# US 7,608,302 B2 · Method for suppressing reaction of molten metals with refractory materials

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- Number: US 7,608,302 B2
- Document ID: US7608302B2
- Status: Granted
- Kind: B2
- Application number: 11/827,693
- Filed: 2007-07-13
- Published: 2007-11-01
- Granted: 2009-10-27
- Earliest claimed: 2003-12-11
- Assignees: Novelis Inc.
- Inventors: Todd F. Bischoff; Richard S. Bruski; Robert B. Wagstaff
- Web page: https://patentgrep.com/patent/US7608302B2

## CPC

- C04B 35/66: Monolithic refractories or refractory mortars, including those whether or not containing clay {(making or repairing of linings F27D1/16)}
- C04B 35/22: rich in calcium oxide {, e.g. wollastonite (C04B35/195 takes precedence)}
- C04B 2235/3208: Calcium oxide or oxide-forming salts thereof, e.g. lime
- C04B 2235/3213: Strontium oxides or oxide-forming salts thereof
- C04B 2235/3215: Barium oxides or oxide-forming salts thereof
- C04B 2235/3418: Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
- C04B 2235/3436: Alkaline earth metal silicates, e.g. barium silicate
- C04B 2235/3454: Calcium silicates, e.g. wollastonite
- C04B 2235/9676: against molten metals such as steel or aluminium
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

A method is described for improving resistance to chemical attack by aluminum or magnesium in refractory components. In one method, a slurry is formed comprising calcium silicate-containing refractory material and a barium-containing compound. This slurry is placed in a mold, then dewatered to form a component which is hydrothermally processed to form a final component. In a second procedure, a silica-containing porous refractory component is impregnated with an aqueous solution of an oxide or hydroxide of barium or strontium and thereafter dried in air.

## Claims

### Claim 1

A method of stabilizing a porous refractory component made of calcium silicate against reactions with molten aluminum or magnesium, the method consisting of:
(a) forming an aqueous solution of an oxide or hydroxide of a group II alkali earth;
(b) impregnating the component made of calcium silicate with the solution; and
(c) drying the impregnated component in air ready for contact with molten aluminum or magnesium.

### Claim 2 (depends on 1)

A method according to claim 1 wherein the group II alkali earth is selected from the group consisting of barium and strontium.

### Claim 3 (depends on 2)

A method according to claim 2 wherein the porous refractory component is a fired component.

### Claim 4 (depends on 2)

A method according to claim 2 wherein the porous refractory component is an unfired component.

### Claim 5 (depends on 2)

A method according to claim 2 wherein the aqueous solution is formed at a temperature of at least 30° C.

### Claim 6 (depends on 2)

A method according to claim 2 wherein the aqueous solution is formed at a temperature of at least 40° C.

### Claim 7 (depends on 2)

A method according to claim 2 wherein the drying of step (c) is carried out at a temperature of no more than 250° C.

### Claim 8

A method of stabilizing a porous refractory component against reactions with molten aluminum or magnesium, the method comprising:
(a) forming an aqueous solution of an oxide or hydroxide of a group II alkali earth;
(b) impregnating the component made of calcium silicate with the solution;
(c) drying the impregnated component in air; and
(d) further impregnating the impregnated component with a sulfuric acid solution and drying the further impregnated component in air, after step (c), ready for contact with molten aluminum or magnesium.

### Claim 9 (depends on 8)

A method according to claim 8 wherein the group II alkali earth is selected from the group consisting of barium and strontium.

### Claim 10 (depends on 9)

A method according to claim 9 wherein the porous refractory component is a fired component.

### Claim 11 (depends on 9)

A method according to claim 9 wherein the porous refractory component is an unfired component.

### Claim 12 (depends on 9)

A method according to claim 9 wherein the aqueous solution is formed at a temperature of at least 30° C.

### Claim 13 (depends on 9)

A method according to claim 9 wherein the aqueous solution is formed at a temperature of at least 40° C.

### Claim 14 (depends on 9)

A method according to claim 9 wherein the drying of steps (c) and (d) is carried out at a temperature of no more than 250° C.