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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 complex, high hardness, strong resistance, containing a variety of valuable metals and a variety of harmful substances, its resource has always been a problem in the field of electronic disposal of waste disposal. DPC ceramics manufacturers in order to solve the problem of secondary pollution in the process of abandoning the printed circuit board, including exhaust gas and dust pollution, a wet crushing is the use of water as a destroying medium to complete the breaking of printed circuit boards. The low temperature crushing skills are also beginning to be used to discard the broken 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 economic development and scientific and technological progress, the number of abandoned 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 ruin valuable resources, especially precious metals. This status has aroused great concern from governments, environmentalists and the business community around the world. Some countries and regions have taken effective measures to do a lot of work in laws and regulations, recovery of systems and recovery of skills 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 production The prevention and control of environmental pollution in the process is still the main point of future research.

  Hydrometallurgical Skills Recovering the Valuable Metals in Abandoned Printed Circuit Boards is primarily the use of valuable metals in circuit boards that can be dissolved in strong oxidizing media such as nitric acid and aqua regia to enter the liquid phase, making most precious metals and Other metals enter the liquid phase and are separated from others, and then the various metals are withdrawn from the liquid phase.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 the metal in the waste printed circuit board, it needs to be disassembled, selected (large visible metal, no precious metal parts), damaged (generally 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, using the principle of "whirlwind vortex separation", the company independently developed the "complete physical recovery equipment for waste printed circuit boards", effectively completing the separation of metal and non-metal, and further data-based general printed circuits for non-metallic powder materials. The main part of the board is made of thermosetting epoxy resin glass fiber composite material. This material not only has insoluble and non-melting characteristics, but also contains high concentration of brominated flame retardant, heavy metal and other harmful components. Recycling brings great difficulties. Now, most of the recovery is limited to metal parts, and landfill and combustion are still the primary means of disposal. 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 the exposed 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 insulating air, and the organic substance between them is differentiated and converted into oil and gas, which can be recovered after being collected by condensation, and the metal and glass fiber components are basically not changed in nature, leaving As a solid phase residue in the reactor, a simple physical method can be used to recover. Unlike the combustion treatment of electronic waste, the vacuum pyrolysis process is carried out under anaerobic conditions, thus preventing the occurrence of dioxins and furans, and the amount of exhaust gas is small and environmental pollution.

  The basic principle of the chemical treatment method is to use a method of recycling the printed circuit board by using the difference in chemical stability of various components in the waste printed wiring board. This method is carried out by refining a metal rich group or a crushed circuit board, and then gradually refining various metals through a multi-stage chemical reaction.
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