粗硫酸镍中铁钴钙镁深度脱除的工艺研究

研究了以臭氧和氟化钠为脱杂试剂,采用"溶解造液--强氧化除铁钴--氟化除钙镁--结晶析出"为主干的工艺处理粗硫酸镍,深度脱除其中的铁、钴、钙、镁杂质的工艺可行性及最佳工艺条件。试验结果表明,以臭氧为强氧化剂,可深度脱除粗硫酸镍中的铁钴杂质,最佳反应条件为:反应温度80℃,时间8h,终点pH值4.5~5.0,反应终点溶液中铁、钴浓度小于0.005g/L;以氟化钠做添加剂,可深度脱除粗硫酸镍中的钙镁杂质,最佳反应条件为:反应温度90℃,时间2h,pH值5.5,氟化钠添加系数1.5,反应终点溶液中钙0.007g/L,镁0.005g/L;将"强氧化除铁钴"与"氟化钠除钙镁"工序相结合,可获得更好的除杂效果。

Process Research on the Removal of Iron, Cobalt, Calcium and Magnesium from Crude Nickel Sulfate

This paper studies the process feasibility and optimum conditions of removing impurities such as iron, cobalt, calcium and magnesium from the crude nickel sulfate by using ozone and sodium fluoride as the impurity removal reagent, and using the process of "dissolving -- removing iron and cobalt by strong oxidation -- removing calcium and magnesium by fluoridation -- crystallization precipitation" as the main process. The experimental results show that iron and cobalt impurities in crude nickel sulfate can be deeply removed by using ozone as strong oxidant, the optimum reaction conditions are as follows: Reaction Temperature 80 °C, Reaction Time 8 h, end-point pH 4.5~5.0, the concentration of iron and cobalt in the solution at the end of the reaction is less than 0.005g/L; And the calcium and magnesium impurities in crude nickel sulfate can be deeply removed with sodium fluoride as additive, the optimum reaction conditions are as follows: Reaction Temperature is 90 °C, Reaction Time is 2 h, pH 5.5, and the addition coefficient of sodium fluoride 1.5, the calcium concentration in the solution at the end of the reaction is 0.007g/L, and the magnesium concentration is 0.005g/L; Combining the process of "removing iron and cobalt by strong oxidation" and "removing calcium and magnesium by sodium fluoride", a better effect of removing impurities can be obtained.