本研究主要針對廢IC(積體電路)板經電漿熔融後熔渣中之金、銀、銅進行回收研究,本研究方法包括破碎研磨、篩分、磁選、浸漬溶蝕及溶蝕效率分析等。本研究成果顯示,廢IC板電漿熔渣之比重爲3.47、水份爲0.23%,而灰份爲101.81%。熔渣經過粉碎、磁選後可得6.62%之含鐵物,而不感磁物中含有金0.0010%、銀0.0392%及銅33.94%。另不感磁物經篩分得知100目(0.149mm)以上之熔渣含銅量較高,可直接將其售予煉銅廠作爲冶銅之原料,而100目以下,因其粒徑較小且尚含有金、銀、銅有價物,故本研究以鹽酸、硫酸、氨水、硫脲等浸漬劑來進行金、銀、銅之浸漬溶蝕研究。本研究結果顯示以硫脲浸漬效果最好,其最佳浸漬條件爲:硫脲2.5g,硫酸濃度7.2N,硫酸鐵3.3g,固液比0.03(1.5g/50mL),在室溫下浸漬2小時,可得金、銀、銅100%之浸漬回收率。
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.