US4293097A
Expired / Lapsed
US
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Method for brightening natural calcitic ores
Assignee: Anglo American Clays Corp
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Filing: 1979-04-02
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Granted: 1981-10-06
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Expires: 1999-04-02
Abstract
Abstract A method is disclosed for processing a natural calcitic ore to yield a finely divided calcium carbonate particulate of very high brightness characteristics. The natural calcitic ore is initially coarse-milled to produce a product wherein no more than 5% by weight of the particulate is +325 mesh, and no more than 35% by weight of the particles are of less than 2 microns E.S.D. This coarse-milled product is then subjected as an aqueous slurry containing less than 40% and preferably less than 30% solids by weight, to a froth flotation, which separates with the froth the relatively coarse colorbodies liberated in the initial grinding. Preferable compositions for use in the froth flotation comprise 1-substituted-2-alkyl imidazolines or the salt derivatives thereof, with such compounds being utilized in admixture with a substantially non-polar aliphatic compound having from 10 to 20 carbon atoms in its longest straight chain. The purified underflow from the flotation step is dewatered to at least 60% solids by weight, and is wet-milled, as for example in a sand mill, to yield an output product wherein at least 80% by weight of the resultant particulate has an E.S.D. of less than 2 microns, the product being further characterized by a brightness of at least 95 on the G.E. scale.
Inventors
- 👤 Herbert I. Lewis
- 👤 Anthony D. McConnell
- 👤 William M. Price
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:13
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/02; C09C1/021; B; B03; B03D; B03D1/00; B03D1/001; B03D1/004; B03D1/006; B03D1/01; C01; C01F; C01F11/00; C01F11/18; C01F11/185; C09C3/00; C09C3/006; C09C3/04; C09C3/041; C09C3/08; B03D2201/00; B03D2201/007; B03D2201/02; B03D2203/00; B03D2203/02; B03D2203/04; B03D2203/10; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/60
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
151 words
A method for processing a natural calcitic ore to yield a finely divided calcium carbonate particulate of relatively very high brightness characteristics, comprising in sequence the steps of: coarse-milling said natural calcitic ores to produce a coarse-milled product; subjecting said coarse-milled product as an aqueous slurry including less than 40% solids to a froth flotation, and separating with the froth discoloring contaminants; dewatering the underflow product from said froth flotation to at least 60% solids by weight; and wet-milling the dewatered product to yield an output product wherein at least 80% by weight of the resultant particulate has an E.S.D. of less than 2 microns; said flotation step being conducted utilizing as a collector agent a 1-substituted-2-alkyl imidazoline or salt derivative thereof; and said collector agent being employed in conjunction with a promoter comprising a substantially nonpolar aliphatic compound having from 10 to 20 carbon atoms in its longest straight chain.
Claim 2
Independent Claim
151 words
A method for processing a natural calcitic ore to yield a finely divided calcium carbonate particulate of relatively very high brightness characteristics, comprising in sequence the steps of: coarse-milling said natural calcitic ores to produce a coarse-milled product; subjecting said coarse-milled product as an aqueous slurry including less than 40% solids to a froth flotation, and separating with the froth discoloring contaminants; dewatering the underflow product from said froth flotation to at least 60% solids by weight; and wet-milling the dewatered product to yield an output product wherein at least 80% by weight of the resultant particulate has an E.S.D. of less than 2 microns; said flotation step being conducted utilizing as a collector agent a 1-substituted-2-alkyl imidazoline or salt derivative thereof; and said collector agent being employed in conjunction with a promoter comprising a substantially nonpolar aliphatic compound having from 10 to 20 carbon atoms in its longest straight chain.
Claim 3
Dependent Claim
21 words
A method in accordance with claim 1, wherein said froth flotation is conducted with said slurry including less than 30% solids.
Claim 4
Dependent Claim
13 words
A method in accordance with claim 2, wherein said promoter is a hydrocarbon.
Claim 5
Dependent Claim
18 words
A method in accordance with claim 3, wherein said collector agent comprises a 1-hydroxyethyl-2-alkylimidazoline or salt derivative thereof.
Claim 6
Dependent Claim
18 words
A method in accordance with claim 3, wherein said collector agent comprises a 1-aminoethyl-2-alkylimidazoline or salt derivative thereof.
Claim 7
Dependent Claim
15 words
A method in accordance with claim 3, wherein said collector comprises a said salt derivative.
Claim 8
Dependent Claim
14 words
A method in accordance with claim 6, wherein said salt derivative comprises an acetate.
Claim 9
Dependent Claim
25 words
A method in accordance with claim 3, wherein said output product is further characterized by a brightness of at least 95 on the G.E. scale.
Claim 10
Dependent Claim
40 words
A method in accordance with claim 3, wherein said salt is utilized in concentrations of from about 1 to 5 lbs/ton of calcitic ore, and said neutral hydrocarbon in concentrations of from about 3 to 15 lbs/ton of said ore.
Claim 11
Dependent Claim
12 words
A method in accordance with claim 3, wherein said hydrocarbon comprises kerosene.
Claim 12
Dependent Claim
21 words
A method in accordance with claim 10, wherein said kerosene has been purified by separation therefrom of aromatic and cyclic compounds.
Claim 13
Dependent Claim
24 words
A method in accordance with claim 3, wherein the alkyl portion of said alkylimidazoline is the alkyl portion of oleic acid or tall oil.
Claim 14
Dependent Claim
44 words
A method in accordance with claim 3, wherein said coarse-milling effects reduction of said natural calcitic ore such that no more than 5% by weight of the particles thereof are +325 mesh, and no more than 35% are of less than 2 microns E.S.D.
Claim 15
Dependent Claim
15 words
A method in accordance with claim 13, wherein said wet-milling is effected by sand grinding.
Claim 16
Dependent Claim
18 words
A method in accordance with claim 13, wherein said froth flotation product is dewatered to over 65% solids.
Claim 17
Dependent Claim
15 words
A method in accordance with claim 2, wherein said coarse-milling is effected by dry grinding.
Claim 18
Dependent Claim
14 words
A method in accordance with claim 2, wherein said salt derivative is an acetate.
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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) | 1984-10-05 | 1985-04-06 | 1985-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-05 | 1989-04-06 | 1989-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-05 | 1993-04-06 | 1993-10-06 | $7700.00 | Window Closed / Lapsed |