Study on Wet Treatment Process of Waste Printed Circuit Boards

The dry crushing of wasted printed circuit boards (PCBs) can make secondary contamination. In this paper, a wet comminution process is put forward to solve the difficulties. For the comminution product, the distributions of particle size, liberation degree and metal grade are analyzed, and for the product below 1mm, a wet metal beneficiation process combined with shaking table and flotation is employed. The results show that the Whole PCBs could be comminuted by the MX wet impact crusher, and the cumulative yield, liberation degree, total metal content and its copper grade of the product below 1mm is 83.49%, 97%, 83.46% and 20.50%respectively, and that metal concentrates could be beneficiated by XZY wet shaking table, and the yield, total metal weight, copper grade of the metal concentrate, the recovery of total metal and copper is 34.87%, 88.99%, 50.73%,79.90% and 78.07% respectively keeping the feeding concentration at 20% and water consumption in 1100L/h. For these metals included by shaking-table middling, the separation of both flotation and shaking table is carried out, and the total metal content and its copper grade, recovery in metal concentrate 2′ is 72.07% , 31.59% and62.04% respectively, meanwhile the copper grade of tailings in flotation and shaking table are decreased to 1.26% and 2.94%. The wet treatment process can effectively concentrate these valuable metals from waste PCBs.