Study On The Separation Process Of The Waste Printed Circuit Board Recycling

Development of economy and the coming electronic information age lead to continuous metabolism of various Electric and Electronic Equipment (EEE). These products make out of much Waste EEE (WEEE). WEEE destroy environment and endanger people's health. But on the other side, they have great value: they were made of many kinds of metal and nonmetal substance.In this essay, we study on the Printed Circuit Boards (PCB) which is one kind of WEEE. According to the difference of density of metal and nonmetal, we separate difference substance of PCB. By way of crushing, hydro-selection, we recycle WEEE.We used pulverizer to treat these printing circuit boards, and through the optical microscope, we found the optimal granularity distribution. We made sure the content of metal by ICP-AES.The results of these experiments prove that after 5min's pulverizing substance below 1mm diameter occupied 80% of the whole. Under the microscope, we found that when the diameter of the granule less than 1mm, metal and nonmetal of PCB have separated completed. And the metal mainly enrich in the granules ranging from 0.125mm to 1mm, nonmetal mostly mass in granules less than 0.125mm.Within the experiment conditions executed, with an increase of the air velocity, the content of copper in the metal concentrate increases, but its recovery efficiency decreases; and the influence of the input of materials on separation effect is little.Within the four ranges of the paricle sizes investigated in the process of fluidizing separation,it was noted that with the increasing of air velocity,the comprehensive separation efficiencies of the integrated metals and copper both increase in the beginning, then decrease, substance diameter between 0.25～1mm, air velocity is 0.48 m/s, the bulgy rate is 242～650%, the recovery efficiency of copper reached over 97%.