Influence of air flow rate on separation efficiency and metal distribution regularity of high-frequency-vibration-air separator: A case study of waste printed circuit board powder
风量对高频气力分选机分选效率及金属分布规律的影响——以废弃印刷电路板粉末为例

Taking printed circuit board(PCB) with highly enriched metal size ranging from 0.125 mm to 0.5 mm as materials for separation, the influence of air flow rate on the separation efficiency of high-frequency-vibration-air separator and metal distribution regularity was studied by determining the products with ICP-AES. Results show that air flow rate has significant impacts upon the separation efficiency and metal distribution regularity. When the air flow rate is 200 m3/h, the total separation efficiency reaches its maximum value of 78.23% and the copper grade is 86.745%. Compared with the copper grade 13.96% in raw materials, the enrichment is about 6.2 times. With the changes of air flow rate, the metal distribution varies regularly. The distribution regularity of metallic particles with density higher or similar to copper, such as Pb, Pt, and Zn, etc, is similar to that of copper and the recovery rate is about 85%. Metallic particles with much lower density than copper, such as Al and Mg, etc, are taken to the light products with nonmetals during the separation as their density is rather close to that of nonmetals. As a result, the grade of Al and Mg are the lowest in the heavy products, even lower than that in raw materials. Therefore, a secondary separation is needed for the enrichment of Al and Mg.