采用废弃电路板粉末(粒级0.75~0.125 mm)为分选物料,通过ICP-AES测定分选产品金属品位,研究高频气力分选机的给料速度对金属回收率、金属品位及金属分布规律的影响。结果表明:给料速度对轻产物的非金属品位影响不明显,对中间产物和重产物金属品位影响显著;给料速度对产品产率的影响不明显;在给料速度相同时,铜的富集效果最明显,最高富集比为6.6。密度比铜密度大的金属铅,在整个分选过程中富集比约为2;密度比铜密度小的金属锌在重产物中的富集比为2.36;锡的变化趋势与铜相似,并且在给料速度为0.39 m/s时,富集比达到最大值3.75;密度比铜密度小很多的金属铝在重产物中没有得到富集,而且低于原料中铝的品位,若要分离富集铝须对分选后的物料进行二次分选。
Taking waste PCB with highly enriched metal size ranging from 0.125 mm to 0.75 mm as materials for separation,the influence of feeding 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 showed that feeding rate has significant impacts upon the grade of medium and heavy product while has little effects on the grade of light product and separation efficiency.At a given feeding rate,the enrichment of Cu is the most obvious,with the biggest enrichment ratio as 6.6. The enrichment ratio of Pb(heavier than Cu) is 2 and that of Zn(lighter than Cu) is 2.36. The separation result of Sn is similar to Cu. Its maximum enrichment ration is 3.75 when the feeding rate is 0.39 m/s. Metal with a much smaller density than Cu(such as Al)is not enriched in the separation and its grade in the separation product is lower than that in the raw material.Therefore,a secondary separation is needed for the enrichment of Al.