US4277253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Granulating an aqueous dispersion of ammonium and potassium salts
Assignee: Adelaide and Wallaroo Fertilizers Ltd
•
Filing: 1979-12-17
•
Granted: 1981-07-07
•
Expires: 1999-12-17
Abstract
Abstract The preparation of dry, stable granular material from water-soluble potassium and ammonium salts and a mixture thereof by subjecting a dispersion of crystals of the salt in an aqueous liquid to the action of a granulating device in the presence of calcium sulphate hemihydrate and a hydrophilic surface active agent to effect agglomeration of said crystals, and thereafter subjecting the agglomerated crystals to a drying operation.
Inventors
- 👤 Karl H. Walter
- 👤 John D. Johnston
- 👤 Dennis Wetherley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:17
CPC Classifications
C; C05; C05D; C05D1/00; C05D1/005; C05C; C05C3/00; C05C3/005
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
138 words
A process for the preparation of dry, stable granular material from a salt selected from the group consisting of water-soluble potassium and ammonium salts selected from the group consisting of potassium sulfate, potassium chloride, ammonium sulfate and mixtures thereof, said process comprising the steps of: (1) crushing the salt, dispersing said crushed salt in an aqueous liquid to produce a dispersion of salt crystals, (2) subjecting said dispersion of crystals of at least one said salt in an aqueous liquid to the action of a granulating device in the presence of 0.5 to 10% w/w of calcium sulfate hemihydrate and 0.1 to 5% w/w of a hydrophilic surface active agent to effect agglomeration of said crystals, and (3) drying the resultant agglomerated crystals to produce the dry, stable granular material, said percentages being with respect to said salt.
Claim 2
Dependent Claim
138 words
A process for the preparation of dry, stable granular material from a salt selected from the group consisting of water-soluble potassium and ammonium salts selected from the group consisting of potassium sulfate, potassium chloride, ammonium sulfate and mixtures thereof, said process comprising the steps of: (1) crushing the salt, dispersing said crushed salt in an aqueous liquid to produce a dispersion of salt crystals, (2) subjecting said dispersion of crystals of at least one said salt in an aqueous liquid to the action of a granulating device in the presence of 0.5 to 10% w/w of calcium sulfate hemihydrate and 0.1 to 5% w/w of a hydrophilic surface active agent to effect agglomeration of said crystals, and (3) drying the resultant agglomerated crystals to produce the dry, stable granular material, said percentages being with respect to said salt.
Claim 3
Dependent Claim
24 words
A process as claimed in claim 1, in which the calcium sulphate hemihydrate is added to the salt in the form of a slurry.
Claim 4
Dependent Claim
24 words
A process as claimed in claim 1, in which the aqueous liquid has a temperature in the range from 15° C. to 100° C.
Claim 5
Dependent Claim
21 words
A process as claimed in claim 1, in which the aqueous liquid is provided by charging steam to the granulating device.
Claim 6
Dependent Claim
21 words
A process as claimed in claim 1, in which the aqueous liquid is an aqueous solution of the water-soluble crystalline salt.
Claim 7
Dependent Claim
22 words
A process as claimed in claim 5, in which the aqueous liquid is an aqueous saturated solution of the water-soluble crystalline salt.
Claim 8
Dependent Claim
17 words
A process as claimed in claim 5 in which said aqueous solution is a hot aqueous solution.
Claim 9
Dependent Claim
20 words
A process as claimed in claim 1 in which a hydrophilic surface active agent comprising an attapulgite clay is used.
Claim 10
Dependent Claim
20 words
A process as claimed in claim 1, in which a hydrophilic surface active agent comprising a bentonitic clay is used.
Claim 11
Dependent Claim
23 words
A process as claimed in claim 1, in which a hydrophilic surface active agent comprising an aqueous dispersion of polyvinyl acetate is used.
Claim 12
Dependent Claim
21 words
A process as claimed in claim 1, in which a hydrophilic surface active agent is selected from calcium and sodium lignosulphonates.
Claim 13
Dependent Claim
25 words
A process as claimed in claim 1, wherein the hydrophilic surface active agent is a dry solid and is admixed with the salt before agglomeration.
Claim 14
Dependent Claim
22 words
A process as claimed in claim 1, wherein the hydrophilic surface active agent is added to the salt with the aqueous liquid.
Claim 15
Dependent Claim
26 words
A process as claimed in claim 1, wherein the hydrophilic surface active agent and the calcium sulphate hemihydrate are added in the form of a slurry.
Claim 16
Dependent Claim
52 words
A process as claimed in claim 1, wherein said hydrophilic surface active agent is selected from the group consisting of attapulgite clay, bentonitic clay, calcium lignosulphonate, sodium lignosulphonate, casein, methyl-cellulose, agar, gelatine, aqueous dispersions of polyvinyl acetate, and high molecular weight water-soluble ionic polymers derived from acrylamine and salts of acrylic acid.
Claim 17
Dependent Claim
116 words
A process for the preparation of dry, stable granular material from a salt selected from the group consisting of water-soluble potassium and ammonium salts and a mixture thereof, said process comprising the steps of: granulating a dispersion of crystals of at least one said salt in an aqueous liquid in a granulating device in the presence of 0.5 to 10% w/w of calcium sulfate hemihydrate and 0.1 to 5% w/w of a hydrophilic surface active agent to effect agglomeration of said crystals, said percentages being with respect to said salt, said aqueous liquid being an aqueous solution of said water-soluble crystalline salt and thereafter drying the resultant agglomerated crystals to produce a dry, stable, granular material.
Claim 18
Dependent Claim
116 words
A process for the preparation of dry, stable granular material from a salt selected from the group consisting of water-soluble potassium and ammonium salts and a mixture thereof, said process comprising the steps of: granulating a dispersion of crystals of at least one said salt in an aqueous liquid in a granulating device in the presence of 0.5 to 10% w/w of calcium sulfate hemihydrate and 0.1 to 5% w/w of a hydrophilic surface active agent to effect agglomeration of said crystals, said percentages being with respect to said salt, said aqueous liquid being an aqueous solution of said water-soluble crystalline salt and thereafter drying the resultant agglomerated crystals to produce a dry, stable, granular material.
Claim 19
Dependent Claim
21 words
A process as claimed in claim 16, wherein the aqueous liquid is an aqueous saturated solution of the water-soluble crystalline salt.
References Cited (Backward Citations)
US1608737A
Cited
US1969980A
Cited
US2867523A
Cited
US3143410A
Cited
US3697245A
Cited
US3853490A
Cited
US3925053A
Cited
US4183738A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-07-06 | 1985-01-05 | 1985-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-06 | 1989-01-05 | 1989-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-06 | 1993-01-05 | 1993-07-07 | $7700.00 | Window Closed / Lapsed |