US4265406A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Comminution process
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1979-05-31
•
Granted: 1981-05-05
•
Expires: 1999-05-31
Abstract
Abstract A process is described for the comminution of a solid material in the presence of a saturated solution of the solid in a liquid in which the solid has a solubility greater than 1%, and also in the presence of an additive dissolved in the saturated solution which can at least partially inhibit regrowth at crystal surfaces of the solid material. The process is of particular interest for the comminution of water-soluble salts in the presence of their saturated aqueous solutions and may be employed to make, inter alia, improved slurry explosives and fluid fertilizer compositions.
Inventors
- 👤 Derek A. Palgrave
- 👤 Frederick A. Waite
- 👤 James D. Birchall
- 👤 John Cooper
- 👤 James A. Enever
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:52
CPC Classifications
C; C05; C05C; C05C1/00; C05C1/02; B; B02; B02C; B02C23/00; B02C23/06; Y; Y10; Y10S; Y10S149/00; Y10S149/11; Y10S149/112
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
113 words
A process for the preparation of a stable suspension of a fine crystalline substance suspended in a saturated solution thereof comprising comminuting the substance by grinding in the presence of a saturated solution of the substance in a liquid in which the substance has a solubility greater than 1% by weight, the mixture of said solution and said substance being in fluid condition with the substance being a separate solid phase during grinding, and said solution having dissolved therein an additive which is a crystal growth inhibitor for the substance whereby crystal growth is inhibited at both existing crystal surfaces and new crystal surfaces created by the breaking down of relatively coarse particles.
Claim 2
Dependent Claim
113 words
A process for the preparation of a stable suspension of a fine crystalline substance suspended in a saturated solution thereof comprising comminuting the substance by grinding in the presence of a saturated solution of the substance in a liquid in which the substance has a solubility greater than 1% by weight, the mixture of said solution and said substance being in fluid condition with the substance being a separate solid phase during grinding, and said solution having dissolved therein an additive which is a crystal growth inhibitor for the substance whereby crystal growth is inhibited at both existing crystal surfaces and new crystal surfaces created by the breaking down of relatively coarse particles.
Claim 3
Dependent Claim
22 words
A process as claimed in claim 1, wherein a water-soluble solid substance is comminuted in the presence of its saturated aqueous solution.
Claim 4
Dependent Claim
42 words
A process as claimed in claim 2, wherein the water-soluble solid substance is a salt selected from the group consisting of ammonium nitrate, sodium nitrate, calcium nitrate, potassium chloride, sodium chloride, ammonium phosphate, ammonium polyphosphate, potassium hydrogen phosphate and disodium hydrogen phosphate.
Claim 5
Dependent Claim
18 words
A process as claimed in any one of claims 1 to 3, wherein the additive is a polysaccharide.
Claim 6
Dependent Claim
21 words
A process as claimed in claim 4 wherein the solid substance is ammonium nitrate and the additive is sodium carboxymethyl cellulose.
Claim 7
Dependent Claim
35 words
A process as in claim 4 wherein the polysaccharide contains an ionic component in the molecule as a result of at least a portion of the hydroxyl groups having been converted to carboxyl group-bearing substituents.
Claim 8
Dependent Claim
25 words
A process as claimed in any one of claims 1 to 3, wherein the additive is a long chain aliphatic amine or a salt thereof.
Claim 9
Dependent Claim
47 words
A process as claimed in claim 7 wherein the solid substance is essentially ammonium nitrate and the additive is an aliphatic primary, secondary or tertiary amine in which the aliphatic group contains between 6 and 18 carbon atoms, or the acetate or oleate of such an amine.
Claim 10
Dependent Claim
22 words
A process as claimed in any one of claims 1 to 3, wherein the additive is a low molecular weight inorganic salt.
Claim 11
Dependent Claim
46 words
A process as claimed in claim 9 wherein said substance is selected from the group consisting of potassium chloride and sodium chloride and the additive is selected from the group consisting of the ferrocyanides and ferricyanides of sodium or potassium borax, cadmium chloride and lead chloride.
Claim 12
Dependent Claim
36 words
A process as claimed in claim 1 wherein the amount of additive employed is at least 0.05% of the total weight of solid substance present in the composition being comminuted, including that dissolved in the liquid.
References Cited (Backward Citations)
US2642335A
Cited
US2662028A
Cited
US2720446A
Cited
US3007773A
Cited
GB951820A
Cited
US3197289A
Cited
US3281206A
Cited
US3317274A
Cited
GB1143516A
Cited
US3558287A
Cited
US3572500A
Cited
DE1782031A1
Cited
US3604634A
Cited
US3607326A
Cited
DE2455005A1
Cited
GB1449268A
Cited
US3989195A
Cited
US4069034A
Cited
US4055449A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-04 | 1984-11-03 | 1985-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-04 | 1988-11-03 | 1989-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-04 | 1992-11-03 | 1993-05-05 | $7700.00 | Window Closed / Lapsed |