Patent US4219590A successfully refreshed from Google Patents.
US4219590A
Expired / Lapsed
US
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Method for improving calcium carbonate
Assignee: Shiraishi Kogyo Kaisha Ltd
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Filing: 1979-04-02
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Granted: 1980-08-26
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Expires: 1999-04-02
Abstract
Abstract A method for improving calcium carbonate by causing calcium carbonate particles to undergo contact reaction with an acid gas capable of reacting with calcium carbonate for finely uniformizing the calcium carbonate particle size and, at the same time, coating the surface of the calcium carbonate particles with the calcium salt of the acid of the acid gas.
Inventors
- 👤 Hiroji Shibazaki
- 👤 Setsuji Edagawa
- 👤 Yoshinaga Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:08
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/18; C01F11/185; C09; C09C; C09C1/00; C09C1/02; C09C1/021; C09C1/022; C09C1/024; C01P; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
79 words
A method for the coating of calcium carbonate particles having an average diameter of not more than 20 μm with an inoganic acid vapor to form a calcium salt of said acid on the surface of said particle to produce more uniform particles of reduced average particle diameter and increased average particle surface area which comprises reacting said calcium carbonate particles with a vapor of said acid, the water content of the acid vapor being below 0.1% by weight.
Claim 2
Independent Claim
79 words
A method for the coating of calcium carbonate particles having an average diameter of not more than 20 μm with an inoganic acid vapor to form a calcium salt of said acid on the surface of said particle to produce more uniform particles of reduced average particle diameter and increased average particle surface area which comprises reacting said calcium carbonate particles with a vapor of said acid, the water content of the acid vapor being below 0.1% by weight.
Claim 3
Dependent Claim
41 words
A method according to claim 1 wherein the acid vapor is at least one member selected from the group consisting of vapors of phosphoric acid, hydrofluoric acid, sulfurous acid, nitric acid, and chlorides and fluorides of aluminum, zinc, silicon and titanium.
Claim 4
Dependent Claim
17 words
A method according to claim 1 wherein the acid vapor is the acid vapor of hydrofluoric acid.
Claim 5
Dependent Claim
17 words
A method according to claim 1 wherein the acid vapor is the acid vapor of titanium tetrachloride.
Claim 6
Dependent Claim
30 words
A method according to claim 1, wherein the concentration of the acid vapor is from 10 to 50% by volume, and the flow velocity is from 5 to 20 cm/sec.
References Cited (Backward Citations)
JPS4845128A
Cited
JPS4934500A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-26 | 1984-02-25 | 1984-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-26 | 1988-02-25 | 1988-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-26 | 1992-02-25 | 1992-08-26 | $7700.00 | Window Closed / Lapsed |