含砷金矿细菌氧化提金废渣综合回收砷

以细菌氧化提金废渣为原料,对其中所含的砷进行回收。分别考察了碱用量、浸出温度、液固比和浸出时间对砷浸出率的影响及溶液初始pH、钙砷摩尔比和沉淀时间对砷沉淀率的影响。通过单因素条件试验确定了浸砷的较优条件为:氢氧化钠浓度240g/L,反应温度60℃,液固比4∶1,搅拌浸出2h。在最优条件下砷浸出率达到85%。从浸出液中沉砷的较优条件为:溶液初始pH=12.0,钙砷摩尔比2∶1,沉淀时间30min。在优化条件下砷沉淀率达到97%以上。

Comprehensive Recovery of Arsenic from Bio-oxidation Gold Ore Slag

With bio-oxidation gold ore slag as raw material,arsenic was recycled from the slag.In arsenic leaching test,four factors had been studied including the usage of sodium hydroxide,leaching temperature,ratio of liquid to solid(L/S),and leaching time.In arsenic precipitate test,three factors including the initial solution pH,mole ratio between Ca and As and the reaction time had been studied.The optimum conditions for arsenic leaching include the optimal amount of NaOH of 240 g/L,60 ℃,L/S=4/1,2 h.Under the optimum conditions,the leaching rate of arsenic was 85%.The optimum conditions for arsenic precipitating include the initial solution pH of 12.0 and the mole ratio between Ca and As of 2∶1,30 min,under which more than 97% of arsenic would be precipitated.