废IC板电浆熔渣之资源回收

Recycling of the Plasma Slag in Scrap IC Boards

本研究主要针对废IC（积体电路）板经电浆熔融後熔渣中之金、银、铜进行回收研究，本研究方法包括破碎研磨、筛分、磁选、浸渍溶蚀及溶蚀效率分析等。本研究成果显示，废IC板电浆熔渣之比重爲3.47、水份爲0.23%，而灰份爲101.81%。熔渣经过粉碎、磁选後可得6.62%之含铁物，而不感磁物中含有金0.0010%、银0.0392%及铜33.94%。另不感磁物经筛分得知100目(0.149mm)以上之熔渣含铜量较高，可直接将其售予煉铜厂作爲冶铜之原料，而100目以下，因其粒径较小且尚含有金、银、铜有价物，故本研究以盐酸、硫酸、氨水、硫脲等浸渍剂來进行金、银、铜之浸渍溶蚀研究。本研究结果显示以硫脲浸渍效果最好，其最佳浸渍条件爲：硫脲2.5g，硫酸浓度7.2N，硫酸铁3.3g，固液比0.03(1.5g/50mL)，在室温下浸渍2小时，可得金、银、铜100%之浸渍回收率。

In this study, various methods for grinding, screening, magnetic separation and leaching are adopted to recover the valuable gold, silver and copper metallic components from the slag of plasma-treated scrap integrated circuit (IC) boards. The results of the compositional analysis reveal that the specific gravity, iron content, moisture and ash content of this slag are 3.47%, 6.62%, 0.23% and 101.08%, respectively. After magnetic separation, the fraction of non-ferrous metal larger than 100 mesh (0.149mm), containing mainly copper, can be sold directly to a copper smelter; moreover, the gold, silver and copper components can be recovered by leaching. The leaching result indicates that a 100% recovery of gold, silver and copper can be achieved by using a thiourea leaching solution.