废弃电路板湿法破碎与分选回收金属研究

为了有效破碎废弃印刷电路板,解决冲击破碎过程中气味和粉尘的二次污染问题,采用以水为介质的湿法冲击式破碎机对废弃电路板进行破碎实验研究。破碎后废弃电路板颗粒的粒度分布是以-1+0.5mm和-0.074mm粒度区间的双峰为特征的。根据电路板金属和非金属选择性分布的特性,建立了电路板破碎产物粒度分布的双峰分布函数,应用Origin7.0软件对破碎产物的双峰分布函数进行非线性拟合,相关系数R2均大于0.999,且残差E值较小。采用变径水介质分选床对破碎至-1mm粒级的废弃电路板物料进行了金属回收的实验研究,结果表明,在水流量5.5m3/h,给料速率250g/min,倾斜度为35°条件下,可获得93.92%的综合效率和93.73%的回收率。论文提出了废弃电路板"湿法冲击破碎+分级+变径分选"回收金属的创新性工艺。

Metal Recovery from Discarded Printed Circuit Board by Mechanical Processing of Wet Crushing and Separation

To effectively crush discarded printed circuit boards (PCB), and solve the problem of secondary pollution of fugitive odor and dust during the crushing process, a wet impacting crusher was adopted to achieve comminution liberation of PCB in water medium. Size distribution of PCB particles was characterized as double peaks at the sizes of -1+0.5mm and -0.074mm. A double Rosin-Rammler function (DRR function) was proposed to describe the size distribution of PCB particles. Correlation coefficients of the fit curves were larger than 0.999, and the residuals were small. Using tapered diameter separation bed to process the -1mm size crushed material of waste PCB, with the discharge of water 5.5m~3/h, feed-rate of the material 250g/min and with an obliquity 350, product with 93.92% in integration efficiency and 93.73% in recovery ratio of the metal were obtained by primary separation. An innovative process of wet impact crushing, classifying, tapered diameter separation recover metal from discarded PCB was developed.