Application of the Phase Transfer Catalysis in Rare Earth Solvent Extraction

ＡｐｐｌｉｃａｔｉｏｎｏｆｔｈｅＰｈａｓｅＴｒａｎｓｆｅｒＣａｔａｌｙｓｉｓｉｎＲａｒｅＥａｒｔｈＳｏｌｖｅｎｔＥｘｔｒａｃｔｉｏｎＹａｎＣｈｕｎｈｕａ（严纯华）；ＺｈａｎｇＹａｗｅｎ（张亚文）；ＬｉａｏＣｈｕｎｓｈｅｎｇ（廖春生）；ＪｉａＪｉａｎｇ...

Application of the Phase Transfer Catalysis in Rare Earth Solvent Extraction

In order to overcome the difficulty in stripping and reduce the equilibrium time in heavy rare earth separation with acidic organophosphorous extractants, the phase transfer catalysis (PTC) technique was introduced to the solvent extraction process, especially applied to the stripping section, which was called phase transfer catalysis stripping (PTCS) process. In the PTCS process,an acidic phosphorous extractant was mixed with another extractant which can transfer hydrogen ion from aqueous phase to organic phase and almost does not extract rare earth ions, so that the stripping efficiency can be improved and the stripping extraction equilibrium be accelerated. The reaction mechanism of the PTCS and the requisite properties for a feasible PTCS catalyst in rare earth extraction were studied. We selected D_2EHPA as the extractant, Alamine 336 as the PTCS catalyst and mixed rare earth chlorides as the feed to test the PTCS phenomenon. Based on the experimental data, the applicability of PTCS technique in rare earth solvent extraction was discussed.