Electrochemical reactor and method for reducing iron from an iron-containing feedstock

Patent metadata

Field	Value
Publication number	US-2025051947-A1
Application number	US-202418795566-A
Country	US
Kind code	A1
Filing date	Aug 6, 2024
Priority date	Aug 7, 2023
Publication date	Feb 13, 2025
Grant date	—

Abstract

An electrochemical reactor, including a channel for containing and directing flow of an electrolyte stream, wherein the electrolyte stream includes an electrolyte and an iron-containing feedstock; an anode and a cathode positioned in contact with the channel; and a source of a magnetic field positioned in proximity to the cathode, wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at a surface of the cathode and in a magnetic field of the source, and wherein the at least a portion of the iron-containing feedstock is electrochemically reduced to the iron metal at a current efficiency of at least 0.75, wherein the current efficiency is a ratio of charge used for the reduction of the iron-containing feedstock to a total charge provided to the cathode.

First claim

What is claimed is:

1 . An electrochemical reactor, comprising:
a channel for containing and directing flow of an electrolyte stream, wherein the electrolyte stream comprises an electrolyte and an iron-containing feedstock; an anode and a cathode positioned in contact with the channel; and a source of a magnetic field positioned in proximity to the cathode, wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at a surface of the cathode and in the magnetic field of the source, and wherein the at least a portion of the iron-containing feedstock is electrochemically reduced to the iron metal at a current efficiency of at least 0.75, wherein the current efficiency is a ratio of charge used for the reduction of the iron-containing feedstock to a total charge provided to the cathode.

2 . The electrochemical reactor of claim 1 , wherein the iron metal comprises an iron metal powder.

3 . The electrochemical reactor of claim 1 , wherein the iron-containing feedstock comprises hematite, maghemite, magnetite, goethite, limonite, pyrite, red mud, or a combination thereof.

4 . The electrochemical reactor of claim 1 , wherein the iron-containing feedstock comprises magnetite or hematite.

5 . The electrochemical reactor of claim 1 , wherein the electrochemical reactor reduces at least a portion of the iron-containing feedstock to an iron metal powder at the surface of the cathode and in the magnetic field of the source.

6 . The electrochemical reactor of claim 1 , wherein the electrolyte comprises an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof.

7 . The electrochemical reactor of claim 1 , wherein the alkali hydroxide, the organic hydroxide, or the combination thereof is present in the aqueous solution in an amount from 20 to 50 weight percent, based on a total weight of the electrolyte.

8 . The electrochemical reactor of claim 1 , wherein the electrochemical reactor is operated at a temperature of 50° C. to 140° C.

9 . The electrochemical reactor of claim 1 , wherein the electrochemical reactor is configured to flow an electrolyte stream through the channel in a unidirectional flow from a region of the channel upstream of the cathode and the anode to a region of the channel downstream of the cathode and the anode during electrochemical reduction of the iron-containing feedstock.

10 . The electrochemical reactor of claim 1 , wherein the electrolyte stream comprises from 0.1 to 30 weight percent of the iron-containing feedstock, based on a total weight of the electrolyte stream.

11 . The electrochemical reactor of claim 1 , wherein the source comprises an electromagnet, a permanent magnet, an electropermanent magnet, or a combination thereof.

12 . The electrochemical reactor of claim 1 , wherein the source is positioned external to the channel comprising the electrolyte stream, wherein the source does not contact the electrolyte stream.

13 . The electrochemical reactor of claim 1 , wherein at least a portion of the source is positioned within the channel comprising the electrolyte stream.

14 . The electrochemical reactor of claim 1 , wherein the cathode comprises aluminum, carbon, molybdenum, nickel, titanium, iron, chromium, an alloy thereof, or a combination thereof; or
wherein the anode comprises carbon, titanium, lead, nickel, platinum, iridium, ruthenium, tantalum, niobium, zirconium, vanadium, hafnium, aluminum, cobalt, antimony, tungsten, an alloy thereof, an oxide thereof, or a combination thereof; or a combination thereof.

15 . The electrochemical reactor of claim 1 , wherein a current density at the cathode for the reduction of the iron-containing feedstock is from 40 to 5,000 milliamperes per square centimeter, based on a total area of the cathode.

16 . The electrochemical reactor of claim 1 , wherein the channel is arranged vertically.

17 . The electrochemical reactor of claim 1 , further comprising a separation unit disposed downstream of the channel, wherein the separation unit is configured to separate at least a portion of the iron metal from the electrolyte stream.

18 . An electrochemical reactor, comprising:
a channel for containing and directing flow of an electrolyte stream, wherein the electrolyte stream comprises an electrolyte and an iron-containing feedstock; an anode and a cathode positioned in contact with the channel; and a source of a magnetic field positioned in proximity to the cathode, wherein the electrochemical reactor electrochemically reduces at least a portion of the iron-containing feedstock to an iron metal at a surface of the cathode and in the magnetic field of the source, and wherein the iron-containing feedstock comprises magnetite or hematite.

19 . The electrochemical reactor of claim 18 , wherein the iron-containing feedstock is not subjected to electrochemical reduction before the electrochemical reduction in the magnetic field.

20 . The electrochemical reactor of claim 18 , wherein the at least a portion of the iron-containing feedstock is electrochemically reduced to the iron metal at a current efficiency of at least 0.75, wherein the current efficiency is a ratio of charge used for the reduction of the iron-containing feedstock to a total charge provided to the cathode.

21 . The electrochemical reactor of claim 18 ,
i) wherein the iron metal comprises an iron metal powder; ii) wherein the iron-containing feedstock further comprises maghemite, goethite, limonite, pyrite, red mud, or a combination thereof; iii) wherein the iron-containing feedstock consists essentially of magnetite or hematite; iv) wherein the electrochemical reactor reduces at least a portion of the iron-containing feedstock to an iron metal powder at the surface of the cathode and in the magnetic field of the source; v) wherein the electrolyte comprises an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof; vi) wherein the alkali hydroxide, the organic hydroxide, or the combination thereof is present in the aqueous solution in an amount from 20 to 50 weight percent, based on a total weight of the electrolyte; vii) wherein the electrochemical reactor is operated at a temperature of 50° C. to 140° C.; viii) wherein the electrolyte stream comprises from 0.1 to 30 weight percent of the iron-containing feedstock, based on a total weight of the electrolyte stream; ix) wherein the source comprises an electromagnet, a permanent magnet, an electropermanent magnet, or a combination thereof; x) wherein the source is positioned external to the channel comprising the electrolyte stream, wherein the source does not contact the electrolyte stream; xi) wherein at least a portion of the source is positioned within the channel comprising the electrolyte stream; xii) wherein the cathode comprises aluminum, carbon, molybdenum, nickel, titanium, iron, chromium, an alloy thereof, or a combination thereof; xiii) wherein the anode comprises carbon, titanium, lead, nickel, platinum, iridium, ruthenium, tantalum, niobium, zirconium, vanadium, hafnium, aluminum, cobalt, antimony, tungsten, an alloy thereof, an oxide thereof, or a combination thereof; xiv) wherein a current density at the cathode for the reduction of the iron-containing feedstock is from 40 to 5,000 milliamperes per square centimeter, based on a total area of the cathode; xv) wherein the channel is arranged vertically;

Assignees

• Form Energy Inc

Inventors

• Rathert Janna
• Manser Joseph S
• Sokol Julia

Classifications

• C25C7/04

  Diaphragms; Spacing elements · CPC title

• C25D3/20

  of iron · CPC title

• C25C1/06 Primary

  or iron group metals, refractory metals or manganese · CPC title

• C25C7/06 Primary

  Operating or servicing · CPC title