METHOD FOR PRODUCING VANADIUM SULFATE SOLUTION

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently and inexpensively producing a vanadium sulfate electrolyte for a redox battery by using a petroleum-based combustion ash such as combustion ash of Orimulsion, etc., as a raw material. SOLUTION: A vanadium-containing petroleum-based combustion ash such as combustion ash of Orimulson obtained by burning Orimulsion, etc., is oozed by using a solution obtained by adding a reducing agent to water or an acid and further a tetravalent vanadium sulfate solution is produced by a solvent extraction method using an acidic phosphorus-based extractant. The obtained tetravalent vanadium sulfate solution is reduced in an electric field to give a trivalent vanadium sulfate solution.