US4282006A
Expired / Lapsed
US
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Coal-water slurry and method for its preparation
Assignee: Alfred University Research Foundation Inc
•
Filing: 1979-10-26
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Granted: 1981-08-04
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Expires: 1999-10-26
Abstract
Abstract A pipeline pumpable coal-water slurry having a novel combination of coal particles and carrier water is prepared by a method wherein the particle sizes and their distribution are controlled in accordance with a particle size distribution formula which is especially beneficial for providing a novel coal compact with a minimum amount of void space between particles and a maximum amount of particle surface area with an advantageous amount of colloidal sized particles present. These features combine to enhance the dispersing effects generated by electrolytes and/or dispersing agents selected and added to the coal compact and/or slurry to provide a near maximum zeta potential to the particles in the slurry and to provide low viscosity to the resulting yield pseudoplastic coal-water slurry. Brookfield viscosities obtained, e.g. 1000 cps, or less, at 60 rpm with 75 wt. % coal, dry basis, make the coal-water slurry especially advantageous for transport by pipeline over long distances. The coal-water slurry can be provided at a high coal content so that the slurry can be burned directly without need for dewatering at its destination.
Inventors
- 👤 James E. Funk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:14
CPC Classifications
C; C21; C21B; C21B5/00; C21B5/001; C21B5/003; C21B5/004; C10; C10L; C10L1/00; C10L1/32; C10L1/326; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134; Y10; Y10S; Y10S48/00; Y10S48/07
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
118 words
A coal compact comprising finely divided coal particles, characterized in that said coal compact comprises finely divided coal particles having a particle size in the range of 1180 μm to 0.05 μm with at least 5 wgt. % of the particles being of colloidal size, said particles in said compact having a particle size distribution substantially in accordance with the following formula: ##EQU6## wherein, when said compact is admixed with dispersing agent and a sufficient amount of water to produce a suspension containing at least about 60 weight percent of said coal and at least about 20 weight percent of said water, said suspension has a Brookfield viscosity at 60 revolutions per minute of less than 4000 centipoise.
Claim 2
Dependent Claim
118 words
A coal compact comprising finely divided coal particles, characterized in that said coal compact comprises finely divided coal particles having a particle size in the range of 1180 μm to 0.05 μm with at least 5 wgt. % of the particles being of colloidal size, said particles in said compact having a particle size distribution substantially in accordance with the following formula: ##EQU6## wherein, when said compact is admixed with dispersing agent and a sufficient amount of water to produce a suspension containing at least about 60 weight percent of said coal and at least about 20 weight percent of said water, said suspension has a Brookfield viscosity at 60 revolutions per minute of less than 4000 centipoise.
Claim 3
Dependent Claim
38 words
A coal compact according to claim 1 characterized in that said colloidal particles are of (-) 3 μm size and said compact contains from about 5.0 to about 35.7 cumulative weight percent of particles finer than 3 μm.
Claim 4
Dependent Claim
161 words
A coal compact according to claim 1 characterized in that said D L , D S , n and the wgt. % of particles of (-) 3 μm size are in accordance with said formula wherein: (a) D L =about 425 μm, D S =0.1 to 1.0 μm, n=0.2 to 0.5, (-) 3 μm sized particles are from 17.7 to 5.8 wgt. %, respectively, (b) D L =about 300 μm, D S =0.05 to 0.5, n=0.2 to 0.635, (-) 3 μm sized particles are from 20.5 to 5.0 wgt. %, respectively, (c) D L =about 1180 μm, D S =0.1 to 1.0, n=0.12 to 0.4, (-) 3 μm sized particles are from 19.5 to 5.7 wgt. %, respectively, and (d) D L =about 38 μm, D S =0.1 to 1.0, n=0.22 to 1.0, (-) 3 μm sized particles are from 35.7 to 7.0 wgt. %, respectively, said wgt. % being based on total weight of coal in said compact, dry basis.
Claim 5
Dependent Claim
121 words
A stable, yield-pseudoplastic coal-water slurry with a Brookfield viscosity at 60 revolutions per minute of less than 4000 centipoise; said slurry containing at least about 60 weight percent of coal, at least about 20 weight percent of water, and dispersing agent; said slurry comprising a compact of finely-divided particles of coal dispersed in said water characterized in that said compact comprises finely-divided coal particles having a particle size in the range of 1180 μm to 0.05 μm with at least 5 wgt. % of the particles being of colloidal size, said particles in said compact having a particle size distribution substantially in accordance with the following formula: ##EQU7## and said coal particles having near maximum zeta potential in said coal-water slurry.
Claim 6
Dependent Claim
121 words
A stable, yield-pseudoplastic coal-water slurry with a Brookfield viscosity at 60 revolutions per minute of less than 4000 centipoise; said slurry containing at least about 60 weight percent of coal, at least about 20 weight percent of water, and dispersing agent; said slurry comprising a compact of finely-divided particles of coal dispersed in said water characterized in that said compact comprises finely-divided coal particles having a particle size in the range of 1180 μm to 0.05 μm with at least 5 wgt. % of the particles being of colloidal size, said particles in said compact having a particle size distribution substantially in accordance with the following formula: ##EQU7## and said coal particles having near maximum zeta potential in said coal-water slurry.
Claim 7
Dependent Claim
49 words
A coal-water slurry according to claim 4 characterized in that said slurry contains from 60 to 75 wgt. % of coal, dry basis, said coal is Black Mesa mine coal, and said slurry has a Brookfield viscosity at 60 rpm of from about 300 to about 4000 cps, respectively.
Claim 8
Dependent Claim
47 words
A coal-water slurry according to claim 4 characterized in that said slurry contains from 65 to 80 wgt. % of coal, dry basis, said coal is West Virginia mine coal, and said slurry has a Brookfield viscosity at 60 rpm of about 200 to about 2400 cps.
Claim 9
Dependent Claim
38 words
A coal-water slurry according to claim 4 characterized in that said colloidal particles are of (-) 3 μm size and said compact contains from about 5.0 to about 35.7 cumulative weight percent of particles finer than 3 microns.
Claim 10
Dependent Claim
160 words
A coal-water slurry according to claim 4 characterized in that said D L , D S , n and the wgt. % of (-) 3 μm size particles are in accordance with said formula wherein: (a) D L =about 425 μm, D S =0.1 to 1.0 μm, n=0.2 to 0.5, (-) 3 μm sized particles are from 17.7 to 5.8 wgt. %, respectively, (b) D L =about 300 μm, D S =0.05 to 0.5, n=0.2 to 0.635, (-) 3 μm sized particles are from 20.5 to 5.0 wgt. %, respectively, (c) D L =about 1180 μm, D S =0.1 to 1.0, n=0.12 to 0.4, (-) 3 μm sized particles are from 19.5 to 5.7 wgt. %, respectively, and (d) D L =about 38 μm, D S =0.1 to 1.0, n=0.22 to 1.0, (-) 3 μm sized particles are from 35.7 to 7.0 wgt. %, respectively, said wgt. % being based on total weight of coal in said compact, dry basis.
Claim 11
Dependent Claim
41 words
A coal-water slurry according to claim 4 characterized in that D L =about 300 μm, D S =<1.0 μm, n=0.2 to 0.635 and (-) 3 μm size particles=20.5 to 5.0 wgt. %, respectively, of the total weight of coal, dry basis.
Claim 12
Dependent Claim
38 words
A coal-water slurry according to claim 4 characterized in that D L =about 300 μm, D S =<0.5 μm, n=about 0.4, and (-) 3 μm sized particles=about 9 wgt. % based on total weight of coal, dry basis.
Claim 13
Dependent Claim
37 words
A coal-water slurry according to claim 4 characterized in that said dispersing agent is present in an amount sufficient to disperse said coal particles and to maintain the dispersed coal particles at said near maximum zeta potential.
Claim 14
Dependent Claim
28 words
A coal-water slurry according to claim 11 characterized in that said amount of dispersing agent is from 0.05 to 2 wgt. % based on dry weight of coal.
Claim 15
Dependent Claim
27 words
A coal-water slurry according to claim 12 wherein said dispersing agent is an organic or inorganic surfactant and characterized in that said surfactant is an anionic surfactant.
Claim 16
Dependent Claim
59 words
A coal-water slurry according to claim 13 characterized in that the anionic surfactant is selected from the group of anionic surfactants consisting of: (i) 2-ethylhexyl polyphosphoric ester acid anhydride and its potassium salt, (ii) complex organic polyphosporic ester acid anhydride and its potassium salt, (iii) alkyl mononaphthalene sulfonic acid and its sodium and ammonium salts, and (iv) mixtures thereof.
Claim 17
Dependent Claim
23 words
A coal-water slurry according to claim 14 characterized in that the anionic surfactant is a sodium salt of an alkyl mononaphthalene sulfonic acid.
Claim 18
Dependent Claim
50 words
A coal-water slurry according to claim 4 further comprising at least one electrolyte and characterized in that said electrolyte is present in an amount effective to modify the structure of the bound water layers of said coal particles and help to maintain said particles at said near maximum zeta potential.
Claim 19
Dependent Claim
27 words
A coal-water slurry according to claim 16 characterized in that said amount of electrolyte is up to about 2 wgt. % based on dry weight of coal.
Claim 20
Dependent Claim
38 words
A coal-water slurry according to claim 17 characterized in that said electrolyte is a compound selected from the group of inorganic compounds consisting of NaOH, K 2 CO 3 , and Na 2 SiO 3 ·9H 2 O.
Claim 21
Dependent Claim
14 words
A coal-water slurry according to claim 18 characterized in that said electrolyte is NaOH.
Claim 22
Dependent Claim
41 words
A coal-water slurry according to claim 16 characterized in that said dispersing agent and said electrolyte are present in a total amount sufficient to disperse said coal particles and to maintain the dispersed coal particles at said near maximum zeta potential.
Claim 23
Dependent Claim
92 words
A coal-water slurry according to claim 20 characterized in that said dispersing agent is an organic surfactant selected from the group of anionic surfactants consisting of: (i) 2-ethylhexyl polyphosphoric ester acid anhydride and its potassium salt, (ii) complex organic polyphosphoric ester acid anhydride and its potassium salt, (iii) alkyl mononaphthalene sulfonic acid and its sodium and ammonium salts, and (iv) mixtures thereof, and said electrolyte is an inorganic compound selected from the group of inorganic compounds consisting of NaOH, K 2 CO 3 , and Na 2 SiO 3 ·9H 2 O.
Claim 24
Dependent Claim
28 words
A coal-water slurry according to claim 21 characterized in that said dispersing agent is a sodium salt of an alkyl mononaphthalene sulfonic acid and said electrolyte is NaOH.
Claim 25
Dependent Claim
22 words
A coal-water slurry according to claim 4 characterized in that said near maximum zeta potential is less than about (-) 100 millivolts.
Claim 26
Dependent Claim
22 words
A coal-water slurry according to claim 4 characterized in that near maximum zeta potential is about (-) 50 to (-) 60 millivolts.
Claim 27
Dependent Claim
71 words
A method for preparing a coal-fluid suspension with a Brookfield viscosity at 60 revolutions per minute of less than 4000 centipoise, comprising the steps of: (a) providing the coal compact of claim 1, and (b) mixing said compact with dispersing agent and a sufficient amount of fluid to produce a suspension containing at least about 60 weight percent of said coal and at least about 20 weight percent of said fluid.
Claim 28
Dependent Claim
12 words
The method as recited in claim 25, wherein said fluid is water.
Claim 29
Dependent Claim
41 words
The method as recited in claim 26, wherein a sufficient amount of said dispersing agent is mixed with said compact to disperse said coal particles and to maintain the dispersed coal particles at near maximum zeta potential in said coal-water slurry.
Claim 30
Dependent Claim
26 words
The method as recited in claim 26, wherein up to about 4 percent of dispersing agent, by weight of dry coal, is mixed with said compact.
Claim 31
Dependent Claim
27 words
The method as recited in claim 28, wherein said suspension has a Brookfield viscosity at 60 revolutions per minute of from about 300 to about 4000 centipoise.
Claim 32
Dependent Claim
27 words
The method as recited in claim 28, wherein said suspension has a Brookfield viscosity at 60 revolutions per minute of from about 200 to about 2400 centipoise.
Claim 33
Dependent Claim
161 words
The method as recited in claim 28, wherein said D L , D S , n, and the weight percent of (-) 3 μm size particles are in accordance with said formula, wherein: (a) D L =about 425 μm, D S =0.1 to 1.0 μm, n=0.2 to 0.5, (-) 3 μm sized particles are from 17.7 to 5.8 wgt. %, respectively, (b) D L =about 300 μm, D S =0.05 to 0.5 μm, n=0.2 to 0.635, (-) 3 μm sized particles are from 20.5 to 5.0 wgt. %, respectively, (c) D L =about 1180 μm, D S =0.1 to 1.0 μm, n=0.12 to 0.4, (-) 3 μm sized particles are from 19.5 to 5.7 wgt. %, respectively, and (d) D L =about 38 μm, D S =0.1 to 1.0, μm, n=0.22 to 1.0, (-) 3 μm sized particles are from 35.7 to 7.0 wgt. %, respectively, said wgt. % being based on total weight of coal in said compact, dry basis.
Claim 34
Dependent Claim
39 words
The method as recited in claim 28 wherein D L =about 300 μm, D S =1.0 μm, n=0.2 to 0.635, and (-) 3 μm size particles=20.5 to 5.0 wgt. % respectively, of the total weight of coal, dry basis.
Claim 35
Dependent Claim
36 words
The method as recited in claim 28, wherein D L =about 300 μm, D S =0.5 μm, n=about 0.4, and (-) 3 μm sized particles=about 9 wgt. % based on total weight of coal, dry basis.
Claim 36
Dependent Claim
29 words
The method as recited in claim 28, wherein from about 0.05 to about 2.0 percent of said dispersing agent, by weight of dry coal, is mixed with said compact.
Claim 37
Dependent Claim
15 words
The method as recited in claim 34, wherein said dispersing agent is an anionic surfactant.
Claim 38
Dependent Claim
54 words
The method as recited in claim 35, wherein said anionic surfactant is selected from the group consisting of: (i) 2-ethylhexyl polyphosphoric ester acid anhydride and its potassium salt, (ii) complex organic polyphosphoric ester acid anhydride and its potassium salt, (iii) alkyl mononaphthalene sulfonic acid and its sodium and ammonium salts, and (iv) mixtures thereof.
Claim 39
Dependent Claim
21 words
The method as recited in claim 36, wherein said anionic surfactant is a sodium salt of an alkyl mononaphthalene sulfonic acid.
Claim 40
Dependent Claim
25 words
The method as recited in claim 28, wherein up to about 2 percent, by weight of dry coal, of electrolyte is mixed with said compact.
Claim 41
Dependent Claim
14 words
The method as recited in claim 38, wherein said electrolyte is an inorganic compound.
Claim 42
Dependent Claim
31 words
The method as recited in claim 39, wherein said electrolyte is selected from the group consisting of NaOH, K 2 CO 3 , and Na 2 SiO 3 ·9H 2 O.
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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) | 1984-08-03 | 1985-02-02 | 1985-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-03 | 1989-02-02 | 1989-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-03 | 1993-02-02 | 1993-08-04 | $7700.00 | Window Closed / Lapsed |