TRIVALENT AND TETRAVALENT MIXED VANADIUM COMPOUND PRODUCING METHOD AND VANADIUM ELECTROLYTE PRODUCING METHOD

摘要

The present invention provides method of producing atrivalent and tetravalent mixed vanadium compound havingexcellent solubility with sulfuric acid directly from atetravalent or pentavalent vanadium compound by using a reducingagent, and a method of producing a vanadium electrolyte.For example, a vanadium compound mainly containing a pentavalentvanadium compound; sulfur and concentrated sulfuric acid inmolar ratios with respect to (one mol of vanadium atom in thepentavalent vanadium compound) 0:35 to 0.4 : 1.2 to 1.9 arekneaded into paste form, and the paste-form mixture is calcinedat a temperature of not less than 150°C to less than 440°C sothat a trivalent and tetravalent mixed vanadium compound isobtained, and a redox flow battery-use vanadium electrolyteis obtained by dissolving the trivalent and tetravalent mixedvanadium compound in a sulfuric acid solution.