(中南大学 冶金与环境学院，长沙 410083)
摘 要: 根据带元器件废弃电路板多金属料成分特点，采用梯级碱溶处理工艺，实现多金属料中有价金属选择性分离。该工艺由低碱浸出和高碱氧化浸出两级组成。第一段主要实现Al的选择性分离，最佳工艺条件：NaOH溶液浓度1.25 mol/L，与多金属料液固比为10:1，浸出温度30 ℃，浸出时间30 min；第二段主要实现Zn、Pb、Sn与Cu的选择性分离，最佳工艺条件：初始NaOH溶液浓度5mol/L，体系溶液(80%的碱溶液+20%的H2O2溶液)与低碱浸出渣液固比10:1，H2O2溶液滴加速度0.4 mL/min，浸出温度50 ℃，浸出时间60 min。在此优化工艺条件下，金属的浸出率依次为Al 91.25%，Zn 83.65%，Pb 79.26%，Sn 98.24%；此外，98%以上的Cu和100%的贵金属在高碱浸出渣中富集。
关键字: 废弃电路板；梯级碱溶；两性金属；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
