| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of producing tungsten oxide, capable of recovering high purity tungsten at a low cost, and a method of producing tungsten employing the same.SOLUTION: There is provided tungsten oxide soluble in an amount of at least 70 mass% to ammonia water of a concentration of 25% at 70°C, by applying an oxidation treatment to a powder of a raw material mixture comprising a tungsten component. The oxidation treatment at 420 to 600°C is applied to the powder of the raw material mixture comprising the tungsten component. The temperature in the oxidation treatment preferably is 470 to 550°C. Tungsten is obtained by a step of obtaining ammonia solution of tungsten oxide by causing ammonia to dissolve the tungsten oxide subsequent to the step of obtaining tungsten oxide, a step of obtaining ammonium paratungstate by neutralizing the ammonia solution of tungsten oxide with an acid, and by reducing the ammonium paratungstate with hydrogen. |
