STUDIES OF THE SEPARATION OF RARE EARTHS WITH SOLVENT IMPREGNATED RESIN

1992年，我们研究了溶剂浸渍树脂的制备方法、所得树脂的化学性能以及稀土的批量吸附试验。用本报告所述的方法制备溶剂浸渍树脂是可行的。溶剂浸渍树脂对稀土的吸附机理是基于水溶液中的金属离子与浸渍溶剂PC-88A中的氢离子之间的离子交换；随着溶液pH的增大，对稀土的吸附率较高。吸附速率与普通阳离子交换树脂几乎相当。1993年研究了轻稀土Nd、Sm的分离试验，重稀土Tb、Dy、Ho的分离试验。在吸附步骤中，原子序数较低的稀土得到了高纯度的回收，而原子序数较高的稀土在洗脱步骤中得到了更多的回收。由于吸附柱内轻稀土与重稀土的交换，原子序数较低的稀土从吸附柱中泄漏出来。从树脂的寿命试验结果来看，溶剂浸渍树脂可重复使用至少20次。通过改变柱高和柱径来提高分离效率。当进料流量增大时，由于吸附塔内缺乏交换反应，分离效率降低。在洗脱过程中，使用稀盐酸可逐步洗脱，回收产物浓度低，而使用浓盐酸可提供尖锐的高洗脱曲线，回收产物浓度高。通过对突破曲线和洗脱曲线的积分，计算出Nd和Sm的收率和纯度。钕的回收率为100%，收率为70%以上；钐的回收率为80%以上，收率为100%。少

In the year of 1992, we investigated the preparation method of solvent impregnated resin, the chemical properties of the obtained resin and the batch adsorption test of rare earths. It is possible to prepare the solvent impregnated resin by the method described in this report. The adsorption mechanism of rare earths with the solvent impregnated resin is based on the ion exchange between metal ions in aqueous solution and hydrogen ions in the impregnated solvent, PC-88A ; the adsorption percent of rare earths being high when the solution pH is increased. The adsorption rate is almost similar to that of usual cation exchange resin.In the year of 1993, we investigated the separation test of Nd and Sm, which belong to light rare earths, and the separation test of Tb, Dy and Ho, which belong to heavy rare earths by using separation column. In the adsorption step, the rare earth which has the lower atomic number is recovered with high purity, while the rare earth which has the higher atomic … More number is recovered in the elution step. The rare earth which has the lower atomic number leaks from the adsorption column due to the exchange between lighter rare earth and heavier rare earth in the column. The solvent impregnated resin can be repeatedly utilized at least 20 times from the results of life test of the resin. The separation efficiency is improved by changing column hight and column diameter. When the flow rate of feed is increased, the separation efficiency decreases due to the lack of exchange reaction in the adsorption column. In the elution process, the use of dilute hydrochloric acid gives gradual elution with low concentration of recovered product, while the use of concentrated hydrochloric acid provides the sharp and high elution curve with high concentration of recovered product. From the integration on breakthrough and elution curves, yield and purity of Nd and Sm is calculated. Neodymium is recovered with 100% purity at the yield more than 70%, whereas Sm is recovered with the purity more than 80% at 100% yield. Less