低品位铂钯精矿的富氧压浸出

Oxygen pressure leaching of low-grade Pt-Pd concentrate

对高镁低品位复杂铂钯精矿进行工艺矿物学分析,提出采用硫酸氧压浸出工艺对该精矿中的贱金属铜、镍、铁选择性浸出分离并富集铂钯的处理工艺。考察磨矿粒度、反应温度、时间、初始硫酸浓度、氧压、搅拌速度、木质素磺酸钙用量、液固比对铜、镍、铁浸出率及渣率的影响,确定最佳工艺参数。实验结果表明:当精矿粒度小于43μm占有率为93%、时间3 h、浸出温度150℃、初始硫酸浓度2 mol/L、氧分压0.7 MPa、搅拌速度400 r/min、添加剂木质素磺酸钙用量0.6 g、液固比5:1的最佳工艺条件下,铜浸出率达99.27%、镍浸出率达98.04%、渣率为37%左右,铂钯几乎不被浸出,铂和钯在浸出渣中富集近3倍。

The process mineralogy investigation and the oxygen pressure leaching of low grade Pt-Pd concentrate with high content of magnesium were studied.Sulfuric acid pressure-oxidation leaching process was employed to achieve the selective leaching of copper,nickel,iron and enrichment of Pt-Pd.The effects of process parameters including the particle size,sulphuric acid concentration,the amount of calcium lignosulfonate,oxygen pressure,stirring speed,liquid-solid ratio,leaching temperature and time on the slag rate and leaching rates of copper,nickel and iron were investigated.The results show that leaching rates of copper and nickel are 99.27% and 98.04%,respectively,and slag rate is 37% under the leaching conditions of concentrate particle size d93 < 43 μm,leaching time of 3 h,leaching temperature of 150 ℃,sulphuric acid concentration initial 4 mol/L,oxygen pressure of 0.7 MPa,stirring speed of 400 r/min,calcium lignosulfonate of 0.4% and liquid-solid ratio of 5:1.Moreover,Pt and Pd are still not leached and the grade of Pt-Pd concentrate could be increased by 3 times after leaching process.