It is necessary to control and reduce the high content of Al 3+ , Cu 2+ and Pb 2+ ions in the leachate of weathered crust elution-deposited rare earth ore to facilitate the rare earth recovery and the quality of rare earth products. Neither NH 4 HCO 3 nor Na 2 S are suitable for removal of all impurity ions and meanwhile maintain high rare earth recovery. Conventionally, NH 4 HCO 3 is firstly adopted to remove Al 3+ , and then Cu 2+ and Pb 2+ are removed by using Na 2 S. This two steps

more »

... ion process is quite long and results in lots of complication in operation. In this paper, a one-step purification by using the compound of NH 4 HCO 3 and Na 2 S was proposed to remove Al 3+ , Cu 2+ and Pb 2+ . The results showed that after purification 89% Cu, 92% Pb and 74% Al were removed from the leachate solution by using 0.1 M compound of NH 4 HCO 3 /Na 2 S, while maintaining 89% rare earth. The optimal purification parameters were: volume ratio of NH 4 HCO 3 to Na 2 S of 9:1, volume ratio of compound to leachate of 0.05:1, precipitation time of 30 min.