System and process for sustainable electrowinning of metal

Patent metadata

Field	Value
Publication number	US-2023279572-A1
Application number	US-202218054277-A
Country	US
Kind code	A1
Filing date	Nov 10, 2022
Priority date	Apr 26, 2022
Publication date	Sep 7, 2023
Grant date	—

Abstract

A process for production of metal(s) by molten-salt electrolysis includes direct non-carbothermic chlorinating of ore containing metal oxide(s) to produce metal chloride(s); and electrolysis of molten salt(s) of the metal chloride(s) for electrowinning of metal(s) product.

First claim

1 - 46 . (canceled)

47 . A system for production of metal(s) from a metal ore containing a metal oxide, the system comprising:
a chlorination reactor configured for non-carbothermic chlorination of ore containing metal oxide to metal chloride(s); an electrolysis reactor configured for molten salt electrolysis of the metal chloride(s) to metal and chlorine gas; and optionally a reactor for converting the chlorine gas generated in the electrolysis reactor to HCl, the HCl being optionally transferred to the chlorination reactor for non-carbothermic chlorination of metal oxides.

48 . The system of claim 47 , further comprising a means for separating the metal from the molten salt, wherein the metal is in solid or liquid form.

49 . The system of claim 47 , where the chlorination reactor includes HCl converted from the generated chlorine gas at a molarity effective to convert the metal oxide to metal chloride(s).

50 . The system of claim 47 , wherein the ore comprises an oxide of at least one of Nd, Dy, Pr, La, Ce, or Fe.

51 . The system of claim 47 , wherein the electrolysis reactor includes an electrochemical cell, the electrochemical cell including an anode and cathode provided in a molten salt, the anode being non-consumable and/or dimensionally stable during electrolysis.

52 . The system of claim 51 , wherein the anode comprises at least one of titanium or graphite optionally coated with mixed-metal oxide.

53 . The system of claim 51 , wherein the cathode comprises an inert metal.

54 . The system of claim 53 , wherein the inert metal includes tungsten or molybdenum.

55 . The system of claim 47 , wherein the electrolysis reactor is configured for batch molten salt electrolysis and wherein the molten salt electrolysis is conducted at temperature effective for electrodeposition of the metal on the cathode.

56 . The system of claim 55 , wherein the molten salt includes a eutectic of at least one of LiCl, KCl, NaCl, CsCl, MgCl 2 , SrCl 2 , BaCl 2 or CaCl 2 ) and the molten salt electrolysis is conducted at a temperature of about 400° C. to about 800° C.

57 . The system of claim 51 , wherein the anode and cathode are separated from one another in the electrochemical cell and the electrochemical cell further includes a porous separator or diaphragm positioned between and separating the anode and cathode, the separator or diaphragm inhibiting redox shuttling and back reaction between metal plated on the cathode and chlorine gas generated at the anode.

58 . The system of claim 57 , wherein the separator or diaphragm includes a ceramic with a porosity of about 10% to about 60%.

59 . The system of claim 47 , wherein the electrolysis reactor includes at least one bipolar electrode having a cathode first surface and an opposite anode surface.

60 . The system of claim 47 , wherein the electrolysis reactor includes a plurality of bipolar electrodes.

61 . The system of claim 59 , wherein the bipolar electrode(s) comprise graphite electrodes, the graphite electrodes being arranged in at least one stack.

62 . The system of claim 59 , wherein the electrolysis reactor is configured for continuous molten salt electrolysis.

63 . The system of claim 60 , wherein the molten salt electrolysis is conducted at temperature effective to form a molten metal that accumulates in the electrolysis reactor and wherein the accumulated metal is removed periodically from or continuously from the electrolysis reactor.

64 . The system of claim 63 , the molten salt includes a eutectic of SrCl 2 , BaCl 2 , and optionally at least one of LiCl, KCl, NaCl, CsCl, MgCl 2 , or CaCl 2 ) and the molten salt electrolysis is conducted at a temperature of at least about 800° C.

65 . The system of claim 47 , further comprising a current source for supplying current effective for molten salt electrolysis of the metal chloride(s) to metal and chlorine gas.

66 . The system of claim 47 , wherein electrolysis is conducted at a current density of about 50 mA/cm 2 to about 1 A/cm 2 .

67 . The system of claim 47 , wherein the ore comprises neodymium oxide, such as Nd 2 O 3 .

68 . The system of claim 47 , producing substantially no CO 2 or perfluorocarbon emission.

Assignees

• Univ Case Western Reserve

Inventors

• Akolkar Rohan

Classifications

• C25C1/22 Primary

  of metals not provided for in groups C25C1/02 - C25C1/20 · CPC title

• C25C7/025

  used in cells for the electrolysis of melts · CPC title

• C25C3/34

  of metals not provided for in groups C25C3/02 - C25C3/32 · CPC title

• C25C3/00

  Electrolytic production, recovery or refining of metals by electrolysis of melts (C25C5/00 takes precedence) · CPC title

• C25C3/28

  of titanium · CPC title