METHOD FOR PRODUCING AMMONIUM TUNGSTATE AQUEOUS SOLUTION

• Main Authors: SASAYA KAZUO, YAMAMOTO RYOJI, ITAKURA TAKESHI, ITO HIDEAKI, SATO FUMIATSU, IKEGAYA AKIHIKO, OKUNO TAKUYA, YAMANAKA SHUNSUKE
• Format: Patent
• Language: English; Japanese
• Published: 06.11.2014
• Subjects: CHEMISTRY; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; INORGANIC CHEMISTRY; METALLURGY

PROBLEM TO BE SOLVED: To produce an ammonium tungstate aqueous solution of high purity.SOLUTION: There is provided a method for producing an ammonium tungstate aqueous solution which comprises: a step of producing a polyacid solution containing poly tungstate ions and Mo-containing polyacid ions; a step of adsorbing the poly tungstate ions to an anion exchange resin constituted of a first anion exchange resin, a second anion exchange resin and a third anion exchange resin, which are connected to one another in this order, without adsorbing the Mo-containing polyacid ions to the first anion exchange resin by previously passing the polyacid solution through the first anion exchange resin; a step of separating the first anion exchange resin and the second anion exchange resin; and a step of bringing ammonia water into contact with the first anion exchange resin after the separating step. 【課題】高純度のタングステン酸アンモニウム水溶液を製造する。【解決手段】ポリタングステン酸イオンおよびＭｏ含有ポリ酸イオンを含むポリ酸溶液を製造する工程と、ポリ酸溶液を第１の陰イオン交換樹脂と第２の陰イオン交換樹脂と第３の陰イオン交換樹脂がこの順に連結されてなる陰イオン交換樹脂に第１の陰イオン交換樹脂から先に通液させて第１の陰イオン交換樹脂にＭｏ含有ポリ酸イオンを吸着させることなくポリタングステン酸イオンを吸着させる工程と、第１の陰イオン交換樹脂と第２の陰イオン交換樹脂とを分離する工程と、分離する工程後の第１の陰イオン交換樹脂にアンモニア水を接触させる工程と、を含む、タングステン酸アンモニウム水溶液の製造方法である。【選択図】図６