EXTRACTION AND SEPARATION METHOD OF LIGHT RARE EARTH ELEMENT

文件类型：PDF文档
文件大小：65K
PROBLEM TO BE SOLVED : To provide an extraction and separation method of light rare earth elements which enables extraction and separation of light rare earth elements with good separation efficiency, is feasible with an additionally simplified process and a small-scale installation, and has high industrial utility values because of suppression of investment in plant and equipment, and running costs. SOLUTION : An organic phase containing, as an extractant, a dialkyl diglycolamic acid of formula R1R2 NCOCH2OCH2COOH (R1 and R2 are identical or different and a linear or branched alkyl group, with at least one of them being a 6C or higher alkyl group) for extraction of light a rare earth element selected from lanthanum, cerium, praseodymium and neodymium and a water phase containing the light rare earth element are brought into mutual contact, with addition of an alkali solution, by using a countercurrent multistage mixer-settler so as to extract the extraction target element in the organic phase, and bringing the organic phase into contact with an acid aqueous solution to extract the target element reversely, and the alkali amount of the alkali solution and the acid amount of the acid aqueous solution are set to be 1.2-2.9 equivalents to the light rare earth element contained in the water phase. COPYRIGHT : (C)2016, JPO&INPIT