US4522628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for removing ash mineral matter of coal with liquid carbon dioxide and water
Assignee: Mobil Oil AS
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Filing: 1983-07-19
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Granted: 1985-06-11
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Expires: 2003-07-19
Abstract
Abstract A method for removing the ash mineral matter content of coal and transporting the ash free coal from the point of ash removal to a coal use point comprising grinding run-of-mine coal to a desired particle size, mixing the coal particles with water and liquid carbon dioxide in a vessel in a swirling, fluidized state at a pressure, temperature, and for a residence time sufficient to free substantially all of the ash mineral matter from the coal and form an ash free coal/mineral matter slurry, separating the ash free coal particles from the slurry by froth floatation, drying the ash free coal particles, forming a slurry of the ash free coal particles with liquid carbon dioxide, transporting the ash free coal/liquid carbon dioxide slurry by pipeline to a coal use point, deslurrying the ash free coal/liquid carbon dioxide slurry, recovering the ash free coal particles for intended use and recycling the coal-free liquid carbon dioxide recovered from deslurrying for treating additional coal in the ash removal step.
Inventors
- 👤 Joseph G. Savins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:18
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0391
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
126 words
A method for removing the ash mineral matter content of run-of-mine coal comprising: (a) grinding the run-of-mine coal to a particle size to form a suitable slurry; (b) mixing the coal particles with water and liquid carbon dioxide in a vessel; (c) determining the solubility parameter of said coal and maintaining the mixture of coal particles, liquid carbon dioxide, and water in the mixing vessel in a swirling, fluidized state at a pressure, temperature, and for a residence time sufficient to separate ash mineral matter from the coal particles and form an ash free coal/mineral matter slurry; and (d) separating the ash free coal particles from the ash free coal/mineral matter slurry by froth floatation and recovering the coal particles substantially free of ash mineral matter.
Claim 2
Independent Claim
126 words
A method for removing the ash mineral matter content of run-of-mine coal comprising: (a) grinding the run-of-mine coal to a particle size to form a suitable slurry; (b) mixing the coal particles with water and liquid carbon dioxide in a vessel; (c) determining the solubility parameter of said coal and maintaining the mixture of coal particles, liquid carbon dioxide, and water in the mixing vessel in a swirling, fluidized state at a pressure, temperature, and for a residence time sufficient to separate ash mineral matter from the coal particles and form an ash free coal/mineral matter slurry; and (d) separating the ash free coal particles from the ash free coal/mineral matter slurry by froth floatation and recovering the coal particles substantially free of ash mineral matter.
Claim 3
Dependent Claim
35 words
The method of claim 1 wherein the pressure during step (c) is within the range of 900 to 3000 psia and the temperature is sufficient to produce a single phase of carbon dioxide and water.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein the pressure during step (c) is about 1000 psia and the temperature is about 104° F.
Claim 5
Dependent Claim
21 words
The method of claim 1 further comprising withdrawing large ash forming mineral matter particles from the bottom of said mixing vessel.
Claim 6
Independent Claim
230 words
A method for removing the ash mineral matter content of run-of-mine coal and transporting the low ash content coal from the ash demineralizing point to a coal use point comprising: (a) grinding the run-of-mine coal to a particle size to form a suitable slurry; (b) mixing the coal particles with water and liquid carbon dioxide in a vessel; (c) determining the solubility parameter of said coal and maintaining the mixture of coal particles, liquid carbon dioxide, and water in the mixing vessel in a swirling, fluidized state at a pressure, temperature, and for a residence time sufficient to separate ash mineral matter from the coal particles and form an ash free coal/mineral matter slurry; (d) separating the low ash coal particles from the coal/mineral slurry by froth floatation and recovering the coal particles substantially free of ash mineral matter; (e) drying said recovered ash free coal particles; (f) slurrying said dried ash free coal particles with liquid carbon dioxide to form an ash free coal/carbon dioxide slurry; (g) pumping said slurry through a pipeline to said coal use point; (h) deslurrying said ash free coal/carbon dioxide slurry at said coal use point to separate said ash free coal and said liquid carbon dioxide; and (i) recovering said coal-free liquid carbon dioxide and passing said liquid carbon dioxide through a pipeline for admixture with said coal being treated in step (b).
Claim 7
Independent Claim
230 words
A method for removing the ash mineral matter content of run-of-mine coal and transporting the low ash content coal from the ash demineralizing point to a coal use point comprising: (a) grinding the run-of-mine coal to a particle size to form a suitable slurry; (b) mixing the coal particles with water and liquid carbon dioxide in a vessel; (c) determining the solubility parameter of said coal and maintaining the mixture of coal particles, liquid carbon dioxide, and water in the mixing vessel in a swirling, fluidized state at a pressure, temperature, and for a residence time sufficient to separate ash mineral matter from the coal particles and form an ash free coal/mineral matter slurry; (d) separating the low ash coal particles from the coal/mineral slurry by froth floatation and recovering the coal particles substantially free of ash mineral matter; (e) drying said recovered ash free coal particles; (f) slurrying said dried ash free coal particles with liquid carbon dioxide to form an ash free coal/carbon dioxide slurry; (g) pumping said slurry through a pipeline to said coal use point; (h) deslurrying said ash free coal/carbon dioxide slurry at said coal use point to separate said ash free coal and said liquid carbon dioxide; and (i) recovering said coal-free liquid carbon dioxide and passing said liquid carbon dioxide through a pipeline for admixture with said coal being treated in step (b).
Claim 8
Dependent Claim
35 words
The method of claim 5 wherein the pressure during step (c) is within the range of 900 to 3000 psia and the temperature is sufficient to produce a single phase of carbon dioxide and water.
Claim 9
Dependent Claim
22 words
The method of claim 5 wherein the pressure during step (c) is about 1000 psia and the temperature is about 104° F.
Claim 10
Dependent Claim
37 words
The method of claim 4 further comprising recycling at least a portion of said coal-free liquid carbon dioxide recovered during step (h) back to said ash removal point for reuse in forming said slurry during step (f).
Claim 11
Dependent Claim
67 words
The method of claim 5 further comprising withdrawing a portion of the separated coal particles substantially free of ash mineral matter prior to drying, reducing the particle size of said ash free coal particles to a particle size that will pass a 325 mesh screen, and then mixing the resulting finely divided ash free coal particles with the ash free coal particles being dried during step (e).
Claim 12
Dependent Claim
34 words
The method of claim 5 further comprising adding a viscosity-increasing additive to the ash free coal/carbon dioxide slurry formed during step (f) to improve the suspending ability of the ash free coal/carbon dioxide slurry.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |