CA1200697A - Coal - aqueous mixtures - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE Coal-aqueous mixture having high solids content and excellent stability are provided by an improved process involving selective mixing and other conditions.

Description

40~6 c37 COAL-AQUEOUS MIXTURES
The present invention relates to the dispersion of carbonaceous materials and more particularly to coal-aqueous coal mixtures.
Coal as an energy source is in abundant supply.
It is estimated that in the ~nited States there is more energy avaiable in coal than in petroleum, natural gas, oil shale and tar sands combined. The substitution of coal ~or natural gas and oil on a large scale would there-10 fore seem a ready-made solution to our ener~y problems.
Unfortunately, however, unli~e oil and gas consumption, coal use is limited not by reserves or production capacity but rather by the extraordinary industrial and regulatory difficulties of burning it in a convenient, efficient and 15 environmentally acceptable manner.
A number of techniques are being explored to provide coal as a more useful energy source. One such technique employs gasification methods such as destructive distillation, to effect the conversion of coal to a low 20or medium Btu gas. In another approach, high pressure hydrogenation is utilized to liquefy coal to make it more suited for transport, burning and the like.
Another technique suggested, and the one to which the present invention relates, is the technique 25 whereby solid coal particles are dispersed in a fluid carrier medium, such as fuel oil or water to form coal-aqueous or coal-oil mixtures.
Coal-oil and coal-aqueous mixtures, however, are distinct systems, each having its own difficulties 300f formulation. For example, while coal and oil are relatively compatible,coal and water are not. Thus, unlike in the formulation of coal-oil admixutres, in .,~ , .....
' ~1~, ., ~Z0~9~

1 the formulation of coal-aqueous admixtures, the initial dispersing of the coal in the continuous water phase, eSpecially large amounts of coal, represents a challenging obstacle. Moreover, after dispersion, stabilizing,i.e.
5keeping the coal from settling out of the water phase, must be also achieved~
Such coal mixtures offer considerable advantages.
They are more readily transported then dry solid coal, are more easily stored and are less subject to the risks lOof explosion by spontaneous ignition, the latter being a significant factor in handling coal. In addition, providing coal in a fluid form can permit its burning in apparatus normally used for burning fuel oil. This can greatly acilitate the transition from fuel oil to 15coal as a primary energ~ source, another highly desirable result.
Various coal-oil and coal-aqueous mixtures have been described in the literature. For example, British Patent No. 1,523,193 discloses a mixture comprised of 20 fuel oil and from 15 to 55% by weight of finely ground coal particles reduced in particle size to 10 microns or finer. The effort required to grind coal to such fine sizes, however, makes the process less economically attractive. Moreover, the use of fuel oil as a carrier 25medium negates the requirement of lessening our dependence upon fuel oil.
U.S. Patent No. 4,251,229 is an example of coal-oil mixtures stabili.zed with high molecular weight adduc~s of alkylene oxide and an alcohol, an amine, a carboxylic 30acid or phenol having at least three active hydrogens.
In this patent, oil is the continuous carrier phase and '~ `

~Z~697 accordingly, the stabillzation of the coal, as emphasized repeatedly therein, in the continuous oil phase,is essen-tially the only concern.
~.S. Patent No. 4,2a2,098 discloses aqueous 5coal slurry compositions containing water soluble polymers, which are thickeners,SUCh as xanthan gum, hydroxypropyl guar gum or poly(ethylene oxide) having a molecular weight over 100,000.
In United States Patent No. 3,762,887, there is lOdisclosed a dispersion of coal in an aqueous medium wherein the coal is ground to a defined array of particle sizes, a substantial portion of which being about 325 mesh Tyler Standard screen or even finer. Here again, substantial and selective grinding of the coal is xequired.
United States Patent No. 4,217,109, discloses a technique for cleaning and dispersing coal in water utilizing dispersing agents which by selective adsorption impart different electrical charges to the carbon particles and the impurities. The dispersing agents taught are 20polyelectrolytes, such as alkali metal and ~m~n; um salts of polycarboxylic acids and polyphosphates.
The article titled "Development and Evaluation of }lighly-Loaded Coal Slurries" published in the 2nd Inter-national Symposium on Coal-Oil Mixture Combustion, 25No~ember 27-29, 1979, teaches coal-aqueous mixtures using coal of bimodal particle si~e distributions and containing modified starches, biocides and a wetting agent such as TRI~ON X, an octylphenoxy (ethyleneoxy? ethanol surfactant of low molecular weight.
And according to United States Patent No. 3,617,095 a still further method is mentioned in the literature for ~2~i97 1 forming emulsions of bulk solids by admixing the solid, such as coal, with water and oil in the presence of an oxyal~ylated oc~yl phenol emulsifying agent.
Finally, a number of further patents disclose 5 mechanical treatmentS and dispersants for providing coal in a carrier medium. See, e.g., United States Patents Nos. 4,088,453; 4,104,035; 3,620,698; 3,764,547; 3,996,026;
3,210,168; 3,524,682; 4,330,301; 4,305,72~; European Patent No. 0 050-412 and ~CT International Application No. I~O 81-01152.
While the art has attempted to provide coal in dispersed fluid form, as evidenced by the above-described procedures, there still remains the need for improving these methods in order to provide coal mixtllres without undue mechanical or chemical treatment. It would be 15highly desirable to provide coal in aqueous mixture form wherein only minor amounts of additive materials are needed to disperse the coal to high solids concentrations of 70% by weight, or higher. It would be further desirable to provide coal-aqueous mixtures wherein the coal is pre-20cleaned of impurities so that the resultant mixtures areclean burning or relatively clean burning and thus more environmentally acceptable.
- ~ U.S. Patent No. 4,358,293 dated November 9, 1982, discloses the surprising discovery that certain polyalkylene-25Oxide nonionic surfactants are excellent additives forforming coal-aqueous mixtures having high coal solids concentrations. It is also disclosed therein that polyalkyl-eneoxide nonionic surfactants of high molecular weight having a hydrophobic portion and a hydrophilic portion, 30the hydrophilic portion being comprised of at least about 100 ethylene oxide repeating units, provide coal-water dispersions having very high coal solids concentrations of , 1 about 70% by ~eight coal, or higher, when the surfactant is present in an amount sufficient to disperse the particu~
late coal in water. The resultant mixtures are free-flowing and are adapted to provide coal in a form ready 5for transport, storage and clean-burning. Surprisingly, the surfactants employed can differ in chemical structure so long as they are of the selected type, are of sufficient molecular weight and are comprised of at least about 100 units of ethylene oxide.
It has now been further surprisingly discovered that by employing certain processing conditions, herein-aft~r described in detail, in the preparation o~ the coal-a~ueous slurries disclosed in the afore-mentioned U.S.
Patent No. ~,358,293, even more improved coal-a~ueous 15slurries are provided. For example, the coal slurries pre-pared in accordance with the present invention are charac-terized by high solids content, excellent long term storage stability and other advantages which will become apparent hereinafter.
The present invention relates to a method for forming a coal-aqueous mixture by (i) admixing a polyalkyl-eneoxide nonionic surfactant having a hydrophobic portion and a hydrophilic portion, said hydrophilic portion being comprised of at least about 100 units of ethylene oxide, 25with water, under low speed agitation conditions; (ii) admixing particulate coal with the admixture resulting from step (i) under medium speed agitation conditions; and (iii) agitating the resultant coal containing mixture of step (ii) under high speed agitation. The present invention 30also relates to a stabilized, high solids content coal-aqueous mixture comprising particulate coal as a dispersed solid material; water as a carrier medium; a polyalkyleneoxide 69'7 1 nonionic surfactant having a hydrophobic portion and a hydrophilic portion, said hydrophilic portion comprising at least about 100 units of ethylene oxide, said polyalkyl-eneoxide nonionic surfactant being present in said mixture 5in an amount to disperse said particulate coal in said water carrier; and a viscosity stabilizer.
The coal-a~ueous slurries of the present invention are comprised of coal or other carbonaceous material as the dispersed solid; water as the carrier lOmedium; and a polyalkyleneoxide nonionic surfactant, as further described herein.
As used herein "polyalkyleneoxide nonionic surfactant" connotes all compositions, compounds, mix-tures, polymers, etc. having i~ whole or in part an 15alkylene oxide repeating unit of the structure:

~C--I _0,,~

and having a hydrophobic portion and a hydrophilic por~
tion and which does not dissociate or ionize in solution.
These surfactants have a polymeric portion comprised of repea~ing units of ethylene oxide of the general formula:

--C C--O
3o ~Z0~6!~

1 Moreover, the polyalkyleneoxide nonionic surfactant compositions employed in this invention are of high molecular weight, i.e., from about 4,000 or higher, depending on the particular surfactant employed, 5 are hydrophilic and are comprised of at least about 100 repeating units of the ethylene oxi~e monomer. In addi-tion, the surfactants utilized have a hydrophobic portion and a hydrophilic portion and are nonionic. Being nonionic, these compositions are ge~erally not subject 10 to ionization in aqueous solutions of acid or alkali.
Suitable hydrophilic polyalkyleneoxide nonionic sl1rfactants for use in this invention are the commercially available glycol ethers of alkyl phenols of the following general formula I:

R ~ 2 2 )n 2 2 wherein R is substituted or~nsubstituted alkyl of from 201 to 18 carbon atoms, preferably 9 carbon ato~s; sub-stituted or unsubstituted aryl, or an amino group and n is an integer of at least about 100.
These nonionic surfactants are available in a wide array of molecular weights depending primarily 25on the value of "n", i.-e., the number of ethylene oxide repeating units. Surprisingly, it has been found that these surfactants of a high molecular weight of about 4,000 or higher wherein "n" is at least 100, or higher are particularly effective as dispersants for forming 30 coal-aqueous mixtures to high coal solids concentration requiring little if any further additives, etc., to form highly flowable`liquids.

-8~ 697 1 Procedures for the prepar~tionof the glyco~
ethers of formula I are well known and are described, for example, in United States Patents Nos. 2,213,477 and 2,496~582 Generally, the production of these compo-sitions involves the condensation of substituted phenols with molar porportions of ethylene oxide monomer.
Thus, polyalkyleneoxide nonionic surfactants suitable for use in the invention include the glycol ethers lO of alkylated phenols having a molecular wei~ht of at least about 4,000 of the general formula:

R ~ ~ O - (CH2cH2O)n-cH2 CH2 1~
wherein R i5 substituted or unsubstituted alkyl of from 1 to 18 carbon atoms~ preferably 9 carbon atoms; sub-stituted or unsubstituted aryl, or an amino group, andn is an integer of at least about 100. The substituents 20Of the alkyl and aryl radicals can include halo~en, hydroxy, and the like.
Other suitable nonionic surfactants are the poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) or, as otherwise described, propoxylated9 ethoxylated propylene 25glyco~ nonionic surfactant block polymers having a molecu-lar weight of at least about 6,000 of the general formula-HO(CH2CH2O)a[CH(CH3)CH2O]b(CH2 2 c 3o `~
.~

6~37 lwherin a, b and c are whole integers and wherein a and ctotal at least about 100.
Still other polyalkyleneoxide nonionic surfac-tants suitable for use in the invention are the bloc~
5polymers of ethylene and propylene oxide derived from nitrogen~cOntaining compositions such as ethylene diamine and having a molecular weight of at least about 14,000 of the general formula:

H(C2H4O)e( R2)a (R2O~)C(C2H4O)gH

N-R -N

H(C2H4O)f( R2)b (R2O-)d(C2H4O)hH

wherein Rl is an alkylene radical having 2 to 5 carbon atoms,preferably 2; R2 is alkylene radical having 3 to 205 carbon atoms, preferably 3; a, b, c, d, e, f, g and h are whole integers; and e, f, g and h total at least about 100.
The coal-aqueous mixture compositions of the invention herein are characterized by having a high coal solids 25content and a relatively low viscosity of about 2,000 to 6,000 centipoise(cP) or lower as measured, e.g., in a Brookfield viscometer, model #RVT, fitted with a number 3 spindle, at 100 r.p.m. even at solids levels of 70~ by weight, or higher, based on the total weight of the mix-30ture. These compositions can also include amounts of con-ventional flow modifying materials,such as thickeners, glues, defoaming agents, salts, etc., depending upon the use intende~.

~;~OO~i97 1 The product6 of the invention contain only minor amounts of surfactant additives in the order of about 0.1.
to 3.0 percent by weight. They further contain particulate coal as th~ dispersed solid in an amount from about 45 to 580 percent; water as the carrier medium in an amount of from about 19.9 to 52 percent and, if desired, from about 0.1 to 2 percent o a thickener or thickeners; about 0.01 to 2 percent of a defoaming agent and about 0.1 to 2 per-cent of salts, anti-bacterial agents,caustic or other 10additive flow control agents, all of the percentages given being based on the total weight of the mixture.
The most preferred glycol ethers of the type generally describe in formula I are the nonylphenoxy (polyethyleneoxy) ethanol compositions of the formula:

C9H19~ (cH2cH2o)n-cH2-cH:~-oH
wherein n is about 100 or higher.
Commercially available surfactants of this type 20are supplied by the GAF Corporation under the designations IGEPAL CO-990 and IGEPA~ C0-997. Other commercially available surfactants of this type are supplied by the -Thompson-Hayward Chemical Co. under the designation T-Det N-10~, and Whitestone Chemical Co. under the designation 25ICONOL NP-100.
As stated hereinbefore, another group of poly-alkyleneoxide nonionic surfactants useful in the inven-tion are the well known poly(oxyethylene)-poly(oxypro-pylene) poly(oxyethylene) nonionic surfactant block poly-30mers. These suractants comprise the block polymers ofethylene oxide and propylene oxide with the repeating --units of propylene oxide cons~ituting the hydrophobic * Tra~e Mark ~`

1 portion of the surfactant, and the repeating units of ethylene oxide constituting the hydrophilic portion of the surfactant. These block polymer compositions are of the general formula II:

HO(CH2CH2O)a~C~(CH3)CH2O]b(CH2 2 c II
wherein a, b and c are whole integers an~ wherein a and c total at least about 100.
These compositions~can be prépared, and àre lOcommercially available, in a variety of molecular weights, depending primarily on the number of repeating units of propylene and ethylene oxide. It has been found that these block polymers having a molecular weight of at least about 6,000 and comprising at least about 100 15repeating units of ethylene oxide are excellent additives for dispersing coal in a water carrier to the desired high coal solids concentrations of about 45 to 80 percent, preferably about 70 percent coal particles, based on the weight of the total mixture. Thu$rwith reference to the 20 above formula II, the poly(oxyethylene)-poly(oxypropylene)-poly (oxyethylene) nonionic surfactants suitable for use in the invention are those wherein a, ~ and c a*e integers and a and c total about 100 or higher~
Suitable procedures for the production of the 25 block polymers of Formula II are described in the patent literature in, for example, United States Patents Nos.

2,674,619; 2,677,700 and 3,101,374, 3o ~, 1'~

~00697 1 General-ly, these block polymers are prepared -by a controlled addition of propylene oxide to the two hydro~yl groups of propylene glycol to form the hydro-phobe~ followed by the controlled addition of ethylene 5oxide to "sandwich" in the hydrophobe between the two hydrophilic polyethyleneoxide groups.
The nonionic surfactants of this type (Formula II) having the requisite number of at least 100 units of ethylene oxide are available from the BASF-Wyandotte 10 Corporation under the PLURONIC designation, Series Nos~
F-77, F-87, F-68, F-88, F-127, F-98, and F-108. These compositions have at least 100 ethylene oxide units, as per the following~ table of these PLURONIC surfactants:
% Ethylene Numher of Ethylene 15PLURONIC F Mol. Wt. Oxide Oxide Units F-77 6,600 70 105 F-87 - 7,700 70 120 F-68 8,350 80 151 -20F-88 10,800 80 195 . F-127 12,500 70 200 F-98 13,000 80 235 F-108 14,000 80 255 . As also described hereinbefore, a further group 250f polyalkyleneoxide nonionic surfactants suitable as coal dispersants herein are the nitrogen containing block poly-mers of ~he general formula IIIC
H~C2H40)e( R2)a (R20~)C(C2H40)gH

N-Rl-\
H(C2H40)f~ R2)b (R20-)d(C2H40~h * Trade Mark ~`

lZ~97 1 wherein Rl is an alkylene radical having 2 to 5 carbon atoms, preferably 2; R is an alkylene radical having

3 to 5 carbon atoms, preferably 3; a, b, c, d, e, f, g and h are whole integers; and e, f, g and h total at least about 100.
These materials are prepared by the addition of a C3 to C5 alkylene oxide to a~ alkylene diamine under conditions to add-two polyoxyalkylene groups to each of the nitrogen groups in the presence of a catalyst so as to polymerize the oxyalkylene groups into the desired long-chained polyoxyalkylene radicals. After the desired addition and polymerization of the C3 to C5 alkylene oxide group has been completed, ethylene oxide is introduced and is added to the polyoxyalkylene groups to impart the 15 desired hydrophilic characteristics to the compound.
The preparation of these materials from commercially available alkylene diamines and alkylene oxides is known in the art.
In general, the agents are prepared by mixing 20 the C3 to C5 alkylene oxide with the alkylene diamine at atmospheric or elevated pressures, at temperatures between about 50 to 150 centigrade and in the presence of an alkaline catalyst such as an alkali metal hydroxide or alcoholate. The degree of polymerization or the size 25 of the hydrophobic group is controlled by the relative proportions of C3 to C5 alkylene oxide and alkylene dia-mine;~ the alkylene oxide being introduced in a sufficient quantity to obtain a hydrophobic base weight of about 2000 to 3600 units although other weights can be provided.
3o ~2006"3~

1 These surfactants (Formula III~ having the requisite num~er of at least 100 ethylene oxide repeating units are available from the BASF ~yandotte Chemicals Corp-- oration under thP TETRONIC designations Series Nos~ 1107;
5 1307; 908 and 1508. These compositions have at least 100 ethylene oxide units, as per the following table of these TETRONIC surfactants.

% EthyleneNumber of Ethy-lene lO TETRONICMol. Wt. OxideOxide Repeating Units 1107 14,500 70 230 1307 15,500 70 245 908 16,500 80 300 1508 17,000 80 309 Any of a wide array of coals can be used to form the coal-aqueous mixtures of the invention, including anthra-cite, bituminous, sub-bituminous, mine tailings, fines, lignite and the like. Other finely divided solid carhona-ceous materials may also be used, e.g;, coke, prepared either from coal or from petroleum.
To form the coal-aqueous mixtures,coal is pul-vexized to approximately 90% finer than a 200 mesh Tyler 25 Standard screen size, although courser or finer particle sizes can be employed, if desired.
Advantageously, according to the invention, the untreated pulverized raw coal, is beneficiated, i.e., cleaned of amounts of ash and sulfur. The art will appre-30 ciate that mixtures formed of beneficiated coal offer con-siderable advantage. They are clean burning or relatively clean burning, and are more suited for burning in apparatus for powering utilities, home burners and the like without undue burdensome and expensive cleaning apparatus.
* Trade Mark 6~g7 1 Any of a wide array o~ beneficiating treatments can be employed in preparing the par.iculate coals, includ-ing conventional heavy-media separations, magnetic separa-tion and the like. The preferred method for providing the beneficiated coal particles is by a chemical treatment process such as described in U.S. Patent No. 4~304,573.

Generally, according tO the preferred chemical beneficiation treatment method, raw-as-mined coal is ground in the presence of water to a particle size of about 200 mesh. The ground coal is treated in an aqueous medium with a monomeric compound, generally an unsaturated polymerizable composition such as readily available tall oil fatty acids in the presence of a metal initiator such as cupric nitrate; and minor amounts of ~uel oil, all in an aqueous phase are also present. The ground coal so treated is made hydrophobic and oleophilic and is separated from the unwanted ash and sulfur by a froth flotation technique.
The cleaned coal recovered from the preferred chemical treatment process, now in tne form of beneficiated coal particles, is suited for the coal-aqueous mi~tures of the invention. These coal particles are characterized by having an ash content reduced to levels of about O.S to 6.0~ and a sulfur conten~ reduced to levels of about 0.5 to 2~0~.

3o ~ )06~7 1 As in said U.S. Patent No. 4,358,293 it is preferred herein to form the coal-aqueous mixture by first adding the surfactant to water together with other additives such as conventional de~oaming agents, if de-5 sired. This admixing can be done with stirring at con-ditions of atmospheric or nearly atmospheric temperature and pressure~ Thereafter, the particulate coal, preferably beneficiated coal particles, is added to the mixture to produce a coal-aqueous mixture of high coal solids content 10 of about 45 to 80% by weight coal, based on the total weight of the mixture at atmospheric or nearly atmospheric temperatures and pressures. If desired, thickeners can then be added to further stabilize the mi~ture to assist in preventing the coal particles from settling when the 15 mixture is to be stored for extended periods. Caustic soda or other bases can also be added at this point. As will be apparent, adding thickeners in or near the final stage is preferred so that the stirring requirements are kept at a minimum. The coal~aqueous mixtures can be 20 pxepared in a batch operation or in the continuous mode.
In continuous production, the coal can be admixed with water in a first stage along with other flow control agents such as the surfactant. The compositions of the first stage can then be transferred continuously to a second 25 stage wherein the thickener is added. Again, adding the thickener at the later stage results in reduced stirring requirements.
I

3o l In accordance with the dlscovery of the pre-sent invention, it has now been found that further speci-fic processing conditions provide for a more impro~7ed coal~aqueous product, as well as, avoiding certain problems, such as deleterious foaming and flocculation during pro-cessing. More particularly, in preparing the coal-aqueou~
compositions of the present invention, the surfactant and other additives, such as conventional defoaming agents, if desired, are first added to water and mixed, under low speed agitation conditions, such as at from about 500 rpm to about 1500 rpm, preferably about lO00 rpm, for a time of from about 30 seconds to about 3 minutes, preferably about l minute.
Thereafter, the particulate coal, preferably beneficiated coal particles, is added to the mixture and admixed therein under moderate or medium agitation conditions, for example, at an rpm in the range of from about lO00 rpm to about 3000 rpm, preferably about 2000 rpm for a time sufficient to provide a wetted out admixture. Usually this time is in the range of from about 5 minutes to about 20 minutes. At this time, the agitation of the admixture is increased to a high speed, for example, from above about 3000 rpm to about ~000 rpm,preferably about 4000 rpm for a time sufficient to disperse the coal, usually from about 5 minutes to about 15 minutes, preferably about 10 minutes. If desired, thickeners are then added to the slurry under the afore-described high speed agitation con-ditions, e.g. 4000 rpm, for a further time of from about 1 minute to about 3 minutes, preferably about 2 minutes. In the preparation of a most preferred formulation, other ingre-dients, such as viscosity stabilizers and antibacterial agents 3o are then added to the formulation at hi~h speed agitation for a further~ time of from about l minute to about 3 minutes, preferably about 2-minutes. By wetted out or wet as used herein, it is meant that the surface of each coal particle is covered water.

~2~97 1 Typical mixing or dispersing apparatus employed herein include for example Premier ~lill Co.'s Hi-Vispersator High-Speed Disperser.
It is to be understood that the above indicated residence times, temperatures, mixing speeds, etc. may vary according to specific process requirements such as the volume of ingredients, size of apparatus, mixing efficiency, etc. Thus, for example, depending on the scale of the operation, e.g. pilot plant, plant, etc., -these process conditions of the present invention may be adjusted accord-ingly.
It has been found that by employing these afore-described specific conditions of the present invention, the coal is allowed to be dispersed in a surfactant/antifoam solution at relatively low viscosity, while the surfactant i5 orienting at the coal-water interface. The anti-foam agent controls the level of foam caused by the surfactant being agitated in solution. The thickeners are aaded after the coal is adequately dispersed to impart the desired rheological and suspension properties from flocculating by forming a protective colloid.
As indicated above, additives that can be added to the coal-aqueous mixture include defoaming agents, thick-eners, salts, bases, other flow modifying agents and com-binations of these materials.
Generally, the defoaming agents that can beused are conventional and include both silicon and non-silicon containing compositions. A commercially available defoaming agent suitable for use in the mixtures is COLLOID
691, supplied by Colloids, Inc. This composition generally comprises a mixture containing mineral oil, amide and an ester.

* Trade Mark ~lZ~069~

l Thickeners can also he added to the mixture. They are added to increase the non-settling characteristics of the composition. Suicable thickeners include, for example, xanthan gum, guar gum, glue and tne like. Other ~hickeners include, for example~ alkali soluble acrylic polymers (e.g.
ACRYSOL*ICS-l sold by the Rohm and Haas Company3. Co~bina-tions of these thickeners are also contemplated herein.
For the purposes herein, the thickeners are generally used in amounts xanging from about 0.01 to about 3.0~ by weight, based on the total weight of the mixture.
In preparing the compositions containing the preferred 70% by weight coal, based on the weight of the total mixture, the polyalkyleneoxide nonionic surfactants axe preferably mixed with water in a proportion of about 0.3 part by weight surfactant to 29.3, parts by weight, water at atmospheric or nearly atmospheric temperatures and pressures. A defoaming a~ent is also added to the water in an amount of about 0.03, part bv weight, to -assist in processing. The pulverized coal is then mixed 20 with the water in a proportion of 70 parts by weight coal-to 29.3 parts by weight of water to obtain a flowable li~uid. If desired, to the mixture can then be added about 0.12 to about 0.15, part by weight, of thickener or thickeners to provide protection against settling.
25 Other additives such as salts or bases, antibacterial agents such as formaldehyde, and the like, viscosi-ty stabilizers, such as ammonia, etc. can also be added in about 0.2 to about 0.3, part by weight, of the total mixture to further assist in dispersing the coal and 30j pr~viding the other obvious advantages.
The following examples will further illustrate the invention:

* Trade Mark t ~

1 EXA~LE 1 Preparation of a coal-aqueous mixture.

-A coal-aqueous mixture using unbeneficiated par-ticulate coal is prepared of the following composition.

Component Weight %
Particulate Coall 70.00 Water2 29.37 Salt 0.60 Defoaming Agent 0.30 15 Polyethyleneoxide nonionic surfactant having 100 ethylene oxide repeating 5 units and a molecular weight of 4680 0.57 20 1 - Pocohontas seam coal 2 - Industrial water 3 - Industrial grade sodium chloride

4 - COLLOID 691 from Colloids, Inc., Newark, N.J.

5 - IGEPAL C0-997 from the GAF Corporation, N.Y., N.Y.

The coal is ground to about 90 percent finer than 200 mesh Tyler Standard screen size. The surfactant defoaming agent, and salt in the amounts specified are added to the 29.37 grams of water in a Hi-~ispe~sator 30 high-speed disperser available from the Premium Mill Co., e~uipped with a 1 3/4 inches Cowles-type blade operating at 2000 r.p.m. The disperser is operated at atmospheric temperature and pressure. The particulate coal is then added to the mixture with continued mixing.

~2~0697 1 The mixture is seen to disperse the entire 70%
by weight coal and is observed to~be free flowing.

Preparatlon of a coal-aqueous mixture.

A coal aqueous mixture using another unbene-ficiated particulate coal is prepared of the followin~
10 Composition-Component Weight %

Pariculate Coall 70.00 15 Water 29.03 Salt 0.60 Defoaming Agent 0.03 Polyethyleneoxide nonionic surfactant having 245 ethylene oxide repeating 5 units and a molecular weight of 15,500 0.34 1 - Pocohontas seam coal 2 - Industrial water 3 - Industrial grade sodium chloride 4 - COLLCID 691 from Colloids, Inc., Newark N.J.
5 - TETRONIC 1307 from BASF Wyandotte Chemicals, Corp., Parsippany, N.J.
The coal is ground to about 90% finer than 200 3O mesh`Tyler Standard screen size. The surfactant, defoaming agent, and salt in the amounts specified are added to the 29.46 grams of water in a high speed disperser equipped with a 1 3/4 inches Cowles-type blade operating at 2000 r.p.m. The particulate coal is then added to the mixture ~

~Z~6~7 1 with continued mixing. The vessel is operated at atmos-pheric temperatures and pressure.
The mix~ure is seen to disperse the entire 70%
by weight coal and is observed to be free Elowing.

Preparation of particulate cleaned coal.

200 grams of Pittsburgh seam coal having 6.3%
ash content and a 1.5% sulfur content based on the weight of dry coal was pulverized in the presence of water to a 200 mesh Tyler Standard size using a ball mill grinding unit. The coal was then transferred to a mixing vessel.
Into this vessel was also introduced 0.03 gram of corn oil, 5.0 grams of No. 2 "fuel oil, 1.0 cubic centimeter of a 5% solution of hydrogen peroxide i~ water, 2.0 cubic centimeters of a 5.0P6 solution of cupric nitrate in water and 200 grams of the 200 mesh coal. The mix-20 ture was stirred and heated to 86F. for 2 minutes. ~hemi,xture was sprayed into the water surface and a frothing ensued. Coal, in the froth phase, having a 3.4~ ash and 0.9% sulfur ~based on the weight of dry coal was skimmed from the surface of the water and recovered. The water -phase containing large amounts of ash and sulfur wasdiscarded. '' The recovered coal was slightly dried using a Buchner filter drying unit.

3o ~2(~ 7 Preparation of a coal-aqueous mixture.

Beneficiated coal, treated in accord~nce with the procedure of Example 3, was formed into a coal-a~ueous mixture of the following composition.

Component ~eight %
Particulate Coall 70.21 Water2 29~04 Xanthan gum3 0.06 Guar gum4 0.03 15 Salt5 0.06 Defoaming Agent6 0.03 Polye~hyleneoxide nonionic surfactant having about 100 repeating units of ethylene oxide and a molecular weight of about 46807 0.57 1 - Pocohontas seam-coal- cleaned-in accordance--~7ith-the teachings ~ Example 3. The weight percent given being on a moisture free basis.
25 2 Industrial water 3 - BIOZAN SPX-5423, Hercules Inc., Wilmington, De~aware 4 - GUAR THKX-225, Hercules Inc./ Wilmington, Delaware 5 - Industrial grade soaium chloride

6 - COLLOID 691 from Colloids, Inc., Mewark, N.J.

7 - IGEPAL C0-397 from the GAF Cor~oration, N.Y., N.Y.

* Trade Mark ~.

6~'7 -~4-1 The surfactant, de~oaming agent and salt in the amounts specified were added to the 29.04 grams of water in a high speed disperser equipped ~ith a 1 3/4 inches Cowles-type blade operated at 2000 r.p.m. The disperser was operated at atmospheric temperature and pressure. The particulate coal was then added to the mixture with continued mixing at 4500 r.p.m. To the mixture was then added the xanthan gum and guar gum thickeners with mixing at 4500 r.p.m.
The mixture was observed to disperse the entire 70.21 wt.% coal particles and was observed to be free flowing. The viscosity was measured with a Brookfield viscometer model ~RVT and found to be 2000 cP at 100 r.p,m. using a ~6 spindle.

3o .5 Preparation of a coal-aqueous mixture.

Beneficiated coal, trea'ed in accordance with the procedure of Example 3, was formed into a coal-aqueous mixture of the following composition.

Component Weight Particulate Coal 7~.00 Water 29.56 Xanthan gum 0.06 Guar gum 0-03 15 Amino-hydroxy material 0.05 Defoaming Agent6 0.03 Polyethyleneoxide nonionic surfactant having a~out 245 repeating units of ethylene oxide and a molecular weight of about 15,5007 0.30 1 - Pocohontas seam coal cleaned in accordance with the teachings of Example 3. The weight percent given being on a moisture free basis.
2 - Industrial water 3 - KELZAN, Kelco Co., division of ~lerck & Co., Inc., San Diego, California 4 - GUAR THKX-225, Hercules Inc., Wilmington, Delaware 5 - AMP-95 International rlinerals & Chemical Corp., Des Plains, Illinois 6 - COLLOID 691 from Colloids, Inc., Newark, N.J.
7 - TETRQNIC 1307 from BASF Wyandotte Chemicals, CorpO, Parsippany, N.J.

* Trade Mark ~2~6g~7 l The surfactant and defoaming agent in the amounts specified were added to the 29.56 grams of water in a hlgh speed disperser equipped with a 1 3/4 inches Cowles-type blade operated at 2000 r.p.m. The disperser was operated at atmospheric temperature and pressure. The particulate coal was then added to the mixture with contlnued stirring at ~500 r.p.m. To the mixture was then added the xanthan gum and guar gum thickeners while mixing at 4500 r.p.m.
The mixture was observed to disperse the entire 70.00 wt.~ coal particles and was observed to be free flowillg. The viscosity was measured with a Brookfield viscometer model #RVT and ~ound to ~e 2000 cP at 100 r.p~m.
using a ~6 spindle.

These examples compare mixtures which can he prepared to high coal solids concentrations utilizing polyalkyleneoxide nonionic surfactants having a high molecular weight and at least 100 repeating units of ethylene oxide with compositions which do not disperse the coal to high solid levels using similar surfactants, but which do not have the required 100 repeating units of ethylene oxide and high molecular weight.
In each example the same or sl~stantially the same amounts of particulate coal, water, thickeners, salt and defoaming agents were used and a similar surfactant was used, i.e., a poly~oxyethylene)-poly(oxypropylene)-poly(oxyethylene) surfactant, except that the different surfactants tested had different molecular weights and a 3 different number of ethylene oxide repeating unitsO

~Z~ 97 l The mixtures were each prepared in accordance with the procedures of Example 4. The surfactant, defoam-ing agent, and salt in the amount specified were added to water in a high speed ~isperser equipped with a 1 3/4 inches Cowles-type blade operated at 2000 r.p.m. The disperser was operated at atmospheric temperature and pressure. The particulate coal was then added to the mixture with continued mixing. To the mixture was then adde~ the xanthan gum and guar gum thickeners in the stated amounts with mixing.
The following table A tabulates the results of Examples 6-14 showing that coal dispersions of high solid concentrations were prepared utilizing the poly(oxyethy-lene)-poly(oxypropylene)-poly(oxyethylene) surfactants having the requisite lO0 repeating units of ethylene oxide and a molecular weight in excess of 6000, whereas, the same amount or substantially the same amount of coal was not fully dispersed utilizing surfactants not having the requisite lO0 repeating units of ethylene oxide and ~ high molecular weight.

lZ~69~
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1 TABLE A (cont'd) 1 - Pocohontas seam coal cleaned in accordance with the teachings of Exam~le 3 and containing 10 moisture 2 - Industrial water 3 - BIOZAN SPX-5423, Hercules Incorporated, Wilmington, Delaware 4 - GUAR THKX-225, Hercules Incorporated, Wilmington, Delaware 5 - Industrial grade sodium chloride 6 - COLLOID 691 from Colloids, Inc~, Newark, N.J.
5 N.I. - The amount of coal specified was not fully incor-porated into the water.

3o ~2~0;9'~

1 EXP~IPLES 15-21 These examples compare mi~tures which can be prepared to high coal solid concentrations utilizing poly-alkyleneoxide nonionic surfactants having a high molecu-lar weight and at least 100 repeating units of ethylene oxide with compositions which do not disperse the coal to high solid levels using similar surfactants but which do not have the required 100 repeating units of ethylene 10 oxide and high molecular weight.
In each example the same amounts or substan-tially the same amounts of particulate coal, water, thlckeners, salt and defoaming agents were used and a similar surfactant was used, i.e., nitrogen containing 15 block polymers of propylene and ethylene oxide, except that the different surfactants tested had different molecular weights and a different number of ethylene oxide xepeating units.
The mixtures were each prepared in accordance 20 with the procedures of Example 4. The surfactant, defoaming agent, and salt in the amount specified were added to water in a high speed disperser equipped with a 1 3/4 inches Cowles-type blade operated at 4500 r.p.m.
The disperser was operated at atmospheric temperature 25 and pressure. The particulate coal was then added to the mixture with continued mixing. To the mixture was then added the xanthan gum and guar gum thickeners ln the stated amounts with mixing.
The ~ollowing table B tabulates the results of 3 Examples 15-21 showing that coal dispersions of high ~ solid concentrations were prepared utilizing the nitrogen )6~7 1 containing propylene and ethylene oxide block polymer surfactants having the requisite 100 repeating units of ethylene oxide and a molecular weight in excess of 14,000 whereas, the same amount of coal was not dispersed utiliz-ing surfactants not having the requisite 100 repeatingunlts of ethylene oxide and high molecular weight.
Tetronics 1107, 1307, 908, 1508 have a higher ratio of ethylene oxide to propylene oxide, i.e. ethylene oxide con-tent greater than propylene oxide content,while tetronics 304, 504 and 70~ have a higher ratio of propylene oxide to ethylene oxide, i.e. propylene oxide content greater than ethylene oxide.

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~Z~6~7, l TABLE B (cont'd) 1 - Pocohontas seam coal cleaned in accordance with the teachings of Example 3 and containing 10 moisture 2 - Industrial water 3 - BIOZAN SPX 5423, Hercules Incorporated, h7ilmington, Delaware 4 - GUAR THKX-225, Hercules Incorporated, Wilmington, Delaware 5 - Industrial grade sodium chloride 6 - COLLOID 691 from Colloids, Inc., Newark, N.J.
5 N.I. - The amount of coal specified was not fully incorporated into the water.

3o 6~
, 1 EX~MPLES 22-28 These examples compare mixtures which can be prepared to high coal concentrations utilizing polyalky-leneoxide nonionic surfactants having a high molecularweight and at least 100 repeating units of ethylene oxide with compositions which do not disperse the coal to high solid levels using similar surfactants but which do not have the required 100 repeating units of ethylene oxide and high molecular weight.
In each example the same amounts or substan-tially the same amounts of particulate coal, water, thickeners, salt and defoaming agents were used and a similar surfactant was used, i.e., a glycol ether of an alkylated phenol, except that the different surfactants tested had different molecular weights and a different number of ethylene oxide repeating units.
The mixtures were each prepared in accordance with the procedures of Example 4. The surfactant, 20 defoaming agent, and salt in the amount specified were added to water in a high speed disperser equipped with a 1 3/4 inches Cowles-type blade operated at 4500 r.p.m.
The disperser was operated at atmospheric temperature and pressure. The particulate coal was then added to the 25 mixture continued mixing. To the mixture was then added the xanthan gum and guar gum thickeners in the stated amounts with mixing.
The following table C tabulates the results of Examples 22T28 showing that coal dispersions of high 30 solid concentrations were prepared utili~ing the glycol ether of alkylated phenol surfactants havlng the requisite ~Z~,6g~

1 100 repeating units of ethylene oxide and a molecular weight in excess of 4000, whereas, the same amount or substantially the same amount of coal was not fully dis-persed utilizing surfactants not having the requisite 100 repeating units of eth~lene oxide and high molecular weight .

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1 TABLE C (co~t'd) 1 - Pocohontas seam coal cleaned in accordance with the teachings of Example 3 and containing 10 moisture 2 - Industrial water 3 - BIOZAN SPX-5423, Hercules Incorporated, Wilmington, ~elaware 4 - GUAR THKX-225, Hercules Incorporated, Wilmington, Delaware 5 - Industrial grade sodium chloride 6 - COLLOID 691 from Colloids, Inc., Newark, N.J.
5 N.I. - The amount of coal specified was not fully incor-porated into the water.

As the Examples show, coal-aqueous mixtures are provided having high coal solids content. The 20 resultant mixtures are stable, have low viscosity and incorporate large amounts of solid coal particles, typically 70~ by weight coal or higher. Examples 6-14 demonstrate that polyalkylene oxide nonionic surfactants of high molecular weight of at least 6000 and having at 25 least 100 repeating units of ethylene oxide units are excellent dispersants for forming coal-aqueous mixtures.
~xamples 6 to 14 further demonstrate that for the sur-factants of the same basic structure, i.e., block poly-mers of propylene and ethylene oxide, advantageous 30 results are achieved by employing the composition of a molecular weight of 6000 or higher having at least 100 repeating units of ethylene oxide.

~Z()(3 6~

1 Similarly, Examples 15 to 21 demonstrate that for the polyalkyleneoxide nonionic surfactants of the block polymer type derived from nitrogen containing com~
positions such as ethylene diamine, compositions of 14,000 molecular weight or higher having 100 repeating units of ethylene oxide provide the same or nearly the same advantageous results. Similarly, as Examples 22-28 show the glycol ether of alkylated phenol surfactants having the 100 repeating units of ethylene oxide and 10 high molecular weight also are excellent coal dispersants.

:12~06~

1 EXAMPL~ 29 The following formulation is used to prepare an aqueous coal slurry in accordance with the improvement of the present invention.

Ingredient MaterialParts by Weight 1 Water 29.236 2 Tetronic 1307.34 3 Colloid 691 .03 4 Cleancoal 70.00 Kelzan .014 6 Guar THIX .10 7 37% Formalde~yde .14

8 28~ Ammonia .14 100.00 1. Industrial Water 2. Surfactant - BASF Wyandotte Corp.
3. Anti-foam Agent - Colloids, Inc.
4. Pocahontas Clean Coal 5. Xanthan Gum Xelco Division, Merck & Co., Inc.
6. Guar Gum - Hercules, Inc.
7. Formaldehyde Solution- Borden Cher,~icals 8. Ammonium Hydroxide - Fischer Scientific Slurry Properties Solids - 70.0 + 1.0 ~ pH - 8.0 + 1.0 Brookfield Viscosity, cp 10 rpm - 14,000 + 4,000 100 rpm - 6,500 + 1,500 Settling (spatula probe) 6 weeks - None 8 weeks ~ Slight amount of soft sediment lZ~ 69~

1 The ingredients are added in the order listed.
A high-speed disperser, namely a High-~ispersator is used to stir, mix and disperse the materials into a stable homogeneous slurry. Ingredients 1, 2 and 3 are stirred together for one minute at low speed (1,000 rpm).
The coal is added to this solution at medium speed (2000 rpm) for a sufficient time to wet the coal particles and disperse the coal in in~redients I,-2 and 3. Then the speed of the disperser is increased to high speed (4000 rpm) for 10 minutes to further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser at high speed. After two minutes ingredients 7 and 8 are added and the batch is considered complete after an additional two minutes of mixing at high speed. All mixing is carried out at atmospheric temperatures and pressures.

3o ~2~(~69~

The following formulation is used to prepare an aqueous coal slurry in accordance with the lmprovement of the present invention.

Ingredient MaterialParts by l~eight 1 Water 29.236 1 2 Tetronic 908 .34 3 Colloid 691 .03 4 Cleancoal 70.00 Kelzan .014 6 Guar THIX .10 37% Formaldehyde .14 8 28% Ammonia .14 100 . 00 ' 1. Industrial Water 2~ Surfactant - BASF Wyandotte Corp.
3. Anti-foam Agent - Colloidsj Inc.
4. Pocahontas Clean Coal 5. Xanthan Gum - Kelco Division, Merck & Co., Inc.
6. Guar Gum - Hercules, Inc.
7. Formaldehyde Solution- Borden Chemicals 8. Ammonium Hydroxide - Fischer Scientific Slurry Properties Solids - 70.0 + 1.0 3o ~ pH - 8.0 + 1.0 Brookfield Viscosity, cp 10 rpm - 14,000 ~ 4,000 100 rpm - 6,500 + 1,500 Settling (spatula probe) 6 weeks - None 8 weeks - Slight amount of soft sediment lZ(~

1 The ingredients are added in the order listed.
A high-speed disperser, namely a High-Vispersator is used to stir, mix and disperse the materials into a stable homogeneous slurry. Ingredients 1~ 2 and 3 are stirred together for one minute at low speed (1,000 rpm).
The coal is added to this solution at medium speed (2,000 rpm) for a sufficient time to wet the coal particles and disperse the coal in ingredients 1, 2 and 3. Then the speed of the disperser is increased to high speed (4,000 rpm) for 10-minutes to further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser at high speed~ After two minutes ingredients 7 and ~ are added and the batch is considered comple~e after an additional two minutes of mixing at high speed. All mixing is carried out at atmospheric temperatures and pressures.

3o ~Z~6g7, The following formulation is used to prepare an aqueous coal slurry in accordance with the improvement of the present invention.

Ingredient Material Parts by Weight 1 Water 29.236 2 Tetronic 1508 .34 3 Colloid 691 .03 4 Cleancoal 70.00 Kelzan .014 6 Guar THIX .10 37~ Formaldehyde .14 8 28~ Ammonia .14 100 . 00;

1. Industrial Water 2. Surfactant - BASF Wyandotte Corp.
3. Anti-foam Agent - Colloids, Inc.
4. Pocahontas C]ean Coal 5. Xanthan Gum - Kelco Division, Merck & Co., Inc.
6. Guar Gum - - Hercules, Inc.
7. Formaldehyde Solution- Borden Chemicals 8. Ammonium Hydroxide - Fischer Scientiic Slurry Properties Solids - 70.0 + 1.0 pH - 8.0 + 1.0 Brookield Viscosity, cp 10 rpm - 14,000 + 4,000 100 rpm - 6,500 + 1,500 Settling (spatula probe) 6 weeks - None 8 weeks - Slight amount of soft sediment ~0(~69~

1 The ingredients are added in the order listed.
A hi~h-speed disperser, namely a High-VispersatOr is used to stir, mix and disperse ~he materials into a stable homogeneous slurry. Ingredients 1, 2 and 3 are stirred together for one minute at low speed (1,000 rpm)O
The coal is added to this solution at medium speed (2,000 rpm) for a sufficient time to wet the coal particles and disperse the coal in ingredients 1, 2 and 3. Then the speed of ~he disperser is increased to high speed (4,000 rpm) for lO minutes to further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser a~
high speed. After two minutes ingredients 7 and 8 are added and the batch is co~sidered complete aEter an additional two minutes of mixing at high speed. All mixing is carried out at atmospheric temperatures and pressures.

3o The following formulation is used to prepare an aqueous coal slurry in accordance with the improvement of the present invention.

Ingredient Material Parts by Weight 1 Water 29.236 2 Pluronic-F-98 ,34 3 Colloid 691 .03 4 Cleancoal 70.00 Kelzan .014 6 Guar THIX .10 37% Formaldehyde .14 8 28% Ammonia .14 100.00 1. Industrial Water 2. Surfactant - BASF Wyandotte Corp.
3. Anti-foam Agent - Colloids, Inc.
4. Pocahontas Clean Coal 5. Xanthan Gum - Kelco Division, Merck & Co., Inc.
6. Guar Gum - Hercules, Inc.
7' Formaldehyde Solution- Borden Chemicals 8. Ammonium Hydroxide - Fischer Scientific Slurry Properties Solids - 70.0 ~ 1.0 pH - 8.0 ~ 1.0 Brookfield Viscosity, cp 10 rpm - 14,000 - 4,000 100 rpm - 6,500 + 1,500 Settling (spatula probe) 6 weeks - None 8 weeks - Slight amount of soft sediment l The ingredients are added in ~he order listed.
A hiah speed disperserl namely a High-Vispersator is used to stir, mix and disperse the materials into a stable homogeneous slurry. Ingredients l, 2 and 3 are stirred together for one minute at low speed (l,000 rpm).
The coal is added to this solution at medium speed ~2,000 rpm) for a sufficient time to wet the coal particles and disperse the coal in ingredients 1, 2 and 3. Then the speed of the disperser is increased to high speed (4,000 rpm) for lO minutes to further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser a~
high speed. After two minutes ingredients 7 and 8 are added and the batch is considered complete after an additional two minutes of mixing at higll speed. All mixing is carried out at atmospheric temperatures and pressures.

~2~6g~

l EXAMPLE 33 The following formulation is used to prepare an aqueous coal slurry in accordance with the improvement of the present invention.

Ingredient MaterialParts by ~eight 1 Water 29.236 2 Pluronic-F-108 .34 3 Colloid 691 .03 4 Cleancoal 70.00 Kelzan .014 6 Guar THIX .lO
37% Formaldehyde .14 8 28% Ammonia .14 lnn nn~

1. Industrial Water 2. Surfactant - BASF Wyandotte Corp.
3. Antl-foam Agent A Colloids, Inc.
4. Pocahontas Clean Coal 5. Xanthan Gum - Kelco Division, Merck & Co., Inc.
6. Cuar Gum - Hercules, Inc.
7. Formaldehyde Solution- Borden Chemicals 8. Ammonium Hydroxide - Fischer Scientific Slurry Properties Solids - 70.0 + l.0 3o ~ pH - 8.0 + l.0 Brookfield Viscosity, cp lO rpm - 14,000 ~ 4,000 lO0 rpm - 6,500 + 1,500 Settling (spatula probe) 6 weeks - None 8 weeks - Slight amount of soft sediment ~0~69~

1 The ingredients are added in the order listed.
A high-speed disperser, namely a High-Vispersator is used to stir, mix and disperse the materials into a stable hcmogeneous slurry. Ingredients 1, 2 and 3 are stirred together for one minute at low speed (1,000 rpm).
The coal is added to this solution at medium speed (2,000 rpm) for a sufficient time to wet the coal particles and disperse the coal in ingredients 1, 2 and 3. Then the speed of the disperser is increased to high speed (4,000 rpm) for lO minutes to-further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser at high speed. After two minutes ingredients 7 and 8 are added and the batch is considered complete after an additional two minutes of mixing at high speed. A11 mixing is carried out at atmospheric temperatures and pressures.

3o ~IL2~9~

The following formulation is used to prepare an aqueous coal slurry in accordance with the improvement of the present invention.

Ingredient Matexial Parts by ~eight l Water 29.236 2 Pluronic-F-127 .34 3 Colloi~ 691 .03 4 Cleancoal 70.00 Kelzan .014 6 Guar THIX .l0 37% Formaldehyde .14 8 28% Ammonia .14-100.00 l. Industrial Water 2. Surfactant - BASF Wyandotte Corp.
3. Anti-foam Agent - Colloids, Ine.
4. Pocahontas Clean Coal 5. Xanthan Gum - Keleo Division, Merck & Co., Inc.
6. Guar Gum - Hereules, Ine.
7. Formaldehyde Solution- Borden Chemieals 8. Ammonium Hydroxide - Fiseher Seientifie Slurry Properties Solids - 70.0 + l.0 pH - 8.0 + l.0 Brookfield Viseosity, ep lO rpm - 14,000 + 4,000 ~lO0 rpm - 6,500 + 1,500 Settling (spatula probe) 6 weeks - None . 8 weeks - Slight amount of soft sediment ;97, 1 The ingredients are added in the order listed.
A hiah-speed disperser, namely a ~igh-Vispersator is used to stir, mix and disperse the materials into a stable homogeneous slurry. Ingredients 1, 2 and 3 are stirred together ~or one minute at low speed (1,000 rpm).
The coal is added to this solution at medium speed (2,000 rpm) for a sufficient time to wet the coal particles and disperse the coal in ingredients 1, 2 and 3. Then the speed of the disperser is increased to high speed (4,000 rpm) for lO minutes to further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser at high speed. After two minutes ingredients 7 and 8 are added and the batch is considered complete after an additional two minutes of mixing at higll speed. All mixing is carried out at atmospheric temperatures and pressures.

3o 6g~

1 EXAMPL~ 35 The following formulation is used to prepare an aqueous coal slurry in accordance with the improvement o$ the present invention.

Ingredi.ent MaterialParts by Weight 1 Water ~9.176 2 Igepal CO-9900.40 3 Colloid 691 .03.
4 Cleancoal 70.00 Kelzan .014 6 Guar THIX .lD
37% Formaldehyde .14 8 2.8% Ammonia .14 100.00 1. Industrial Water 2. Surfactant --.GAF Corp.-3. Anti-foam Agent - Colloids, Inc.
4. Pocahontas Clean Coal 5. Xanthan Gum - Kelco Dlvision, Merck & Co~, Inc.
6. Guar Gum - Hercules, Inc.
7~ Formaldehyde Solution- Borden Chemicals 8. Ammonium Hydroxide - Fischer Scientific Slurry Propexties Solids - 70.0 ~ 1.0 pH ~ 8.0 ~ 1.0 Brookfield Viscosity, cp 10 rpm - 14,000 ~ 4,000 100 rpm - 6,500 + 1,500 Settling (spatula probe) 6 weeks - None 8 weeks - 51ight amount of soft sediment ~2~ 7 1 The ingredients are added in the order listed.
A high-speed disperser, namely a High-Vispersator is used to stir, mix and disperse the materials into a stable homogeneous slurry. Ingredients 1, 2 and 3 are stirred together for one minute at low speed (1,000 rpm).
The coal is added to this solution at medium speed (2,000 rprn) for a suf~icient time to wet the coal particles and disperse the coal in ingredients 1,;2 and 3. Then the speed of the disperser is increased to high speed (4,000 rpm) for lO minutes to further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser a~
high speed. After two minutes ingredients 7 and 8 are added and the batch is considered complete after an additional two minutes of mixing at high speed. All mixing is carried out at atmospheric temperatures and pressures.

~3o lZ~(~69~

1 ~XA~1~LE 36 The following formulation is used to prepare an a~ueous coal slurry in accordance wi~h the improvement of the present invention.

Ingredient Material Parts by l~eight 1 Water 29. 176 2 T-Det-N-100 .40 3 Colloid 691 .03 4 Cleancoal 70.00 Kelzan .014 6 Guar THIX .10 37% Formaldehyde .14 8 28% Ammonia .14 100.00 1. Industrial Water 2. Surfactant - Thompson Haywood Cnemical Co.
3. Anti-foam Agent - Colloids, Inc.
4. Pocahontas Clean Coal 5. Xanthan Gum . - Kelco Division, Merck & Co., Inc.
6. Guar Gum - Hercules, Inc.
7. Formaldehyde Solution- Borden Chemicals 8. Ammonium Hydroxide - Fischer Scientific Slurry Properties Solids - 70.0 + 1.0 ~ pH - 8.0 + 1.0 Brookfield Viscosity, cp 1~ rpm - 14,000 + 4,000 100 rpm - 6,500 + 1,500 Settling (spatula probe) 6 weeks - None 8 weeks - Slight amount of 35 soft sediment ~Z0~69~

1 The ingredients are added in the order listed.
A hiah-speed disperser, namely a High-Vispersator is used to stir, mix and disperse the materials into a stable homogeneous slurry. Ingredients 1, 2 and 3 are stirred together for one minute at low speed ~1,000 rpm).
The coal is added to this solution at medium speed (2,000 rpm) for a su~ficient time to wet the coal particles and disperse the coal in ingredients 1, 2 and 3. Then the speed o the disperser isiincreased to high speed (4,000 rpm) for lO minutes to further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser at high speed. After two minutes ingredients 7 and 8 are added and the batch is considered complete after an additional two minutes of mixing at high speedO All mixing is carried out at atmospheric temperatures and pressures.

3o ~20~ 7~

The followin~ formulation is used to prepare an aqueous coal slurry in accordance with the lmprovement of the present invention.

Ingredient MaterialParts by ~eight 1 Water 29.176 2 NP-100 .40 3 Colloid 691 .03 4 Cleancoal 70.00 Kelzan .014 6 Guar THIX .lQ
37% Formaldehyde .14 8 28% Ammonia .14 100 . 00 1~ Industrial Water 2. Surfactant - Whitestone Chemica-l-3. Anti-foam Agent - Colloids, Inc.
4. Pocahontas Clean Coal 5. Xanthan Gum - Kelco Division, ~erck & Co., Inc.
6. Guar Gum - Hercules, Inc.
7' Formaldehyde Solution- Borden Chemicals 8. Ammonium Hydroxide - Fischer Scientific Slurry Properties Solids _ 70,0 t 1 . O
~ p~ - 8.0 + 1.0 Brookfield Viscosity, cp 1~ rpm - 14,000 t 4,000 100 rpm - 6,500 -t 1,500 Settling (spatula probe) 6 weeks - None 8 weeks - Slight amount of soft sediment ~2~

1 The ingredlents are added in the order listed.
A hiah-speed disperser, namely a Hiah-Vispersator is used to stir, mix and disperse the materials into a stable homogeneous slurry. Ingredients 1, 2 and 3 are stirred toyether for one minute at low speed (1,000 rpm).
The coal is added to this solution at medium speed (2,000 rpm) for a sufficient time to wet the coal particles and disperse the coal in ingredients 1,;2 and 3. Then the speed of the disperser is increased to high speed (4,000 rpm) for lO minutes to further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser a~
high speed. After two minutes ingredients 7 and 8 are added and the batch is considered complete after an additional two minutes of mixing at high speed. All mixing is carried out at atmospheric temperatures and pressures.

3o ~ ~Q69~

The following formulation is used to prepare an aqueous coal slurry in accordance with the improvement of the present invention.

Ingredient Material Parts by ~1eight 1 Water - 29.176 2 Tetronic 908 .40 3 Colloid 691 .03 4 Coal(non-beneficiated) 70.00 Kel~an .014 6 Guar THIX .10 37~ Formaldehyde .14 8 28% Ammonia .14 100.00 1. Industrial Water 2. Surfactant - BASF Wyandotte Corp.
3. Anti-foam Agent - Colloids, Inc.
4. Pocahontas Coal S. Xanthan Gum , - Kelco Division, Merck & Co., Inc.
6. Guar Gum - Hercules, Inc.
7. Formaldehyde Solution- Borden Chemicals 8. Ammonium Hydroxide - Fischex Scientific Slurry Properties Solids - 70.0 + 1.0 3~ pH - 8.0 + 1.0 Brookfield Viscosity, cp 10 rpm ~ - 14,000 + 4,000 ~100 rpm - 6,500 + 1,500 Settling (spatula probe) 6 weeks - None 8 weeks - Slight amount of soft sediment ~L21)C)~

1 The ingredients are added in the order listed.
A hioh-speed disperser, namely a High-Vispersator is used to stir, mi~ and disperse the ma~erials into a stable homogeneous slurry. Ingredients 1, 2 and 3 ar~
stirred together for one minute at low speed ~1,000 rpm).
The coal is added to ~his solution at medium speed (2,000 rpm) for a sufficient time to wet the coal particles and disperse the coal in ingredients 1, 2 and 3. Then the speed of the disperser is increased to high speed (4,000 rpm) for lO minutes to further disperse the coal particles.
Ingredients 5 and 6 are then added with the disperser a~
high speed. After two minutes ingredients 7 and 8 are added and the batch is considered complete after an additional two minutes of mixing at high speed. All mixing is carried out at atmospheric temperatures and pressures.

~3o -.

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1 From the foregoing it ~ be seen tllat coal-aqueous mixtures are readily provided having significantly high solld concentrations. The mixtures can be provlded in a clean form ready for burning in utility burners, home burners and the like with little if`any need for additional cleaning to remove ash and sulfur.

1~

3o

Claims (23)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEDGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method for forming a coal-aqueous mixture, said method comprising the steps of:
(i) admixing a polyalkyleneoxide nonionic surfactant having a hydrophobic portion and a hydrophilic portion, said hydrophilic portion being comprised of at least about 100 units of ethylene oxide, with water, under low speed agitation conditions;
(ii) admixing particulate coal with the admixture resulting from step (i) under medium speed agitation conditions; and (iii) agitating the resultant coal containing mixture of step (ii) under high speed agitation.

2. The method of Claim 1 wherein said medium speed agitation in step (ii) is carried out for a time sufficient to wet the coal particles and said high speed agitation is carried out for a time sufficient to disperse the coal.

3. The method of Claim 1 wherein an anti-foam agent is added to the mixture during step (i).

4. The method of Claim 3 wherein said anti-foam agent is comprised of a mixture of mineral oil, amide and polyethylene glycol oleate ester.

5. The method of claim 1, 2, or 4 wherein the particulate coal is added in an amount from about 45 to 80 percent; the water is added in an amount from about 19.9 to 52 percent; and the polyalkyleneoxide nonionic sur-factant is added in an amount from about 0.1 to 3.0 percent based on the total weight of the mixture.

6. The method of Claim 1 wherein the polyalkyleneoxide nonionic surfactant comprises a composition of the formula wherein R is substituted or unsubstituted alkyl of from 1 to 18 carbon atoms; substituted or unsubstituted aryl or an amino group, and n is an integer of at least about 100 or a composition of the formula wherein R1 is an alkylene radical having 2 to 5 carbon atoms;-R2 is an alkylene radical having 3 to 5 carbon atoms; a, b, c, d, e, f, g, and h are whole integers and e, f, g, and h total at least about 100 or a composition of the formula HO(CH2CH2O)a[CH(CH3)CH2O]b(CH2CH2O)cH

wherein a, b and c are whole integers and a and c total at least about 100.

7. The method of Claim 1 wherein said polyalkyleneoxide nonionic surfactant has a molecular weight of at least about 4000.

8. The method of Claim 6 wherein R1 is an alkylene radical having 2 carbon atoms and R2 is an alkylene radical having 3 carbon atoms and R is nonyl.

9. The method of Claim 1 including the further steps of:
(iv) admixing a thickening agent under high speed agitation conditions, to the admixture resulting from step (iii).

10. The method of Claim 9 wherein said thickening agent is xanthan gum, guar gum, cellulose gum, glue or alkali soluble acrylic polymer.

11. The method of Claim 9 including the further step of:
(v) admixing an anti-bacterial agent, a viscosity stabilizer or mixtures thereof to the mixture resulting from step (iv), under high speed agitation.

12. The method of Claim 11 wherein said vis-cosity stabilizer is ammonia.

13. The method of claim 1, 6, or 12 wherein said particulate coal is characterized by having a sulfur content of from 0.5 to 2.0 percent by weight, an an ash content of from about 0.5 to 6.0 percent, based on the weight of dry coal and is about 200 mesh in tyler standard screen size.

14. A stabilized, high solids content coal-aqueous mixture comprising particulate coal as a dispersed solid material; water as a carrier medium; a polyalkylene-oxide nonionic surfactant having a hydrophobic portion and a hydrophilic portion, said hydrophilic portion comprising at least about 100 units of ethylene oxide, said polyalkyl-eneoxide nonionic surfactant being present in said mixture in an amount to disperse said particulate coal in said water carrier; and a viscosity stabilizer.

15. The stabilized, high solids content coal-aqueous mixture of Claim 14 further comprising a thickening agent and/or an anti-foam agent.

16. The stabilized, high solids content coal-aqueous mixture of Claim 14 wherein said polyalkyl-eneoxide nonionic surfactant comprises a composition of the formula wherein R is substituted or unsubstituted alkyl of from 1 to 18 carbon atoms; substituted or unsubstituted aryl or an amino group, and n is an integer of at least about 100 or a composition of the formula wherein -R1 is an alkylene radical having 2 to 5 carbon atoms; R2 is an alkylene radical having 3 to 5 carbon atoms; a, b, c, d, e, f, g and h are whole integers and e, f, g and h total at least about 100 or a composition of the formula HO(CH2CH2O)a[CH(CH3)CH2O]b(CH2CH2O)cH
wherein a, b and c are whole integers and a and c total at least about 100.

17. The stabilized, high solids content coal-aqueous mixture of Claim 16 wherein R1 is an alkylene radical having 2 carbon atoms and R2 is an alkylene radical having 3 carbon atoms and R is nonyl.

18. The stabilized, high solids content coal-aqueous mixture of claim 14, 16 or 17 the polyalkylene-oxide nonionic surfactant has a molecular weight of at least about 4000.

19. The stabilized, high solids content coal-aqueous mixture of claim 14, 16 or 17, wherein the viscosity stabilizer comprises ammonia.

20. A stabilized, high solids content coal aqueous mixture comprising particulate coal as a dispersed solid material;
water as a carrier medium; a polyalkylene-oxide nonionic surfact-ant having a hydrophobic portion and a hydrophilic portion, said hydrophilic portion comprising at least about 100 units of ethylene oxide, said polyalkyleneoxide nonionic surfactant being present in said mixture in an amount to disperse said particulate coal in said water carrier; a viscosity stabilizer and an anti-bacterial agent.

21. A mixture according to claim 20 wherein the viscosity stabilizer is ammonia.

22. A mixture according to claim 20 or 21, further comprising a thickening agent and/or an anti-foam agent.

23. A mixture according to claim 20 or 21 wherein the anti-bacterial agent is formaldehyde.