共生氧化物对锌硅酸盐矿物氨浸行为的影响研究

Effects of Associated Oxides on Ammonia Leaching of Refractory Zinc Silicate Ore

为探讨高碱性脉石型低品位氧化-硫化混合锌矿氨浸行为的影响因素,采用水热氨浸法研究了混合矿中异极矿氨浸的较佳工艺条件,并研究了低品位矿石中共生的氧化物(MgO、CaO、SiO_2、MnO_2)对异极矿浸出行为的影响。研究结果表明:异极矿水热氨浸较佳条件为:搅拌速度400 r/min,浸出时间30 min,总氨浓度5 mol/L,氨∶氯化铵摩尔比1∶1,浸出温度60℃,液固比20∶1,此时锌浸出率为81.9%。共生氧化物MgO、CaO、SiO_2均对异极矿的浸出有抑制作用,其中,CaO使得锌的浸出率呈规律性减小,MnO_2抑制作用不明显。

In order to discuss the influencing factors for ammonia leaching of the combination of oxidized-sulfide zinc ore with low grade and high content of alkaline gangues,hydrothermal ammonia-leaching process was adopted in the experiment to investigate the optimal conditions for ammonium leaching of hemimorphite,as well as effects of associated oxides( MgO,CaO,SiO_2,MnO_2) in the low-grade ores on the leaching rate of hemimorphite. Results indicated that zinc leaching rate reached 81. 9% under the optimal conditions,including agitation rate at 400 r/min,reaction time of30 min,the total concentration of NH_3 and NH_4Cl at 5 mol/L,molar ratio of NH_3 to NH_4Cl at 1∶ 1,liquid/solid ratio at20 ∶ 1,leaching temperature at 60 ℃. It is also shown that the associated oxides( MgO,CaO,SiO_2) all brought inhibiting effects on hemimorphite leaching behavior and zinc leaching rate decreased regularly along with the increasing of CaO,however,MnO_2 brought little inhibiting effect.