Method for preventing early damage to furnace refractory shapes

Claim 2

In a method for preventing early damage to the refractory lining in a metallurgical furnace having an outer metallic shell, a basic refractory lining laid-up in courses against the interior of said shell, a basic refractory bottom and a refractory roof, the improvement comprising: a. laying-up a plurality of basic refractory shapes in a plurality of courses in non-critical wear areas of said refractory lining, b. laying-up a plurality of metal encased basic refractory shapes in a plurality of courses in critical wear areas of said refractory lining, said metal extending a predetermined distance beyond the hot faces of the refractOry shapes, and c. forming a layer of pulverulent basic refractory material on the surfaces of said basic refractory shapes laid-up in critical wear areas of said refractory lining.

Claim 3

The method for preventing early damage to the refractory lining in a metallurgical furnace as claimed in claim 1 wherein the basic refractory shapes in steps (a) and (b) are made from at least one material taken from the group consisting of magnesia-chrome ore and chrome ore-magnesia.

Claim 4

The method for preventing early damage to the refractory lining in a metallurgical furnace as claimed in claim 1 wherein the metal surrounding the basic refractory shapes in step (b) extends at least 2 1/2 inches beyond the hot faces of the refractory shapes.

Claim 5

The method for preventing early damage to the refractory lining in a metallurgical furnace as claimed in claim 1 wherein the layer of pulverulent basic refractory material in step (c) is about 3 inches to about 6 inches in depth.

Claim 6

In a method for preventing early damage to the refractory lining in an electric arc furnace including a metallic shell, a basic refractory lining laid-up in courses of refractory shapes along the interior of the metallic shell, a refractory-lined hearth, a movable refractory-lined roof having a plurality of ports formed therein, and a plurality of electrodes vertically movable into or out of said furnace through said ports, the improvement comprising: a. initially laying-up a plurality of basic refractory shapes having a hot face and a cold face made from at least one material taken from the group consisting of magnesia, magnesia-chrome ore mixtures, and magnesite, in non-critical wear areas in said refractory lining, b. laying-up a plurality of basic refractory shapes having hot faces and cold faces, made from at least one material taken from the group consisting of magnesia, magnesia-chrome ore mixtures, chrome ore-magnesia mixtures, and magnesite, encased in metal, which metal extends a predetermined distance beyond the hot faces of said refractory shapes in a grid-like pattern, in critical wear areas in said refractory lining, and c. forming a layer of initially pulverulent basic refractory material compatible with the basic refractory shapes, over the hot faces of the basic refractory shapes and within the confines of the metal grid extending beyond the hot faces of the basic refractory shapes whereby the pulverulent refractory material serves to protect the hot face of the metal encased refractory shapes from a detrimental heat gradient during initial operation of the furnace.

Claim 7

In a method for preventing early damage to the refractory lining in an electric arc furnace including a metallic shell, a basic refractory lining laid-up in courses of refractory shapes along the interior of the metallic shell, a refractory-lined hearth, a movable refractory-lined roof having a plurality of ports formed therein, and a plurality of electrodes vertically movable into or out of said furnace through said ports, the improvement comprising: a. initially laying-up a plurality of basic refractory shapes having a hot face and a cold face made from at least one material taken from the group consisting of magnesia, magnesia-chrome ore mixtures, and magnesite, in non-critical wear areas in said refractory lining, b. laying-up a plurality of basic refractory shapes having hot faces and cold faces, made from at least one material taken from the group consisting of magnesia, magnesia-chrome ore mixtures, chrome ore-magnesia mixtures, and magnesite, encased in metal, which metal extends a predetermined distance beyond the hot faces of said refractory shapes in a grid-like pattern, in critical wear areas in said refractory lining, and c. forming a layer of initially pulverulent basic refractory material compatible with the basic refractory shapes, over the hot faces of the basic refractory shapes and within the confines of the metal grid extending beyond the hot faces of the basic refractory shapes whereby the pulverulent refractory material serves to protect the hot face of the metal encased refractory shapes from a detrimental heat gradient during initial operation of the furnace.

Claim 8

The method for preventing early damage to the refractory lining in an electric arc furnace as claimed in claim 5 wherein the basic refractory shapes laid-up to form the refractory lining in said furnace are made from at least one material taken from the group consisting of the magnesia-chrome ore mixtures and chrome ore-magnesia mixtures.

Claim 9

The method for preventing early damage to the refractory lining in an electric arc furnace as claimed in claim 5 wherein the metal case of step (b) extends between about 2 1/2 inches to about 4 inches beyond the hot faces of the refractory shapes.

Claim 10

The method for preventing early damage to the refractory lining in an electric arc furnace as claimed in claim 5 wherein the layer of pulverulent refractory material formed in step (c) is between about 3 inches to about 6 inches in depth.

Claim 11

A composite refractory lining the interior of the wall of an electric arc furnace, said furnace including an outer metallic shell, a refractory-lined hearth, a refractory-lined removable roof having a plurality of ports, a plurality of electrodes vertically movable into or out of said furnace through said ports in said roof, said refractory wall comprising: a. a plurality of basic refractory shapes laid-up in a plurality of courses in non-critical wear areas in the refractory lining, b. a plurality of basic refractory shaPes encased in metal, said metal extending outwardly a predetermined distance from a hot face of the refractory shapes, said shapes being laid-up in a plurality of courses in critical wear areas in the refractory lining, and c. a coating upon said hot face of said metal-cased refractory shapes with a predetermined thickness of a pulverulent basic refractory material compatible with the materials in the refractory shapes.

Claim 12

A composite refractory lining the interior of the wall of an electric arc furnace, said furnace including an outer metallic shell, a refractory-lined hearth, a refractory-lined removable roof having a plurality of ports, a plurality of electrodes vertically movable into or out of said furnace through said ports in said roof, said refractory wall comprising: a. a plurality of basic refractory shapes laid-up in a plurality of courses in non-critical wear areas in the refractory lining, b. a plurality of basic refractory shaPes encased in metal, said metal extending outwardly a predetermined distance from a hot face of the refractory shapes, said shapes being laid-up in a plurality of courses in critical wear areas in the refractory lining, and c. a coating upon said hot face of said metal-cased refractory shapes with a predetermined thickness of a pulverulent basic refractory material compatible with the materials in the refractory shapes.

Claim 13

The composite refractory lining as claimed in claim 9 wherein the metal case enclosing the refractory shapes in step (b) extends a distance of about 2 1/2 inches to about 4 inches beyond the hot faces of the refractory shapes.

Claim 14

In an electric arc furnace having an outer metallic shell, a refractory lining laid-up against the inner surface of the intermetallic shell, a refractory-lined hearth, a refractory-lined roof and electrodes whereby raw materials charged into the electric arc furnace are melted and refined, an improved composite refractory lining comprising: a. a plurality of courses of basic refractory shapes taken from the group consisting of magnesia, magnesia-chrome ore mixtures and magnesite, laid-up in non-critical wear areas of the refractory lining, and b. a plurality of courses of basic refractory shapes encased in metal taken from the group consisting of magnesia, magnesia-chrome ore and magnesite, said metal extending a predetermined distance beyond the hot face of said refractory shapes to form a box-like extension and adapted to receive a spray coating of a pulverulent refractory material compatible with the refractory material in the refractory shapes into the box-like extensions.

Claim 15

In an electric arc furnace having an outer metallic shell, a refractory lining laid-up against the inner surface of the intermetallic shell, a refractory-lined hearth, a refractory-lined roof and electrodes whereby raw materials charged into the electric arc furnace are melted and refined, an improved composite refractory lining comprising: a. a plurality of courses of basic refractory shapes taken from the group consisting of magnesia, magnesia-chrome ore mixtures and magnesite, laid-up in non-critical wear areas of the refractory lining, and b. a plurality of courses of basic refractory shapes encased in metal taken from the group consisting of magnesia, magnesia-chrome ore and magnesite, said metal extending a predetermined distance beyond the hot face of said refractory shapes to form a box-like extension and adapted to receive a spray coating of a pulverulent refractory material compatible with the refractory material in the refractory shapes into the box-like extensions.

Claim 16

In a refractory lining in a metallurgical furnace having a metal outer shell, a refractory hearth and a refractory lining, said metal outer shell an improved composite refractory lining comprising: a. a plurality of courses of refractory shapes laid against the outer metallic shell, said refractory shapes being selected from the group consisting of magnesia, magnesia-chrome ore and magnesite, b. said plurality of refractory shapes being encased in metal, the metal case extending from the inner surface of the refractory shapes to form a grid-like pattern adapted to receive a coating of pulverulent refractory material.

Claim 17

In a refractory lining in a metallurgical furnace having a metal outer shell, a refractory hearth and a refractory lining, said metal outer shell an improved composite refractory lining comprising: a. a plurality of courses of refractory shapes laid against the outer metallic shell, said refractory shapes being selected from the group consisting of magnesia, magnesia-chrome ore and magnesite, b. said plurality of refractory shapes being encased in metal, the metal case extending from the inner surface of the refractory shapes to form a grid-like pattern adapted to receive a coating of pulverulent refractory material.

Claim 18

The refractory lining as claimed in claim 12 wherein the metal case surrounding the refractory shapes in step (b) extends a predetermined distance of about 2 1/2 inches to about 4 inches beyond the hot faces of the refractory shapes.