China Nonferrous Metallurgy

P204 and P507 are commonly used as extractants for the extraction of rare earth leaching solution. It is difficult to effectively separate and enrich rare earths by single extractant.In this paper, the characteristics of weak extraction ability of P507 and strong extraction ability of P204 for light rare earth were used in the extraction of high concentration rare earth solution.P507 and TBP were innovatively used to extract medium and heavy rare earths, and then P204 and TBP were used to extract light rare earths. The extraction and back extraction experiments were carried out,and the following conclusions are drawn.Under the conditions of the test raw materials, the two-stage extraction process was adopted. When the phase ratio A/O=10/1, pH 4.0, room temperature, P507 volume fraction 35%, TBP volume fraction 5%, the extraction rate of P507 for medium and heavy rare earths is better, which can reach more than 90%. The extraction rate of light rare earth by P204 reached 97% under the conditions of P204 volume fraction of 35%, TBP volume fraction of 5%, phase ratio A/O=15/1, room temperature and extraction time of 5 min. Under appropriate acidic conditions, P507 loaded organic phase after two countercurrent stripping, P204 loaded organic phase after three countercurrent stripping can get high concentration of rare earth enrichment solution, and the concentration value can meet the requirements of direct entry into the extraction separation line. This study provides a reference for the recovery and separation of high concentration rare earth.