Preparation method for high-purity vanadyl sulfate solution

Abstract

The invention belongs to the field of wet-process metallurgy, and mainly relates to a preparation method for a high-purity vanadyl sulfate solution. The preparation method for the high-purity vanadyl sulfate solution provided by the invention comprises the following steps: a), oxidation of Fe2+; b), removal of Fe3+; c), removal of chromium ions and preparation of oxovanadium hydroxide; and d), preparation of the high-purity vanadyl sulfate solution, wherein the rough vanadyl sulfate solution is the vanadyl sulfate solution with the chromium content of greater than or equal to 550.3 mg / L and the iron content of greater than or equal to 269.6 mg / L. The chromium content is less than or equal to 0.002% and the iron content is less than or equal to 0.0027 g / L in the vanadyl sulfate solution prepared by the method.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy, and mainly relates to the preparation of a high-purity vanadyl sulfate solution, its electrolyte solution and a vanadium battery. Background technique [0002] As an emerging energy storage system, vanadium battery has many advantages such as long service life, large capacity, high power, and high safety. It can be widely used in power grid peak regulation, public transportation airborne power supply, wind energy and solar energy storage system . The main reason restricting the development of vanadium battery at present is that its cost remains high, and the root cause is that the preparation cost of electrolyte is too high. The method of high-purity vanadium oxide and high-concentration electrolyte for vanadium battery), prepare battery-grade vanadyl sulfate based on high-purity vanadium pentoxide, and the process of preparing high-purity vanadium pentoxide often involves remelting, separation an...

AI Technical Summary

Problems solved by technology

The main reason restricting the development of vanadium battery at present is that its cost remains high, and the root cause is that the preparation cost of electrolyte is too high. The method of high-purity vanadium oxide and high-concentration electrolyte for vanadium battery), prepare battery-grade vanadyl sulfate based on high-purity vanadium pentoxide, and the process of preparing high-purity vanadium pentoxide often involves remelting, separation and purification , precipitation, calcination and other steps, the process is complicated, the process is long and the effect of impurity removal is not ideal. The main impurities such as chromium and iron are high in content. The existence of iron and chromium will seriously reduce the energy efficiency of vanadium batteries and corrode electrode materials. , which seriously affects the operation of the vanadium battery system

[0003] At present, the impurity removal of vanadyl sulfate is mainly divided into two types, one is to remove impurities in raw materials (including qualified liquid of vanadium pentoxide and vanadium), and the main step is to return vanadium pentoxide to the qualified liquid or directly to the qualified liquid Add precipitant, such as magnesium salt, aluminum salt and calcium salt, etc. to remove anionic impurities such as silicate, chromate, phosphate in the solution, and then remove most of cationic impurities, such as sodium, potassium, calcium, Magnesium etc. (referring to patent CN103515642A a kind of preparation method of high-concentration high-purity vanadium battery electrolyte; Another example Hou Haijun discloses a kind of preparation technology research of high-purity ammonium metavanadate (referring to iron and steel vanadium titanium, 2013,34 (3) ), the method has a long process flow, complex operation process, unsatisfactory impurity removal effect and the introduction of new impurity ions

Another method of impurity removal is mainly through the method of extraction-back extraction. Although this method saves the processes such as leachate removal of impurities, ammonium salt precipitation of vanadium, and redissolution, the production process is simplified, production time is saved, and the preparation process is unnecessary. Introduce other impurities, but extraction and ion exchange have problems such as small processing capacity, expensive reagents, high cost, deteriorating operating environment, and low purity of products (refer to patent CN103151549A, which is based on an extraction-back extraction system to prepare high-purity vanadium battery electrolyte Methods)

[0004] The above two impurity removal methods in the process of preparing the electrolyte have their own shortcomings, which limit their industrial application and hinder the development of vanadium batteries to a certain extent.