US4627945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing an injection molded refractory shape and composition thereof
Assignee: Dresser Industries Inc
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Filing: 1984-07-27
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Granted: 1986-12-09
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Expires: 2004-07-27
Abstract
Abstract An alumina-carbon shape is manufactured from a composition comprising 1-8 weight percent fine silicon, 1-16 weight percent reactive alumina, 1-30 weight percent calcined fluidized bed coke, 1-30 weight percent of a spalling inhibiting additive, and the balance of the mix synthetic alumina, plus the additions of 5-10 weight percent of a high carbon yielding resin as a molding vehicle and 0.5-4 weight percent solvent, and up to 2 weight percent of a low temperature curing agent, such as, paraformaldehyde or hydrochloric acid. The mix is formed at ambient temperature into a shape through an injection molding process. Solidification is accomplished by curing in the mold at a temperature less than 100° C. After stripping the shape from the mold, the solvents are removed from the shape by drying at a temperature above 100° C. The shapes are then heated to a temperature above 550° C. to coke the resin. The shapes may be tar impregnated to decrease coked porosity and to increase their resistance to mold powder.
Inventors
- 👤 Howard M. Winkelbauer
- 👤 Ke-Chin Wang
- 👤 Frank H. Walther, Jr.
- 👤 Donald F. Stock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:32
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/634; C04B35/63448; C04B35/63472; B; B22; B22D; B22D41/00; B22D41/50; B22D41/52; B22D41/54; C04B35/01; C04B35/013; C04B35/10; C04B35/101
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
141 words
A method for manufacturing an alumina-carbon shaped object comprising the steps of: mixing 1-8 weight percent fine silicon, 1-16 weight percent reactive alumina, 1-30 weight percent calcined fluidized bed coke, 1-30 weight percent of a spall inhibiting additive, and the balance of the mix synthetic alumina with the additions of 5-10 weight percent of a high carbon yielding resin as a molding vehicle, 0.5-4 weight percent solvent and up to 2 weight percent of a low temperature curing agent; injection molding the mix to produce shaped objects; initially curing the shapes at a temperature less than 100° C.; stripping the shape from the mold; further curing the shape at a temperature above 100° C.; and enhancing the strength of the shape by heating the shape at a relatively high temperature above 550° C. to promote coking of the resin molding vehicle.
Claim 2
Independent Claim
141 words
A method for manufacturing an alumina-carbon shaped object comprising the steps of: mixing 1-8 weight percent fine silicon, 1-16 weight percent reactive alumina, 1-30 weight percent calcined fluidized bed coke, 1-30 weight percent of a spall inhibiting additive, and the balance of the mix synthetic alumina with the additions of 5-10 weight percent of a high carbon yielding resin as a molding vehicle, 0.5-4 weight percent solvent and up to 2 weight percent of a low temperature curing agent; injection molding the mix to produce shaped objects; initially curing the shapes at a temperature less than 100° C.; stripping the shape from the mold; further curing the shape at a temperature above 100° C.; and enhancing the strength of the shape by heating the shape at a relatively high temperature above 550° C. to promote coking of the resin molding vehicle.
Claim 3
Dependent Claim
34 words
A method in accordance with claim 1 further including the step of: impregnating the shaped object with tar to decrease coked porosity and to increase the resistance of the shape to molten mold powder.
Claim 4
Dependent Claim
15 words
A method in accordance with claim 2 wherein the spall inhibiting additive is silicon carbide.
Claim 5
Dependent Claim
31 words
A method in accordance with claim 1 wherein the fine silicon comprises 3 weight percent, said reactive alumina comprises 8 weight percent, said calcined fluidized bed coke comprises 15 weight percent.
Claim 6
Dependent Claim
72 words
An alumina-carbon shape made from a batch consisting essentially of, by weight, 1-8 percent fine silicon, 1-16 percent reactive alumina, 1-30 weight percent calcined fluidized bed coke, 1-30 percent of a spall inhibiting additive, and the balance of the mix synthetic alumina, plus the additions of 5-10 weight percent of a high carbon yielding resin as a molding vehicle, 0.5-4 percent solvent, and 0.5-2 weight percent of a low temperature curing agent.
Claim 7
Dependent Claim
72 words
An alumina-carbon shape made from a batch consisting essentially of, by weight, 1-8 percent fine silicon, 1-16 percent reactive alumina, 1-30 weight percent calcined fluidized bed coke, 1-30 percent of a spall inhibiting additive, and the balance of the mix synthetic alumina, plus the additions of 5-10 weight percent of a high carbon yielding resin as a molding vehicle, 0.5-4 percent solvent, and 0.5-2 weight percent of a low temperature curing agent.
Claim 8
Dependent Claim
17 words
An alumina-carbon shape in accordance with claim 5, wherein the shape is formed as a shroud tube.
Claim 9
Dependent Claim
33 words
An alumina-carbon shape in accordance with claim 5, wherein the micronized silicon comprises 3 weight percent, the reactive alumina comprises 8 weight percent, and the calcined fluidized bed coke comprises 15 weight percent.
Claim 10
Dependent Claim
16 words
An alumina-carbon shape in accordance with claim 5, wherein the spall inhibiting additive is silicon carbide.
Claim 11
Dependent Claim
44 words
An alumina-carbon shape in accordance with claim 5, wherein the high carbon yielding resin is a liquid resin composed of a mixture of di- and tri-hydroxy diphenyl and other high molecular weight phenolic compounds and paraformaldehyde is used as a low temperature curing agent.
Claim 12
Dependent Claim
53 words
An alumina-carbon shape in accordance with claim 5, wherein the high carbon yielding resin is a liquid phenol formaldehyde resin with a viscosity of 90-120 centipoise at 25° C., a relatively high free phenol content, and a relatively high tolerance for strong acids which can be used to initiate a low temperature cure.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-08 | 1990-06-09 | 1990-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-08 | 1994-06-09 | 1994-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-08 | 1998-06-09 | 1998-12-09 | $7700.00 | Window Closed / Lapsed |