(中南大學 冶金與環(huán)境學院，長沙 410083)
摘 要: 根據(jù)帶元器件廢棄電路板多金屬料成分特點，采用梯級堿溶處理工藝，實現(xiàn)多金屬料中有價金屬選擇性分離。該工藝由低堿浸出和高堿氧化浸出兩級組成。第一段主要實現(xiàn)Al的選擇性分離，最佳工藝條件：NaOH溶液濃度1.25 mol/L，與多金屬料液固比為10:1，浸出溫度30 ℃，浸出時間30 min；第二段主要實現(xiàn)Zn、Pb、Sn與Cu的選擇性分離，最佳工藝條件：初始NaOH溶液濃度5mol/L，體系溶液(80%的堿溶液+20%的H2O2溶液)與低堿浸出渣液固比10:1，H2O2溶液滴加速度0.4 mL/min，浸出溫度50 ℃，浸出時間60 min。在此優(yōu)化工藝條件下，金屬的浸出率依次為Al 91.25%，Zn 83.65%，Pb 79.26%，Sn 98.24%；此外，98%以上的Cu和100%的貴金屬在高堿浸出渣中富集。
關鍵字: 廢棄電路板；梯級堿溶；兩性金屬；浸出率
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:A cascading alkali leaching process was developed to recover metals in crushed metal enrichment (CME) selectively according to metal contents in CME. This process was combined with low alkali leaching and high alkali oxidation leaching. The results show that the optimum conditions for the aluminum selective leaching are as follows: alkali concentration of 1.25 mol/L, liquid to CME of 10:1, leaching temperature of 30 ℃, leaching time of 30 min. And the optimum conditions for selective separation of zinc, lead, tin and copper are as follows: alkali concentration of 5mol/L, liquid (alkali solution of 80% and hydrogen peroxide of 20%) to low alkali leaching residue (LAR) of 10:1, dropping speed of hydrogen peroxide of 0.4 mL/min, leaching temperature of 50 ℃, leaching time of 60 min. By optimizing the experimental conditions, the recoveries of aluminum, zinc, lead, tin reach 91.25%, 83.65%, 79.26%, 98.24%, respectively. In addition, more than 98% of copper and 100% of precious metals are enriched in high alkali leaching residue (HAR).
Key words: waste printed circuit board; cascading alkali leaching; amphoteric metal; leaching efficiency
