Methods and systems for converting metal oxides to metal using metal carbide as an intermediate

Patent metadata

Field	Value
Publication number	US-12129176-B2
Application number	US-202117344406-A
Country	US
Kind code	B2
Filing date	Jun 10, 2021
Priority date	Jun 10, 2021
Publication date	Oct 29, 2024
Grant date	Oct 29, 2024

Abstract

Systems and methods for converting metal oxide to metal using metal carbide as an intermediate, include: reacting the metal oxide with carbon to produce the metal carbide, wherein the metal carbide is in a form of powder or pellets; and subjecting the metal carbide produced from the metal oxide and the carbon to electrolysis in an electrorefiner to produce and purify the metal.

First claim

What is claimed is:

1. A method for converting metal oxide to metal using metal carbide as an intermediate, the method comprising:
reacting the metal oxide with carbon to produce the metal carbide, wherein the metal carbide is in a form of powder or pellets; and
subjecting the metal carbide produced from the metal oxide and the carbon to electrolysis in a first electrorefiner to produce and purify the metal, wherein the electrolysis comprises:
providing the first electrorefiner into which the metal carbide is transferred, the first electrorefiner comprising a bath vessel holding a dry salt mixture, the dry salt mixture comprising a dry salt medium, and the dry salt mixture is configured to be heated to form a molten salt bath;
heating the dry salt mixture to form the molten salt bath;
disposing a cathode assembly into the molten salt bath;
depositing the metal carbide into an anode feed basket and disposing the anode feed basket with the metal carbide therein into the molten salt bath; and
coupling a power supply to the anode feed basket and the cathode assembly, wherein the power supply produces a current flow causing oxidization of the metal at the anode feed basket, and reduction of the metal on the cathode assembly as electrorefined dendritic metal which includes salt, wherein graphite and salt accumulates in the anode feed basket;
the method further comprising processing the electrorefined dendritic metal which includes salt in a salt recovery chamber to evaporate the salt from the dendritic metal by heating to between about 700° C. and about 1100° C., and
processing the anode feed basket including the accumulated graphite and salt therein in the salt recovery chamber to evaporate the salt from the anode feed basket by heating to between about 700° C. and about 900° C.

2. The method of claim 1 , comprising reacting the metal oxide with the carbon under vacuum and at an elevated temperature between about 1500° C. to and about 1800° C. to produce the metal carbide.

3. The method of claim 2 , wherein the metal oxide comprises metal oxide powder or pellets and the carbon comprises graphite powder or pellets, and blending the metal oxide powder or pellets and the graphite powder or pellets to produce a blended mixture of the metal oxide and the carbon, which is heated at the elevated temperature to produce the metal carbide.

4. The method of claim 3 , comprising ball-milling of the metal oxide powder or pellets and the graphite powder or pellets to produce a homogenized mixture, which is heated at the elevated temperature to produce the metal carbide.

5. The method of claim 1 , wherein the metal oxide comprises at least one metal oxide selected from the group consisting of oxides of rare earth and actinide metals.

6. The method of claim 1 , wherein the metal carbide comprises at least one metal carbide selected from the group consisting of carbides of Hf, Th, U, Ln, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.

7. The method of claim 3 , wherein the metal oxide is uranium oxide and the metal carbide is uranium carbide.

8. The method of claim 1 , comprising:
after evaporating the salt from the dendritic metal, consolidating the dendritic metal by heating to between about 1100° C. and about 1500° C. to melt the dendrites and produce bulk metal.

9. The method of claim 1 , comprising providing a salt recycling stream from the salt recovery chamber to the first electrorefiner, and a graphite recycling stream from the salt recovery chamber to an initial feed of graphite powder or pellets to a feed preparation chamber.

10. The method of claim 9 , comprising removal of the accumulated graphite from the anode feed basket returning the anode feed basket now clean to the first electrorefiner.

11. The method of claim 8 , comprising further purifying the bulk metal by further electrolysis in a second electrorefiner.

12. The method of claim 11 , wherein the further electrolysis comprises:
providing the second electrorefiner, the second electrorefiner comprising a second bath vessel holding a second dry salt mixture, the second dry salt mixture comprising a second dry salt medium, and the second dry salt mixture is configured to be heated to form a second molten salt bath;
heating the second dry salt mixture to form the second molten salt bath;
disposing a second cathode assembly into the second molten salt bath;
depositing the bulk metal into the molten salt bath for further purification; and
coupling a second power supply to the bulk metal and the cathode assembly, wherein the second power supply produces a second current flow; and wherein the bulk metal is further electrorefined.

13. The method of claim 12 , comprising providing a second salt recycling stream from the salt recovery chamber to the second electrorefiner.

14. The method of claim 12 , comprising providing the further refined bulk metal and salt to the salt recovery chamber for removal of the salt from the further refined bulk metal.

15. The method of claim 1 , wherein the dry salt medium comprises a dry salt medium eutectic, and the dry salt mixture is heated to melt the eutectic and form the molten salt bath, which is a molten salt eutectic bath.

16. The method of claim 15 , wherein the dry salt medium comprises one or more of LiCl, NaCl, KCl, RbCl, CsCl, MgCl 2 , CaCl 2 , SrCl 2 and BaCl 2 .

Assignees

• Cons Nuclear Security Llc

Inventors

• Holland Justin Matthew

Classifications

• C25C3/34

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

• C25C5/04

  from melts · CPC title

• C25C7/025 Primary

  used in cells for the electrolysis of melts · CPC title

• C25C7/06

  Operating or servicing · CPC title

• C01B32/914 Primary

  Carbides of single elements · CPC title