湿法冶金

针对河北某金品位较高的炭浸尾渣，在进行理化性质分析和金的化学物相分析基础上，研究了采用超细磨—化学预氧化—氰化浸出工艺提取其中的金。考察了超细磨磨矿细度、矿浆pH、氰化钠用量、浸出温度和时间等因素对提金的影响，并探讨了化学预氧化—氰化浸金过程动力学。研究结果表明：在超细磨磨矿细度-10 μm占80%，空气流量为0.3 m³/h条件下预氧化14 h后，再在氰化钠用量为1.5 kg/t、浸出时间为24 h、矿浆pH=12.5、浸出温度为303 K、通入0.1 m³/h空气条件下进行氰化浸出，金浸出率可达70.23%；动力学研究结果表明，浸金过程符合经典的未反应收缩核模型，浸出反应速率受界面化学反应和扩散混合控制；SEM和浸出渣金化学物相分析结果表明，该炭浸尾矿中存在极其微细嵌布金或是晶格金，难以浸出。研究结果可为该尾矿进一步提金提供一定理论指导和技术参考。

Aiming at a carbon-in-leach tailings with relatively high gold grade in Hebei Province，based on the analysis of physicochemical properties and gold chemical phase， the process of ultrafine grinding–chemical pre-oxidation–cyanide leaching was adopted to extract gold from the tailings. The effects of ultrafine grinding fineness， pulp pH， sodium cyanide dosage， leaching temperature and time on gold extraction were investigated， and the kinetics of the chemical pre-oxidation–cyanide leaching process was discussed. The results show that under the conditions of ultrafine grinding fineness of -10 μm accounting for 80%， pre-oxidation for 14 h at an air flow rate of 0. 3 m3/h， followed by cyanide leaching with sodium cyanide dosage of 1.5 kg/t， leaching time of 24 h， pulp pH of 12.5， leaching temperature of 303 K， and air flow rate of 0.1 m3/h， the gold leaching rate can reach 70.23%. The kinetic study results indicate that the gold leaching process conforms to the classical unreacted shrinking core model， and the leaching reaction rate is controlled by the mixed control of interfacial chemical reaction and diffusion. The SEM and gold chemical phase analysis of the leaching residue show that there exist extremely finely disseminated gold or lattice gold in the carbon-in-leach tailings， which are difficult to leach. The research results can provide certain theoretical guidance and technical reference for further gold extraction from this tailings.