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

Patent metadata

Field	Value
Publication number	US-2022364204-A1
Application number	US-202017618727-A
Country	US
Kind code	A1
Filing date	Jun 11, 2020
Priority date	Jun 12, 2019
Publication date	Nov 17, 2022
Grant date	—

Abstract

A production method includes: an alkali extraction step of adding an alkali and water, or an alkali solution, to raw material ash containing an ammonium sulfate component, sulfuric acid, vanadium, and at least one other metal selected from nickel, iron, and magnesium, wherein a pH of 13 or higher is achieved, to obtain an alkali leachate; a solid-liquid separation step on the alkali leachate to obtain a leach filtrate containing vanadium; an evaporation concentration step of evaporating and concentrating the leach filtrate to obtain a concentrated liquid; and a crystallization/solid-liquid separation step of cooling and crystalizing the concentrated liquid and recovering a precipitate containing a vanadium compound. Another production method includes an alkali extraction step, a solid-liquid separation step, an evaporation concentration step, an alkali concentration adjustment step of further adding an alkali or alkali solution to a concentrated liquid to obtain a concentration-adjusted liquid, and a crystallization/solid-liquid separation step.

First claim

1 - 24 . (canceled)

25 . A production method for a vanadium compound, comprising:
an alkali extraction step of adding an alkali and water, or an alkali solution, to raw material ash containing at least an ammonium sulfate component including ammonium sulfate and/or ammonium hydrogen sulfate, sulfuric acid, vanadium, and at least one other metal selected from nickel, iron, and magnesium, such that a pH of 13 or higher is achieved, to leach the vanadium into a liquid phase to obtain an alkali leachate; a solid-liquid separation step of performing solid-liquid separation on the alkali leachate to remove insoluble matter as a solid component and obtain, as a leach filtrate, the alkali leachate containing vanadium; an evaporation concentration step of evaporating and concentrating the leach filtrate to obtain a concentrated liquid; and a crystallization/solid-liquid separation step of cooling the concentration liquid to a predetermined cooling temperature to crystalize the concentration liquid, and recovering, as a solid component, a precipitate containing a vanadium compound, wherein in the concentrated liquid, at the cooling temperature, a concentration of the vanadium compound is not less than a saturation concentration thereof and a concentration of an alkali sulfate is not greater than a saturation concentration thereof.

26 . The production method for a vanadium compound according to claim 25 , further comprising a raw material ash washing step of washing the raw material ash, at a stage previous to the alkali extraction step.

27 . The production method for a vanadium compound according to claim 25 , further comprising a recycling step of reusing a crystallization filtrate separated from the solid component in the crystallization/solid-liquid separation step, in the alkali extraction step, at a stage subsequent to the crystallization/solid-liquid separation step.

28 . The production method for a vanadium compound according to claim 27 , further comprising a crystallization filtrate amount adjustment step of adjusting an amount of the crystallization filtrate to be recycled, such that a total of sulfate ion brought in by the crystallization filtrate and sulfate ion brought in from the raw material ash in the alkali extraction step is not greater than an amount equivalent to a saturation concentration after cooling in the crystallization/solid-liquid separation step.

29 . The production method for a vanadium compound according to claim 25 , further comprising an oxidizing step of oxidizing the raw material ash, at a stage before the alkali extraction step.

30 . The production method for a vanadium compound according to claim 25 , further comprising a solid component washing step of washing the solid component, recovering a washing liquid containing vanadium, and transferring the washing liquid to the evaporation concentration step together with the leach filtrate, at a stage subsequent to the alkali extraction step.

31 . A production method for a redox-flow battery electrolyte, comprising an electrolyte production step of producing a redox-flow battery electrolyte using, as a raw material, the vanadium compound separated by the production method for a vanadium compound according to claim 25 .

32 . A production apparatus for a vanadium compound, comprising:
alkali extraction means that adds an alkali and water, or an alkali solution, to raw material ash containing at least an ammonium sulfate component including ammonium sulfate and/or ammonium hydrogen sulfate, sulfuric acid, vanadium, and at least one other metal selected from nickel, iron, and magnesium, such that a pH of 13 or higher is achieved, to leach the vanadium into a liquid phase to obtain an alkali leachate containing vanadium; solid-liquid separation means that performs solid-liquid separation on the alkali leachate to remove insoluble matter as a solid component and obtain, as a leach filtrate, an alkali leachate containing vanadium; evaporation concentration means that evaporates and concentrates the leach filtrate to obtain a concentrated liquid; and crystallization/solid-liquid separation means that cools the concentration liquid to a predetermined cooling temperature to crystalize the concentration liquid, and recovers, as a solid component, a precipitate containing a vanadium compound, wherein in the concentrated liquid, at the cooling temperature, a concentration of the vanadium compound is not less than a saturation concentration thereof and a concentration of an alkali sulfate is not greater than a saturation concentration thereof.

33 . The production apparatus for a vanadium compound according to claim 32 , further comprising raw material ash washing means that washes the raw material ash, at a stage before the alkali extraction means.

34 . The production apparatus for a vanadium compound according to claim 32 , further comprising recycling means that reuses a crystallization filtrate separated from the solid component in the crystallization/solid-liquid separation means, in the alkali extraction means, at a stage subsequent to the crystallization/solid-liquid separation means.

35 . The production apparatus for a vanadium compound according to claim 32 , further comprising crystallization filtrate amount adjustment means that adjusts an amount of the crystallization filtrate to be recycled, such that a total of sulfate ion brought in by the crystallization filtrate and sulfate ion brought in from the raw material ash in the alkali extraction means is not greater than an amount equivalent to a saturation concentration after cooling in the crystallization/solid-liquid separation means.

36 . The production apparatus for a vanadium compound according to claim 32 , further comprising oxidizing means that oxidizes the raw material ash, at a stage before the alkali extraction means.

37 . The production apparatus for a vanadium compound according to claim 32 , further comprising solid component washing means that washes the solid component, recovers a washing liquid containing vanadium, and transfers the washing liquid to the evaporation concentration means together with the leach filtrate, at a stage subsequent to the alkali extraction means.

38 . A production apparatus for a redox-flow battery electrolyte, comprising electrolyte production means that produces a redox-flow battery electrolyte using, as a raw material, the vanadium compound separated by the production apparatus for a vanadium compound according to claim 32 .

39 . A production method for a vanadium compound, comprising:
an alkali extraction step of adding an alkali and water, or an alkali solution, in an amount that achieves a pH of 13 or higher, to raw material ash containing at least an ammonium sulfate component including ammonium sulfate and/or ammonium hydrogen sulfate, sulfuric acid, and vanadium, to leach the vanadium into a liquid phase to obtain an alkali leachate containing vanadium; a solid-liquid separation step of performing solid-liquid separation on the alkali leachate to obtain a leach filtrate containing vanadium; an evaporation concentration step of evaporating and concentrating the leach filtrate to obtain a concentrated liquid; an alkali concentration adjustment step of further adding an alkali or an alkali solution to the concentrated liquid to obtain a concentration-adjusted liquid; and a crystallization/solid-liquid separation step of cooling the concentration-adjusted liquid to a predetermined cooling temperature to crystalize the concentration-adjusted liquid, and recovering, as a solid component, a precipitate containing a vanad

Assignees

• Kawasaki Heavy Ind Ltd

Inventors

• Masamoto Manabu
• Nishino Takashi
• Kitagawa Yuta
• Akagi Daichi

Classifications

• C22B3/14

  containing ammonia or ammonium salts · CPC title

• C22B7/02

  Working-up flue dust · CPC title

• C22B7/008

  by an alkaline or ammoniacal leaching · CPC title

• Y02P10/20

  Recycling · CPC title

• C01G31/00 Primary

  Compounds of vanadium · CPC title