| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for recovering Ce at high purity which enables a high-purity Ce to be selectively recovered from a raw material containing Ce and other rare-earth elements and impurities in a short period of time without using a solvent extraction method incurring a high cost, and which is therefore excellent in economical efficiency.SOLUTION: The method for recovering Ce at high purity comprises: a Ce removal step of feeding an oxidizing agent to a solution containing at least Ce as a rare-earth element to oxidize Ce and also adding a pH adjusting agent to the solution to adjust the pH of the solution in the range of 0.5 to 2.5 to thereby precipitate Ce, followed by subjecting the precipitated Ce to solid-liquid separation to obtain a Ce precipitate; a Ce dissolution step of dissolving the precipitate into inorganic acid; and a Ce recovery step of adding an oxalic acid type or a carbonic acid type precipitation-forming agent to the Ce solution obtained by the dissolution step to respectively adjust the pH of the solution in the range of 1.0 to 3.0 when the oxalic acid type precipitation-forming agent is added and in the range of 3.0 to 6.0 when the carbonic acid type precipitation-forming agent is added to precipitate Ce, followed by subjecting the precipitated Ce to solid-liquid separation to recover Ce as a precipitate.</p> |
