(中南大学 冶金与环境学院，长沙 410083)
摘 要: 采用氢氧化钠-硫化钠浸出体系对高砷烟尘进行脱砷研究，在氢氧化钠与高砷烟尘质量比为0.5、硫化钠与高砷烟尘的质量比为0.2、液固质量比为5:1、反应温度为90 ℃、反应时间为2.0 h、搅拌速度为400 r/min条件下，砷的浸出率为89.64%，锑的浸出率为10.11%，铅的浸出率为1.16%，浸出渣中砷的含量为0.89%。碱浸液采用氧化-冷却结晶回收砷酸钠，结晶母液补加适量氢氧化钠和硫化钠返回浸出过程中循环利用，浸出渣可以直接返回铅厂回收铅锑。整个脱砷工艺闭路循环，实现了高砷烟尘中砷与其他金属的有效分离。
关键字: 高砷烟尘；碱性浸出；脱砷；湿法冶金
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The high-arsenic dust is produced from the jamesonite in pyrometallurgical process, and contains large amount of valuable metals, such as lead, antimony and indium. Because of the complex composition and high content of arsenic in high-arsenic dust, the current main processing is stockpiling. Arsenic was leached from high-arsenic dust by sodium hydroxide and sodium sulfide mixed solution. The optimum conditions were determined as follows: alkali material ratio 0.5, ratio of sodium sulfide to high-arsenic dust 0.2, leaching temperature 90 ℃, leaching time 2 h, liquid-to-solid ratio 5 and stirring speed 400r/min. Under these conditions, the leaching efficiencies of arsenic, antimony and lead are 89.64%, 10.11% and 1.16%, respectively, and the content of arsenic in leaching residue is 0.89%. The leaching residue can be returned to lead smelter for recycling lead and antimony. The leaching solution was treated by hydrogen peroxide oxidation and cooled to recover sodium arsenate. The filtrate was recycled with additional sodium hydroxide and sodium sulfide to alkaline leaching step. NaOH-Na2S alkaline leaching process provides a simple and highly effective way for the removal of arsenic from high-arsenic dust.
Key words: high arsenic dust; alkaline leaching; arsenic removal; wet metallurgy
