(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 采用氫氧化鈉-硫化鈉浸出體系對高砷煙塵進(jìn)行脫砷研究，在氫氧化鈉與高砷煙塵質(zhì)量比為0.5、硫化鈉與高砷煙塵的質(zhì)量比為0.2、液固質(zhì)量比為5:1、反應(yīng)溫度為90 ℃、反應(yīng)時間為2.0 h、攪拌速度為400 r/min條件下，砷的浸出率為89.64%，銻的浸出率為10.11%，鉛的浸出率為1.16%，浸出渣中砷的含量為0.89%。堿浸液采用氧化-冷卻結(jié)晶回收砷酸鈉，結(jié)晶母液補(bǔ)加適量氫氧化鈉和硫化鈉返回浸出過程中循環(huán)利用，浸出渣可以直接返回鉛廠回收鉛銻。整個脫砷工藝閉路循環(huán)，實(shí)現(xiàn)了高砷煙塵中砷與其他金屬的有效分離。
關(guān)鍵字: 高砷煙塵；堿性浸出；脫砷；濕法冶金
（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
