一步法浸取氰化尾渣中金、铁、铅的实验研究

Experimental Study of Leaching of Au,Fe and Pb from Gold Cyanidation Tailings Using One-step Process

文章研究了用盐酸一步法浸出氰化尾渣中金、铁、铅的工艺过程,结果表明,浸取反应优化工艺条件为:在沸腾状态下回流,盐酸起始浓度9.8 mol/L,盐酸过量系数1.6,反应时间1.5 h。此优化工艺条件下,金、铁、铅的浸出率分别为89.32%、93.45%、99.97%,浸出渣主要物相为硅化合物等,实现了有价金属与硅化合物的分离。从热力学角度分析了大量三价铁离子存在时,盐酸浸出金的可行性,而且,随着温度的升高,金的浸出率越高,因此,浸出反应在沸腾状态下进行回流。实验证明,一步法浸取氰化尾渣中金、铅、铁是可行有效的。

A study regarding recovery of Au, Pb and Fe from cyanidation tailings was conducted using one-step process with leaching by hydrochloride acid, focusing on optimum operating parameters that, when refluxing at the boiling temperature, were found as follows： initial hydrochloride acid concentration 9.8 mol/L, reaction time 1.5 h, hydrochloride acid excess coefficient 1.6. Under the optimum condition, the achieved leaching efficiencies for Fe, Pb and Au were 93.45%, 99.97%, 89.32%, respectively, while the high silica-containing by-product was obtained as the final residue, thus value metals and silicon were separated effectively. Furthermore, in view of thermodynamics, the possibility of gold leached out from hydrochloride acid medium in the presence of a large amount of ferric ions was analysis. The results showed that the leaching rate of gold increased when temperature rose. Therefore, leaching temperature must be at boiling point. In conclusion, leaching of Au, Pb and Fe from cyanidation tailings using one-step process with hydrochloride acid was proven to be effective and reliable.