| 简介 |
PROBLEM TO BE SOLVED : To provide an inexpensive process of efficiently recovering rare earth oxides of high quality from waste grinding slurry containing rare earth elements.
SOLUTION : In a method of recovering rare earth elements, rare earth oxides are recovered from waste grinding slurry containing rare earth elements in a first process (I) including steps (1)-(5), and ammonium bicarbonate (precipitant) is reproduced and recycled in a second process (II) including steps (6)-(7). The process (I) comprises steps of : (1) mixing slurry containing rare earth oxides with oxidizing and reducing agents and acid, and heating and solving the slurry; (2) dissociating non-soluble components after adjusting the pH value of rare earth element solution; (3) adding ammonium bicarbonate to the solution to form rare earth carbonate; (4) dissociating the rare earth carbonate from the slurry; and (5) of baking the rare earth carbonate to recover it as rare earth oxides. The process (II) comprises steps of : (6) adding strong alkaline agent to a dissociated solution of rare earth carbonate to generate, condense and recover ammonium; and (7) bringing ammonium into contact with generated carbon dioxide to form ammonium bicarbonate solution and to recycle the welding as a precipitant for forming rare earth carbonates.
COPYRIGHT : (C)2009, JPO&INPIT |
客服热线：
手机版
二维码
