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CN-122025716-A - Method for directly preparing vanadium electrolyte from vanadium-containing solution

CN122025716ACN 122025716 ACN122025716 ACN 122025716ACN-122025716-A

Abstract

The application relates to the field of vanadium-containing solution impurity removal, in particular to a method for directly preparing vanadium electrolyte from vanadium-containing solution, which comprises the following steps of adding ferrous sulfate into the vanadium-containing solution, reacting at pH8-9, and filtering to obtain the arsenic-removing vanadium-containing solution; adding a reducing agent into the arsenic-removing vanadium-containing solution, reacting at the pH of 8-9,60-70 ℃ and filtering to obtain the chromium-removing vanadium-containing solution, wherein the reducing agent comprises at least one of sulfur dioxide, sodium sulfite and sodium thiosulfate, removing manganese and titanium, adding sodium phosphate into the chromium-removing vanadium-containing solution, reacting at the pH of 3-3.5,45-55 ℃ and filtering to obtain the manganese-removing titanium-containing vanadium-containing solution, extracting, mixing an extracting agent with the manganese-removing titanium-containing vanadium-containing solution, extracting, mixing an organic phase with 1.5-2.5mol/L dilute sulfuric acid, and back extracting to obtain a vanadium electrolyte, wherein the extracting agent is a P204-sulfonated kerosene mixed extracting agent. The vanadium electrolyte is obtained by step-by-step impurity removal and extraction back extraction.

Inventors

  • LIU ZHUO
  • YIN XINGRONG
  • XU HUI

Assignees

  • 江西银钒新材料有限公司

Dates

Publication Date
20260512
Application Date
20260205

Claims (9)

  1. 1. The method for directly preparing the vanadium electrolyte from the vanadium-containing solution is characterized by comprising the following steps of: Adding ferrous sulfate into the vanadium-containing solution, reacting at pH8-9, and filtering to obtain arsenic-removing vanadium-containing solution; adding a reducing agent into the arsenic-removing vanadium-containing solution, reacting at the pH of 8-9,60-70 ℃ and filtering to obtain the chromium-removing vanadium-containing solution, wherein the reducing agent comprises at least one of sulfur dioxide, sodium sulfite and sodium thiosulfate; adding sodium phosphate into the chromium-removing vanadium-containing solution, reacting at the pH of 3-3.5,45-55 ℃ and filtering to obtain the manganese-removing titanium-removing vanadium-containing solution; And extracting, namely mixing an extracting agent with the demanganizing and titanium removing vanadium-containing solution, extracting, and then mixing an organic phase with 1.5-2.5mol/L dilute sulfuric acid for back extraction to obtain vanadium electrolyte, wherein the extracting agent is a P204-sulfonated kerosene mixed extracting agent.
  2. 2. The method for removing impurity ions of arsenic, manganese, titanium and chromium from a vanadium-containing solution according to claim 1, further comprising the steps of: pre-oxidizing, namely adding hydrogen peroxide into the chromium-removing vanadium-containing solution, reacting, and filtering to obtain a pre-oxidized vanadium-containing solution; And (3) removing manganese and titanium, namely adding sodium phosphate into the pre-oxidized vanadium-containing solution, reacting at the pH of 3-3.5,45-55 ℃ and filtering to obtain the manganese and titanium-removing vanadium-containing solution.
  3. 3. The method for removing impurity ions from arsenic, manganese, titanium and chromium in a vanadium-containing solution according to claim 2, wherein the pH is in the range of 2 to 3 in the step of pre-oxidizing.
  4. 4. The method for removing impurity ions from arsenic, manganese, titanium and chromium in a vanadium-containing solution according to claim 2, wherein the reaction temperature in the step of pre-oxidizing is in the range of 40 to 60 ℃.
  5. 5. The method for removing impurity ions of arsenic, manganese, titanium and chromium from a vanadium-containing solution according to claim 1, further comprising the steps of: Adding a zirconium phosphate adsorbent into the demanganizing and titanium removing vanadium-containing solution, and filtering after adsorption to obtain an adsorbed vanadium-containing solution; and extracting, namely mixing an extracting agent with the adsorption vanadium-containing solution, extracting, and then mixing an organic phase with 1.5-2.5mol/L dilute sulfuric acid for back extraction to obtain the vanadium electrolyte.
  6. 6. The method for removing arsenic, manganese, titanium and chromium impurity ions from vanadium-containing solution according to claim 5, wherein the pH is in the range of 2.5 to 4.0 in the step of adsorbing.
  7. 7. The method for removing arsenic, manganese, titanium and chromium impurity ions in a vanadium-containing solution according to claim 5, wherein the zirconium phosphate adsorbent is a pretreatment adsorbent; The preparation method of the pretreatment adsorbent comprises the following steps of adding zirconium phosphate into ZrOCl 2 solution for heating reaction to obtain the pretreatment adsorbent.
  8. 8. The method for removing impurity ions of arsenic, manganese, titanium and chromium from a vanadium-containing solution according to claim 1, further comprising the steps of: Introducing oxygen into the arsenic-removing vanadium-containing solution, reacting at pH4.5-5.0, and filtering to obtain the iron-removing vanadium-containing solution; Adding a reducing agent into the solution containing the iron and the vanadium, reacting at the pH of 8-9,60-70 ℃ and filtering to obtain the solution containing the chromium and the vanadium.
  9. 9. The method for removing impurity ions from arsenic, manganese, titanium and chromium in a vanadium-containing solution according to claim 1, wherein in the step of removing chromium, the reducing agent is sulfur dioxide.

Description

Method for directly preparing vanadium electrolyte from vanadium-containing solution Technical Field The application relates to the field of impurity removal of vanadium-containing solutions, in particular to a method for directly preparing vanadium electrolyte from a vanadium-containing solution. Background The large-scale high-efficiency energy storage technology gradually becomes a research hot spot in the field of new energy, and the safety problem is a key factor of the development of the energy storage industry. Under the background that safety problems frequently occur in lithium battery and sodium-sulfur battery energy storage power stations, the vanadium electrolyte battery has the advantages of high safety, long service life, adjustable power and the like, and stands out in a large-scale energy storage racetrack. The vanadium electrolyte is used as an active material of the all-vanadium redox flow battery, is a key component of the vanadium battery, and directly affects the performance of the battery. The electrolyte has long process flow and complex composition system, and has strict requirements on trace element content in order to maintain the electrochemical performance of the electrolyte. The impurity ions in the vanadium-containing solution are common as arsenic, manganese, titanium and chromium, and the elements such as arsenic, manganese, titanium and chromium are commonly associated in the raw materials such as vanadium pentoxide for preparing the electrolyte. These several ions often interfere with electrochemical activity in the vanadium-containing solution, destroying the stability of the electrolyte, resulting in degradation of the cell performance. Disclosure of Invention In order to solve the problem that the prepared vanadium-containing solution contains impurity ions and influences the battery performance caused by accompanying elements in raw materials such as vanadium pentoxide, the application provides a method for directly preparing vanadium electrolyte from the vanadium-containing solution. The application provides a method for directly preparing vanadium electrolyte from vanadium-containing solution, which adopts the following technical scheme: a method for directly preparing vanadium electrolyte from vanadium-containing solution comprises the following steps: Adding ferrous sulfate into the vanadium-containing solution, reacting at pH8-9, and filtering to obtain arsenic-removing vanadium-containing solution; adding a reducing agent into the arsenic-removing vanadium-containing solution, reacting at the pH of 8-9,60-70 ℃ and filtering to obtain the chromium-removing vanadium-containing solution, wherein the reducing agent comprises at least one of sulfur dioxide, sodium sulfite and sodium thiosulfate; adding sodium phosphate into the chromium-removing vanadium-containing solution, reacting at the pH of 3-3.5,45-55 ℃ and filtering to obtain the manganese-removing titanium-removing vanadium-containing solution; And extracting, namely mixing an extracting agent with the demanganizing and titanium removing vanadium-containing solution, extracting, and then mixing an organic phase with 1.5-2.5mol/L dilute sulfuric acid for back extraction to obtain vanadium electrolyte, wherein the extracting agent is a P204-sulfonated kerosene mixed extracting agent. By adopting the technical scheme, under the weak alkaline condition of pH8-9, ferrous ions are oxidized into ferric ions by dissolved oxygen in the solution, and pentavalent arsenic is reduced into trivalent arsenic. The ferric ions and the trivalent arsenic form ferric arsenate composite precipitate through electrostatic adsorption and coprecipitation. Sulfur dioxide, sodium sulfite or sodium thiosulfate is used as a reducing agent, and hexavalent chromium is reduced to trivalent chromium under the condition of 60-70℃, pH <8 > -9. The solubility product of trivalent chromium is far lower than that of vanadium ions, and the trivalent chromium is precipitated in a chromium hydroxide form by regulating the pH value, so that the vanadium remains in a dissolved state. Under the weak acid condition with the pH value of 3-3.5 and the temperature of 45-55 ℃, sodium phosphate is taken as a precipitator to generate phosphate radical ions through hydrolysis reaction, and the phosphate radical ions and manganese ions and titanium ions in the solution are subjected to selective complexation reaction. Manganese ions and phosphate ions form manganese phosphate precipitates, and titanium ions form titanium phosphate precipitates. The P204-sulfonated kerosene mixed extractant is selected, vanadium ions are selectively extracted through the interfacial action of an organic phase and a water phase, and simultaneously impurity ions such as sodium ions, iron ions and the like introduced in the previous stage are cooperatively removed. The organic phase is back extracted with dilute sulfuric acid after extraction, vanadium enters the water phase in the