METHOD FOR PRODUCING AMMONIUM TUNGSTATE AQUEOUS SOLUTION

摘要

PROBLEM TO BE SOLVED: To provide a method for producing an ammonium tungstate aqueous solution extremely efficiently by using an anion exchange resin without precipitating salt even via a polytungstate ion.

SOLUTION: The method for producing the ammonium tungstate aqueous solution includes: a first step of producing an alkali metal polytungstate aqueous solution by adjusting the pH of an alkali metal tungstate aqueous solution to 3.5-8; a second step of adsorbing the polytungstate ion on the anion exchange resin by bringing the alkali metal polytungstate aqueous solution into contact with the anion exchange resin; a third step of recovering the liquid discharged at the second step; and a fourth step of decomposing the polytungstate ion to elute a tungstate ion by bringing ammonia water containing≥8 mol/L ammonia into contact with the polytungstate ion-adsorbed anion exchange resin.

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