US3961022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicate dissolving
Assignee: PQ Corp
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Filing: 1974-12-12
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Granted: 1976-06-01
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Expires: 1994-12-12
Abstract
Abstract Solutions of soluble alkali metal silicates of exceptional clarity are prepared by dissolving anhydrous alkali metal silicate glass at atmospheric pressure by a novel process comprising the constant classification of alkali metal silicate glass particles according to size and the constant removal of the polymer-like silicate that forms as a semi-solid on the wetted glass surface. The constant classification of the silicate glass particles and removal of this polymeric silicate to yield nascent glass surfaces can be achieved by charging silicate glass particles to aqueous media in a vibrating or vibro energy mill and subjecting said particles to impacts of varying frequency and amplitude or by subjecting the solution and glass particles, during dissolution, to agitation of different intensity and duration in a vertically stacked series of dissolving chambers.
Inventors
- 👤 Richard H. Pierce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:50
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/32; C01B33/325; B; B01; B01F; B01F21/00; B01F21/02; B01F21/10; B01F31/00; B01F31/80; B01F31/86; B01F33/00; B01F33/80; B01F33/81; Y; Y10; Y10S; Y10S65/00; Y10S65/13
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
197 words
In the known process of dissolving alkali metal silicate glass in water at elevated temperatures to form alkali metal silicate solutions, the improvement allowing the formation of homogeneous and sparkling clear alkali metal silicate solutions and comprising: a. contacting particles of said alkali metal silicate glass with water and alkali metal silicate solution at temperatures between 80°C and the boiling point of the solution formed and at atmospheric pressure in a vertical stack of connected dissolving chambers each having an impeller of independent speed and pitch; b. introducing hot water into the bottom chamber of said vertical stack so that the flow of liquid and entrained particles of silicate glass finer than 325 mesh is upward through said vertical stack of chambers; c. operating said impellers of each successively lower chamber at an increased speed; d. introducing said particles of alkali metal silicate to the uppermost chamber so that the flow of alkali metal silicate particles larger than 325 mesh is downward through the vertically stacked chambers; e. discharging alkali metal silicate solution from the uppermost chamber to a centrifuge; and f. returning the fine particles from the centrifuge to the bottom chamber of said vertical stack.
Claim 2
Dependent Claim
197 words
In the known process of dissolving alkali metal silicate glass in water at elevated temperatures to form alkali metal silicate solutions, the improvement allowing the formation of homogeneous and sparkling clear alkali metal silicate solutions and comprising: a. contacting particles of said alkali metal silicate glass with water and alkali metal silicate solution at temperatures between 80°C and the boiling point of the solution formed and at atmospheric pressure in a vertical stack of connected dissolving chambers each having an impeller of independent speed and pitch; b. introducing hot water into the bottom chamber of said vertical stack so that the flow of liquid and entrained particles of silicate glass finer than 325 mesh is upward through said vertical stack of chambers; c. operating said impellers of each successively lower chamber at an increased speed; d. introducing said particles of alkali metal silicate to the uppermost chamber so that the flow of alkali metal silicate particles larger than 325 mesh is downward through the vertically stacked chambers; e. discharging alkali metal silicate solution from the uppermost chamber to a centrifuge; and f. returning the fine particles from the centrifuge to the bottom chamber of said vertical stack.
Claim 3
Dependent Claim
50 words
The process of claim 1 wherein the alkali metal silicate glass particles have a mole ratio of SiO 2 /M 2 O between 1.2/1.0 and 3.8/1.0, a particle size of less than 1/2 inch and are selected from a group consisting of sodium silicate, potassium silicate and sodium-potassium double silicate.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein the temperature is between 95° and 102°C.
Claim 5
Dependent Claim
22 words
The process of claim 1 wherein the impeller of each chamber has a rotation opposite to the impellers of the adjacent chambers.
References Cited (Backward Citations)
US1138595A
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US1341288A
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US1763845A
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US2055836A
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US2086230A
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US2251515A
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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) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |