A Synergistic Extraction for the Separation of Scandium with Cyanex572 and Cyanex923

Abstract

This paper investigates the synergistic extraction performance of Scandium using a mixture of Cyanex572 and Cyanex923 in sulfuric acid medium. The results show that the best synergistic effect is achieved when the pH value of the aqueous phase is 2 and the mole fraction of Cyanex572 is 0.5, with a synergy coefficient value R of 4.78. In addition, the extraction mechanism of this synergistic system is discussed, and the extracted complex is determined to be [Sc(SO4)0.5(HL2)2B2] by slope analysis. The loaded Scandium can be stripped within two times by 2 mol/L sulfuric acid to obtain a stripping efficiency of 99.4 %. Finally, this synergistic system was applied to extract Scandium, demonstrating the potential application in separation of Scandium from the leachate of laterite nickel ore.