System and method for producing high-purity high-activity vanadium electrolyte

A system and method for producing high-purity high-activity vanadium electrolyte; using fluidised bed (2) gas phase ammoniation to convert high-purity vanadium oxytrichloride into ammonium salt, and in another fluidised bed (3), reducing the ammonium salt into low-valence vanadium oxide having an average vanadium valence of 3.5, adding clean water and sulphuric acid dissolution, and further using ultrasonic activation to obtain a 3.5-valence vanadium electrolyte that can be directly used for a new all-vanadium redox flow battery stack. The process of producing ammonium salt containing vanadium by means of fluidised bed (2) gas phase ammoniation is short and highly efficient; implementing accurate regulation and control of the state of the reduction product by arranging internal components in a reduction fluidised bed (3) and using ultrasound processing to activate the vanadium ions greatly improves electrolyte activity. The present method has the advantages of a short procedure, efficiency and cleanliness, and stable product quality, and can be used in large-scale industrial production, having good economic and social benefits.