红土镍矿黄铵铁矾法除铁及杂质铁的高值化利用

Removal of iron and high value utilization of iron impurity from laterite nickel ore by ammonium jarosite

以红土镍矿为原料,采用硫酸铵焙烧—水浸—黄铵铁矾法除铁,然后再以黄铵铁矾水解所得Fe2O3为原料,加入一定比例的Li2CO3、NH4H2PO4和蔗糖进行还原焙烧制备锂离子电池正极材料LiFePO4/C。采用X射线衍射(XRD)、扫描电子显微镜(SEM)和化学分析等手段对实验样品进行了分析和表征。研究了工艺参数对除铁率和黄铵铁钒形貌以及黄铵铁钒形貌对磷酸铁锂电化学性能的影响。结果表明,最佳造矾条件为:反应时间4 h、反应温度95℃、终点pH值2.5、搅拌速度400 r/min,在此条件下浸出液除铁率超过98.35%;煅烧温度750℃、煅烧时间10 h时制备的片状磷酸铁锂具有较好的电化学性能,在0.1 C倍率下的首次放电比容量为164.12 mA·h/g,0.1 C、0.5 C、1 C、2 C、5 C倍率下循环10周的容量保持率较高。研究结果可为红土镍矿资源的高效、综合利用提供新技术及理论支持。

Lateritic nickel ore resources were chosen to be the research objects.Through iron removal by Ammonium sulfate roasting-Water leaching-Ammonium jarosite process and using Fe2O3 product as raw material,the electrode material LiFePO4/C was obtained.A certain proportion of Li2CO3,NH4H2PO4 and sucrose were added for reduction roasting to prepare LiFePO4/C.The samples were analyzed and characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and chemical analysis.The effects of process parameters on the iron removal rate and morphology of ferrovanadium xanthamine as well as the electrochemical properties of lithium iron phosphate were studied.The results indicate that the best conditions were as follows:reaction time 4 h,reaction temperature 95℃,end point pH value 2.5,stirring speed 400 r/min,iron removal rate above 98.35%.The first discharge specific capacity of lithium iron phosphate flake was 164.12 mA·h/g at the calcination temperature of 750℃and the calcination time of 10 h.The capacity retention rate of lithium iron phosphate flake for 10 weeks at the calcination rate of 0.1 C,0.5 C,1 C,2 C and 5 C was higher than that of lithium iron phosphate granular for 10 weeks,indicating that lithium iron had better electrochemical performance.The high value-added lithium ion battery LiFePO 4 anode material is synthesized from iron in laterite nickel ore,which provides new technology and theoretical support for the efficient and comprehensive utilization of laterite nickel ore resources.