US4270926A
Expired / Lapsed
US
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Process for removal of sulfur and ash from coal
Assignee: Atlantic Richfield Co
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Filing: 1979-06-19
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Granted: 1981-06-02
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Expires: 1999-06-19
Abstract
Abstract A process for reducing the sulfur and ash content of coal wherein coal particles are treated in an aqueous slurry with a minor amount of hydrocarbon oil to form coal-oil aggregates. The coal-oil aggregates are separated from ash and mineral matter in the slurry by dissolved gas flotation. Optionally, the coal particles may be treated with a conditioning agent prior to the aggregation step. Recovered coal particles comprise a substantial part of the feed carbon values.
Inventors
- 👤 Emmett H. Burk, Jr.
- 👤 Jui-Yuan Sun
- 👤 Lloyd A. Baillie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:53
CPC Classifications
B; B03; B03D; B03D1/00; B03D1/02; B03D1/14; B03D1/1431; C; C10; C10L; C10L9/00
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
71 words
A process for reducing the sulfur and ash content of coal comprising the steps of: (a) providing an aqueous slurry of coal particles containing ash and pyritic sulfur mineral matter; (b) adding to the slurry and minor amount of hydrocarbon oil sufficient to effect aggregation of the coal particles; (c) separating the coal-oil aggregates from the aqueous slurry by dissolved gas flotational means; and (d) recovering coal-oil aggregates of reduced sulfur.
Claim 2
Dependent Claim
71 words
A process for reducing the sulfur and ash content of coal comprising the steps of: (a) providing an aqueous slurry of coal particles containing ash and pyritic sulfur mineral matter; (b) adding to the slurry and minor amount of hydrocarbon oil sufficient to effect aggregation of the coal particles; (c) separating the coal-oil aggregates from the aqueous slurry by dissolved gas flotational means; and (d) recovering coal-oil aggregates of reduced sulfur.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein the hydrocarbon oil is derived from petroleum, shale oil, tar sands or coal.
Claim 4
Dependent Claim
35 words
The process of claim 1 wherein the hydrocarbon oil is selected from the group consisting of light cycle oil, heavy cycle oil, gas oil, vacuum gas oil, clarified oil, kerosene, light naphtha, and heavy naphtha.
Claim 5
Dependent Claim
19 words
The process of claim 1 wherein the hydrocarbon oil is added to the slurry as an emulsion in water.
Claim 6
Dependent Claim
31 words
The process of claim 1 wherein the aggregation of coal particles is effected by adding hydrocarbon oil to the slurry at a temperature within the range from 0° to 100° C.
Claim 7
Dependent Claim
31 words
The process of claim 5 wherein the aggregation of coal particles is effected by adding hydrocarbon oil to the slurry at a temperature within the range from 20° to 70° C.
Claim 8
Dependent Claim
19 words
The process of claim 5 wherein the hydrocarbon oil is added to the slurry as an emulsion in water.
Claim 9
Dependent Claim
26 words
The process of claim 1 wherein the coal-oil aggregates contain from about 2 wt. % to about 10 wt. %, based on coal, of hydrocarbon oil.
Claim 10
Dependent Claim
26 words
The process of claim 1 wherein the coal-oil aggregates contain from about 3 wt. % to about 8 wt. %, based on coal, of hydrocarbon oil.
Claim 11
Dependent Claim
50 words
The process of claim 1 wherein the coal particles are minus 24 mesh, and the gas flotation means is a gas dissolved in the aqueous slurry under super-atmospheric pressure and the aqueous slurry is introduced to a flotation chamber such that at least a portion of the coal-oil aggregates float.
Claim 12
Dependent Claim
42 words
The process of claim 10 wherein the coal particles are minus 48 mesh the gas dissolved in the aqueous slurry is selected from the group consisting of air, carbon dioxide, nitrogen and methane under a pressure of from 1 to 200 psig.
Claim 13
Dependent Claim
11 words
The process of claim 11 wherein the dissolved gas is air.
Claim 14
Dependent Claim
18 words
The process of claim 11 wherein the floating coal-oil aggregates are separated from the aqueous slurry by skimming.
Claim 15
Dependent Claim
24 words
The process of claim 1 wherein coal particles having a reduced pyritic sulfur and ash content are recovered from the recovered size-modified coal-oil aggregates.
Claim 16
Dependent Claim
20 words
The process of claim 1 wherein the coal is selected from the group consisting of bituminous and higher ranked coal.
Claim 17
Dependent Claim
20 words
The process of claim 1 wherein the ash content of the recovered coal is reduced by at least about 20%.
Claim 18
Dependent Claim
21 words
The process of claim 1 wherein the pyritic sulfur content of the recovered coal is reduced by at least about 40%.
Claim 19
Dependent Claim
65 words
The process of claim 1 wherein, prior to aggregation, the slurried coal particles are contacted with a promoting amount of at least one conditioning agent capable of modifying or altering the existing surface characteristics of the ash and pyritic sulfur mineral matter under conditions whereby there is effected modification or alteration of at least a portion of the contained ash and pyritic sulfur mineral matter.
Claim 20
Dependent Claim
21 words
The process of claim 18 wherein the conditioning agent is an inorganic compound capable of hydrolyzing in the presence of water.
Claim 21
Dependent Claim
24 words
The process of claim 19 wherein the conditioning agent is an inorganic compound hydrolyzable in water to form a high surface area inorganic gel.
Claim 22
Dependent Claim
81 words
The process of claim 19 wherein the conditioning agent is selected from the group consisting of metal oxides and hydroxides having the formula M a O b .×H 2 O or M(OH) c .×H 2 O wherein M is Al, Fe, Co, Ni, Zn, Ti, Cr, Mn, Mg, Pb, Ca, Ba, In or Sb; a, b and c are whole numbers dependent upon the ionic valence of M; and x is a whole number within the range from 0 to 3.
Claim 23
Dependent Claim
23 words
The process of claim 21 wherein the conditioning agent is selected from the group consisting of calcium oxide, magnesium oxide and mixtures thereof.
Claim 24
Dependent Claim
31 words
The process of claim 21 wherein the conditioning agent is selected from the group consisting of aluminum oxide, aluminum hydroxide and mixtures thereof, hydrolyzed in water to form an alumina gel.
Claim 25
Dependent Claim
66 words
The process of claim 18 wherein the conditioning agent is selected from the group consisting of metal aluminates having the formula M' d (Al O 3 ) e or M' f (Al O 2 ) g , wherein M' is Fe, Co, Ni, Zn, Mg, Pb, Ca, Ba or Mo; and de, e, f and g are whole numbers dependent upon the ionic valence of M'.
Claim 26
Dependent Claim
24 words
The process of claim 24 wherein the conditioning agent is selected from the group consisting of calcium, magnesium, and iron aluminates and mixtures thereof.
Claim 27
Dependent Claim
41 words
The process of claim 18 wherein the conditioning agent is selected from the group consisting of aluminosilicates having the formula Al 2 O 3 .×SiO 2 , wherein x is a number within the range from about 0.5 to about 5.0.
Claim 28
Dependent Claim
28 words
The process of claim 18 wherein the conditioning agent is selected from the group consisting of metal silicates wherein the metal is calcium, magnesium, barium, iron or tin.
Claim 29
Dependent Claim
23 words
The process of claim 27 wherein the conditioning agent is selected from the group consisting of calcium silicate, magnesium silicate and mixtures thereof.
Claim 30
Dependent Claim
24 words
The process of claim 18 wherein the conditioning agent is selected from the group consisting of inorganic cement materials capable of binding mineral matter.
Claim 31
Dependent Claim
29 words
The process of claim 29 wherein the conditioning agent is selected from the group consisting of portland cement, natureal cement, masonry cement, pozzolan cement, calcined limestone and calcined dolomite.
Claim 32
Dependent Claim
13 words
The process of claim 30 wherein the cement material is hydrolyzed portland cement.
References Cited (Backward Citations)
US3458044A
Cited
US3747757A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-01 | 1984-12-01 | 1985-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-01 | 1988-12-01 | 1989-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-01 | 1992-12-01 | 1993-06-02 | $7700.00 | Window Closed / Lapsed |