US4339511A
Expired / Lapsed
US
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Preparation of powders suitable for conversion to useful β-aluminas
Assignee: United States Department of Energy
•
Filing: 1981-04-16
•
Granted: 1982-07-13
•
Expires: 2001-04-16
Abstract
Abstract A process for forming a precursor powder which, when suitably pressed and sintered forms highly pure, densified β- or β"-alumina, comprising the steps of: (1) forming a suspension (or slurry) of Bayer-derived Al(OH) 3 in a water-miscible solvent; (2) adding an aqueous solution of a Mg compound, a Li compound, a Na compound or mixtures thereof to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel; (3) drying the gel at a temperature above the normal boiling point of water to produce a powder material; (4) lightly ball milling and sieving said powder material; and (5) heating the ball-milled and sieved powder material at a temperature of between 350° to 900° C. to form the β- or β"-alumina precursor powder. The precursor powder, thus formed, may be subsequently isopressed at a high pressure and sintered at an elevated temperature to produce β- or β"-alumina. BACKGROUND OF THE INVENTION
Inventors
- 👤 Peter E. D. Morgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:08
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/028; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/113; C01P; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 84
Claim 1
Independent Claim
125 words
A precursor powder which, when suitably pressed and sintered, forms a highly pure monophase, densified β-alumina, which is formed by the steps comprising: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound and either a Li compound or a Mg compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β"-alumina precursor powder.
Claim 2
Dependent Claim
125 words
A precursor powder which, when suitably pressed and sintered, forms a highly pure monophase, densified β-alumina, which is formed by the steps comprising: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound and either a Li compound or a Mg compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β"-alumina precursor powder.
Claim 3
Dependent Claim
16 words
The precursor powder of claim 1, wherein the aqueous solution has dissolved therein a Li compound.
Claim 4
Dependent Claim
16 words
The precursor powder of claim 1, wherein the aqueous solution has dissolved therein a Na compound.
Claim 5
Dependent Claim
14 words
The precursor powder of claim 1, wherein the aqueous solution has dissolved therein LiOH.
Claim 6
Dependent Claim
16 words
The precursor powder of claim 1, wherein the aqueous solution has dissolved therein NaHCO 3 .
Claim 7
Dependent Claim
18 words
The precursor powder of claim 1, wherein the gel-like material is dried at a temperature of 120° C.
Claim 8
Dependent Claim
19 words
The precursor powder of claim 1, wherein the powder material is ball milled and sieved through a 200-mesh screen.
Claim 9
Dependent Claim
22 words
The precursor powder of claim 1, wherein said ball-milled and sieved powder material is heated within the temperature range of 500°-700° C.
Claim 10
Dependent Claim
17 words
The precursor powder of claim 1, wherein the aqueous solution has dissolved therein NaHCO 3 and LiOH.
Claim 11
Dependent Claim
22 words
The precursor powder of claim 1, wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C.
Claim 12
Dependent Claim
29 words
The precursor powder of claim 1 wherein said ball-milled and sieved powder material is heated gradually within the range of 500°-700° C. and held at the upper temperature limit.
Claim 13
Dependent Claim
29 words
The precursor powder of claim 1 wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C. and held at the upper temperature limit.
Claim 14
Dependent Claim
19 words
The precursor powder of claim 1, wherein the water-miscible suspending agent is a low molecular weight ketone or alcohol.
Claim 15
Dependent Claim
14 words
The precursor powder of claim 1, wherein the water-miscible suspending agent is isopropyl alcohol.
Claim 16
Independent Claim
125 words
A method of forming a β"-alumina precursor powder from Bayer-derived Al(OH) 3 which produces a highly pure monophase alumina comprising the steps of: (1) forming a suspension on slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound and either a Li compound or a Mg compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β"-alumina precursor powder.
Claim 17
Independent Claim
125 words
A method of forming a β"-alumina precursor powder from Bayer-derived Al(OH) 3 which produces a highly pure monophase alumina comprising the steps of: (1) forming a suspension on slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound and either a Li compound or a Mg compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β"-alumina precursor powder.
Claim 18
Dependent Claim
15 words
The method of claim 15, wherein the aqueous solution has dissolved therein a Li compound.
Claim 19
Dependent Claim
15 words
The method of claim 15, wherein the aqueous solution has dissolved therein a Na compound.
Claim 20
Dependent Claim
13 words
The method of claim 15, wherein the aqueous solution has dissolved therein LiOH.
Claim 21
Dependent Claim
15 words
The method of claim 15, wherein the aqueous solution has dissolved therein NaHCO 3 .
Claim 22
Dependent Claim
17 words
The method of claim 15, wherein the gel-like material is dried at a temperature of 120° C.
Claim 23
Dependent Claim
18 words
The method of claim 15, wherein the powder material is ball milled and sieved through a 200-mesh screen.
Claim 24
Dependent Claim
21 words
The method of claim 15, wherein said ball-milled and sieved powder material is heated within the temperature range of 500°-700° C.
Claim 25
Dependent Claim
16 words
The method of claim 15, wherein the aqueous solution has dissolved therein NaHCO 3 and LiOH.
Claim 26
Dependent Claim
21 words
The method of claim 15, wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C.
Claim 27
Dependent Claim
28 words
The method of claim 15 wherein said ball-milled and sieved powder material is heated gradually within the range of 500°-700° C. and held at the upper temperature limit.
Claim 28
Dependent Claim
28 words
The method of claim 15 wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C. and held at the upper temperature limit.
Claim 29
Dependent Claim
18 words
The method of claim 15, wherein the water-miscible suspending agent is a low molecular weight ketone or alcohol.
Claim 30
Dependent Claim
13 words
The method of claim 15, wherein the water-miscible suspending agent is isopropyl alcohol.
Claim 31
Independent Claim
98 words
A method of forming a highly pure monophase β"-alumina from Bayer-derived Al(OH) 3 comprising the steps of: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound, and either a Li compound or a Mg compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material;
Claim 32
Independent Claim
98 words
A method of forming a highly pure monophase β"-alumina from Bayer-derived Al(OH) 3 comprising the steps of: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound, and either a Li compound or a Mg compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material;
Claim 33
Dependent Claim
42 words
(5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β"-alumina precursor powder;. (6) isopressing said β"-alumina precursor powder at from 25,000 to 100,000 p.s.i.; (7) sintering at a temperature of from 1400°-1800° C.
Claim 34
Dependent Claim
42 words
(5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β"-alumina precursor powder;. (6) isopressing said β"-alumina precursor powder at from 25,000 to 100,000 p.s.i.; (7) sintering at a temperature of from 1400°-1800° C.
Claim 35
Dependent Claim
17 words
The method of claim 29, wherein isopressing of the β"-alumina precursor is carried out at 50,000 p.s.i.
Claim 36
Dependent Claim
22 words
The method of claim 29, wherein sintering of the β"-alumina precursor is carried out at a temperature of 1500° to 1650° C.
Claim 37
Dependent Claim
15 words
The method of claim 29, wherein the aqueous solution has dissolved therein a Li compound.
Claim 38
Dependent Claim
15 words
The method of claim 29, wherein the aqueous solution has dissolved therein a Na compound.
Claim 39
Dependent Claim
13 words
The method of claim 29, wherein the aqueous solution has dissolved therein LiOH.
Claim 40
Dependent Claim
15 words
The method of claim 29, wherein the aqueous solution has dissolved therein NaHCO 3 .
Claim 41
Dependent Claim
16 words
The method of claim 29, wherein the gel is dried at a temperature of 120° C.
Claim 42
Dependent Claim
18 words
The method of claim 29, wherein the powder material is ball milled and sieved through a 200-mesh screen.
Claim 43
Dependent Claim
21 words
The method of claim 29, wherein said ball-milled and sieved powder material is heated within the temperature range of 500°-700° C.
Claim 44
Dependent Claim
16 words
The method of claim 29, wherein the aqueous solution has dissolved therein NaHCO 3 and LiOH.
Claim 45
Dependent Claim
21 words
The method of claim 29, wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C.
Claim 46
Dependent Claim
28 words
The method of claim 29 wherein said ball-milled and sieved powder material is heated gradually within the range of 500°-700° C. and held at the upper temperature limit.
Claim 47
Dependent Claim
28 words
The method of claim 29 wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C. and held at the upper temperature limit.
Claim 48
Dependent Claim
18 words
The method of claim 29, wherein said water-miscible suspending agent is a low molecular weight alcohol or ketone.
Claim 49
Dependent Claim
13 words
The method of claim 29, wherein said water-miscible suspending agent is isopropyl alcohol.
Claim 50
Dependent Claim
116 words
A precursor powder which, when suitably pressed and sintered, forms a highly pure monophase, densified β-alumina, which is formed by the steps comprising: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β-alumina precursor powder.
Claim 51
Dependent Claim
116 words
A precursor powder which, when suitably pressed and sintered, forms a highly pure monophase, densified β-alumina, which is formed by the steps comprising: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β-alumina precursor powder.
Claim 52
Dependent Claim
16 words
The precursor powder of claim 45, wherein the aqueous solution has dissolved therein NaHCO 3 .
Claim 53
Dependent Claim
18 words
The precursor powder of claim 45, wherein the gel-like material is dried at a temperature of 120° C.
Claim 54
Dependent Claim
19 words
The precursor powder of claim 45, wherein the powder material is ball milled and sieved through a 200-mesh screen.
Claim 55
Dependent Claim
22 words
The precursor powder of claim 45, wherein said ball-milled and sieved powder material is heated within the temperature range of 500°-700° C.
Claim 56
Dependent Claim
22 words
The precursor powder of claim 45, wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C.
Claim 57
Dependent Claim
29 words
The precursor powder of claim 45 wherein said ball-milled and sieved powder material is heated gradually within the range of 500°-700° C. and held at the upper temperature limit.
Claim 58
Dependent Claim
29 words
The precursor powder of claim 45 wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C. and held at the upper temperature limit.
Claim 59
Dependent Claim
19 words
The precursor powder of claim 45, wherein the water-miscible suspending agent is a low molecular weight ketone or alcohol.
Claim 60
Dependent Claim
14 words
The precursor powder of claim 45, wherein the water-miscible suspending agent is isopropyl alcohol.
Claim 61
Independent Claim
120 words
A method of forming a highly pure monophase a β-alumina precursor powder from Bayer-derived Al(OH) 3 which produces a highly pure monophase alumina comprising the steps of: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β-alumina precursor powder.
Claim 62
Independent Claim
120 words
A method of forming a highly pure monophase a β-alumina precursor powder from Bayer-derived Al(OH) 3 which produces a highly pure monophase alumina comprising the steps of: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β-alumina precursor powder.
Claim 63
Dependent Claim
15 words
The method of claim 55, wherein the aqueous solution has dissolved therein NaHCO 3 .
Claim 64
Dependent Claim
17 words
The method of claim 55, wherein the gel-like material is dried at a temperature of 120° C.
Claim 65
Dependent Claim
18 words
The method of claim 55, wherein the powder material is ball milled and sieved through a 200-mesh screen.
Claim 66
Dependent Claim
21 words
The method of claim 55, wherein said ball-milled and sieved powder material is heated within the temperature range of 500°-700° C.
Claim 67
Dependent Claim
21 words
The method of claim 55, wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C.
Claim 68
Dependent Claim
28 words
The method of claim 55 wherein said ball-milled and sieved powder material is heated gradually within the range of 500°-700° C. and held at the upper temperature limit.
Claim 69
Dependent Claim
28 words
The method of claim 55 wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C. and held at the upper temperature limit.
Claim 70
Dependent Claim
18 words
The method of claim 55, wherein the water-miscible suspending agent is a low molecular weight ketone or alcohol.
Claim 71
Dependent Claim
13 words
The method of claim 55, wherein the water-miscible suspending agent is isopropyl alcohol.
Claim 72
Independent Claim
127 words
A method of forming β-alumina from Bayer-derived Al(OH) 3 comprising the steps of: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound, to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β-alumina precursor powder; (6) isopressing said β-alumina precursor powder at from 25,000 to 100,000 p.s.i.; (7) sintering at a temperature of from 1400°-1800° C.
Claim 73
Independent Claim
127 words
A method of forming β-alumina from Bayer-derived Al(OH) 3 comprising the steps of: (1) forming a suspension or slurry of Bayer-derived Al(OH) 3 in a water-miscible suspending agent; (2) adding an aqueous solution of a Na compound, to the Bayer-derived Al(OH) 3 suspension while agitating the mixture formed thereby, to produce a gel-like material; (3) drying said gel-like material at a temperature above the normal boiling point of H 2 O to produce a powder material; (4) lightly ball milling and sieving said powder material; (5) heating said ball-milled and sieved powder material at a temperature of between 350°-900° C. to form the β-alumina precursor powder; (6) isopressing said β-alumina precursor powder at from 25,000 to 100,000 p.s.i.; (7) sintering at a temperature of from 1400°-1800° C.
Claim 74
Dependent Claim
17 words
The method of claim 65, wherein isopressing of the β-alumina precursor is carried out at 50,000 p.s.i.
Claim 75
Dependent Claim
22 words
The method of claim 65, wherein sintering of the β-alumina precursor is carried out at a temperature of 1500° to 1650° C.
Claim 76
Dependent Claim
15 words
The method of claim 65, wherein the aqueous solution has dissolved therein NaHCO 3 .
Claim 77
Dependent Claim
16 words
The method of claim 65, wherein the gel is dried at a temperature of 120° C.
Claim 78
Dependent Claim
18 words
The method of claim 65, wherein the powder material is ball milled and sieved through a 200-mesh screen.
Claim 79
Dependent Claim
21 words
The method of claim 65, wherein said ball-milled and sieved powder material is heated within the temperature range of 500°-700° C.
Claim 80
Dependent Claim
21 words
The method of claim 65, wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C.
Claim 81
Dependent Claim
28 words
The method of claim 65 wherein said ball-milled and sieved powder material is heated gradually within the range of 500°-700° C. and held at the upper temperature limit.
Claim 82
Dependent Claim
28 words
The method of claim 65 wherein said ball-milled and sieved powder material is heated gradually within the range of 350°-900° C. and held at the upper temperature limit.
Claim 83
Dependent Claim
18 words
The method of claim 65, wherein said water-miscible suspending agent is a low molecular weight alcohol or ketone.
Claim 84
Dependent Claim
13 words
The method of claim 65, wherein said water-miscible suspending agent is isopropyl alcohol.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1985-07-12 | 1986-01-11 | 1986-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-12 | 1990-01-11 | 1990-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-12 | 1994-01-11 | 1994-07-13 | $7700.00 | Window Closed / Lapsed |