Apparatus for electrorefining a ferrous molten metal and method associated therewith

Patent metadata

Field	Value
Publication number	US-2023235470-A1
Application number	US-202017918938-A
Country	US
Kind code	A1
Filing date	Apr 16, 2020
Priority date	Apr 16, 2020
Publication date	Jul 27, 2023
Grant date	—

Abstract

Electrorefining cells and methods for electrorefining ferrous molten metal (e.g. steels), that includes impurities (e.g., carbon), are described. Liquid metal is provided in ladle with a molten electrolyte on top of it to form a metal-electrolyte interface. An electrode connection is put into contact with the metal for electronic conduction therewith, while a counter electrode is put into contact with the electrolyte for forming an electrolyte-counter electrode interface. Both the electrode connection and the counter electrode remain in the solid form in, and inert to, the metal and the electrolyte, respectively. The electrode connection and the counter electrode are made of an electronically conductive material. Therefore, during electrorefining operations, an electromotive force can be supplied between the electrode connection and the counter electrode so as to induce electrochemical reactions to occur at both the metal-electrolyte interface and the electrolyte-counter electrode connection, producing a ferrous molten metal depleted of the impurities.

First claim

1 . A method for electrorefining a ferrous molten metal that includes iron and impurities, the method comprising:
providing the ferrous molten metal to be refined in a treatment ladle with a molten electrolyte on top of the ferrous molten metal so as to form a metal-electrolyte interface; contacting an electrode connection made of a first electronically conductive material remaining in a solid form in, and being substantially inert to, the ferrous molten metal with the ferrous molten metal for electronic conduction therewith; contacting a counter electrode made of a second electronically conductive material remaining in a solid form in, and being substantially inert to, the molten electrolyte with the molten electrolyte so as to form an electrolyte-counter electrode interface; and
during electrorefining operations:
supplying an electromotive force between the electrode connection and the counter electrode so as to induce electrochemical reactions to occur at both the metal-electrolyte interface and the electrolyte-counter electrode interface; and
producing a ferrous molten metal depleted of the impurities.

2 . The method of claim 1 , wherein a reaction by-product is recovered at the counter electrode during the electrorefining operations.

3 . The method of claim 1 or 2 , wherein the impurities comprise carbon.

4 . The method of any one of claims 1 to 3 , wherein the impurities comprise sulfur.

5 . The method of any one of claims 1 to 4 , wherein the impurities comprise oxygen.

6 . The method of any one of claims 1 to 5 , wherein the impurities comprise phosphorus.

7 . The method of any one of claims 1 to 6 , wherein the ferrous molten metal comprises molten steel.

8 . The method of any one of claims 1 to 6 , wherein the ferrous molten metal comprises a molten iron-alloy.

9 . The method of any one of claims 2 to 8 , wherein the reaction by-product comprises silicon.

10 . The method of any one of claims 2 to 9 , wherein the reaction by-product comprises ferrosilicon.

11 . The method of any one of claims 2 to 8 , wherein the reaction by-product comprises aluminum.

12 . The method of any one of claims 3 to 11 , wherein the impurities content of the ferrous molten metal prior to the electrorefining operations is between about 0.01% and about 10%, between about 0.05% and about 5%, or between about 0.1% and about 1%.

13 . The method of any one of claims 3 to 12 , wherein the impurities content of the ferrous molten metal prior to the electrorefining operations is between about 40 ppmw and about 100 ppmw, between about 50 ppmw and about 90 ppmw, or between about 60 ppmw and about 80 ppmw.

14 . The method of any one of claims 3 to 13 , wherein the impurities content of the ferrous molten metal depleted of the impurities after the electrorefining operations have been performed is below about 100 ppmw, below about 75 ppmw, below about 50 ppmw or below about 10 ppmw.

15 . The method of any one of claims 1 to 14 , wherein the connection material has a melting temperature higher than about 1600° C., higher than about 1700° C., or higher than about 1800° C.

16 . The method of any one of claims 1 to 15 , wherein the first electronically conductive material is an electronically conducting ceramic.

17 . The method of any one of claims 1 to 16 , wherein the first electronically conductive material comprises a refractory metal boride.

18 . The method of any one of claims 1 to 17 , wherein the first electronically conductive material comprises zirconium diboride (ZrB 2 ).

19 . The method of any one of claims 1 to 18 , wherein the first electronically conductive material comprises titanium diboride (TiB 2 ).

20 . The method of any one of claims 1 to 19 , wherein the first electronically conductive material comprises hafnium diboride (HfB 2 ).

21 . The method of any one of claims 1 to 20 , wherein the first electronically conductive material comprises tantalum diboride (TaB 2 ).

22 . The method of any one of claims 1 to 21 , wherein the first electronically conductive material comprises niobium diboride (NbB 2 ).

23 . The method of any one of claims 1 to 22 , wherein the first electronically conductive material comprises vanadium diboride (VB 2 ).

24 . The method of any one of claims 1 to 23 , wherein the first electronically conductive material comprises chromium boride (CrB).

25 . The method of any one of claims 1 to 24 , wherein the first electronically conductive material comprises chromium diboride (CrB 2 ).

26 . The method of any one of claims 1 to 25 , wherein the first electronically conductive material comprises a molybdenum boride.

27 . The method of any one of claims 1 to 26 , wherein the first electronically conductive material comprises a tungsten boride.

28 . The method of any one of claims 18 to 27 , wherein the first electronically conductive material comprises between about 40% v/v and about 100% v/v, between about 50% v/v and about 95% v/v, or between about 60% v/v and about 90% v/v of zirconium diboride.

29 . The method of any one of claims 19 to 28 , wherein the first electronically conductive material comprises between about 40% v/v and about 100% v/v, between about 50% v/v and about 95% v/v, or between about 60% v/v and about 90% v/v of titanium diboride.

30 . The method of any one of claims 20 to 29 , wherein the first electronically conductive material comprises between about 40% v/v and about 100% v/v, between about 50% v/v and about 95% v/v, or between about 60% v/v and about 90% v/v of hafnium diboride.

31 . The method of any one of claims 21 to 30 , wherein the first electronically conductive material comprises between about 40% v/v and about 100% v/v, between about 50% v/v and about 95% v/v, or between about 60% v/v and about 90% v/v of tantalum diboride.

32 . The method of any one of claims 22 to 31 , wherein the first electronically conductive material comprises between about 40% v/v and about 100% v/v, between about 50% v/v and about 95% v/v, or between about 60% v/v and about 90% v/v of niobium diboride.

33 . The method of any one of claims 23 to 32 , wherein the first electronically conductive material comprises between about 40% v/v and about 100% v/v, between about 50% v/v and about 95% v/v, or between about 60% v/v and about 90% v/v of vanadium diboride.

34 . The method of any one of claims 24 to 33 , wherein the electronically conductive material comprises between about 40% v/v and about 100% v/v, between about 50% v/v and about 95% v/v, or between about 60% v/v and about 90% v/v of chromium boride.

35 . The method of any one of claims 25 to 34 , wherein the first electronically conductive material comprises between about 40% v/v and about 100% v/v, between about 50% v/v and about 95% v/v, or between about 60% v/v and about 90% v/v of chromium diboride.

36 . The method of any one of claims 26 to 35 , wherein the first electronically conductive material comprises between about 40% v/v and about 100% v/v, between about 50% v/v and about 95% v/v, or between about 60% v/v and about 90% v/v of the molybdenum boride.

37 . The method of any on

Assignees

• Governing Council Univ Toronto
• Tenova Goodfellow Inc

Inventors

• Azimi Gisele
• Judge William D
• Vittorio Scipolo

Classifications

• C25C3/34 Primary

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

• C25C7/025

  used in cells for the electrolysis of melts · CPC title

• C25C7/005

  of cells for the electrolysis of melts (C25C7/02 - C25C7/06 take precedence) · CPC title

• C21C1/00

  Refining of pig-iron; Cast iron · CPC title

• C25C7/06

  Operating or servicing · CPC title