Electroslag smelting system and method

• US 20080130704A1
• Filed: 10/31/2007
• Published: 06/05/2008
• Est. Priority Date: 11/30/2006
• Status: Abandoned Application

• Current Assignee: Battery Reduction Systems, LLC
• Original Assignee: Battery Reduction Systems, LLC
• Inventors: LaPoint, Brian A., LaPoint, Albert E.
• Application Number:
  US11/981,328
• Publication Number:
  US 20080130704A1
• Time in Patent Office: Days
• US Class Current: 373/55
• CPC Class Codes: C22B 13/02 by dry processes
• CPC Class Codes: C22B 13/025 Recovery from waste materials
• CPC Class Codes: C22B 13/06 Refining
• CPC Class Codes: C22B 4/04 Heavy metals C22B4/005 takes precedence
• CPC Class Codes: C22B 4/08 Apparatus C22B4/005 takes precedence; electric heating elements H05B
• CPC Class Codes: C22B 9/18 Electroslag remelting electroslag casting B22D23/10
• CPC Class Codes: H05B 3/60 Heating arrangements wherein the heating current flows through granular powdered or fluid material, e.g. for salt-bath furnace, electrolytic heating H05B3/38 takes precedence
• CPC Class Codes: Y02P 10/20 Recycling

Abstract

A system and a method for electroslag smelting, involving a furnace having a wall, an internal atmosphere, and an external atmosphere; a trough for accommodating an ore being smelted into a molten metal and a slag, the trough being disposed within the furnace; and a carbon electrode having a proximal end and a distal end, the electrode distal end being disposed in the trough, the electrode being submersible in the molten metal, and the electrode being separated from the slag by a ceramic barrier.

Claims

1. A system for electroslag smelting, comprising:

a furnace having a wall, an internal atmosphere, and an external atmosphere;

a trough for accommodating an ore being smelted into a molten metal and a slag, the trough being disposed within the furnace, and the trough having an outer housing and an inner liner; and

a carbon electrode having a proximal end and a distal end, the electrode distal end being disposed in the trough, the electrode being submersible in the molten metal, and the electrode being separated from the slag by a ceramic barrier.

2. A system, as recited in claim 1, further comprising a stainless steel bus bar having a proximal end and a distal end, the stainless steel bus bar distal end being coupled to the electrode proximal end at a position above a level of the molten metal, the stainless steel bus bar proximal end extending through the furnace wall and into the external atmosphere, the stainless steel bus bar providing mechanical stability to the electrode, the stainless steel bus bar dissipating heat from the electrode, and the stainless steel bus bar nominally conducting heat from the furnace.

3. A system, as recited in claim 2, further comprising a copper bus bar having a proximal end and a distal end, the copper bus bar distal end being coupled to the stainless steel bus bar proximal end in the external atmosphere, and the copper bus bar dissipating heat from the stainless steel bus bar at a greater rate than the stainless steel bus bar nominally conducting heat from the furnace.

4. A system, as recited in claim 3,

wherein a thermal gradient is effected across the stainless steel bus bar, and

wherein the copper bus bar radiates heat to the external atmosphere at a high rate.

5. A system, as recited in claim 4,

whereby a corrosion of the electrode is minimized, and

whereby a low temperature equilibrium is effected at an electrical source connection.

6. A system, as recited in claim 1, wherein the molten metal comprises lead.

7. A system, as recited in claim 1, wherein the slag comprises sodium sulfate.

8. A system, as recited in claim 1, wherein the ceramic barrier comprises a refractory material.

9. A system, as recited in claim 7, wherein the refractory material comprises aluminum oxide

10. A system, as recited in claim 1, wherein the trough comprises a vacuum port disposed therethrough for facilitating removal of any residual gases from the molten metal.

11. A system, as recited in claim 1, wherein the trough comprises a thermocouple bracket assembly for accommodating at least one thermocouple.

12. A system, as recited in claim 1, wherein the carbon electrode comprises a stainless steel foil disposed on at least one outer surface.

13. A system as recited in claim 1, further comprising:

a stainless steel bus bar having a proximal end and a distal end, the stainless steel bus bar distal end being coupled to the electrode proximal end at a position above a level of the molten metal, the stainless steel bus bar proximal end extending through the furnace wall and into the external atmosphere, the stainless steel bus bar providing mechanical stability to the electrode, the stainless steel bus bar dissipating heat from the electrode, and the stainless steel bus bar nominally conducting heat from the furnace; and

a copper bus bar having a proximal end and a distal end, the copper bus bar distal end being coupled to the stainless steel bus bar proximal end in the external atmosphere, and the copper bus bar dissipating heat from the stainless steel bus bar at a greater rate than the stainless steel bus bar nominally conducting heat from the furnace,

a thermal gradient being effected across the stainless steel bus bar, the copper bus bar radiating heat to the external atmosphere at a high rate,

a corrosion of the electrode being minimized, and

a low temperature equilibrium being effected at an electrical source connection.

14. A method of electroslag smelting, comprising the steps of:

providing a furnace having a wall, an internal atmosphere, and an external atmosphere;

providing a trough for accommodating the ore being smelted into a molten metal and a slag, the trough being disposed within the furnace, and the trough having an outer housing and an inner liner;

providing a carbon electrode having a proximal end and a distal end, the electrode distal end being disposed in the trough, the electrode being submersible in the molten metal, and the electrode being separated from the slag by a ceramic barrier; and

smelting the ore in the furnace, thereby providing a molten metal and a slag, the electrode being submersed in the molten metal, and the electrode being separated from the slag by the ceramic barrier.

15. A method, as recited in claim 14, further comprising the step of providing a stainless steel bus bar having a proximal end and a distal end, the stainless steel bus bar distal end being coupled to the electrode proximal end at a position above a level of the molten metal, the stainless steel bus bar proximal end extending through the furnace wall and into the external atmosphere, the stainless steel bus bar providing mechanical stability to the electrode, the stainless steel bus bar dissipating heat from the electrode, and the stainless steel bus bar nominally conducting heat from the furnace.

16. A method, as recited in claim 15, further comprising the step of providing a copper bus bar having a proximal end and a distal end, the copper bus bar distal end being coupled to the stainless steel bus bar proximal end in the external atmosphere, and the copper bus bar dissipating heat from the stainless steel bus bar at a greater rate than the stainless steel bus bar nominally conducting heat from the furnace.

17. A method, as recited in claim 16,

thereby effecting a thermal gradient across the stainless steel bus bar, and

thereby radiating heat via the copper bus bar to the external atmosphere at a high rate.

18. A method, as recited in claim 17,

thereby minimizing a corrosion of the electrode, and

thereby effecting a low temperature equilibrium at an electrical source connection.

19. A method, as recited in claim 14, wherein the smelting step comprises providing the molten metal with lead.

20. A method, as recited in claim 14, wherein the smelting step comprises providing the slag with sodium sulfate.

21. A method, as recited in claim 14, wherein the smelting step comprises providing the ceramic barrier with a refractory material.

22. A method, as recited in claim 20, the smelting step comprises providing the ceramic barrier with a refractory material comprising aluminum oxide.

23. A method, as recited in claim 14, wherein the trough providing step comprises providing a vacuum port disposed therethrough for facilitating removal of any residual gases from the molten metal.

24. A method, as recited in claim 14, wherein the trough providing step comprises providing a thermocouple bracket assembly for accommodating at least one thermocouple.

25. A method, as recited in claim 14, wherein the carbon electrode providing step comprises providing a stainless steel foil disposed on at least one outer surface.

26. A method, as recited in claim 14, further comprising the steps of:

providing a stainless steel bus bar having a proximal end and a distal end, the stainless steel bus bar distal end being coupled to the electrode proximal end at a position above a level of the molten metal, the stainless steel bus bar extending through the furnace wall an into the external atmosphere, the stainless steel bus bar providing mechanical stability to the electrode, the stainless steel bus bar dissipating heat from the electrode, the stainless steel bus bar nominally conducting heat from the furnace; and

providing a copper bus bar having a proximal end and a distal end, the copper bus bar distal end being coupled to the stainless steel bus bar proximal end in the external atmosphere, and the copper bus bar dissipating heat from the stainless steel bus bar at a greater rate than the stainless steel bus bar nominally conducting heat from the furnace,

thereby effecting a thermal gradient across the stainless steel bus bar, the copper bus bar radiating heat to the external atmosphere at a high rate,

thereby minimizing corrosion of the electrode, and

thereby effecting a low temperature equilibrium at an electrical source connection.

27. A method of fabricating an electroslag smelting system, comprising the steps of:

providing a furnace having a wall, an internal atmosphere, and an external atmosphere;

providing a trough for accommodating the ore being smelted into a molten metal and a slag, the trough being disposed within the furnace, and the trough having an outer housing and an inner liner;

providing a carbon electrode having a proximal end and a distal end, the electrode distal end being disposed in the trough, the electrode being submersible in the molten metal, and the electrode being separated from the slag by a ceramic barrier.

28. A method, as recited in claim 27, further comprising the step of providing a stainless steel bus bar having a proximal end and a distal end, the stainless steel bus bar distal end being coupled to the electrode proximal end at a position above a level of the molten metal, the stainless steel bus bar proximal end extending through the furnace wall and into the external atmosphere, the stainless steel bus bar providing mechanical stability to the electrode, the stainless steel bus bar dissipating heat from the electrode, and the stainless steel bus bar nominally conducting heat from the furnace.

29. A method, as recited in claim 28, further comprising the step of providing a copper bus bar having a proximal end and a distal end, the copper bus bar distal end being coupled to the stainless steel bus bar proximal end in the external atmosphere, and the copper bus bar dissipating heat from the stainless steel bus bar at a greater rate than the stainless steel bus bar nominally conducting heat from the furnace.

30. A method, as recited in claim 29,

thereby effecting a thermal gradient across the stainless steel bus bar, and

thereby radiating heat via the copper bus bar to the external atmosphere at a high rate.

31. A method, as recited in claim 30,

thereby minimizing a corrosion of the electrode, and

thereby effecting a low temperature equilibrium at an electrical source connection.

32. A method, as recited in claim 27, wherein the smelting step comprises providing the molten metal with lead.

33. A method, as recited in claim 27, wherein the smelting step comprises providing the slag with sodium sulfate.

34. A method, as recited in claim 27, wherein the smelting step comprises providing the ceramic barrier with a refractory material.

35. A method, as recited in claim 34, wherein the smelting step comprises providing the refractory material with aluminum oxide.

36. A method, as recited in claim 27, wherein the trough providing step comprises providing a vacuum port disposed therethrough for facilitating removal of any residual gases from the molten metal.

37. A method, as recited in claim 27, wherein the trough providing step comprises providing a thermocouple bracket assembly for accommodating at least one thermocouple.

38. A method, as recited in claim 27, wherein the carbon electrode providing step comprises providing a stainless steel foil disposed on at least one outer surface.

39. A method, as recited in claim 27, further comprising the steps of:

providing a stainless steel bus bar having a proximal end and a distal end, the stainless steel bus bar distal end being coupled to the electrode proximal end at a position above a level of the molten metal, the stainless steel bus bar extending through the furnace wall an into the external atmosphere, the stainless steel bus bar providing mechanical stability to the electrode, the stainless steel bus bar dissipating heat from the electrode, the stainless steel bus bar nominally conducting heat from the furnace; and

providing a copper bus bar having a proximal end and a distal end, the copper bus bar distal end being coupled to the stainless steel bus bar proximal end in the external atmosphere, and the copper bus bar dissipating heat from the stainless steel bus bar at a greater rate than the stainless steel bus bar nominally conducting heat from the furnace,

thereby effecting a thermal gradient across the stainless steel bus bar, the copper bus bar radiating heat to the external atmosphere at a high rate,

thereby minimizing corrosion of the electrode, and

thereby effecting a low temperature equilibrium at an electrical source connection.