碳酸氢铵沉淀钇基重稀土时共存铁、铝杂质离子的行为研究

本文对钇基重稀土碳酸盐沉淀过程中杂质铁、铝离子的共沉淀行为以及对碳酸稀土的结晶性能和结晶效果的影响进行了研究。结果表明 :用碳酸氢铵沉淀稀土时 ,杂质铝可沉淀完全 ,但在上清液中仍存在微量铁。同时在碳酸稀土的陈化结晶过程中有少量铁溶出 ;常温下钇基重稀土碳酸盐在低配比区域的结晶活性差 ,而在高配比区域结晶速度较快。杂质的存在会显著影响碳酸稀土的结晶 ,使结晶速度明显减小 ,结晶过程的值下降不明显 ,结晶产品的沉降性能变差

Effect of Impurity Ions on the Crystallization of Yttrium-Base-Heavy Rare Earth Carbonate

The co precipitation behavior and the effects of impurity ions on the crystallization properties of yttrium base heavy rare earth carbonate were investigated.The results show that Fe 3 and Al 3 ions will be co precipitated when rare earth precipitated by ammonium bicarbonate,but some of the Fe 3 will be dissolved out during crystallization.Based on the examination of pH value variety,it was suggested that yttrium base heavy rare earth carbonate had poor crystallization property in lower molar ratio of ammonium bicarbonate to rare earth at room temperature,but had more fast crystallization rate in higher molar ratio district.This is similar to that of yttrium carbonate.However,the exist of Fe 3 and Al 3 ions will greatly affect the crystallization properties of rare earth carbonate due to the formation of ferric hydroxide and aluminum hydroxide,lowing crystallization rate and making precipitating characteristic poor.