Waste circuit board recycling production line
A new waste circuit board recycling process and equipment with strong applicability and high environmental protection. The production line is a fully automatic production line and adopts advanced physical method recycling technology. It can effectively mechanically crush and recycle all kinds of waste printed circuit boards, processing waste, and waste electrical appliances. The metal recovery rate is high, and the purity of recovered metals is as high as 98%.
Waste printed circuit board is a mixture of glass fiber reinforced resin and various metals, which is a typical electronic waste. The metal grade in the circuit board is equivalent to tens to hundreds of metal grades in ordinary minerals, and the metal content is high. Up to 40%, most of which are copper, in addition to gold, aluminum, nickel, lead, silicon metals, etc., among which there are many rare metals; and the content of rich ore metals in nature is only 3%-5%. If it is not properly handled and disposed of, it will not only cause a large loss of useful resources, but also contain a large number of teratogenic, mutagenic, and carcinogenic substances such as cadmium brominated flame retardants, which will seriously affect the environment and human health.
The circuit board recycling production line is mainly composed of conveyors, primary crushers, secondary crushers, magnetic separators, pulverizers, sorters and other auxiliary equipment. Its process flow is shown in Figure 1. After the discarded circuit boards are manually disassembled, the harmful electrical components such as batteries, transformers, etc. and reusable parts are removed, and the remaining parts are sent to the primary crusher through the scraper conveyor, and the materials are crushed to less than 20mm , and then sent to the secondary crusher to crush the material to less than 5mm, the iron-containing material is separated by a magnetic separator, and the remaining material is crushed to a powder of about 2mm by the crusher to separate the copper in the multi-layer machine board , the light dust will be separated by winnowing first, and the material with larger specific gravity will be sent to the electrostatic separator to separate and recover about 20% of non-ferrous metals (copper, etc.).
The circuit board has high hardness and good toughness: it has good bending resistance; it is mostly flat, and it is difficult to separate metal and non-metal through one-time crushing; there are many types of substances contained, and the metal has winding phenomenon after dissociation, etc. . The primary crusher uses a double-roller shearing method to shear large pieces of waste circuit boards. It is mainly composed of drive body, spline shaft (knife shaft), blade, sparse board, frame and other components. Among them, the spline shaft (knife shaft) and the blade are the key components to ensure the coarse crushing process. After the PCB is crushed to 20 mm, it is sent to the secondary crushing. The spline shaft (knife shaft) can optimize the power transmission of the blade. Through special heat treatment and ultrasonic flaw detection test, the blade and spacer ring can be easily removed for easy replacement of the blade. The blade is made of forged high-alloy steel material, which has been heat-treated and finished many times. The sparse plate is made of high wear-resistant stainless steel, which plays the role of material guidance, cleaning blades, and preventing material recovery after crushing.
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