Patent ID: 8888985
Filing Date: 2014-11-18
Classification: C22B,C25C,Y02P

Abstract:
1. A process for producing a rare-earth metal, the process comprising: leaching a mineral source with a solution to obtain a first residual solution comprising a primary target rare-earth metal; adjusting a pH level of the first residual solution to within a range of pH 3 or higher and lower than pH 5 to generate a precipitate, and then removing the precipitate from the first residual solution to obtain a second residual solution; extracting a rare-earth metal ion with at least one of a cation exchange resin and an organic solvent from the second residual solution; back extracting the rare-earth metal ion contained in the cation exchange resin or the organic solvent to obtain an eluant; adding an oxalic acid to the eluant to precipitate a rare-earth metal oxalate; recovering the rare-earth metal oxalate, and then converting the rare-earth metal oxalate into a rare-earth metal oxide; and electrolyzing the rare-earth metal oxide in a molten salt to collect a rare-earth metal at a cathode.