A kind of vanadyl sulfate electrolyte copper removal method of vanadium redox flow battery

Abstract

A method for removing copper from a vanadyl sulfate electrolyte for an all-vanadium redox flow battery. The vanadium sulfate electrolyte is obtained by leaching vanadium slag and stone coal, back extraction, and resin analysis. After multi-stage countercurrent extraction and impurity removal, sulfuric acid The vanadyl concentration is 0.5~2.0mol / L, and the copper content is greater than 50mg / L. It consists of the following steps: adjust the pH of the vanadyl sulfate solution to 4.0~5.5 with a basic compound, add a metal replacement agent; add hydrogen peroxide, stand still, Filtrate, add reducing agent in filtrate; With P204:TBP:sulfonated kerosene extractant, extract above-mentioned solution, after two-phase separation, wash vanadium-loaded organic phase with deionized water; Back-extract vanadium-loaded organic phase with sulfuric acid solution, two After phase separation, a copper-removing vanadyl sulfate electrolyte is obtained. The method for removing copper from the vanadyl sulfate electrolyte provided by the invention can remove impurity copper contained in the vanadyl sulfate electrolyte, and can effectively improve the comprehensive electrical performance of the electrolyte. The method has the advantages of simple and reliable process, good copper removal effect, low production cost, and the obtained reaction copper slag can be recycled and reused.

Description

technical field [0001] The invention relates to a method for removing copper from a battery electrolyte, in particular to a method for removing copper from a vanadyl sulfate electrolyte of an all-vanadium redox flow battery. Background technique [0002] The all-vanadium redox flow battery is a kind of electrical energy storage and conversion device that has received widespread attention. It occupies a small area and has no potential safety hazards of inflammability and explosion. The capacity of the battery depends on the amount of electrolyte and the concentration of vanadium ions. The capacity can be adjusted arbitrarily. The electrolyte can be placed separately from the battery. The battery has a long service life, good safety performance, high reliability, and can be charged and discharged quickly. There are great prospects for development in aspects such as cutting valleys and flat peaks. Since the all-vanadium redox flow battery adopts liquid-liquid chemical reaction...

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Problems solved by technology

[0007] CN201710031190.7 discloses a method for preparing high-purity vanadyl sulfate, which uses a strong alkaline solution to dissolve vanadium salt or vanadium compound, then adds strong reducing properties to obtain a tetravalent vanadium compound solution for precipitation and separation, and then dissolves to obtain a high-purity vanadyl sulfate solution , the method does not mention the method and effect of removing impurities, especially copper