Study On Technology And Machinery To Crush And Separate The WPCBs By Separation-impact Mill

With rapid development of information technology, al l kinds of electronic applications upgrading accelerate, plenty of WPCBs is produced. On one hand, serious harm to human health and ecological environment would produce if WPCBs can not be handled correctly; on the other hand, WPCBs have high value of recycling in case that it contains a variety of metal and nonmetal materials. The recycling of WPCBs is attracting more and more attention.The paper study on the crushing and sorting of WPCBs by separation-impact mill. According to the composition characteristics of WPCBs, the structure of the separation-impact mill is designed, and its crushing perform ance is verified by experiments. Numerical simulation and test combination is used to choose the rotate speed of the classifier in separation-impact mill, finish study on fine break and initial separate WPCBs by separation-impact mill. Finally, screen the particles less than 0.5mm into different granularity period, second time separation experiment was carried out by classifier.The results show that, the separation-impact mill can quickly break the WPCBs, selective fragmentation phenomenon is find during breaking. When the particle size smaller than 0.312 mm, continue to broken, the unit power consumption of the surface will increase sharply. The classifier and millstone rotate direction opposite is good for crushing. When the speed of classifier in separation-impact mill rotate higher than 2500r/min, the classification flow field is relatively stable. When the speed is higher than 3500r/min, the metal separation effect is best. First time separate the WPCBs, metal rich collective mass fraction is 48.39%, metallic taste in metal rich collective is 41.15%, the metal recovery rate is 98.77%; nonmetal rich collective mass fraction is 51.61%, nonmetal rich collective metallic taste is 0.78%. The second time separate by the classifier show that, under the best conditions of comprehensive recovery effect, in the-0.5~+0.3mm,-0.3~+0.125 mm,-0.125 mm particle size segment, metal rich collective mass fraction respectively reach 67.25%, 53.68%, 56.28%, metal taste respectively reach 58.93%, 68.93%, 68.45%, the metal recovery rate is 95.73%; nonmetal rich collective mass fraction respectively reach 32.75%, 46.32%, 43.72%, metallic taste respectively reach 0.57%, 3.00%, 7.86%. The total recovery rate of metal is 94.55%. The research of this paper provides a new idea for the treatment of WPCBs by mechanical and physical method.