Hearth for a metallurgical furnace having an improved wall lining

Patent metadata

Field	Value
Publication number	US-9587882-B2
Application number	US-201113812335-A
Country	US
Kind code	B2
Filing date	Jul 26, 2011
Priority date	Jul 27, 2010
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A hearth for a metallurgical reactor, in particular for a blast furnace, has an outer shell and an annular wall lining of refractory material inside the shell, the wall lining having a lower region with a multi-layered construction, a radially inner layer faces the interior of the hearth and includes at least one inner ring of refractory elements, radially outer layer faces the outer shell and has at least one outer ring of refractory elements, where in the at least one inner ring elements are made of a first carbonaceous refractory material that is different from one or more carbonaceous refractory materials of the elements in the outer layer such that, the first refractory material contains, in a proportion of at least 5% by mass in total, at least one property-enhancing additive other than metallic silicon or silicon carbide. In beneficial combination therewith, the at least one inner ring has a wall thickness of less than 45%, of the corresponding total wall thickness of the wall lining.

First claim

The invention claimed is:

1. A hearth for a metallurgical reactor, said hearth comprising:
an outer shell and an annular wall lining having a height that is arranged inside said shell and made of refractory material for containing a bath including molten metal;
said wall lining having a lower region comprising:
a radially inner layer facing the interior of said hearth and comprising a plurality of inner rings of refractory elements, said inner rings having outer faces disposed away from the interior of said hearth, said outer faces aligned in a vertical direction with one another;
a radially outer layer facing said outer shell and comprising a plurality of outer rings of refractory elements, said outer rings having inner faces disposed away from said outer shell, said inner faces aligned in a vertical direction with one another and opposing and spaced from the outer faces of said inner rings to define a continuous, substantially vertical, cylindrical, intermediate gap between them;
at least one of said inner rings comprising elements made of a first carbonaceous refractory material different from one or more carbonaceous refractory materials of which said elements of said outer layer are made;

wherein said first refractory material contains, in a proportion of at least 5% by mass in total, at least one additive other than metallic silicon or silicon carbide, and
wherein said at least one inner ring has a wall thickness of less than 45%, of the total wall thickness along the height of said wall lining, and
wherein at least one inner ring comprises elements having an anchoring portion on their outer faces and at least one outer ring comprises elements having an anchoring portion on their inner faces, each pair of anchoring portions cooperating for securing an element of said inner ring against dislocation in a radially inward direction and a circumferential direction with respect to a corresponding element of said outer ring,
and
wherein said first refractory material contains 50-85% by mass of carbon and, as an additional additive, 5-20% by mass in total of at least one material selected from the group consisting of metallic titanium, titanium carbide, titanium nitride, titanium carbonitride, and titanium oxide.

2. The hearth according to claim 1 , wherein said first refractory material further contains
5-15% by mass in total of metallic silicon; and
5-15% by mass in total of alumina.

3. The hearth according to claim 1 , wherein one of said cooperating anchoring portions comprises a recess having a minimum circumferential measure and the other of said anchoring portions comprises a protrusion having a maximum circumferential measure recess engaged within the recess, said maximum circumferential measure of said protrusion being greater than said minimum circumferential measure of said recess, and wherein said protrusion and said recess engage to secure said inner ring against dislocation in a radially inward direction and a circumferential direction with respect to said outer ring.

4. The hearth according to claim 1 , wherein said lower region further comprises a granular intermediate ramming layer disposed in said intermediate gap that extends vertically in between said outer layer and said inner layer.

5. The hearth according to claim 4 , wherein said ramming layer is made of a composition that comprises:
a fine granular phase consisting essentially of graphite;
a coarse granular phase consisting essentially of microporous carbon.

6. The hearth according to claim 3 , wherein said at least one outer ring comprises large-width blocks made of a second carbonaceous refractory material, said at least one outer ring comprising large-width blocks that have a width greater than 65% of the total wall thickness along the height of said wall lining, and in that said at least one inner ring comprises small-width blocks having a width of less than 35% of the total wall thickness along the height of said wall lining.

7. The hearth according to claim 1 , wherein
said at least one inner ring comprises small-width blocks that have a mushroom-shaped anchoring protrusion comprising said protrusion on their outer face; and
said at least one outer ring comprises large-width blocks that have a conjugated mushroom-shaped anchoring recess comprising said recess on their inner face;
said anchoring protrusions and said anchoring recesses being engaged and cooperating to secure said small-width blocks against dislocation in the radially inward direction and the circumferential direction with respect to said large-width blocks.

8. The hearth according to claim 1 , wherein said at least one inner ring comprises small-width blocks of a first type and small-width blocks of a second type arranged in alternating fashion, said first type comprising an anchoring portion and said second type being devoid of anchoring portion, said first and second type of small-width blocks having respective conjugated horizontal cross-section that cooperate to secure said second type of small-width blocks.

9. The hearth according to claim 1 , wherein said first refractory material has a thermal conductivity of at least 15 W/mK at 600° C.

10. The hearth according to claim 1 , wherein said at least one inner ring is made, in radial direction, of a single refractory block having a width equal to the thickness of said inner ring and in that said at least one outer ring is made, in radial direction, of a single refractory block having a width equal to the thickness of said outer ring.

11. The hearth according to claim 1 , wherein said inner layer comprises a sequence of at least two vertically stacked inner rings of refractory elements comprising refractory blocks, made of said first refractory material.

12. The hearth according to claim 1 , wherein
said inner layer forms the hot face of said lining and, at the level of the lowermost inner ring, said inner layer has a thickness in the range of 200 mm to 600 mm, and said wall lining has a total wall thickness of less than 1350 mm; or
said wall lining further comprises an annular ceramic layer provided on the inside face of said inner layer, at the level of the lowermost inner ring, said inner layer has a thickness (d) in the range of 250 mm to 400 mm and said wall lining, including said ceramic layer, has a total wall thickness of less than 1500 mm.

13. The hearth according to claim 1 , wherein the metallurgical reactor comprises a blast furnace.

14. A hearth for a metallurgical reactor, said hearth comprising:
an outer shell and an annular wall lining having a height that is arranged inside said shell and made of refractory material for containing a bath including molten metal;
said wall lining having a lower region comprising:
a radially inner layer facing the interior of said hearth and comprising at least one inner ring of refractory elements;
a radially outer layer facing said outer shell and comprising at least one outer ring of refractory elements, the inner ring disposed radially entirely within the outer ring;
said at least one inner ring comprising elements made of a first carbonaceous refractory material different from one or more carbonaceous refractory materials of which said elements of said outer layer are made;

wherein said first refractory material contains, in a proportion of at least 5% by mass in total, at least one additive other than metallic silicon or silicon carbide, and
wherein said at least one inner ring comprises elements having an anchoring portion on their outer face and said at least one outer ring comprises elements having an anchoring portion on their inner face, each pair of anchorin

Assignees

• Piret Jacques
• Kass Gilles
• Wurth Paul Sa

Inventors

• Piret Jacques
• Kass Gilles

Classifications

• F27B1/14 Primary

  Arrangements of linings · CPC title

• F27D1/14

  Supports for linings (supports for monolithic linings F27D1/10) · CPC title

• C21B7/06

  Linings for furnaces · CPC title

• C21C5/44

  Refractory linings · CPC title

• F27D1/0006

  Linings or walls formed from bricks or layers with a particular composition or specific characteristics · CPC title