Smelting process and apparatus

• US 10,451,348 B2
• Filed: 12/04/2014
• Issued: 10/22/2019
• Est. Priority Date: 12/06/2013
• Status: Active Grant

• Current Assignee: TATA Steel Limited
• Original Assignee: TATA Steel Limited
• Inventors: Davis, Mark Preston, Pilote, Jacques
• Primary Examiner(s): Kastler, Scott R
• Application Number:
  US15/039,456
• Publication Number:
  US 20170176104A1
• Time in Patent Office: 1,783 Days
• Field of Search: 266193
• CPC Class Codes: C21C 5/46 Details or accessories
• CPC Class Codes: C21C 5/5241 in an inductively heated furnace
• CPC Class Codes: C21C 5/54 Processes yielding slags of special composition
• CPC Class Codes: C21C 7/076 Use of slags or fluxes as treating agents C21C7/06, C21C7/064, C21C7/068 take precedence
• CPC Class Codes: F27B 1/14 Arrangements of linings linings in general F27D1/00
• CPC Class Codes: F27B 3/24 Cooling arrangements
• CPC Class Codes: F27D 1/12 incorporating cooling arrangements constructions of tube assemblies in general F28
• CPC Class Codes: F27D 9/00 Cooling of furnaces or of charges therein F27D1/00, F27D3/00 take precedence
• CPC Class Codes: Y02P 10/20 Recycling
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A smelting vessel (4) for producing molten metal includes a refractory lined hearth that in use is in contact with molten slag or molten metal in the smelting vessel, and the hearth includes a plurality of heat pipes (2.1) positioned in a refractory lining of at least a part of the hearth for cooling the refractory lining.

Claims

1. A smelting vessel for producing molten metal including a refractory lined hearth that in use is in contact with molten slag or molten metal in the vessel, a passageway for discharging the molten metal to a forehearth, with the hearth including an upper part defined above the passageway that in use is in contact with molten slag in a slag zone in the vessel and a lower part defined up to and including the passageway that in use is in contact with molten metal in a metal zone in the vessel, with the hearth including (a) a slag zone cooler positioned in a refractory lining of the upper part of the hearth for cooling the refractory lining and (b) a plurality of heat pipes positioned in a refractory lining of the upper part of the hearth for cooling the refractory lining, and with the heat pipes being positioned in a plurality of radially spaced-apart rings completely around the hearth, wherein an upper section of each of the plurality of heat pipes are in heat transfer relationship with the slag zone cooler for transferring heat from the plurality of heat pipes to the slag zone cooler.

2. The vessel defined in claim 1 wherein the heat pipes include lower sections that extend vertically in the refractory lining.

3. The vessel defined in claim 2 wherein the lower sections of the heat pipes are curve shaped having regard to the geometry of the hearth.

4. The vessel defined in claim 2 wherein the lower sections of the heat pipes are parallel to each other.

5. The vessel defined in claim 2 wherein the lower sections of the heat pipes are spaced apart from each other.

6. The vessel defined in claim 5 wherein the spacing of the lower sections of the heat pipes is the same in one section of the hearth and different in another section of the hearth.

7. The vessel defined in claim 1 wherein the length of the heat pipes increase with radial spacing of the heat pipes from an inner surface of the upper part of the hearth in which the heat pipes are located.

8. The vessel defined in claim 1 wherein the heat pipes include upper sections that are arranged to extend radially in the vicinity of the slag zone cooler to maximize heat transfer to the slag zone cooler.

9. The vessel defined in claim 8 wherein the heat pipes are generally L-shaped or hockey-stick shaped with vertically extending lower sections and radially or generally radially extending upper sections.

10. The vessel defined in claim 1 includes a device for tapping molten metal and a device for tapping slag from the vessel, one or more than one lance for supplying solid feed materials including solid metalliferous material and/or carbonaceous material into the vessel, and one or more than one lance for supplying an oxygen-containing gas into the vessel to post-combust gaseous reaction products generated in the direct smelting process.

11. The vessel defined in claim 10 wherein the device for tapping molten metal is the forehearth.

12. The vessel defined in claim 1 includes a smelt cyclone for partially reducing and partially melting solid metalliferous material for the vessel.

13. The vessel defined in claim 1 wherein the slag zone cooler comprises a plurality of cooler elements and is formed as a ring within and extending around the circumference of the hearth.

14. The vessel defined in claim 13 wherein each cooler element comprises a hollow open backed cast shell structure having a base wall, a pair of side walls, a front wall and a top wall formed integrally in the cast shell structure and incorporating coolant flow passages for flow of coolant therethrough.

15. A process for smelting a metalliferous feed material comprising smelting the metalliferous feed material in a molten bath in the smelting vessel defined in claim 1.

16. The process defined in claim 15 includes (a) at least partially reducing and partially melting the metalliferous feed material in a smelt cyclone and (b) completely smelting the at least partially reduced/melted material in the molten bath of the smelting vessel.