Patent US3604634A successfully refreshed from Google Patents.
US3604634A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Comminution of solid materials
Assignee: Imerys Minerals Ltd
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Filing: 1969-10-28
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Granted: 1971-09-14
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Expires: 1989-10-28
Abstract
Abstract A method of grinding calcium carbonate minerals, e.g. chalk, calcite and marble, in order to obtain a pigment suitable for use in paper coating compositions. The mineral is ground in aqueous suspension using a particulate grinding material, and the amount of mineral in the aqueous suspension, the size of the particulate grinding material, the relative proportions of the mineral, the aqueous suspension and the grinding material, and the duration of the grinding are adjusted to be within specified ranges in order to ensure that a pigment have the desired properties is obtained.
Inventors
- 👤 William Windle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:33
CPC Classifications
B; B02; B02C; B02C23/00; B02C23/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
25 words
A method according to claim 1, wherein said particulate grinding material consists of particles ranging in size from 500 microns to 2 mm. in diameter.
Claim 2
Dependent Claim
51 words
A method according to claim 1, wherein said aqueous suspension contains from 40 percent to 75 percent by weight of said calcium carbonate mineral and further contains a water-soluble nonmucilaginous dispersing agent which is a salt having a macromolecular anion with an average molecular weight in the range 100 to 10,000.
Claim 3
Dependent Claim
31 words
A method according to claim 3, wherein said water-soluble nonmucilaginous dispersing agent is selected from the group consisting of the sodium, potassium and ammonium salts of polyacrylic acids and polymethacrylic acids.
Claim 4
Independent Claim
120 words
A method of grinding a calcium carbonate mineral which comprises the steps of (a) forming an aqueous suspension containing at least 25 percent by weight of said calcium carbonate mineral, and (b) grinding said aqueous suspension of calcium carbonate mineral with a particulate grinding material, wherein the particulate grinding material consists of particles ranging in size from 150 microns to 1/4 inch and the quantity thereof used is such that the weight ratio of the particulate grinding material to the calcium carbonate mineral is in the range of from 2:1 to 5:1 and wherein the aqueous suspension is grouNd for a time sufficient to dissipate therein at least 250 horsepower hours of energy per ton of dry calcium carbonate mineral.
Claim 5
Dependent Claim
25 words
A method according to claim 5, wherein said particulate grinding material consists of particles ranging in size from 500 microns to 2 mm. in diameter.
Claim 6
Dependent Claim
51 words
A method according to claim 5, wherein said aqueous suspension contains from 40 percent to 75 percent by weight of said calcium carbonate mineral and further contains a water-soluble nonmucilaginous dispersing agent which is a salt having a macromolecular anion with an average molecular weight in the range 100 to 10,000.
Claim 7
Dependent Claim
31 words
A method according to claim 7, wherein said water-soluble nonmucilaginous dispersing agent is selected from the group consisting of the sodium, potassium and ammonium salts of polyacrylic acids and polymethacrylic acids.
Claim 8
Independent Claim
151 words
A method of grinding a calcium carbonate mineral which comprises the steps of (a) forming an aqueous suspension containing at least 25 percent by weight of said calcium carbonate mineral, and (b) grinding said aqueous suspension of said calcium carbonate mineral with a particulate grinding material, wherein the particulate grinding material consists of particles ranging in size from 150 microns to 1/4 inch and the quantity thereof used is such that the ratio of the volume occupied by the particulate grinding material to that occupied by the aqueous suspension of calcium carbonate mineral is in the range 0.5:1 to 1.5:1 and the weight ratio of the particulate grinding material to the calcium carbonate mineral is in the range of from 2:1 to 5:1 and wherein the aqueous suspension is ground for a time sufficient to dissipate therein at least 250 horsepower hours of energy per ton of dry calcium carbonate mineral.
Claim 9
Dependent Claim
25 words
A method according to claim 9, wherein said particulate grinding material consists of particles ranging in size from 500 microns to 2 mm. in diameter
Claim 10
Dependent Claim
15 words
A method according to claim 10, wherein said particulate grinding material is a silica sand.
Claim 11
Dependent Claim
53 words
A method according to claim 9, wherein said aqueous suspension contains from 40 percent to 75 percent by weight of said calcium carbonate mineral and further contains a water-soluble nonmucilaginous dispersing agent which is a salt having a macromolecular anion with an average molecular weight in the range of from 100 to 10,000.
Claim 12
Dependent Claim
31 words
A method according to claim 12, wherein said water-soluble nonmucilaginous dispersing agent is selected from the group consisting of the sodium, potassium and ammonium salts of polyacrylic acids and polymethacrylic acids.
References Cited (Backward Citations)
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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) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |