US4499062A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrothermal decomposition of aluminum silicates
Assignee: Henkel AG and Co KGaA
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Filing: 1983-05-27
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Granted: 1985-02-12
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Expires: 2003-05-27
Abstract
Abstract A process for the hydrothermal fusion of aluminum silicate and alkali aluminum silicates with aqueous sodium hydroxide solution under pressure and at elevated temperatures in the presence of soluble silicates, in which an aqueous solution containing from about 20 to about 50% by weight of NaOH is mixed with aluminum silicates and/or alkali aluminum silicates, and with a hydrothermally fusible silicate component, wherein the ratio by weight of SiO 2 to Al 2 O 3 in the mixture amounts to at least 30:1 and the ratio by weight of SiO 2 to Na 2 O amounts to at least 1.5:1, and the mixtures are reacted at temperatures of from about 180° to about 250° C. and under the saturated steam pressures corresponding to those temperatures. The resulting sodium silicate solution, which contains the dissolved aluminum, is then separated off.
Inventors
- 👤 Peter Christophliemk
- 👤 Rudolf Novotny
- 👤 Jurgen von Laufenberg
- 👤 Josef Sadlowsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:56
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/26; B; B01; B01J; B01J8/00; B01J8/08; B01J8/10; B01J8/18; B01J8/20; B01J2219/00; B01J2219/18; B01J2219/182
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
142 words
A process for the hydrothermal decomposition of aluminum silicates and alkali aluminum silicates with aqueous sodium hydroxide solution in the presence of soluble silicates comprising the steps of: (a) forming a reaction mixture of (i) an aqueous solution containing from about 20 to about 50% by weight of NaOH, (ii) at least one silicate selected from the group consisting of an aluminum silicate and an alkali aluminum silicate, and (iii) at least one hydrothermally decomposable silicate component wherein the ratio by weight of SiO 2 to Al 2 O 3 in the mixture is at least 30:1, and the ratio by weight of SiO 2 to Na 2 O in the mixture is at least 1.5:1; and (b) heating the reaction mixture at a temperature of from about 180° to about 250° C. under the saturated steam pressure corresponding to said temperature.
Claim 2
Dependent Claim
142 words
A process for the hydrothermal decomposition of aluminum silicates and alkali aluminum silicates with aqueous sodium hydroxide solution in the presence of soluble silicates comprising the steps of: (a) forming a reaction mixture of (i) an aqueous solution containing from about 20 to about 50% by weight of NaOH, (ii) at least one silicate selected from the group consisting of an aluminum silicate and an alkali aluminum silicate, and (iii) at least one hydrothermally decomposable silicate component wherein the ratio by weight of SiO 2 to Al 2 O 3 in the mixture is at least 30:1, and the ratio by weight of SiO 2 to Na 2 O in the mixture is at least 1.5:1; and (b) heating the reaction mixture at a temperature of from about 180° to about 250° C. under the saturated steam pressure corresponding to said temperature.
Claim 3
Dependent Claim
25 words
A process in accordance with claim 1 wherein the silicate component in (a) (iii) is at least one of silica, sand, and an alkali silicate.
Claim 4
Dependent Claim
25 words
A process in accordance with claim 1 wherein the temperature in step (b) is in the range of from about 200° to about 210° C.
Claim 5
Dependent Claim
26 words
A process in accordance with claim 1 wherein in step (a) (i) the aqueous solution contains from about 25 to about 35% by weight of NaOH.
Claim 6
Dependent Claim
34 words
A process in accordance with claim 1 wherein in step (a) the ratio by weight of SiO 2 to Al 2 O 3 is in the range of from about 50:1 to about 150:1.
Claim 7
Dependent Claim
88 words
A process in accordance with claim 1 wherein the silicate component in step (a) (iii) is at least one of silica, sand, and an alkali silicate, the temperature in step (b) is in the range of from about 200° to about 210° C., in step (a) (i) the aqueous solution contains from about 25 to about 35% by weight of NaOH, and in step (a) the ratio by weight of SiO 2 to Al 2 O 3 is in the range of from about 50:1 to about 150:1.
Claim 8
Dependent Claim
26 words
A process in accordance with claim 1 wherein step (b) is carried out in a rotating cylindrical pressure vessel mounted for rotation about its horizontal axis.
Claim 9
Dependent Claim
26 words
A process in accordance with claim 6 wherein step (b) is carried out in a rotating cylindrical pressure vessel mounted for rotation about its horizontal axis.
Claim 10
Dependent Claim
102 words
A process in accordance with claim 1 wherein step (b) is carried out in a stationary pressure vessel in which filter sludge is introduced into the pressure vessel which, together with the hydrothermally decomposable silicate component (a) (iii), forms a solids bed; and the liquid phase of the reaction mixture is pump-recirculated by means of a bypass conduit leading from the upper section of the pressure vessel to the lower section thereof, resulting in the formation of a fluidized bed from the solids bed, until the concentration of SiO 2 in the liquid phase of the reaction mixture reaches a desired level.
Claim 11
Dependent Claim
14 words
A process in accordance with claim 1 wherein the reaction is carried out continuously.
Claim 12
Dependent Claim
23 words
A process in accordance with claim 9 wherein the reaction is carried out continuously while continuously removing reaction mixture from the reaction vessel.
References Cited (Backward Citations)
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FR2017745A1
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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) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |