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Waste Printed Circuit Boards are a Problem of Pollution? These Methods Will Help You to do It Easily.

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  Printed circuit board is an important part of electronic and electrical products.Its composition is complex,hardness is high,toughness is strong,contains a variety of valuable metals and a variety of harmful substances,its recycling has been a difficult problem in the field of resource disposal of electronic discards.The investigation of ceramic substrates shows that some manufacturers have invented a wet crushing method which uses water as the destructive medium to complete the crushing of printed circuit boards in order to solve the secondary pollution problems in the crushing process of discarded printed circuit boards,including exhaust gas and dust pollution.Low-temperature crushing technology has also begun to be applied to the crushing of discarded printed circuit boards.Eddy current separation is a method of separating and discarding metal and non-metal parts in printed circuit boards.

  With the development of economy and the progress of science and technology,the number of discarded electronic products has been rising in a straight line.On the one hand,the huge number of discarded printed circuit boards(PCB)electronic products are facing great harm to the environment,on the other hand,they waste precious resources,especially precious metals.This situation has attracted great attention from governments,environmentalists and business circles all over the world.Some countries and regions have adopted effective measures and done a lot of work in the fields of laws and regulations,recovery system and recovery skills research and development.

  From the point of view of the present research level,the selection of"mechanical physical separation+hydrometallurgical recovery"process for disposal of abandoned printed circuit boards has the advantage of being able to achieve industrial production in a short time,but the optimization of the overall process flow and the prevention and control of environmental pollution in the production process are still the focus of future research.

  Hydrometallurgical skills to recover valuable metals from discarded printed circuit boards mainly use the characteristic that valuable metals in circuit boards can dissolve in nitric acid,aqua regia and other strong oxidizing media and enter the liquid phase,so that most precious metals and other metals enter the liquid phase and separate from other substances,and then recover all kinds of metals from the liquid phase.When choosing hydrometallurgical technology to recover metals from waste printed circuit boards,it is necessary to dismantle,select(large visible metals,parts without precious metals),destroy(metal and non-metal separation of damaged powders)and chemical leaching of precious metals or other valuable metals.Therefore,hydrometallurgical technology can be used as a follow-up process for mechanical physical treatment of discarded circuit boards.

  In addition,using the principle of"cyclone separation",we independently developed a"complete physical recovery equipment for waste printed circuit boards"to effectively complete the separation of metal and non-metal,and further material the non-metal powder.The main part of printed circuit boards is made of thermosetting epoxy resin glass fiber composites,which are not only insoluble but also insoluble.The characteristics of non-melting,high concentration of brominated flame retardants,heavy metals and other harmful components make it difficult to recycle.At present,most of the recovery is limited to metal parts,and landfill and incineration are still the main ways to dispose of waste.The heat treatment method mainly includes incineration,vacuum cracking,direct exercise and so on.

  The incineration method is to break up the discards of printed circuit boards to a certain particle size and send them to an incinerator for incineration,which can differentiate the organic components between them,thus separating the gas from the solid.The residue after incineration is bare metal or its oxides and glass fibers,which can be recovered by physical and chemical methods after destruction.Gases containing organic components are discharged after incineration in a secondary incinerator.



ceramic substrates



  Pyrolysis is also called retorting in industry.The discards of printed circuit boards are heated in containers under the condition of isolation of air,so that the organic matter between them can be differentiated into oil and gas,which can be recovered after condensation collection.The properties of metal and glass fibers do not change at all.They are left in the reactor as solid residue and can be separately recovered by simple physical methods.Unlike the incineration treatment of electronic waste,vacuum pyrolysis is carried out under anaerobic conditions,which can prevent the occurrence of dioxins and furans with less waste gas and environmental pollution.

  The basic principle of chemical treatment is to use the different chemical stability of various components in waste printed circuit boards to make the discarded printed circuit boards resource.Ceramic substrate fabrication explains that this process involves liquefaction of metal-rich groups or circuit boards after crushing,thus gradually extracting and recovering various metals through multistage chemical reactions.

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