| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for efficiently removing molybdenum in an alkali tungstate solution by a simple treatment process. SOLUTION: A method for purifying an ammonium tungstate solution includes a molybdenum removal step of adding a sulfide and a copper compound to the ammonium tungstate solution to form a precipitate including molybdenum in the solution and separating the precipitate by solid-liquid separation to remove molybdenum, preferably, further includes a copper removal step of adding an oxidizer to the filtrate obtained at the molybdenum removal step to precipitate copper ions in the filtrate and separating the precipitate including copper by solid-liquid separation. For example, the ammonium tungstate solution is obtained by subjecting a solution of an alkali salt of tangustic acid, which is obtained when cemented carbide scrap is dissolved or which is recovered at a step of smelting tungsten ore, to ion exchange. COPYRIGHT: (C)2011,JPO&INPIT |
