碱性条件下黄铁矿氧化浸出及其动力学研究

On Pyrite Leaching and Its Kinetics Under Alkaline Conditions

为探究黄铁矿在碱性条件下的浸出情况及动力学规律,通过加压碱浸试验,分析矿石粒径、浸出液pH、浸出温度和氧分压等因素对黄铁矿氧化浸出的影响,并采用收缩核模型对黄铁矿浸出过程进行动力学分析.结果表明:温度和浸出液pH对黄铁矿浸出率的影响显著;在粒径为-140μm、固液比为1∶20、氧分压为0.8 MPa、pH值为13、浸出温度为70℃、浸出时间为6 h的条件下,黄铁矿的氧化浸出率可达14.72%;浸出过程主要受固态产物层扩散控制,遵循动力学模型1-3(1-x)^(2/3)+2(1-x)=kt,浸出反应的表观活化能为14.321 kJ/mol.

Through the pressurized alkali leaching experiment, the influence of ore particle size, leaching solution pH, leaching temperature and oxygen partial pressure on the oxidative leaching of pyrite is analyzed, and the kinetics analysis of pyrite leaching process is carried out by using the model of shrinking core model. Results show that temperature and pH have significant influence on the leaching rate of pyrite. When the particle size is-140 μm, solid-liquid ratio is 1∶20, oxygen partial pressure is 0.8 MPa, pH is 13, leaching temperature is 70 ℃, and leaching time is 6 h, oxidatior leaching rate of pyrite can reach 14.72%. The leaching process is mainly controlled by diffusion of solid product layer and follow 1-3(1-x)^(2/3)+2(1-x)=kt kinetic model. The apparent activation energy of leaching reaction is 14.321 kJ/mol.