黑铜泥氢氧化钠氧压碱浸脱砷研究

在氢氧化钠溶液中釆用通氧加压强化浸出工艺对黑铜泥进行脱砷,实验结果表明:在NaOH浓度为50 g/L、浸出温度140 ℃、氧分压0.6 MPa、液固比8 mL/g、浸出时间1.5 h、搅拌速度600 r/min的较优工艺条件下,黑铜泥中砷浸出率为96.74%,铜、锑、铋浸出率分别仅为1.19%、2.23%、1.08%,实现了砷的选择性脱除。碱浸液采用冷却结晶回收砷酸钠,结晶母液补加适量氢氧化钠返回浸出。渣中锑、铋、银等有价金属得到高度富集。

Removing Arsenic from Black Copper Slime with Sodium Hydroxide Medium by Oxygen Pressure Alkaline Leaching Process

Removing arsenic from black copper slime with sodium hydroxide medium by oxygen pressure alkaline leaching process was studied systematically. It is found an experiment with the optimum conditions including: a NaOH concentration at 50 g/L, leaching temperature at 140 ℃, an oxygen partial pressure of 0.6 MPa,liquid-to-solid ratio at 8 mL/g,leaching time of 1.5 h and stirring speed at 600 r/min, resulted in the leaching rate of As from the black copper slime up to 96.74%, while the extent of dissolution of Cu, Sb and Bi as low as 1.19%, 2.23% and 1.08%,respectively, thus making it possible to selectively removing arsenic. The alkali leaching liquid was then processed by cooling and crystallization to recover sodium arsenate, with mother liquor after crystallization back to leaching process together with an appropriate amount of NaOH. The antimony, bismuth and silver were all highly concentrated in the slag.