兰坪低品位氧化锌矿NH_3-(NH_4)_2SO_4体系浸出

Leaching process of low grade zinc oxide ore of Lanping in NH_3-(NH_4)_2SO_4 system

研究NH3-(NH4)2SO4体系pH、总氨浓度、液固比、温度、矿物粒径、搅拌速度等因素对兰坪低品位氧化锌矿中锌及主要杂质元素浸出行为的影响,并在较低pH和总氨浓度条件下,采用二段逆流浸出工艺对该矿进行处理。实验结果表明:pH、总氨浓度、液固比是影响锌及杂质浸出的主要因素,浸出液中硅、铁、镉、铅等杂质离子的含量都较低。在浸出剂总氨浓度为3 mol/L,pH为9.60,液固比为4,反应时间为4 h的条件下,通过二段逆流浸出工艺处理,锌的浸出率>90%,浸出液pH<9.0,能很好地满足萃取工序的处理要求。

The leaching process of low grade zinc oxide ore of Lanping in the system of NH3-（NH4） 2 SO4 was studied.The influences of pH,total ammonia concentration,ratio of solid to liquid,temperature,particle size of ore,stirring speed on the leaching behavior of zinc and the main impurity elements were investigated.The low grade zinc oxide ore was leached by two-stage counter-current process under the condition of low pH and total ammonia concentration.The results show that the main parameters for the recovery of zinc and impurities are pH,total ammonia concentration,and ratio of solid to liquid,and the concentration of Si,Fe,Cd,Pb in lixivium is low.The optimum leaching conditions are found to be the total ammonia concentration 3 mol/L,pH 9.60,ratio of solid to liquid 4,and the leaching time 4 h.More than 90% of zinc is extracted,and pH of lixivium is less than 9.0 in the two-stage counter-current process,which satisfies the requirement of the subsequent solvent extraction process.