选择性还原氨浸从高硅低品位铜钴矿中提取铜、钴 的工艺及其浸出动力学

研究了非洲高硅低品位铜钴矿氨浸体系下的浸出工艺与动力学。首先采用控制变量法，通过单因素实验，系统研究了浸出剂浓度、添加剂用量、反应温度、反应时间及液固比对铜钴浸出率的影响，其次通过X射线衍射(XRD)、电感耦合等离子体(ICP)和扫描电镜-能谱(SEM-EDS)对高硅低品位铜钴矿和浸出渣的物相及化学成分进行了分析对比。最后，对高硅低品位铜钴矿氨浸提取铜的动力学模型进行分析。结果表明，用硫酸铵作为浸取剂，在硫酸铵浓度为300 g/L、还原剂用量为0.7 g、浸出温度为353 K、反应时间为240 min、液固比为6:1的工艺条件下，铜的浸出率可达97.29%，钴的浸出率可达95.18%。高硅低品位铜钴矿氨浸提取铜的活化能、硫酸铵浓度的反应级数及粒度的反应级数分别为76.06 kJ/mol, 1.50和0.25，表明其应遵循界面化学反应控制，并建立了相应的动力学方程。

Process and leaching kinetics of extracting copper and cobalt from high silicon low grade copper-cobalt ore by selective reduction ammonia leaching

The leaching process and kinetics of African high silicon low grade copper cobalt ore in ammonia leaching system were studied. Firstly, the controllable variable method was used to systematically study the effects of leaching agent concentration, additive dosage, reaction temperature, reaction time and liquid/solid ratio on the leaching rate of copper and cobalt through single factor experiments. Secondly, the phase and chemical composition of high silicon low grade copper?cobalt ore and leaching residue were analyzed by X-ray diffraction (XRD), inductively coupled plasma (ICP) and scanning electron microscope-energy spectrum (SEM-EDS). The results showed that the leaching rate of copper and cobalt can reach 97.29% and 95.18% respectively, under the technological conditions of ammonium sulfate as leaching agent with the concentration of 300 g/L, reducing agent of 0.7 g, leaching temperature of 353 K, reaction time of 240 min and liquid/solid ratio of 6:1. Finally, by analyzing the kinetic model of copper extraction by high silicon low grade copper?cobalt ore ammonia leaching, the activation energy, reaction order of ammonium sulfate concentration and particle size are 76.06 kJ/mol, 1.50 and 0.25, respectively, indicating that it should follow the interface chemical reaction control, and the corresponding kinetic equation was established.