废弃电路板铜锡多金属粉隔膜电积回收锡实验研究

Experimental Study on Tin Recovery Based on Membrane Electrodeposition from Metal Fractions of Waste Printed Circuit Boards

采用基于隔膜电积湿法冶金新工艺从废弃电路板铜锡多金属粉中高效提取金属锡,研究并优化了铜锡多金属粉浸出及隔膜电积提锡工艺.浸出实验结果表明,在温度为40℃,初始Sn^(4+)质量浓度50 g/L,HCl浓度4 mol/L,液固比为5∶1,循环浸出三次的条件下,锡浸出率约为96%,最终浸出液中Sn^(2+)质量浓度68.58 g/L.锡隔膜电积实验表明,在Sn^(2+)质量浓度40~100 g/L,HCl浓度3 mol/L,温度35℃,电流密度200 A/m2的条件下,阴极电流效率97.51%,能耗低于1 200 k Wh/t.在此优化条件下进行隔膜电积8 h,得到平整、致密且纯度99.9%的阴极锡板.

A new hydrometallurgical progress based on membrane electrodeposition was proposed to effectively extract tin from metal fractions of WPCBs（ waste printed circuit boards）. Leaching experiment results showed that under the conditions of temperature 40℃ ,Sn4＋ concentration 50 g/L , HCl concentration 4 mol /L, liquid （ml） to solid （g ） ratio 5：1 and cycle 3 times, the leaching efficiency of tin was about 96% , and the resultant Sn2 ＋ concentrated in the leach solution was 68. 58 g/L . The electrodeposition tests indicated that under the condition of current density 200 A/m2, temperature 35 C , H ＋ concentration 3 mol/L and Sn2＋ concentration 40 ？100 g / L , a compact and smooth cathode tin layer can be obtained after 8 h electrodeposition. The current efficiency was 97. 51% and the electric consumption was less than 1 200 kW h/t.