US4483934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for beneficiating bentonite
Assignee: SOUTHERN CLAY PRODUCTS Inc A Corp OF TEXAS
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Filing: 1983-05-10
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Granted: 1984-11-20
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Expires: 2003-05-10
Abstract
Abstract Raw bentonite is beneficiated by treating a substantially iron oxide-free bentonite, as an aqueous suspension, with an alkali at a temperature of at least 60° C.; washing the alkali treated bentonite at least once with water; and then subjecting a suspension of the alkali-treated and washed bentonite to shearing, attrition and impact forces in a homogenizer of the type wherein the suspension is forced in the form of a film through a thin, hard-surfaced gap under a pressure of at least 1.7 MPa, and at high velocity. The suspension of bentonite thus obtained can then be dried to a product which has a good white color and is more resistent to bacteriological growth.
Inventors
- 👤 Howard Goodman
- 👤 Ian S. Bleakley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:38
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/26; Y; Y10; Y10S; Y10S106/00; Y10S106/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
136 words
A process for beneficiating raw bentonite which process comprises the steps of: (i) treating a raw bentonite, as mined, to reduce substantially surface staining by iron oxides; (ii) treating the substantially iron oxide-free bentonite, as an aqueous suspension, with an alkali at a temperature of at least 60° C.; (iii) dewatering the aqueous suspension of alkali-treated bentonite; (iv) washing the dewatered bentonite solids from step (iii) at least once with water; (v) resuspending the alkali-treated and washed bentonite in water; (vi) subjecting the suspension formed in step (v) to shearing, attrition an impact forces in a homogeniser of the type wherein the suspension is forced in the form of a film through a thin, hard surfaced gap under a pressure of at least 1.7 MPa and at high velocity; and (vii) drying the suspension of bentonite.
Claim 2
Dependent Claim
136 words
A process for beneficiating raw bentonite which process comprises the steps of: (i) treating a raw bentonite, as mined, to reduce substantially surface staining by iron oxides; (ii) treating the substantially iron oxide-free bentonite, as an aqueous suspension, with an alkali at a temperature of at least 60° C.; (iii) dewatering the aqueous suspension of alkali-treated bentonite; (iv) washing the dewatered bentonite solids from step (iii) at least once with water; (v) resuspending the alkali-treated and washed bentonite in water; (vi) subjecting the suspension formed in step (v) to shearing, attrition an impact forces in a homogeniser of the type wherein the suspension is forced in the form of a film through a thin, hard surfaced gap under a pressure of at least 1.7 MPa and at high velocity; and (vii) drying the suspension of bentonite.
Claim 3
Dependent Claim
55 words
A process according to claim 1, wherein the surface staining by iron oxides is reduced substantially by forming the bentonite into a slurry with water containing at least one of a water-soluble reducing bleaching agent and a complexing agent for ferric iron, and thereafter separating the bentonite from the aqueous solution containing dissolved iron compounds.
Claim 4
Dependent Claim
24 words
A process according to claim 2 wherein the bentonite is crushed and milled before treatment with the reducing bleaching agent and/or the complexing agent.
Claim 5
Dependent Claim
43 words
A process according to claim 1, wherein, in step (ii), the aqueous suspension of the substantially iron oxide-free bentonite which is treated with an alkali has a solids content in the range of from 1% to about 20% by weight of dry bentonite.
Claim 6
Dependent Claim
23 words
A process according to claim 1, wherein, in step (ii), the alkali used is a hydroxide or carbonate of sodium, potassium or lithium.
Claim 7
Dependent Claim
30 words
A process according to claim 1, wherein, in step (ii), the bentonite is treated with the alkali for at least 30 minutes at a temperature of at least 90° C.
Claim 8
Dependent Claim
38 words
A process according to claim 1, wherein, in step (v), the alkali-treated and washed bentonite is formed into a suspension having a solids content in the range of from 1% to about 25% by weight of dry bentonite.
Claim 9
Dependent Claim
36 words
A process according to claim 1, wherein, in step (vi), the suspension is subjected to shearing, attrition and impact forces in the homogeniser with the latter being operated at a pressure of at least 21 MPa.
Claim 10
Dependent Claim
25 words
A process according to claim 1, wherein, in step (vii), the bentonite is dried thermally until it contains less than 10% by weight of water.
Claim 11
Dependent Claim
20 words
A process according to claim 1, wherein the dried bentonite obtained in step (vii) is milled to a fine powder.
References Cited (Backward Citations)
US2305404A
Cited
US3039703A
Cited
US3193344A
Cited
US3162379A
Cited
US3408305A
Cited
US3899343A
Cited
US4371626A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-20 | 1988-05-21 | 1988-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-20 | 1992-05-21 | 1992-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-20 | 1996-05-21 | 1996-11-20 | $7700.00 | Window Closed / Lapsed |