VALUABLE METAL EXTRACTION AGENT AND VALUABLE METAL EXTRACTION METHOD USING SAID EXTRACTION AGENT

摘要

The objective of the present invention is to selectivelyextract light rare earth metals, and by extension, europium,from an acidic solution containing a plurality of types ofrare earth metal. This valuable metal extraction agent isrepresented by the general formula. In the formula: R1 and R2each indicate the same or different alkyl group; R3 indicates ahydrogen atom or an alkyl group; and R4 indicates a hydrogenatom or any given group other than an amino group bonded tothe a carbon as an amino acid. Preferably, the general formulahas a glycine unit, a histidine unit, a lysine unit, anaspartic acid unit, or an N-methylglycine unit. Preferably,when extracting europium using the extraction agent, the pH isadjusted into the range of 2.0-3.0 inclusive, and whenselectively extracting light rare earth metals, the pH isadjusted to 1.7-2.7 inclusive.(see above formula)