powder materials. The main part of the plate is made of thermosetting epoxy fiberglass composite material. This material not only has the characteristics of insoluble and non-melting, but also contains high concentration of brominated flame retardant, heavy metal and other harmful components. Recycling brings great difficulties. At present, most of the recovery is limited to metal parts, and landfill and combustion are still the main ways to dispose of waste. The heat treatment method mainly includes incineration, vacuum cracking, direct smelting and the like.

  The incineration method first breaks the discarded material of the electronic printed circuit board to a certain particle size, and sends it to an incinerator for combustion to differentiate the organic components therebetween, thereby separating the gas from the solid. The residue after combustion is a bare metal or its oxide and glass fiber, which can be recovered by physical and chemical methods after being destroyed. The gas containing organic components is discharged into the secondary incinerator after combustion treatment

  Pyrolysis is also called retorting in industry. The electronic printed circuit board discard is placed in a container and heated under the condition of blocking air, and the organic substance between them is differentiated into oil and gas, and can be recovered after being collected by condensation, and the metal and glass fiber components do not change in nature at all, leaving As a solid phase residue in the reactor, a simple physical method can be used to recover. Unlike the combustion of electronic waste, the vacuum pyrolysis process is carried out under anaerobic conditions, thus suppressing the production of dioxins and furans, generating less waste gas and polluting the environment.

  DPC ceramics Xiaobian introduced, the fundamental principle of chemical treatment is to use the difference in chemical stability of various components in the waste printed circuit board to make the disposal of printed circuit boards. This method gradually refines various metals by multi-stage chemical reaction by refining a metal rich group or a crushed circuit board.
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