Method for recovering high-purity vanadium from spent vanadium electrolyte

Abstract

The invention discloses a method for recovering high-purity vanadium from a spent vanadium electrolyte, and the method comprises the following steps: adding an oxidant into the spent vanadium electrolyte to oxidize vanadium ions in the electrolyte into pentavalent ions, wherein the oxidant is formed by mixing sodium persulfate and potassium permanganate in a mass ratio of 1: (1.9-2.8); then adjusting the pH value of the electrolyte to 2-5; carrying out elution treatment on the filtrate by adopting ion exchange resin; adding a vanadium precipitation agent into the eluted electrolyte to obtain asolid precipitate, wherein the vanadium precipitation agent comprises (NH4)2S2O8 and (NH4)2SO4 in a mass ratio of (1-5): 2; and finally, washing the obtained solid precipitate with a vanadium precipitation agent aqueous solution and deionized water in sequence, drying, and carrying out high-temperature roasting treatment to obtain a vanadium pentoxide solid with the purity of 95% or above. The recycling process is high in operability, large equipment is not needed, and the recycling cost is low.

Description

technical field [0001] The invention relates to the technical field of metal resource recovery and processing, in particular to a method for recovering high-purity vanadium from spent vanadium electrolyte. Background technique [0002] Vanadium battery (namely all-vanadium redox flow battery, referred to as VRB) is a redox battery in which the active material is in a circulating liquid state. VRB has the advantages of high charge-discharge reversibility, long cycle life, high energy conversion efficiency, no cross-contamination of positive and negative electrolytes, and easy scale-up. It has great cost advantages, short construction period, low system operation and maintenance costs, and especially has the characteristics of safe operation and environmental friendliness. [0003] Vanadium battery systems can be widely used in solar and wind power generation energy storage equipment, large-scale emergency power systems, power station energy storage, and peak-shaving and vall...

AI Technical Summary

Problems solved by technology

Although this process realizes the reuse of the spent electrolyte, there are still some defects in the performance of the reused electrolyte, the main reason is that the spent electrolyte contains a large amount of Fe 3+ , SiO 3 2- 、Al 3+ , Mg 2+ Other impurity ions and the valence ratio of vanadium ions in the electrolyte are unstable

[0008] Due to the huge discharge of the electrolyte of the invalid vanadium battery, the recovery of high-purity vanadium metal from the waste liquid has certain economic value, but the current recovery cost is relatively high, and the recovery rate is low, and the recovered vanadium pentoxide contains high impurities , leading to low quality of recycled products, which also restricts the popularization and use of this recycling process