Patent US3545201A successfully refreshed from Google Patents.
Patent US4932166A successfully refreshed from Google Patents.
US4932166A
Expired / Lapsed
US
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Inert autogenous attrition grinding
Assignee: Unifrax I LLC
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Filing: 1988-10-03
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Granted: 1990-06-12
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Expires: 2008-10-03
Abstract
Abstract A method for grinding an oxygen sensitive ceramic material to a powder which comprises grinding an oxygen sensitive ceramic feed material having an average particle size of between 1 and 200 microns in a contamination free high energy autogenous attrition mill in non-oxidizing fluid in the presence of media for a sufficient time to obtain a specific surface area of at least 5 m 2 /g and preferably at least 9 m 2 /g. The media consists essentially of the same ceramic as the feed material is of high purity and has an average particle size of less than 4 mm and preferably less than 2.5 mm. the ground material may be further treated so that the average particle size is less than one micron and so that the greater than 97 numerical percent of the particles of the finished powder is smaller than 5 microns. The invention includes the finished powder.
Inventors
- 👤 Wolfgang D. G. Boecker
- 👤 Tadeusz Korzekwa
- 👤 Lewis M. Koppel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:33
CPC Classifications
B; B02; B02C; B02C17/00; B02C17/14; B02C17/16; B02C17/18; B02C17/20; B02C23/00; B02C23/18; C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565
Claims Analysis
Total Claims: 53
Claim 1
Independent Claim
119 words
A method for grinding an oxygen sensitive ceramic material to a powder which comprises grinding an oxygen sensitive ceramic feed material selected from the group consisting of AlN, TiB 2 , Si 3 N 4 , sialons and any other material more oxygen sensitive than boron carbide having an average particle size of between 1 and 200 microns in an contamination free high energy autogenous attrition mill in non-oxidizing fluid in the presence of media, for a sufficient time to obtain a ground material and a specific surface area of at least 5 m 2 /g, said media consisting essentially of the same ceramic as the feed material and having an average particle size of less than 4 mm.
Claim 2
Independent Claim
119 words
A method for grinding an oxygen sensitive ceramic material to a powder which comprises grinding an oxygen sensitive ceramic feed material selected from the group consisting of AlN, TiB 2 , Si 3 N 4 , sialons and any other material more oxygen sensitive than boron carbide having an average particle size of between 1 and 200 microns in an contamination free high energy autogenous attrition mill in non-oxidizing fluid in the presence of media, for a sufficient time to obtain a ground material and a specific surface area of at least 5 m 2 /g, said media consisting essentially of the same ceramic as the feed material and having an average particle size of less than 4 mm.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the ceramic is selected from the group consisting of AIN, TiB 2 , Si 3 N 4 and sialons.
Claim 4
Dependent Claim
12 words
The method of claim 2 wherein the fluid is a hydrocarbon liquid.
Claim 5
Dependent Claim
25 words
The method of claim 2 wherein the fluid is a mixture of an aliphatic liquid and a gas selected from inert gases, hydrogen and nitrogen.
Claim 6
Dependent Claim
12 words
The method of claim 3 wherein the fluid is an aliphatic hydrocarbon.
Claim 7
Dependent Claim
10 words
The method of claim 5 wherein the fluid is heptane.
Claim 8
Dependent Claim
13 words
The method of claim 2 wherein the fluid is a liquefied cryogenic gas.
Claim 9
Dependent Claim
24 words
The method of claim 7 wherein the gas is a cryogenic gas selected from the group consisting of hydrogen, helium, nitrogen, argon and neon.
Claim 10
Dependent Claim
12 words
The method of claim 7 wherein the cryogenic gas is hydrogen chloride.
Claim 11
Dependent Claim
46 words
The method of claim 1 wherein the ground material is further treated to obtain a powder wherein the average particle size is less than 1 micron and so that greater than 97 numerical percent of the particles of the finished powder is smaller than 5 microns.
Claim 12
Dependent Claim
11 words
The method of claim 10 wherein the powder is aluminum nitride.
Claim 13
Dependent Claim
24 words
The method of claim 10 wherein the ground material is further treated by vibratory grinding to further grind the larger particles of the material.
Claim 14
Dependent Claim
24 words
The method of claim 11 wherein the ground material is further treated by vibratory grinding to further grind the larger particles of the material.
Claim 15
Dependent Claim
56 words
The method of claim 13 wherein the vibratory grinding occurs for from 2 to 8 hours in a vibrational mill containing aluminum nitride cylindrical pellets, said pellets having a maximum dimension of from about 0.5 to 5 centimeters and wherein the diameter of the cylinder is from 0.3 to 4 times the length of the cylinder.
Claim 16
Dependent Claim
22 words
The method of claim 10 wherein the ground material is further treated by sedimentation from a liquid to remove larger size particles.
Claim 17
Dependent Claim
20 words
The method of claim 10 wherein the finished powder has an average particle size of from 0.5 to 0.9 microns.
Claim 18
Dependent Claim
32 words
The method of claim 1 wherein the internal surface of the mill and agitator within the mill are coated with an abrasion resistant material selected from polyurethane, natural rubber and synthetic rubber.
Claim 19
Dependent Claim
23 words
The method of claim 1 wherein the liquid is heptane, and the slurry contains from about 30 to about 70 weight percent solids.
Claim 20
Dependent Claim
15 words
The method of claim 1 wherein the grinding occurs for from 2 to 10 hours.
Claim 21
Dependent Claim
20 words
The method of claim 1 wherein heat developed during grinding is removed by circulating the slurry through a heat exchanger.
Claim 22
Dependent Claim
18 words
The method of claim 17 wherein the tip speed of the agitator is above 7.5 meters per second.
Claim 23
Dependent Claim
16 words
The method of claim 1 wherein the feed material contains less than 800 ppm metal impurities.
Claim 24
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 1.
Claim 25
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 2.
Claim 26
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 3.
Claim 27
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 4.
Claim 28
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 5.
Claim 29
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 6.
Claim 30
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 7.
Claim 31
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 8.
Claim 32
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 9.
Claim 33
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 10.
Claim 34
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 11.
Claim 35
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 12.
Claim 36
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 13.
Claim 37
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 14.
Claim 38
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 15.
Claim 39
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 16.
Claim 40
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 17.
Claim 41
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 18.
Claim 42
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 19.
Claim 43
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 20.
Claim 44
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 21.
Claim 45
Dependent Claim
11 words
Finished powder manufactured in accordance with the method of claim 22.
Claim 46
Dependent Claim
72 words
An oxygen sensitive ceramic powder selected from the group consisting of AlN, TiB 2 , Si 3 N 4 , sialons and any other material more oxygen sensitive than boron carbide having an average particle size smaller than 1 micron, greater than 97 numerical percent of the particles being smaller than 5 microns, a surface area greater than 9 m 2 /g, said powder being low in surface oxygen and being sinterable.
Claim 47
Dependent Claim
72 words
An oxygen sensitive ceramic powder selected from the group consisting of AlN, TiB 2 , Si 3 N 4 , sialons and any other material more oxygen sensitive than boron carbide having an average particle size smaller than 1 micron, greater than 97 numerical percent of the particles being smaller than 5 microns, a surface area greater than 9 m 2 /g, said powder being low in surface oxygen and being sinterable.
Claim 48
Dependent Claim
23 words
The powder of claim 45 wherein the finished powder is at least as pure as the feed material used to make the powder.
Claim 49
Dependent Claim
16 words
The powder of claim 31 wherein the finished powder contains less than 800 ppm metal impurities.
Claim 50
Dependent Claim
20 words
The powder of claim 47 wherein the powder contains less than 10 ppm boron and less than 100 ppm aluminum.
Claim 51
Dependent Claim
15 words
The powder of claim 45 wherein the powder contains less than 6 weight percent oxygen.
Claim 52
Dependent Claim
15 words
The powder of claim 45 wherein the powder contains less than 5 weight percent oxygen.
Claim 53
Dependent Claim
15 words
The powder of claim 45 wherein the powder contains less than 3 weight percent oxygen.
References Cited (Backward Citations)
US3075710A
Cited
US3231203A
Cited
US3268177A
Cited
US3311310A
Cited
US3521825A
Cited
US3485608A
Cited
US3715083A
Cited
US3957210A
Cited
US4129261A
Cited
US4123286A
Cited
US4242842A
Cited
US4275026A
Cited
US4575384A
Cited
US4544376A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |