铜渣中有价金属酸溶出试验研究

Experimental Study on Acid Leaching and Dissolution of Valuable Metals from Copper Slags

利用硫酸溶出铜渣中的有价元素,研究了常压下硫酸体积分数、浸出时间、浸出温度和硫酸用量(固/液比)对铜渣中Fe、Cu、Co和Ni的溶出率及溶出速率的影响。结果表明:随着硫酸体积分数的升高,促进了硅酸凝胶在酸液中的形成,吸附浸出液中的金属离子,导致了溶液中各金属的溶出率有所降低;浸出温度的升高有助于提高铜渣中金属元素的溶出率。通过试验研究获得了铜渣中有价金属浸出的最佳条件:硫酸体积分数20%,硫酸用量为理论用量的7倍,浸出温度90℃,浸出时间2 h,此条件下Fe、Cu、Co和Ni的溶出率分别达到94.5%、69.7%、73.9%、36.4%。

By acid leaching and dissolution of valuable metals form the copper slags under normal pressure, the influence of the sulfuric acid concentration, dissolution time and the leaching temperature on the dissolution degree and dissolution rate of Fe, Cu, Co and Ni in copper slags were investigated. The results showed that the dissolution degree of metals decreased with the higher sulfuric acid concentration. Because over high sulfuric acid concentration would promote the formation of the silica gel, which adsorbed metal ions to form leached solution; The increase of leaching temperature was conducive to increase dissolution degree of metals. The most suitable operating conditions was the volume fraction of sulfuric acid of 20% , leaching time of 2 h, with the leaching temperature of 90 ℃ and the sulfuric acid dosage 7 times as great as the theoretical amount. Under that condition, the dissolution rates of Fe、 Cu、Co and Ni reached 94.5% ,69.7% ,73.9% and 36.4%, respectively.