Method for producing vanadium compound, method for producing vanadium solution, and method for producing redox flow battery electrolyte

Patent metadata

Field	Value
Publication number	US-2018135149-A1
Application number	US-201815863193-A
Country	US
Kind code	A1
Filing date	Jan 5, 2018
Priority date	Jun 3, 2016
Publication date	May 17, 2018
Grant date	—

Abstract

This method for producing a vanadium compound has an alkaline leaching step for immersing incineration ash in an alkaline solution to cause vanadium to leach from the incineration ash into the alkaline solution and obtain a leachate slurry, a solid-liquid separation step for separating the leachate slurry obtained in the alkaline leaching step into a solid and liquid followed by removing insoluble matter to obtain a leachate, a pH adjustment step for adding acid to the leachate following solid-liquid separation to make the leachate acidic, an aging step for aging the leachate following pH adjustment until a precipitate forms in the leachate, and a separation step for separating the precipitate from the leachate following the aging step.

First claim

1 . A method for producing a vanadium compound, comprising:
an alkaline leaching step for immersing incineration ash in an alkaline solution to cause vanadium to leach from the incineration ash into the alkaline solution and obtain a leachate slurry, a solid-liquid separation step for separating the leachate slurry obtained in the alkaline leaching step into a solid and liquid followed by removing insoluble matter to obtain a leachate, a pH adjustment step for adding acid to the leachate following solid-liquid separation to make the leachate acidic, an aging step for aging the leachate following pH adjustment until a precipitate forms in the leachate, and a separation step for separating the precipitate from the leachate following the aging step.

2 . The method for producing a vanadium compound according to claim 1 , wherein the solid-liquid separation is carried out by filtration.

3 . The method for producing a vanadium compound according to claim 1 , wherein an oxidizing agent is added to the alkaline solution in the alkaline leaching step.

4 . The method for producing a vanadium compound according to claim 1 , wherein the pH of the alkaline solution following immersion of the incineration ash in the alkaline leaching step is 10 or higher.

5 . The method for producing a vanadium compound according to claim 1 , further comprising an impurity removal step for removing impurities from the leachate when the pH of the leachate has been made higher than 6 but lower than 8 by addition of acid in the pH adjustment step.

6 . The method for producing a vanadium compound according to claim 1 , wherein the temperature in the aging step is 20° C. to 200° C.

7 . The method for producing a vanadium compound according to claim 1 , wherein the duration of aging of the leachate in the aging step is 2 hours to 3000 hours.

8 . The method for producing a vanadium compound according to claim 1 , wherein the vanadium compound produced includes at least one compound selected from the group consisting of NaV 3 O 8 .1.5H 2 O, H 0.33 Na 0.67 V 3 O 8 .1.5H 2 O, H 0.2 V 0.8 V 3 O 8 .H 2 O, KV 3 O 8 .1.5H 2 O, H 0.3 K 0.7 V 3 O 8 .1.5H 2 O and H 0.4 K 0.6 V 3 O 8 .2H 2 O.

9 . The method for producing a vanadium compound according to claim 1 , wherein the amount of Fe contained in the vanadium compound produced is less than 0.1% by mass.

10 . The method for producing a vanadium compound according to claim 1 , wherein the material that composes the alkaline solution is sodium hydroxide, sodium carbonate or potassium hydroxide.

11 . The method for producing a vanadium compound according to claim 1 , wherein the incineration ash is fly ash.

12 . The method for producing a vanadium compound according to claim 1 , wherein the incineration ash is furnace ash.

13 . A method for producing a vanadium solution, comprising: a dissolution step for dissolving a vanadium compound, obtained according to the method for producing a vanadium compound according to claim 1 , in sulfuric acid.

14 . The method for producing a vanadium solution according to claim 13 , wherein sulfurous acid gas and aqueous sulfurous acid solution are added to the sulfuric acid in the dissolution step.

15 . A method for producing a redox flow battery electrolyte using a vanadium compound produced according to the method for producing a vanadium compound according to claim 1 , wherein the electrolyte contains at least one of trivalent and tetravalent vanadium ions.

16 . The method for producing a redox flow battery electrolyte according to claim 15 , wherein the iron concentration in the electrolyte is 100 ppm by mass or less and the nickel concentration is 200 ppm by mass or less.

Assignees

• Showa Denko Kk

Inventors

• Oriji Gaku
• Hanawa Kenzo

Classifications

• C01G31/00

  Compounds of vanadium · CPC title

• C22B3/44

  by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42) · CPC title

• C22B7/02

  Working-up flue dust · CPC title

• H01M8/188

  by recharging of redox couples containing fluids; Redox flow type batteries · CPC title

• C22B34/22 Primary

  Obtaining vanadium · CPC title