COAL-WATER SLURRY AND METHOD FOR ITS PREPARATION

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 wgt.% 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.

Description: - COAL-WATER SLURRY AND METHOD FOR ITS PREPARATION TECHNICAL FIELD This invention relates to an improved pipeline 5 pumpable high solids content coal-water slurry having a Brookfield viscosity of about 2000 cps or less at 60 rpm at about 75 wgt. " , dry basis, coal content. The slurry is utilized primarily for generation of heat energy in a furnace provided with slurry conveying means and equipped 10 with either a cyclone or a turbulent type of burner. Further, this invention relates to a* method for making such an improved, high solids content coal-water slurry which is suitable for long distance pumpline con¬ veyance to coal-water slurry combustion, gasification or 15 other coal utilization processes, and, which is especially suitable for direct burning in a furnace into x^hich the coal-water slurry is charged by means of a cyclone or a turbulent burner without further treatment, such as de- watering of the slurry. .20 More particularly, this invention .relates to an improved high solids content coal-water slurry having yield pseudoplastic rheological properties suitable for pipeline transport and to a method for its preparation. The coal preferably is partially de-ashed. .25 Further, this invention relates to a slurry com¬ prising finely divided particles of at least one solid material wherein the particles in the slurry have a particle size range and particle size distribution, and physical, and electrochemical attributes advantageous for trans- 30 porting the slurry in a pipeline in the presence of a carrier fluid. " BACKGROUND QF THE PRIOR ART Processes for preparing and utilizing partially d ashed solid-fuel-water slurries and conveying the slurry b various conveying means, such as pumps, are known. 0. Schw and H. Merten, Brennstoff Xfeerme Kraft 18 (10), 474-8 (196 (Ger) des.cribe a pilot plant in which coal was pulverized dry or wet in ball mills and disk grinders to provide particles up to 77% finer than 0.06 mm (60 ιm). Other processes are described in U.K. Patent No. 711,105; French Patent No. 1,581,112; and U.S.Patents Nos. 3,423,313; 3,682,114; 3,941,552; 3,950,147; and 3,996,026, all of which are discussed in applicant's co- pending U.S. Patent Application Serial No. 790,337, filed April 25, 1977, which portion of said application Serial No. 790,337 is hereby incorporated by reference her In addition to the above-listed patents, McMurtrie, U.S. 3,019,059, issued Jan. 30, 1962, describes a process for transporting finely divided coal solids by forcing through a conduit an aqueous slurry containing up to 50% solids and containing a minor proportion of coal acidswhich areadded to improve pumpability and to prevent settling during pumping. At the receiving end of the conduit, the slurry is filtered or otherwise processed to remove the water and coal acids and to recove the coal solids for use. Alkali metal and ammonium salts of hu ic acids are included in the term "coal acids". Also, Reichl, U.S. 3,073,652, issued January 15, 1963 describes amethodof transporting coal over long distances for conversion at distant locations which comprises obtaining coal having a spectrum of sizes and between about 5 20 and 40 percent by weight of(-)325 mesh particles, (-44 jum) , preparing a water slurry comprising between 35 and 60 percent by weight of said coal in water, pumping said slurry through a pipeline at a velocity of between about 3 and 7 feet per second over long distances to a distant 10 location, interrupting the transportation of said slurry at said distant location, thereafter removing a portion of said water from said slurry to provide a concentrated slurry having a solids concentration of between 60 and 75 percent by weight of said coal in said water, pumping 15 said concentrated slurry through a second pipeline over a shorter distance to a second location, and converting the coal in said concentrated slurry at said second lo¬ cation, or burning the concentrated slurry directly, if the burner is suitable for such burning. 20 Also, Clancey et al. , U.S. 3,762,887, issued October 2, 1973, describes a homogeneous composition of matter suitable for use as a liquid fuel consisting essentially of particulate coal and water in the relative proportions of 54 to 69 percent by volume of coal (61.3 to 75.0 25 wgt %) and 46 to 31 per cent by volume of water, said . particulate coal having a size distribution substantially as follows: 0 percent by weight on 4 mesh Tyler Standard screen, 18 to 33 per cent by weight less than 325 mesh, less than 60 per cent by weight between 4 and 28 mesh, 30 and the balance in the size range of 28 to 325 mesh. The 07 PI ' coal-water slurry is described as being pumpable, storab and directly burnable in a cyclone burner. Commercially operated coal-slurry pipelines hav been in operation for many years in the United States. Such pipelines and their successes, failures, and proble 5 have been described in various publications, including the following: "The Black Mesa Story" by F.K. Love, Pipeline Engineer, November 1969; "Slurry Pipelines, Energy Movers of the Future" 10 by E.J. Wasp, and T.L. Thompson, Oil and Gas Journal, December 24, 1973; "Research and Development for Slurry Pipeline System Design" by T. C. Aude and R. L. Gandhi, Bechtel, - - Inc., San Francisco, prepared for delivery at "The Second Inter¬ national Technical Conference on ■ • . Slurry Transportation", Las Vegas, Nevada, March 2-4, 1977; 20 "Operating Experiences at the 1580 MN Coal Slurry Fired Mohave . Generating Station" by M. L. Din'a, presented at The International Conference on Slurry Transp.or- 25 tation at Battelle Memorial Institute, Columbus, Ohio, February 3, 1976; "Utilization of Pipeline Delivered Coal", by P. E. Snoek et al. , Bechtel, 30 Inc. , San Francisco, for ASME Joint Power Generation Conference, Buffalo, New York, September 20, 1976; and " Coal Slurry Pipelines", Van Nostrand Scientific Encyclopedia, fifth edition, 35 1976, Page 58. The problem of preparing coal-water slurry for long distance delivery through pipelines ranging in diameter from about 4" to 48" to be burned at the delivery depot is to be distinguished from the problem of preparing a coal-water slurry from which a more con¬ centrated slurry or a coal "cake" is prepared at a use site and burning the concentrated coal-water slurry or "cake" so prepared. Also, the problem of burning coal- water slurry in a turbulent burner is to be distinguish¬ ed from burning coal-water slurry in a cyclone burner of a furnace. For examples of burners, see Chemical Tech¬ nology: An Encyclopedic Treatment, J. F. Van Oss, Barnes and Noble Books, Div. Harper & Row, Publ., Inc. N.Y. 1971 Vol. II, Pages 722-725. BRIEF SUMMARY OF THE INVENTION This invention relates to a coal-water slurry comprising a high content, e.g. 60-80 wgt. %, dry basis, of finely-divided particles of coal having in combination physical and electrochemical characteristics which provide the slurry with low viscosity and other rheological prop¬ erties required for transporting the slurry in a pipeline over long distances. The invention further relates to a novel method for making coal-water slurry of the inven- tion. In one aspect, the invention relates to a coal- water slurry suitable for pipeline transport which com¬ prises: (i) a coal compact comprising finely-divided coal particles having particle sizes in the range of about 1180 m. to O.OS^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: SUBSTITUTE SHEE 100, where CPFT = cumulative weight percent, dry basis of particles finer than a particle u stated size, D = diameter of particle μ, D, = diameter of largest particle in comp sieve size or its equivalent, D - diameter of smallest particle in com pact, SEM size or its equivalent, n = numerical exponent, with n being in range of 0.2 to 1.0, and with all di meters sized in μm, (ii) carrier water in an amount at least suffici to transport said coal compact in a pipelin (iii) counterion charged bound" water layers on at least said particles of colloidal size, and (iv) an effective amount of at least one electro lyte and/or dispersing agent(s) present in said carrier water and providing counter- ions to said bound water layers on said particles in an amount sufficient to maintain the zeta potential at near maxi¬ mum zeta potential and sufficient to dis¬ perse said coal particles. The particle size distribution of the coal com¬ pact according to the above formula for CPFT provides a non-undulating size distribution of particles which per¬ mits closer packing of more particles of coal in a specific volume of space in the compact than can be achieved with a particle size distribution which has an undulating distribution of particles. Also, sizes of D_ and D„ have important effects on the suitability of the particle size distribution for use in the coal-water slurry. When D y is too large, large particles can settle out and cause pumping problems. When D ς is too large and less than about 5 wgt. %, dry basis, of particles of colloidal size are present in the coal compact, stability of the yield stress and the rheological properties of the coal-water slurry are adversely affectedand theslurry may segregate or become dilatent or otherwise not pumpable. The value of the numerical exponent n in the formula CPFT is affected by the values of D, and Dg. While n will usually range from 0.2 to 1.0, n preferably will be in the range from about 0.2 to 0.7. D, usually will be in the range from 1180 rn to 38 n and will preferably be in the range of 70 rn (micrometer or micron) to 600 am, and most prefer- ably will be about 300 μ . D g will be less than 3 μ (<3 j u ) and usually will be in the range of 0.05 μm to 0.3 pm, and preferably will be about 0.1 μm . The counterions provided by the electrolyte and/or dispersing agent(s) are of opposite charge to that of the surface of a coal particle, which usually is negative. The counterions also cooperate with counterions which already may be present in the bound water layers on aged wetted coal particle surfaces to provide bound water structures which help to provide zeta potential to disperse the coalparticles in the compact in the carrier water, due to the repulsive electrical charges on the particles. These ions also help to affect the structure of the bound water layers to permit closer packing of the particles, and thereby provide the yield pseudoplastic rheological properties to the slurry. When the surfaces of the coal particles are freshly wet milled surfaces, the electrolyte and/or dispersing agent and the carrier water present during milling cooperate to provide the particles immediately with "near maximum zeta potential"required for dispersion of the particles in accordance with the invention. A near maximum* zeta poten¬ tial is beneficial and must be maintained, Allowing ' the ' zeta ' - potential to rise to maximum is detrimental as discussed below. The amount of coal present in the coal-water slurry usually will range from about 45% to 80%, or even higher, by weight, dry basis. Preferably, the amount of coal will be from about 65% to 80% by weight, dry basis. The amount of electrolyte and/or dispersing agen (s) usually will range up to about 4 wgt. % based on total weight of dry coal, and preferably will range from 0.05 to 2.0 wgt. %, same basis. The amount of carrier water will be an amount sufficient to bring the total weight of coal-water slurry to 100% by weight. Slurry Brookfiel viscosity usually will be less than about 3000 cps at 60 rp . For example, a coal-water slurry made at 76.1 wgt. % coal, dry basis, was found to have a viscosity of about 2000 cps, see Fig. 1, B, and C. The specific electrolyte and/or dispersing agent present in the slurry and its amounthave been found to be peculiar to coal from a particular source and to the carri water used. Accordingly, the electrolyte and/or dispersin - agent(s ; ) and its anountneeded for dispersing a particular co in a particular carrier water in making the coal-water slurry preferably is selected by a method involving a seri of laboratory titrations wherein the zeta potential is measured in a standard way. The candidate electrolytes and/or dispersing agent(s) are tested to determinetheir ze potential maximizing propensities on a <10 μm sample of particles of coal from the above coal compact from a stan¬ dard sized mass of the coal stirred in a sample of the car water. Optimum amounts of agent or agents are similarly determined. In an equivalent selection method, the electroly and/or dispensing agent is selected by measuring shear rate " versus viscosity of a stirred suspension of the coa particles in a sample of the carrier water while titrating with increasing amounts of the agent(s) . It has been found that maximum zeta potential values correlate well with a leveling off in Brookfield viscosities of the slurry as increased amounts of a particular agent are added in incre¬ ments. SUBSTITUTE SHEET • In another aspect, the invention relates to an improved method for preparing a coal-water slurry suitable for pipeline transport comprising dis¬ persing finely-divided coal particles in water.characterized by the steps" which comprise: (i) providing a coal compact comprising finely- divided coal particles having particle sizes in : therange of about1180 μm to 0.05 μm with at least 5 wgt. % of the particles being of col- loidal size, said particles in said compact having a particle size distribution substan¬ tially in accordance with the following formula: 100,. where CPFT = cumulative weight percent, dry basis r of particles finer than a particle μ of stated size, D . = diameter ' of particle μ , D, = diameter of largest particle in compact, sieve size, or its equivalent Dg = diameter of smallest particle in com¬ pact, SEM size, or its equivalent n = numerical exponent, with n being in-Che range of 0.2 to 1.0, and with all diameters sized in μm, (ii) providing carrier water in a total amount a least sufficient to transport said coal com pact in a pipeline, (iii) determining the voltage and polarity of the zeta potential of a sample of coal particles from said coal compact when dispersed in a sample of said carrier water, (iv) determining from the results of step (iii) the type and amount of zeta potential enhancing electrolyte and/or dispersing agent(s) needed to adjust the zeta poten¬ tial of at least the colloidal particles of said coal compact when mixed with said carrier water to a voltage near maximum zeta potential and sufficient to disperse said coal particles. (v) providing in said coal compact of step (i) , in said carrier water of step (ii), or in a mixture thereof the type and amount of zeta potential enhancing electrolyte and/or dis¬ persing agent(s) determined to- be needed fro step (iv) , (vi) blending said coal compact, carrier water,a electrolyte and/or dispersing agent(s).togeth to form said coal-water slurry. In a preferred embodiment, a novel coal-water slurry containing in the range of 45% to 807 o by weight of coal, dry basis, is prepared by the method which comprises (i) pulverizing, in the presence of a pre-deter- mined portion of the total amount of at leas one electrolyte and/or dispersing agent(s) and in a minor amount of all the carrier water needed to transport said coal-water slurry in a pipeline, a first fraction of coal to prepare a pulverized dispersed coal fraction having particles substan¬ tially all finer than about 300 mn, "B < G.V. (ii) providing with a major amount of all said water and in the presence of the remaining por¬ tion said predetermined amount of said at least one electrolyte and/or dispersinga-gent(s) a second fraction of pulverized dispersed coal having coal particles of a fineness such that, when blended with said first fraction of coal particles to form a coal compact, the total blended mass will form a compact which con¬ tains a net of about 10 wgt. % of particles which are less than 3 urn in size, (iii) blending said first and second fractions to¬ gether in amounts by weight sufficient to pro¬ vide a coal-water slurry having a coal com¬ pact with coal particles having a size in the range of about 300 um x 0-1 μm with at least about 10 wgt. %. of said particles less than 3 μm in size and distributed substantially in accordance with the following formula: 100, where CPFT - cumulative weight percent, dry basis,of particles finer than a particle μ of stated size, D - diameter of particle μ , D = 300 μm, sieve size, or its equivalent D, = diameter of smallest particle in com¬ pact, SEM size, or its equivalent n = numerical exponent, with n being in the range of 0.3 to 0.5, and with all dia¬ meters sized in u . In a most preferred embodiment, the above preferred method includes the further improvement wherein: said total amount of said at least one electrolyte and/or dispersing agen (s) being pre-deter ined by. (iv) determining the voltage and polarity of the zeta potential of a sample of coal particles milled to -^10 uπi from said coal and dispersed in a sample of said carrier water, and 5 • (v) determining from the results of step (iv) the type and amount of zeta potential enhancing electrolyte and/or dispersing agent(s) needed to adjust the zeta potential of at least the colloidal particles of said coal compact when 10 mixed with said carrier water to a voltage near maximum zeta potential and sufficient to disperse said coal particles. Preferably, the electrolyte and/or dispersing agent(s) will be an organic anionic surfactant, or an in- 15 organic salt selected from NaOH, K 2 C0 3 , or Na-.SiOgSH-.O. Most preferably, a combination of the organic anionic surfactant and at least one of the above electrolytes is used. The coal preferably will be de-ashed to remove a 20. substantial amount of unwanted minerals, such as clays and sulfur. Definition of Terms • The following definitions of terms are provided for a clearer understanding of the invention. 5 . Particles of solids, their sizes and other characteristics, and methods for determining their sizes and size distributions and other characteristics in a "consist" are well-known. As used herein, and in the prior art, the term "consist" means the particle 0 size distribution of the solid phase of the coal-water slurry. For example, in the prior art, the term "8 mesh x 0" indicates coal with a graded size, or consist, of coal particles distributed in the range of 8 mesh and zero • (dust), or 2360 μm x zero (dust). Similarly, as used 5 herein, the term "about 1180 μm. Is intended to mean and indicates coal with a nominally measurable graded size, or "consist", of coal particles distributed in the range of from about 1180 microns to a measurable colloidal size, e.g. at least about 0.05 microns. The term "about 1180 microns" is nominally equivalent to a U.S. Series 16 mesh sieve, substantially as defined in Handbook of Chemistry and Physics,- 54th Edition 1973-1974 CRC Press, Cleveland, Oh., page F-143 "Standard Test Sieves (wire cloth)". Unless otherwise stated, the weight of coal is on a moisture free or "dry basis" herein. The term "coal compact" as used herein defines a mass of finely-divided coal particles which are closely packed in accordance with the invention. The term "Alfred formula consist" defines a par¬ ticle size distribution in accordance with the Alfred formula. The term "Alfred formula compact" defines a coal compact having an 'Alfred formula consist". The term "Alfred formula coal-water slurry"defines a * coal-water slurry made with an "Alfred formula compact" and/or a coal-water slurry wherein the coal consist is an "Alfred" formula consist". The term "pulverized coal" or "P.C." as used in the prior art defines coal which has been milled or ground to a "consist" of about 40 mesh X 0 as indicated in Handbook of Chemistry and Physics, supra, 51st Edition, 1970 1971, page F-199. Unless otherwise indicated, the term "P.C." has the same meaning herein. In view of the manner in which coal fractures dur¬ ing milling, coal particles will have irregular shapes wh±ch however, are of a body, or maximum side-to-side thickness, such that the sub-sieve sized discrete particles will pass through a specified mesh of a sieve. The size of the discrete particle can be expressed in terms of a spherical O PI Vf. O diameter which, as used herein, is defined as a U.S. sie size of from 16 mesh to 400 mesh (38 /am) or its equival in microns through which a coal particle from a sample o coal or coal-water slurry will pass. For particles fine than 200 mesh, the size of the particles can be expresse in μm as determined by means of a sieve, or a Sedigraph, a scanning electron microscope (SEM) . Accordingly, both sieve size and SEM sizes or their equivalents, however determined, are used in describing the invention. Means for crushing, milling, including ball milling and roller milling, disc grinding, screening, re¬ cycling, dry (air) and wet (water) separating, and blend or otherwise combining coal fractions to obtain a compac of a desired particle size and consist are well known, as may be ascertained from the above cited prior art. For measuring particle sizes and for determinin particle size distributions of pulverized and fine grind coal particles used for preparing a coal-water slurry of the present invention, the following three means of meas ing particle sizes were used and are preferred: 1. U.S. Series sieves Nos. 16, 20, 30, 40, 50, 70, 100, 140, and 200 were used to determine weights of c particles passing through each sieve in the range of abo (-) 1180 um to (-) 75 μm, including D, where it is at lea 75 μm in size in the coal and the coal-water slurry. The cumulative weight percents of coal particles, dry basis, finer than (CPFT) a particular stated sieve size in micro were charted against the sizes in microns on a log-log chart, referred to herein as a "CPFT chart", to indicate the nature of the particle size distribution of 20 mesh X 200 mesh particles, substantially as shown in Figs. 9-12. 2. A Sedigraph 5500L (made by Micromeritics, C Georgia, U.S.) was used to measure particle sizes and num bers of particles in coal and in the coal-water slurry in the range of (-) 75 μm to about 0.3 u . The Sedigraph 5500L uses photo-extinction of settling particles dispers in water according to Stoke's law as a means for making t above determinations. Although some measure of inaccurac exists in measuring the range above 30 μm and below 1 μm, the determinations are found to be reasonably accurate an -- suitable for purposes of the invention in the range of 30 am to 0.1 um. Other instruments, such as a Coulter Counter can also be used for similar accuracy. The results were plotted on the above CPFT chart. 3. A scanning electron microscope (SEM) at 40,000 x magnification was used to determine D g in the colloidal range below 1.0 μm in the coal compact or in the coal-water slurry. The determination is made by prepar¬ ing a dilute suspension of coal particles or by diluting a sample of disperse coal-water slurry to a dilution of about 10 wgt. % of coal per weight of solution. The dilute sus¬ pension is allowed to settle for two hours, (for example in a 100 ml graduate) and samples of the finest sizes are taken from the top one ml. of the suspension. This sample is further diluted with alcohol, and the diluted suspension or dispersion is examined on a copper pedestal using the SEM in a known way to find and measure the diameter, Dg, of the smallest coal particle. This data is also plotted on the above CPFT chart. The plots from the three measurements are connected to obtain a "CPFT chart line", or curve. It is to be noted that in view of the nature of the measuring means available, the values of D, and Dg must be considered as values which are precise only within the limits of the means used for their determin- ation. In addition to the above, particle size measure¬ ments can be estimated from methylene blue index measure¬ ments to obtain an approximate determination of the wgt % of colloidal particles of size below about l^μ .Such a procedure is described in A.S.T.M. Standard C837-76. The term "particle size distribution line" as used herein in relation to a coal particle compact herein means a "CPFT chart line" representative of the consist of the coal compact, (i.e. its particle size distribution) measured as described above. For example, when CPFT, e.g. in wgt %, is plotted against particle sizes, e.g. in microns (um) on a log-log chart, a smooth line is formed on thechart when the points of the plots are connected by a continuous line. The 'CPFT chart line" may be straight or curved and may have a slope .of up to 1.0, but should be substantially free of peaks and valleys, referred to herein as "inflec¬ tions" or "undulations", indicative of irregularities in content of amounts of the various particle sizes required in a compact in order for a non-undulating CPFT chart line to be obtained. Preferably, the CPFT chart plot line should be a smooth, or substantially "non-undulating", line from 100% to 1% CP A "non-undulating line" is defined herein as a CPFT chart line of which the slope of a tangent at any point on the chart line is within the upper and lower values for n in t Alfred formula. Small undulations, within these outer limits for n may be tolerated. Large undulations may rend slurry unsuitable for pumping especially at high concentra tions, e.g. over 65 wgt. %. The particle size distributio of coal particles in the compact depicted by the non-undul ing line of the chart will correlate with a "smooth" dis¬ tribution of particles of sizes ranging from D, to Dg. The significance of this distribution will be discussed later herein in relation to the packing of particles in accordance with the invention. The term "high solids content slurry" means a coal-water slurry, e.g. over about 60 wgt. %, dry basis, wherein the coal solids are present at a solids loading level at which interparticle reactions would normally pre¬ vent fluidity of the slurry, making it unpumpable; the fluidity required for pumping is obtained and maintained b practice of the method of this invention as herein describ The term "zeta potential", which is used in describing the invention herein, has the meaning given it in the field of colloid chemistry. Concise discus¬ sions and descriptions of the zeta potential and methods for its measurement are found in many sources, including, T.M. Riddick, U.S. 3,454,487, issued July, 1969; Douglas et al. , U.S. 3,976,582, issued August 24, 1976 ; Enc y clo p edia of Chemistry, 2nd edition, Clark et al., Reinbold Publ. Corp. 1966, pages 263=265; Chemical and Process Technology Encyclopedia, D.M. Considine, editor- in-chief, McGraw-Hill Book Company, N.Y. , pages 308-309; Chemical Technology: An Encyclopedic Treatment, supra,. Vol. VII, pages 27-32; Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd Edition, Vol. 22, pages 90-97; and T.M. Riddick, Control of Colloid Stability Through Zeta Potential, Zeta-Meter, Inc. New York City. "Zeta potential" may be measured by conventional techniques and apparatus of electroosmosis such as those described, e.g., in Potter, "Electro Chemistry"; Cleaver- Hume Press, Ltd.,; London (1961). Zeta potential can also be determined by measuring electrophoretic mobility (EPM) in any of several commercial apparatuses. In the present invention, a Pen-Ke System 3000 (made by Pen-Ke Co. Inc. of Croton-on-Hudso ή , N.Y.).was used for determiningzeta potential in the examples herein. This instrument is cap ¬ able of automatically taking samples of coal particles and producing an (EPM) distribution by Fast Fourier Transform Analysis of millivolts from which the zeta potential can be calculated. The zeta. potential is measured using very dilute samples of the -^10 um sized coal particles in the coal compact of the coal-water slurry. The zeta potential is measured both to determine its polarity and charge in milli¬ volts and to determine the effectiveness of a dispersing agent or combinations thereof, such as surfactant combina¬ tions, alone or with inorganic electrolytes present, for providing a suitable near maximum zeta potential for the coal particles in the coal-water slurry. "Near maximum zeta potential", as used herein, means a value of zeta potential, measured at constant elec¬ trical conductivity, below the maximum zeta potential as defined and discussed in the references above. It is neces- sary to normalize the zeta potential values with respect to electrical conductivity, since zeta potential is, itself, a function of the electrical conductivity. This is a function of the above instrument. The term "near maximum zeta poten- tial", as used herein means a zeta potential having a val in the range of about -40 to -70 millivolts, compared to absolute maximum zeta potential, e.g. of about -80 to -10 millivolts, found to be obtainable in samples of Alfred formula coal-water slurry. The near maximum zeta potenti must be of a millivoltage and polarity sufficient to pro coal particles with a repulsive charge great enough to di perse the coal particles in an Alfred formula coal-water slurry. However, the potential should not be allowed to reach a maximum, millivoltage .zeta potential, because the polarity of the charge on the particles may be reversed, causing the particles to flocculate. The zeta potential, therefore, need only be within close range of the maximum zeta potential to be effective for maintaining a coal- water slurry of the invention in a yield pseudoplastic rheology suitable for pipeline transport. The term "surface-active agent", or "surfac¬ tant", as used in the prior art indicates any sub¬ stance that alters energy relationships at interfaces, and, in particular, a synthetic organic compound dis¬ playing surface activity including wetting agents, detergents, penetrants, spreaders, dispersing agents, foaming agents, etc. Concise Chemical and Technical Dictionary, H. Bennett, Chemical Publ. ' , Inc. N.Y. , 1962. The term "dispersing agent" as used herein is a form of " •" . surface-active agent which may be organic • or inorganic and which is present on or in or is added to the coal or water or to the coal-water slurry and acts to create or to promote formation of a repulsive electrostatic charge on a coal particle in an aqueous medium at the interface of the bound water layer on a particle and of the diffuse layer of the bulk or "carrier water" surrounding the particle, thereby creating or ampl fying the zeta potential, or electrostatic charge at the interface. The term "wetting" as used herein indicates covering or penetrating the coal particle surface with a bound water layer. The terms"wetting agent" or "surfactant" as used herein indicate a dispersing agent ^Zl which acts to provide or promote "wetting" of the coal particle surface. The term "surfactant" includes both organic and inorganic surfactants. Some coal surfaces are inherently wetted as mined and milled and may not require the aid of an additional wetting agent for practicing the present invention. As used herein "wetted coal" means both coal which has been wetted with a "wetting agent" and coal which is "wetted" by natural means when mined. The term "deflocculating" as used herein in¬ dicates formation of a colloidal dispersion of colloid sized coal particles. "Colloids" are substances of which at least one component is subdivided physically in such a way that one or more of its dimensions lies o in the range of 100A and 3 μm. As is known, these are not fixed limits and, occasionally, systems containing larger particles are classed as colloids. See Encyclo¬ pedia of Chemistry, supra, page 263. The term "defloc¬ culating agent" as used herein indicates a dispersing agent which promotes formation of a colloidal dispersion of colloidal sized particles in the coal-water slurry. In accordance with the above definitions, the term "dispersing agent" as used herein includes surface- active agents which also may be "wetting agents", "surfactants" and/or "deflocculating agents", any and/ or all of which can be used to create or to amplify the zeta potential on a coal particle in an aqueous medium to a near maximum zeta potential in accordance with known ways in the preparation of a coal-water slurry in accordance with the method of the present invention. The term "Brookfield viscosity" is used herein to define "viscosity" as measured by the conventional technique used in determining viscosity by means of a Brookfield . Synchro-Lactric Viscosimeter (made by the Brookfield Engineering Laboratories, BUREΛTJ v__J __> 1 -■<_? i I "UTE SHEET Stoughton, Mass.). The Brookfield viscosity as reported herein, unless stated otherwise, was measured as centi- poises (cps) at 60 rpm. Coal-water slurry made according to the present invention usually is non-Newtonian fluid having yield pseuodoplastic rheological properties, and as such has no ordinary viscosity. A "yield pseudoplasti fluid" is a power law fluid with a yield stress, as more fully defined herein. The term "electrolyte" means any substance which dissolves into electrically charged ions when dissolved in water or other polar solvent in the coal- water slurry. Thus, the substance can be an acid, base, or salt. Certain electrolytes have been found more • beneficial than others for the practice of the present invention, as more fully discussed herein. The term "stability" as used herein includes static and dynamic stability and as applied to a coal- water slurry of this invention means the capability of the slurry to maintain its level of homogenity over a selected period of time, such as, for example, a time measured from formation of the slurry with its particles dispersed at near maximum zeta potential to the time at which the slurry tends to undergo a change in its rheo- logical properties. The term stability implies that the physical state of the slurry will not readily change • or undergo fluctuations which would impair its use. For example, it implies that coarser particles will not settle out of the suspension and that neither segregat of coarse from fine particles nor flocculation of the coal particles will occur. Segregation of particles would alte particle packing efficiency and adversely affect the rheo¬ logical properties of the slurry. The term "bound water" as used herein means wate re.- ~ .- ± ~ > -d in the "bound water layer" as defined and illus- trated at page 91 of Kirk-Othmer, above, and as illustrate in Fig. 8 hereof and includes a fixed water layer adjacent to the surface of a particle. The term "carrier water" as used herein means the bulk or free water dispersed between the coal particles and contiguous to the bound water layers on the particles. Zeta potential as used herein means the charge present at the interface of the bound water layer and the carrier water. The term "yield pseudoplastic fluid" as used in describing the invention has the usual meaning associated with it in the field of fluid flow. Specifically, a yield pseudoplastic fluid is one which requires that a yieldstress be exceeded before flow commences, and one whose apparent viscosity decreases with increasing rate of shear. In a shear stress vs. shear rate diagram, the curve for a yield pseudoplastic fluid shows a non-linearly increasing shear stress with a linearly increasing rate of shear. In ' a ."pure 1 '' pseudoplastic system, no yield stress is observed so that the curve passes through the origin. However, most real systems do exhibit a yield stress indicating " some plasti¬ city. For a yield pseudoplastic fluid, the viscosity de¬ creases with increased shear rate. This is an indication that the lower the yield stress, the more pumpable such a fluid will be. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully under¬ stood by reference to the following detailed description thereof, when read in conjunction with the attacheddrawings, wherein like reference numerals refer to like elements and wherein; Fig. 1 is a chart showing correlations between Brookfield viscosities in centipoises (cps) at 60 rp and wgt. % of coal, dry basis, content of several Alfred formula consist coal-water slurries. Referring to Fig. 1, Fig. 1,A* is a viscosity curve derived from Alfred formula coal-water slurry having a consist according to blend A of Fig. 11; Fig. 1,B is a viscosity curve derived from Alfred formula coal- water slurry having a consist according to blend B of Fig.11 Fig. 1,D is a viscosity curve derived from Alfred formula coal-water slurry having a consist according to blend C o Fig. 11; Fig. 1, C is a viscosity curve derived from Alfr formula coal-water slurryjiaving a consist according to t Alfred formula milled W. . Virginia coal of Fig. 12. Fig. 2 is a chart showing correlation among Brookfield viscosities in cps at 30 rpm, zeta potentials in milTivolts (mv) and pe cents of dispersing agent used determining amount of dispersing agent needed to obtain n maximum zeta potential in a 55 wgt. % coal-water slurry as further shown in Fig. 13. Figs. 3, 4 and 5 are charts showing titration curves and illustrating correlations between Brookfield viscosities and amounts of electrolyte and/or dispersing agent(s) used in determining optimum amounts of agent(s) be used to obtain lowest viscosities. Fig. 6 is a flow diagram illustrating an inte¬ grated process for preparing Alfred formula consist coal- water slurry and utilizing the slurry in a furnace. ■ Fig. 7 is a cross-sectional view of a typical atomizer, or turbulent flow, burner in which Alfred formu consist coal-water slurry can be burned. Fig. 8 is a chart illustrating effect on solids content of monospheres of solids as adsorbed bound water layer film thickness is increased and showing the signi¬ ficance and importance of the minus 3 u particle fractio in the Alfred formula consist of a coal compact and its effect on the yield pseudoplastic properties of the coal- water slurry in which"the coal compact is present. Fig. 9 is a chart showing correlations between particle size distributions (consists) by wgt, % andparti sizes in microns of: (A) typical Alfred formula coal com¬ pacts of this invention; (B) coal compacts having a theo¬ retical Andreasen distribution, (C) a composite of coal BU compacts as determined from descriptions of coal-water slurries in prior art patents; and (D) a coal compact used in Black Mesa coal-water slurry, as described by Dina in the literature. Fig. 10 is a chart showing correlations between particle size distributions (consists) by wgt. % and particle sizes in microns of ranges of coal compacts made according - to the Alfred Consist formula at D,=1180 μm and at -0^=38 ιm with D s <3 μm in each consist, and further compared with a chart line plot of a coal compact representative of a com¬ mercial Black Mesa coal-water slurry. . Fig. 11 is a chart showing correlations between consists by wgt. % and particle sizes in microns of coal compacts made according to the Alfred consist formula from blends of coarse and fine fractions of Black Mesa coal and of West Virginia coal, respectively, with L as shown Fig. 12 is a chart showing correlations between consists by wgt. % and particle sizes in microns of a. coal compact milled from West Virginia coal to an Alfred consist with D,=300 μm and D s =<1.0 um and a coal compact representa¬ tive of Black Mesa coal-water slurry, and further illustrat¬ ing nominal upper and lower n value limits for the Alfred consist. SUBSTITUTE SHEE Fig. 13 is a chart illustrating titration curve derived in experimentally selecting electrolyte and/or dispersing agent(s) and determining the optimum wgt. % needed for dispersing coal particles in carrier water- by addition of incremental amounts of agent; measuring shear rate in rpm after each addition, and correlating the shear rate in rpm with Brookfield viscosity in centi- poises. Fig. 2 is based on the data shown in Fig. 13. Negative slope in Fig. 13 indicates yield pseud plasticity and the lowest 30 rpm viscosity with yieldpseu plasticity indicates an optimum amount of dispersing agen to use to obtain an optimum slurry. Zeta potential measu ments can be made at each addition and correlated to the wgt. % of dispersing agent at each reading as shown in th inset. DERAILED DESCRIPTION OF THE INVENTION As is well known, pipeline transportation of coa water slurry may create many mechanical problems, such as, line, plugging, settling during shit-downof flow, start-up flow after shut-down, slope of pipelines, and corrosion an erosion of pipelines. Many of these problems have been overcome by the known processes. However, current technol still requires that the coal-water slurry be pumped in a turbulent regime, at a rate higher than a usual minimum velocity for a fluid of similar viscosity, in order to mai tain the coal and water mixed in the slurry. Consequently the known coal-water slurry pipeline systems must be operated either at a high flow rate or stopped. Also, coal-water slurry preparation and usage as presently practiced create major economic problems includi providing an adequate supply of water for slurrypreparati l^ and involving expensive processing operations, such as, for dewatering and drying of coa^ which in prior art processes is recovered as about 75% coal centri¬ fuge cake from the coal-water slurry, at the delivery site for burning in furnaces. A further major economic problem which exists is that "underflow" from the dewatering operation causes a serious dispos¬ al problem for effluent coal fines, as well as being a significant economic waste of the coal fines. For example, Dina, supra, reports that to 1976 over 400,000 tons of underflow had not been utilized because of inability to burn it, or to difficulties associated with processing it. Accordingly, at the time of this invention a great need existed for an improved high solids content coal-water slurry which can be easily prepared, which has static and dynamic stability and can be pumped through a pipeline for long distances at controllable speeds, and which then can be burned directly in a turbulent (atomizer) burner with a minimum amount of N0 γ formation, as well as in a cyclone burner furnace intended to burn low- grade coal having a high ash content. The present invention provides such a coal-water slurry and sig¬ nificantly avoids many of the above mentioned mechani- cal, dewatering, and waste problems. Furthermore the rheological properties of the coal-water slurry are such that the pumping rate of the slurry in a pipeline can be controlled, i.e. accelerated or decelerated, to accommo¬ date varying demand rates at the user's facilities, without causing flocculation or settling of larger particles in the pipeline. -26- The present invention relates to a novel coal-w slurry of high solids content and of relatively low visco which usually has yield pseudoplastic " rheological prope ties to enhance controllable pumpability,. to permit stori prior to use, if desired, and to permit direct burning of the slurry. In the slurry, a compact of comminuted coal particles of an advantageous particle size distribution a having a content of a critical amount of particles of col loidal size is maintained by means of an electrolyte and/ dispersing agent in deflocculated condition with at least the colloidal particles at near maximum zeta potential in the ' carrier water. The larger coal particles in the slur thereby are dispersed, and the slurry may be further r dered rheologically yield pseudoplastic by providing in t slurry a further effective amount of the electrolyte and/ dispersing agent(s) which preferably is an organicor inorga surfactant, an inorganic electrolyte, or a combination of both, and which serves further to maintain the particles near maximum zeta potential. The invention also relates to a method for pre¬ paring such a novel coal-water slurry having its advantag eously distributed coal particles maintained at near maxi zeta potential. The invention further relates to utilizing coal water slurry of the invention as a fuel for generation of heat and/or electrical energy in a suitable furnace, and other uses, such as chemical, gasification and/or metallu gical uses, to all of which uses the slurry can be delive by pipeline and conveying means for said slurry, such as pumps, at controllable flow rates. The coal-water slurry of this invention Is especially advantageous in that the slurry can be prepare for most uses as a 70-80 wgt % (dry basis) coal-water slu which can be prepared at a distant location, pumped throu suitably sized pipelines, such as those now in . commercial use, and used directly in many cases without the need for dewatering of the slurry after pumping or without need for concentration of the slurry, for example, by evaporation, to obtain a burnable product, and/or to remove water which would interfere with the particular use intended. In the prior art, the efficiency of coal-water slurry transportation is stated to depend upon a number of variables, the most important of.which from an hydraulic standpoint are listed as (1) size consist; (2) velocity; and (3) concentration. The selection of a proper consist (size gradation) is stated to be important in order that homogeneous flow can be achieved at economic oper¬ ating velocities. In the above described commercial Black Mesa 50 wgt % coal-water slurry, such a consist is of 8 mesh by 0 (approximately 0.1 inch particle size to dust) . Homogeneous flow (solids evenly distributed across the pipe diameter) is stated to be important if excess¬ ive wear in the bottom of the pipe is to be avoided and stable operation achieved. The prior art further teaches that equally important and- directly related to size consist is the proper selection of velocities for transport. The velocity cannot be excessive so as to cause abrasion of pipe wall and high-pressure drops. Conversely, the velocity should not be so low as to cause hetero¬ geneous flow, with resultant excessive wear in the pipe bottom or bed formation which will cause unstable oper¬ ation. Generally, practical operating velocities with the above 50 wgt % coal-water slurry are taught to be in the range of 4 to 7 feet per second. Q! !!_5_- SζTITUTE SHEET Finally, slurry concentration must be consider¬ ed. The relationship between concentration and viscosity for any given slurry can be determined in laboratory benc testing. Although it varies for different slurries, all prior art systems generally demonstrate a point In inflec tion where a small increase in concentration causes a large viscosity increase. Hence, with such systems it is important to maintain a concentration range below the in¬ flection point in order to provide good operation with- out excessive velocities. For coal, the practical concen tration range of prior art coal-water slurry appears to be from 45 to 55% solids, according to the above-cited Va Nostrand Scientific Encyclopedia summary of coal slurry p line technology. In contrast to the above limitation of concentr tion of coal-water slurry solids to 45 to 55 wgt % solids dry basis, for pipeline transportation, the present inven tion provides a high solids content coal-water slurry hav from 45 to 80 wgt 7 β , or more, dry basis, coal solids conc tration for pipeline transportation at velocities which c be less than those needed with the prior art systems, if desired, but which can be at least as high as those of th prior art. Furthermore, an inflection point in flow wher a small increase in concentration causes a large increase in viscosity has not been evident in flow of Alfred formu coal-water slurry. Instead, it has been found that the change in viscosity with increase in concentration is a gradual change in keeping with the yield pseudoplastic rheological properties of the slurry. SUBSTITUTE SHE The invention is also beneficial and advantageous in that the amount of water required to prepare and pump the 75 wgt % slurry is about 1/3 that required to prepare and deli¬ ver 50 wgt % coal-water slurries via long distance pipelines. 5 1 . For example,a coal-water slurry at 50 wgt % solids requires about 250 gals, of water per ton of dry coal, while slurry of this invention at 75 wgt % solids content requires about 83 gals, of water per ton of dry coal. Moreover, because water in a 70 to 80 wgt % coal-water slurry of 10 this invention does not need to be removed from the slurry in order to be able to burn the coal, a considerable reduc¬ tion results in the cost of the pipeline-delivered coal- water slurry. Furthermore, no waste "underflow" fines are left over to be dumped into a waste pond with the attendant 15 evaporation of waste water required to form a dry mass. Such "waste water" is defined, as brown or black water which for environmental protection purposes may not be allowed to seep into streams or water tables and therefore must be evaporated in order to dispose of the water content 20 of the "underflow". In summary, the Alfred formula coal-water slurry is a novel combination of coal particles and carrier water wherein the particle sizes and their distribution are con¬ trolled in accordance with a particle size distribution for- 25 mula which is especially beneficial for providing a coal compact with a minimum amount of void space betweenparticles! and a maximum amount of particle surface area with an advan¬ tageous amount of colloidal sized particles present, all of which features combine to enhance the dispersing effects 30 generated by electrolytes and/or dispersing agents selected to provide a near maximum zeta potential to the particles and are added to disperse them and to thereby provide low viscosity to the resulting yield pseudoplastic coal-water slurry. The low viscosities obtained, e.g. 1000 cps at 35 75 wgt. coal, dry basis, as shown for example in Fig. 1 C, are so far as is known to the inventor hereof, significantly lower than viscosities of pipeline pumpable coal-water J K fc_4 CΓ.PI slurries of the prior art at similar solids content. Accordingly, the Alfred formula coal-water slurry hereof represents an advantageous and beneficial improvement in the coal-water slurry art to which the claims hereof are directed. The coal-water slurry of the invention is prepar by a process which comprises in combination at least three steps which cooperate to achieve production of a high soli content pipeline pumpable coal-water slurry suitable for transport in long distance pipelines. These three steps a their functions may be summarized as follows : (i) providing a coal compact of finely-divided coal particles wherein the particle size distribution is designed to minimize the void space between particles and to maximize the packing efficiency of coal particles of a broad spectrum of particle sizes in the range from 1180 um to 0.05 μm, thereby also providing anoptimum amount of particle surface area in the compact, (ii) providing an effective amount of an electro lyte, which may be a dispersing agent, in carrier water to provide advantageous counterions to the bound water layer surrounding each coal particle, thereby to enhance the structure and electrochemistry of the bound water layer an to minimize the total water content of the slurry, and, (iϋ) dispersing the coal particles of the coal compact in a sufficient amount of carrier water by means o a dispersing agent which is effective to raise and maintai zeta potential of the coal particles dispersed in the carrier water and which is provided in an amount sufficien alone or in combination with the electrolyte, to provide t coal particles in the coal-water slurry with a zeta poten¬ tial which is near, but essentially below, the maximum zet potential to which the coal particles could be raised in t slurry, thereby promoting yield stress required in a slurr having yield pseudoplastic rheology while avoiding dila- tency which could causepumping difficulties. The particle size distribution, or consist, of t present invention, provides a major means for minimizing t carrier water content of the slurry and minimizes the por- osity of the packed coal particles of the coal compact which must be filled with carrier water before adequate fluidity for transportation of the coal-water slurry in a pipeline is obtained. The principle on which this is based may be explained as follows. In the case of a theoretical powder which consists ofmono-sized spheres which pack in a simple orthorhombic array, the volume percent solids is cal¬ culated to be 60.51% and the porosity to be 30.49%. By filling the interstices with spheres which exactly fit into the voids, it is calculated that the solids content becomes (.6051 x .3039 + .6051) 100 = 84.48% and the porosity is reduced to 15.59%. This procedure can be repeated with still smaller spheres to further re- duce the porosity. Andreasen, cited in G. Herdan, Small Particle Statistics, 2nd Edition, Butterworth, London (1960) , in 1929 showed a particle size distribution with a power law function which he described by the equation CPFT -=/ * 2 y.100 and which he believed will produce optimum packing of particles when n is between 0.33 and 0.50. In Andreasen's formula, CPFT = cumulative weight percent of particles finer than a selected particle size in microns μ = any selected particle size In microns B =- the largest particle size in microns in the mass n = slope of the plotted line of the values of CPFT vs particle size in microns on a log-log chart. Andreasen's power law function in effect teaches perfect packing by ignoring the size of the smallest parti- cle size, which therefore can be infinitely small. In com¬ paring chart lines of the particle size distributions of prepared compacts of the present invention with Andreasen CPFT chart lines, it was found that the Andreasen formula did not provide chart lines which properly fit the distri- butions for the coal compacts found to provide low vis¬ cosities. It is believed that the reason for this discrep¬ ancy is that, as a practical matter, any particle size dis¬ tribution must contain a finite smallest size for a rti¬ cle, which Andreasen's formula does not do. Therefore , a correction was made in the Andrease formula to take into account the size of a finite sized sm est " • particle. Accordingly , a new expression for particl packing was derived which is as follows : where Ω„ is the smallest particle size, and CPF and D,_. are the same as in Andreasen's formula above, B μ is diameter of a particle μ of a stated size, and n is a num erical exponent. The modified Andreasen formula is refer to herein as the "Alfred consist formula" for particle si distributions. It depicts closely the particle size para¬ meters needed for describing practical particle packing i a coal compact of this ' invention and in similar compacts. In the Alfred consist formula, the value of n is dependent on the sizes of D, and D g . The size of D, for particular coal is a fully controllable functionof the gr ing operation. It can be controlled by grinding coal unti a desired size of D-. is obtained. The size of B g is a les controllable function. It is dependent on the grindabilit of a particular coal, and will usually be the same D ς size for that coal ground in the same mill. However, in some cases, it may be advantageous to obtain a larger D s , for example, by screening out fine particles below a selected particle size. SUBSTITUTE SHEET ^E The Alfred formula was used to prepare a series of computer printouts of CPFT values for various stated particles over a range of particle sizes for ju ranging from s to B, for a range of nominal exponent n values in a parameter range which would provide at least 5 wgt. 7. of particles of size <3 m for each value of n at selected D, and Dg values. Illustrative typical and preferred values com¬ puted for typical consists of coal compacts which can be made in accordance with the Alfred formula while meeting the above limitation of at least 5 wgt.%of (-) 3 um" ' particles in the compact are shown in Tables 1, 2 and 3. Table 1 illustrates the compositions of typical and preferred consists of 1180 /am x 0.3 yam coal compacts which can be made in accordance with the Alfred formula for coal compacts having D, of about 1180 yum, B < - of about 0.3 um and nominal n values of 0.1, 0.2, 0.35 and 0.4 while providing at least 5 wgt. %> of particles of minus 3 yam size. From the data, it is seen that at an n value of 0.1, the consist will have CPFT of about 19.5 wgt. % of a stated particle of 3 μm size, and at an n value of 0.4, the consist will have CPFT of about 5.7 wgt. % for a stated particle μ of :3 um. Table 2 illustrates the compositions of typical and preferred consists of 300 um x 0.3 m coal compacts which can be made in accordance with the Alfred formula for coal compacts having D, of about 300 μm, g of about 0.3 μm and nominal n values of 0.2, 0.3, 0.5 and 0.6 while providing at least 5 wgt. % of particles of minus 3 u size. As can be seen from the data, at an n value of 0.2, the consist will have CPFT of about 20.5 wgt. 7 ° for a stated particle μ of 3 μm size, and at an n value of 0.6, the consist will have CPFT of about 5.0 wgt. %, for a stated particle α of <<3 μm size. Table 3 illustrates a range of coal consists with particle sizes, denominated by usually used U.S. sie mesh sizes as well as corresponding particle sizes in μ . The values ' for nominal wgt. % of particle μ finer than 3 and the nominal n limits where ιis (-) 3um when CPFT is present at less than 5 wgt. % are tabulated from computer printout tables such as those shown in Tables 1 and 2. Consist Examples No. 1-22 were all computed with decreas¬ ing values for B, and a constant value of 0.3 μm for B g . Consist Examples 23-28 were computed with a constant valu of B,=300 /a (about 50 mesh) and values of B g which varie from 0.05 um to 0.50 μm. It is seen from the nominal n values which correspond to the various B L - B g combinatio in consist Examples 23-28 that the lower (on the chart) value of n decreased with increase in size of B g . This information is of value for controlling the yield stress properties of the coal-water slurry by providing a known range of B < - which can be used to modify the properties. As stated above, the data for Tables 1-3 was c puted by fixing B g constant at 0.3 in the Alfred form It is to be understood that B g can be any D g in the rang from 3 μm to 0.05 u . Accordingly, comparable computer printouts of typical consists can be made where D g in th Alfred formula is held constant at any value between 0.0 Jim and 3 ιm. The data §0 derived can then be used to prepare an Alfred formula compact and an Alfred formula coal-water slurry having a consist in accordance with th corresponding Alfred formula consist. Table 4 shows an analysis of the consist of Fig 12 identified. as Consist A, Alfred Formula West Virginia Coal Compact. Referring to Fig. 12, it is seen that the CPFT chart line for Consist A is well within the upper (n=0.2) and lower (n=0.6) parameter lines on the chart. SUBSTITUTE SHEET TABLE 1 TYPICAL ' CONSISTS OF 1180 m * 0 .3 um ' " COAL COMPACT S 36.1 47.7 37.9 25.4 21.9 55.9 53.3 43.5 30.5 26.8 86.4 59.1 49.6 36.5 32.6 133.6 65.2 56.3 43.5 39.6 206.5 71.5 • 63.6 51.6 47.9 319.3 78.2 71.5 61.1 57.7 493.7 85.1 80.2 72.1 69.4 763.2 92.4 89.6 85.0 83.4 1179.9 99.9 99.9 99.9 99.9 SUBSTITUTE SHEET TABLE 2 TYPICAL CONSISTS OF 300 μm x : 0.3 μm ' COAL " COMPACTS " 10 .3 .0 .0 .0 .0 .4 2.5 1.6 .6 .3 .6 5.2 3.5 1.4 .8 .8 8.1 5.5 2.3 1.4 1.2 11.3 7.8 3.4 2.2 15 1.8 14.7 10.4 4.8 3.1 2.6 18.3 13.3 6.4 4.3 3.8 22.2 16.5 8.3 5.8 5.4 26.4 20.0 10.7 7.6 7.9 30.9 24.0 13.5 9.8 20 11.3 35.8 28.4 16.8 12.6 16.3 41.0 33.4 20.8 16.1 23.5 46.7 38.9 25.6 20.4 33.8 52.7 45.0 31.4 25.8 48.7 59.2 51.9 38.3 32.5 25 70.0 66.2 59.5 46.6 40.8 100.7 73.8 68.0 56.5 51.2 144.9 81.9 77.5 68.5 64.0 208.5 90.6 88.1 82.8 80.0 299.9 99.9 99.9 99.9 99.9 SUBSTITUTE SHEET -37 TABLE 3 TYPICAL CONSISTS OF VARIOUS " COAL -COMPACTS - 25 50 300 0.20 5.0 - ' 0.607 26 50 300 0.30 5.0 - 0.590 27 50 300 0.40 5.0 - 0.574 28 50 300 0.50 - .5.0 . . - .. . 0.557- SUBSTITUTE SHEET TABLE 4 ANALYSIS OF CONSIST OF 300 μm xθ.52 μm WEST VIRGINIA COAL COMPACT 0.52 . 1.8 0.6 2.0 10 0.8 2.8 1.0 3.5 1.5 5.2 3.0 9.0 5.0 13.0 15 10.0 20.0 20.0 30.0 30.0 38.0 50.0 48.0 70.0 56.0 20 100.0 65.0 200.0 88.0 300.0 99.9 SUBSTITUTE SHEET When the Alfred formula consist is followed close¬ ly, as shown in Fig. 12 and Tables 1-4, for example, optimum practical particle packing with minimum void space volume is obtained for a coal-water slurry. By minimizing void spaces of a compact of coal particles it is obvious that a minimum amount of carrier water is needed to fill those voids . This in turn reduces the total amount of water needed for obtain¬ ing system fluidity. For obtaining maximum fluidity in a prepared Alfred coal-water slurry, the consist of the Alfred formula compact used to make the slurry should follow the Alfred equation from D, to B g as closely as practically possible, and preferably, exactly, with n having a substantially constant value in the formula depicting the acutal dis- tribution size. Some fluctuations are found to commonly occur in the bimodal blends and tend to decrease the pack¬ ing efficiency. Such fluctuations will cause " n values to fluctuate also. However, it is still possible to obtain pipeline pumpable slurries if the actual distribution is ' relatively close to that required by the Alfred formula for particular values of D τ and B < - It has been further found that rapid fluctuations in the values of n over the range of particle sizes from B, to B g are indicative of a non-uniform distribution of particle sizes in a com- pact in the range between and B g . It has been found that producing in a coal com¬ pact a total particle size spectrum described by the Alfred distribution formula will produce a low viscosity slurry in the presence of appropriate electrolyte and/or dispersing agents(s), and unless the size distribution is in accordance with the formula distribution those same agents will not produce a pipeline pumpable, low viscosity slurry. For practice of this invention, it is important that the coal particles present in the coal compact and in the slurry be provided to have as close a particle size distribution as possible to the Alfred formula. In one method, this can be done by grinding coal under grinding conditions which can be carried out and controlled in a known way until the desired D L , D g and Alfred particle size distribution in a desired n range for the coal com pact is obtained. In a second method, a similar coal c pact can be provided by blending several grinds of mill powders of coal to make a blend to obtain a similar Alf particle size distribution in the compact as described the above values, with a maximum solids content and wit minimum void volume. Coal compacts prepared according the Alfred formula can be used to prepare pipeline pump¬ able coal-water slurries having a minimum carrier water content and a low viscosity. For example, slurries of this invention have been produced having 77.5 wgt. % of coal, dry basis, and a Brookfield viscosity at 60 rpm le than 2000 cps. (Fig. 1C) . Similarly, by using a proper combination of steps (i) , (ii) , and (iii) as disclosed herein, slurries may be produced having 80% wgt. % of co dry basis, and a Brookfield viscosity at 60 rpm less than 4000 cps (Fig. 1C) and be suitable for pumping in a long distance pipeline. In practicing the invention, it has been found that a large yield stress is required in the coal-water slurry when D τ is large, e.g. llδO tim, whereas a small yield stress is required when D-. is smal e.g. 100 ^ ιm. Also, if low viscosity pumping requirement are more important for a particular use condition than I storage stability, then a lower n Newtonian or pseudo¬ plastic slurry to no yield stress can be produced. The other two steps required for making the co water slurry hereof, i.e. the electrolyte enhancement of the bound water layer to control the water structure, and the dispersing of the coal particles and maintaining them at near maximum zeta potential, are both achieved by chemical treatments of the water present on and be¬ tween coal particles in the coal-water slurry. Together with the Alfred consist compact, these elements determin the nature of the plasticity, i.e. the rheological prop¬ erties, of the coal-water slurry. It has been found that efficient packing of coal particles in a compact BU . according to the invention provides a minimum porosity, or free pore space, into which a minimum amount, compared to prior art amounts, of carrier water needs to be pro¬ vided in order to have sufficient water present to obtain fluidity of the mass and to make it suitable for pipe¬ line transportation. Presence of this minimum amount of carrier water, which may be as little as about 20 wgt. % does not in itself render the mass fluid. However, by use of chemical treatment according to the Invention in combination with the carrier water according to the in¬ vention, dispersion of the coal particles is achieved to separate the particles by repulsive charges in a known way in accordance with electrochemical principles. This step provides counterions which are believed to minimize the thickness of the bound water layer on a particle, and in effect affects its structure. Furthermore, it provides a zeta potential on the particles which helps maintain the closely packed particles in dispersed form. More specifically, it has been foundadvantageous and beneficial in order to enhance the structure of the bound water layer and to control the zeta potential of a particle to take into account and, if necessary, to modify, the type and amount of counterions present in the bound water layer present on the individual coal particles and in the carrier water present between coal particles. This is done by controlling the type and amount of electrolyte needed and used in the coal-water slurry. The method steps used to provide the coal par¬ ticles with a zeta potential controlled at near maximum zeta potential will depend in part upon the surface chemistry of the mined coal as it enters the slurry prep¬ aration plant, its treatment there in carrier water, and upon the chemistry, or electrolyte content, of the carrier water, and the water associated with the coal in the slurry. The chemistry of the water associated with the coal can vary from that of the moisture inherent in the coal as mined to that of the residue of primary wash water used at the mine mouth to that of the water used in preparing the slurry. In each case, different electro solution ions may be present in the water, with each source providing different electrolyte content and aff ing pH of these solutions and zeta potential of the particles. " When water is added to a powder comprising finely divided particles, and provided that the water "wets" the powder, a surface water film is adsorbed on each particle which is know to be structually differen from the surrounding "free" or bulk water, in that the film may be described as "semi-rigid", or bound water Depending on the fundamental electrical potential of t surface, this "semi-rigid" or bound water film may be o several molecules thickness. For example, on clays, th film has been estimated to about 80° A thick. Although subject is controversial due to present inability to accurately measure these phenomena, both the thickness the structure of the bound surface water film on the particle (hence its rigidity or non-mobility) can be In fluenced by both anionic and cationic additions to the system, depending on the polarity of the charge at the surface of the coal particle. It is well known that ad ing anions and cations to a dispersion of particles als changes the net residual electrical potential, or zeta potential, at the bound, or surface water film-free wat interface. This zeta potential when maximized by count ions formed by ion exchange reactions between surface groups, such as acid groups and salt-like bonds on the surface of the coal particles and a counterion providin electrolyte deflocculates . the particles, and when ne tralized by other electrolytes allows flocculation of the particles by London-Vander Waals forces. Coal, by its natural chemistry, may be expect to be hydrophobic (nonwetting) , but due probably to its partial oxidation is sometimes hydrophilic. Consequent for example, it has been found that coal from some mine e.g. Black Mesa coal, can be deflocculated almost equal well using as the deflocculating agent either a water soluble anionic organic surfactant (Lomar D) , believed to. provide negative counterions, or a cationic alkali metal base, NaOH, providing positive counterions, or any com¬ bination of Lomar D and NaOH. West Virginia coal on the other hand requires the addition of the organic sur¬ factant first to effect the surface water filmadsorp- tivity, which then is deflocculated further by addition of the cationic NaOH. Another phenomenon which is important is the oxidation state of the surface of the coal particles. Coal, as mined, may exist In various states of oxidation accord¬ ing to the amount and nature of salts dissolved in the bed water in the coal deposit, and the nature of the original flora which formed the precursor of the coal bed. Freshly ground coal is in a lower state of oxidation, compared with coal which has been ground and exposed to air. Therefore ' , it can be stated that the chemistry, including O2, and structure of ground coal and its surface oxidation state will determine the type and exact combination of dispersing agents,such as surfactants,which maximize the effectiveness of deflocculation. Freshly ground coal has been found more advantageous for practicing the process of this invention than older ground coal. Further, different coals may not react the same, because of their chemical constitutions. Thus, some experimentation may be required to determine the optimum combination of oxidation state, fines content and deflocculating agents, required both as to type and amounts for a particular coal. Such experimentation is well within the skills of one working in the coal slurry art. Accordingly, it is to be expected that coal may require a specific chemical treatment depending on the speci¬ fic chemical environments in the coal bed from which it is mined. While need for chemical treatment at least of the free water by means of electrolytes and dispersing agents is found to exist, it is to be emphasized that usually the chemical agents used are not critical. However, some agents have been found more advantageous for use with certain coals •■ than have others, and their use is preferred. In practice of the invention, it is preferred al that addition of any electrolytes and/or surfactants or o dispersing agents be carried out as grinding mill additiv during preparation of the coal compact, for two reasons, follows. First, the agents serve as grinding aids by ma taining a low slurry viscosity during grinding. Second, they are immediately available for ad¬ sorption on the new surfaces generated during comminuati of the coal. Accordingly, need for later treatment with chemical ion species on the surfaces is minimized or eliminated and saves time, energy, and materials cost. When the conditions have been satisfied for pr viding a compact with an Alfred particle size distributi wherein n is between 0.2 and 1.0, and for optimizing the zeta potential, more water is added, as needed to the blend to disperse the particles and produce a desired de gree of plasticity or fluidity of the resulting Alfred formual coal-water slurry for transporting the slurry in pipeline. At this point two serious problems may arise, which could make the slurry useless for long distance pip line pumping. These are: a. the slurry may develop dilatent rheologyja b. the slurry may be unstable and settle. Present day coal slurry technology teaches that to overcome these problems, it Is necessary to dilute the slurry to approximately 50 wgt. % solids, which dilution separates the particles to minimize particle collision frequency sufficiently to overcome dilatency, and then to pump the slurry in the turbulent regime to avoid settling It has been found that when the fluid transport velocity falls below the critical Reynolds number into the laminar flow regime, such slurry will exhibit instability and gradually settle out the larger particles. At the use site the prior art coal slurry is dewatered to bring the coal, as nearly as possible, back to its original state of dryness so that it can be burned. Such is the current ' technology of all commerical slurry pipeline systems, in¬ cluding that used in the largest coal pipeline in operation in the U.S. which runs from Black Mes , Arizona, 273 miles to the Mohave Power Plant.at Davis Bam, Nevada. According to the present invention, it has now been found that the above two problems are avoided pro¬ vided that a sufficient amount,usually from 5 to 20 wgt. %, dry basis, of the coal particles in the slurry are of colloidal size, usually particles of not more than 3 ιm size, and further provided that especially the colloidal coal particles are in a deflocculated state. In thepre-.; sent invention, accordingly, preparation of a high solids content, e.g. 60-80 wgt.%, slurry which is pumpable for long distances in a pipeline, depends first upon a proper preparation of the size distribution of coal particles in accordance with the Alfred consist formula from the coarsest particles down to colloidal particles of less than about 3^ ι size and use of a critical amount of the such particles in the slurry. It has been found also that to maximize solids content of a coal-water slurry while retaining yield pseudoplastic rheology, all parts, including, broadly, a coarse fraction and a fine fraction, of the particle size distribution of a coal compact must be controlled to pro- vide a substantially non-undulating particle size dis¬ tribution. In some cases, depending on the coal and its in¬ herent properties, the desired D, , D g and particle size distribution may be obtained directly by milling the coal, preferably in the presence of a predetermined amount of electrolyte and/or dispersing agent(s), until tests of the grind show that the desired sizes and distribution have been obtained. This is done, for example, as follows: The particle size distribution or consist, of particles in a sample of the compact from a mill grind of coal particles having a desired D τ is determined at grind¬ ing intervals for the whole range of particles, preferably in microns. A CPFT plot of log CPFT vs log of particle sizes is then charted in a line plot on a log-log chart. The CPFT chart line then is compared to a selec Alfred formula CPFT chart line having n value preferabl in the range of 0.2 to 0.7. When the test resultsfrom the sample show tha the desired particle size range and particle size distr bution have been attained in accordance with the Alfred CPFT consist formula, the mill can be stopped and the c compact used directly in preparation of the coal-water slurry by adding carrier water to a desired concentrati In a coal compact ma ~ de by this example, the value of n of the CPFT chart line for the mill ground c compact optimally should be about 0.40 to provide a coa compact having a consist of 100% minus 300^ι (50). mesh having D g of about 0.3 um and having about 11 wgt. % d basis, of coal particles of minus 3 ιm size. Use of su a mill grind coal compact will result in a nearly ideal, pipeline pumpable, coal-water slurrywhen further chemi¬ cally treated if necessary, and mixed with carrier wate in accordance with the present invention. If a* coarser pulverized coal can be used dire ly into a burner, e.g. 40% minus 600 αm (30 mesh), then the value n In the CPFT formula for the coal compact of the above example can be between 0.15 and 0.55, prefera 0.5, with Ω„= -£-l . Q , preferably about 0.5/ιm. Milling t can be carried out to directly obtain a consist of 10 w % particles minus 3 ιm. A higher percentage of fines will improve the fluidity of the slurry, but it will als increase the costs of both milling and the dispersing agents required. It was further found that " the coarser the coar end of the consist of a grind, the more fines are requir to optimize fluid properties, and the finer its coarse e the less fines are required. Stated another way, a "coarser" compact, e.g. all passing 16 mesh, requires a very wide particle size distribution, for example, (D τ = 1180, D g =-^3.0j__m, n » 0.1 to 0.4). A "finer" compact, e.g. all passing 400 mesh, requires a narrower distribu¬ tion, (D L =40/_m, D g =-_11.0/ιm, n = 0.2 to 1.0). Both of these coal compacts or "grinds" will yield consists with 10 wgt. % of particles of (-) 3/an. but in the finer grinds the (-) 3/ιm fraction may vary, and range from 7 to 36 wgt. % in the consist. Pulverized coal (P.C.) as usually commercially ground may be found to form a coal compact with a particle size range which is close to a particular D-. and B g desired for preparing a coal-water slurry of the invention. However, the coal particle size distribution of the P. C. may not have the sufficient amount of colloidal sized particles nor the substantially non-undulating particle size distribution of coal particles required for practice of this invention. In such case, it is necessary to further grind the pulverized coal until the sufficient amount of colloidal particles, i.e. at least 5 wgt. % , dry basis, are present, and a con- sist is obtained in accordance with the Alfred consist formula. Also, it has been found that such a pulverized coal often can be blended as a coarse fraction with a fines fraction which has a large amount of minus 3 um particles to prepare a coal compact provided that the blend approxi¬ mates the Alfred distribution, having an Alfred formula consist. At least 5 wgt. % of all the particles in the resulting blend then should be of colloidal size, usually less than 3 μ in size (SEM) . The total amount of fines of colloidal, or of minus 3 um size, in the blend can range from about 5 to 20 wgt. %, dry basis, and preferably should be about 10 wgt. %. Adding too many fines to the P.C. fraction will increase the viscosity and will reduce the value n of the CPFT chart line of the Alfred formula. Accordingly, if a given coal cannot be ground in a single milling operation to obtain a particle size distri¬ bution conforming to the Alfred CPFT formula chart line, with its n value preferably between 0.3 and 0.5, then a blend of two or more grinds with coarser and finer particle size distributions must be made, or otherwise provided, e.g. usingBlack Mesa slurry waste, to approximate the desired n value while also maintaining a minimum of 5 wgt % -.of colloidal particles in the final blend. Also, in some cases when, due to a pecularity o the grinding characteristics either of a particular coal and/or of a particular milling facility, an unduly undula ing particle size distribution is obtained in the coal compact from the milling facility, steps can be taken to provide coarser or finer coal particles to smooth out the particle size distribution at the undulating part or parts of the distribution. The significance of the colloidal, usually (-) 3 um size, fraction with regard to pseudoplasticity and dilatency of a slurry is illustrated in Fig. 8 of the drawing. One must consider that monospheres typically pack in an average orthorhombic array at 60.51 volume % solids regardless of size with the particles touching each other. If a film of semi-rigid water is adsorbed o each particle, then one must consider that the volumeperc solids is reduced by moving the particles away from each other by twice the water film thickness (inter-particle spacing, or IPS). As shown in Figure 8, for particles of size below 3 μ , the adsorbed water film becomes a signi¬ ficant part of the packing volume. Figure 8 inset furthe shows that if the interparticle spacing of particles P is equal to or greater than (2 - ) times the particle dia- πieter, then this system can be sheared by merely distortin the rigid water films and not causing particle collisions. This condition would at least avoid dilatency and probably induce yield pseudoplasticity. Therefore, improving the "strength" of the rigid water films of the system by addin advantageous counterions in accordance with above step (ii) of the method of the invention should tend toward tru plastic rheology with a yield stress. ITU The above theory is, of course, distorted by the fact that pulverized coal particles are neither mono nor * spheres, and one must work with an actual size distribution of rough, variously shaped particles. Also, there is no simple way of determining precisely how much materialis less than 3 um in size. However, methods, such as electron microscope measuring techniques, as defined, can be used to make such determinations. In any case, the above concept and step (ii) of ensuring that an adequate amount of advan- tageous counterions are present in the bound water layer are- helpful for obtaining a stable, high solids content slurry having low viscosity and suitable for pumping in a long dis¬ tance pipeline. The effect that the presence of a dispersingagent, such as a surfactant, has upon the coal-water slurry to increase its rheological plasticity has also to do with-the structure of the bound water film on the colloidal particles in the slurry. Although the dispersing agent affects every particle present, the effect is most important when there are sufficient colloidal sized, i.e. minus 3 um, particles, present, because the agent influences the particle-particle interactions. A dispersing agent in a coal-^ a ter slurry accord¬ ing to the invention is believed to perform at least three functions, as follows. First, a water soluble dispersing agent which also serves as a wetting agent, such as an or¬ ganic surfactant, functions and may be necessary and may be used to promote wettability of the coal particles by water. Such an agent may or may not be needed, depending upon the surface chemistry of the coal and the associated electro¬ chemistry of its bound water layers. For example, inherent bed moisture and chemical compounds already present in natural coal deposits may also allow wetting of the ground coal by added water, as discussed above. Second, a dispersing agent, such as a water soluble surfactant, whether organic or inorganic, functio and may be necessary to promote deflocculation of colloid and larger sized coal particles in the presence of advan- tageous electrolytes. According to the DLVO theory (Dejaguim, Landau, Verwey, Overbeek) , small monovalent cations such as Na or in proper concentrations will maximize the negative zeta potential of particles, thereb allowing the particles to repulse each other and to slide past one another without bonding. This is the classical concept of deflocculation. Larger, higher valence, catio such as Ca +2, Al+3, and Mg+3, will tend to reduce the particle charge to zero, allowing flocculation of particl by Vander Waal's forces. Further additions of larger cati can change the polarity of the zeta potential and again increase it. Thus, it is possible for deflocculation to occur at both a negative potential, or at a positive pote tial. A residual Na or K on an organic anionic surfact which causes wetting therefore, can be a very effective deflocculant. For practice of the invention, it has been foun that a zeta potential at a maximum attainable millivoltag for a particular coal compact in a particular carrier wat is undesirable at high solids content, particularly in th range above about 60 wgt. %, for the reason that the yiel pseudoplastic rheology of the coal-water slurry may be shifted into a dilatent rheology and become too viscous t be pipeline pumpable. Therefore, zeta potential must be maintained at a near maximum zeta potential as ascertaine by millivoltage values obtained relative to maximum attai able millivoltage, substantially as described in th_Exampl Third,the dispersing agent functions in some cas as an electrolyte and is necessary for enhancing pumpabil of the coal-water slurry by enhancement or inhibition of structure of the bound or, semi-rigid water layer. It do BU SUBSTITUTE SHEET _0_ this by providing a cation as a counterion for the bound water layer which will affect the yield pseudoplastic index (slope of a plot of log viscosity vs log shear rate) of the mass. Preferably, the cation provided by the agent is NH^ > Na or K . A counterion, such as Na , is a structure breaker, whereas a counterion cation, such as Ca +2, is a structure maker. Therefore, the former are preferably used. The structure making or structure breaking tendencies of each of these - counterions is determined by their z/a (valence/ion radius) relationship which increases and decreases entropy, respec¬ tively. For further discussion of this principle, see W.G. Lawrence, Chapter in Clay Water Systems, W.G. Lawrence, ed. N.Y.S. College of Ceramics, Alfred, N.Y. (1965). The phenomenon is believed analogous to lowering the melting point of glass by adding alkali to the glass composition. Therefore, by using the DLVO theory in practice of the invention, it has been found that addition of a sufficient amount of an advantageous electrolyte, such as an ammonium or alkali metal base, to a coal-water slurry has been found effective to increase deflocculation of the slurry and thereby to improve its yield pseudoplasticity, whereas addition of an alkaline earth metal base has been found to be less or completely ineffective. The above steps (i) , (ii) , and (iii) and the related conditions are taken into consideration for the practice of this invention in order to obtain a stable yield pseudoplastic, high solids content, low viscosity slurry. For example, 1. The consist, or particle size distribution, of coal particles of a coal compact to be used to make the coal-water slurry of the invention must be in accordance with the Alfred consist formula. 100, as defined above, and as may be represented in a linear plot thereof on a log-log chart a have n value in a range determined from D, and Dg, substa tially as illustrated in Fig. 12 and Tables 1-4. When at least 10 wgt. % of the particles are (-) 3 μm, pulverized coal (P.C.) at 50 to 70 wgt. % minus 200 mesh (-75 μm) ca be used to make coal compact to be used in making coal-wa slurry by adding additional fines to the P.C. to raise th total fraction of (-) 3 am particles present in the P.C. grind to at least 5 wgt. , and the total distribution to that according to the Alfred consist formula. Any such bimodal blends usually may advantageously be used. Rod milled commercial P.C. coal usually will not contain suffi cient fines, and therefore, blending of ball milled fines with such grind of coal may be necessary to obtain a con- sist in accordance with the Alfred formula. 2. The minus 3 um fraction is a colloidal frac¬ tion and should be between 5 and 20 wgt. %, dry basis, of total particle weight of the coal, with at least 10 wgt. % preferably 10 to 20 wgt. % , the most desirable. 3. Either the coal must be naturally wetted by natural surface oxidation or other chemical state, or wate soluble surfactants, such as the electrolytes and/or dis¬ persing agent(s) discussed herein, must be added to effect wetting. Between 0.05 and 2 wgt of organic or inorganic surfactants of wetting agent capability based on totalweig of coal may be necessary, or both types of surfactants may be necessary together, in an amount totaling up to 4 wgt. "L , dry basis. 4. The repulsive electrical zeta potential of the colloidal coal particles must be raised to amillivolta just short of maximum, as discussed above, by addition of effective amount of zeta potential enhancing dispersingage to obtain yield stress needed to retain yield pseudoplas¬ ticity. The polarity of the zeta potential may be either positive or negative depending on the Ions present in the coal particle surface, and in the bound water layer, but usually, and preferably, will be negative. The kind of water used as carrier water may be any available water, such as mine, well, river, or lake water or desalinated ocean water having a sufficiently low mineral salt content such that the electrochemistry of the bound water layer and carrier water interface can be con¬ trolled in accordance with the invention and corrosion of milling facilities , pipelines and furnaces will be minimized and controllable. The kind of coal used for practice of the inven- tion is not critical. Coals found in the United Statespar¬ ticularly low volatile bituminous coals, from West Virginia, Kentucky, Ohio, Arizona or Montana fields, have been used. However, anthracite, semi-anthracite, medium and high- volatile bituminous, sub-bituminous and lignite coals all may advantageously be used to practice the invention. The coal used to prepare the coal-water slurry can be obtained in finely-divided form by cleaning and pulver¬ izing larger sized coal to the desired particle sizes. The coal content of the pulverized coal can be enriched by use of known clay and mineral separation processes to obtain a coal of low ash content, e.g. under 5 wgt. X. However, the ash content of the coal may be higher or lower than 5 wgt.%, e.g. from 0% to 20 wgt. 7 a while permitting the benefits of the invention to be obtained. The coal for use in the process can be obtained in a dry or wet form and mixed with water to form a coal- water slurry. Preferably, the coal for making a fine particle sized fraction is wet milled in known ways to pre¬ vent dust and explosion hazards, while adding electrolyte and/or dispersing agent(s) to the water in accordance with this invention. The wet milled coal fraction can be milled with all the water or it can be mixed with sufficient addi¬ tional water to make a slurry which will be readily pumpable in a pipeline, when it further is mixed with a coarser particle sized pulverized coal fraction to form a yield pseudoplastic coal-water slurry according to the invention. Usually, the water content of the final coal-water slurry product will be in the range of about 207o to 55% by weigh of slurry. Preferably, the water content will be from 20 to 45% by weight. The total amount of water must, howeve be at least that needed to transport the Alfred coal-wate slurry in a pipeline to its destination if the slurry is be transported in a pipeline. Bulk shipments of the Alfr coal-water slurry can also be made. Further, the Alfred coal compact can be compressed to make a high density coa mass with minimum fluid content particularly in areas whe water is scarce and pipeline transport is not feasible. In carrying out the invention, much work has be expended grinding and blending coals from different field As a result of this work it has been found thatWest Virgi bituminous coal grinds very easily to a particle sizedist bution in accordance with the Alfred CPFT formula. This ground coal then can be deflocculated using 0.1% Lomar D and NaOH as an electrolyte-dispersing agent combination. Black Mesa coal is a western United States sub- bituminous type coal from Arizona deposits having a dry specific gravity of 1.45 and an equilibrium moisture of about 11 percent. Its ash content is about 10 percent * Th consist of coal of typical Black Mesa pipeline coal-water slurry is essentially all minus 14 mesh (1400 μm) x 18 to 20% passing 325 mesh (-44 um) . Solids concentration of t Black Mesa slurry averages 48 percent by weight of theabo coal. While it has been found that Black Mesa coal is considerably more difficult to grind than is West Virgini coal, it has also been found that when a coal compact is prepared from the Black Mesa coal to have a consist accor ing to the Alfred consist formula, much less electrolyte and/or dispersing agent(s) is required to provide yield pseudoplastic fluidity. ' A^B\5 The dispersing agents used in preparing the Alfred formula coal-water slurry can be any synthetic or natural materials having wetting agent properties and which willmaxi¬ mize the zeta potential of the coal particles to near maxi- mum zeta potential as herein described. For -reasons dis¬ cussed above, the dispersing agent effective for use for a particular coal will be selected on the basis of the surface chemistry of the coal particles. Accordingly,the dispersing agent, preferably a surfactant, will usually be a surfactant which in some cases will be an anionic surfactant, in other cases a cationic surfactant, and in some cases even a non- ionic surfactant. Thus, preferred dispersing agent can be an organic or inorganic material. Preferably the material is an anionic surfactant when the coal is a bituminous coal from a West Virginia, Kentucky, Ohio, .or other Appalachian area coal field, and when the coal is a bituminous or sub- bituminous coal from an Arizona or other Western area coal field. Examples of anionic organic surfactants which have been found particularly advantageous for providing yield pseudoplastic rheological properties to Alfred formula coal-water slurries, particularly those containing about 60 to 80 weight % of West Virginia or Black Mesa, Arizona coal, are shown in Table 5. In some cases, mixtures of two or more of these surfactants beneficially can be used. Most preferably the deflocculating agent is selected from the group of anionic organic surfactants consisting of: (i) 2-ethylhexyl polyphosphoric ester acid an- hydride and its potassium salt, (ii) complex organic polyphosphoric ester acid anhydride and its potassium salt, (iii) condensed mononaphthalene sulfonic acid and its sodium and ammonium salts, and (iv) mixtures thereof. TABLE 5 Anionic Organic Surfactant Tradename Form %con 2-ethylhexyl polyphosphoric Strodex ester acid anhydride • MO-100 Liquid 100 Potassium Salt of Strodex Paste 70 MO-100 MOK-70 Complex organic polyphos¬ Strodex phoric ester acid MR-100 Liquid 100 anhydride Strodex SE-100 Liquid 100 Strodex P-100 Liquid 100 Strodex PK- 0 Liquid 90 Potassium salt of complex Strodex organic polyacid anhydride MRK-98 Liquid 1 98 Strodex SEK-50 Liquid 50 Strodex PSK-58 Liquid 58 Strodex V-8 Liquid 85 Sodium salt of an -alkyl Lomar .D Powder 86- mono naphthalene sulfonic Lomar NCO 90 acid Lomar PW Sodium salt of an alkyl mono naphthalene sulfonic Lomar LS Powder 95 acid Ammonia salt of an alkyl mono naphthalene sulfonic Lomar PWA Powder 89 acid Solution of sodium salt of an alkyl mono Lomar PL Liquid 45 naphthalene sulfonic acid ITU R Strodex is a trademark of Dexter Chemical Corporation. Lomar is a trademark of Diamond Shamrock Process Chemicals, Inc. Other suitable anionic organic surfactants can be selected for screening from those.listed in McCutcheon's, Detergents & Emulsifiers North American, 1976 annual edition, McCutcheon Division, MC Publishing Co., idgewood, N.J. 07451 and in Encyclopedia of Surface-Active Agents, J. P. Sisley, Chemical Publishing Company, Inc., New York (1964, Vol II) . Those found to be effective in the environment of a particular coal and its carrier water can then be used for preparing Alfred formula coal-water slurry. While the use of the sodium and ammonium salts of condensed mononaphthalene sulfonic acid are preferably used, it is to be understood that the condensed mononaph¬ thalene sulfonic acid can be used with the addition of sodium or ammonium alkali to form the corresponding sodium or ammonium salt of that acid in situ. In contrast to the tested ' and selected anionic organic surfactants useful in the practice of the inven¬ tion, many organic and inorganic compounds were tested and found unsuitable as effective deflocculants for forming a pipeline pumpable rheologically plastic coal-water slurry, as disclosed in copending application S.N. 957,166, filed November 2, 1978, which disclosure is incorporated herein by reference. Referring specifically to the electrolytes useful in practice of the invention, some alkali metal inorganic compounds were found effective as electrolytes to enhance the dispersing activity of the screened and selected anionic organic surfactants in the presence of West Virginia and Arizona coals. Alkali metal carbonate, hydroxide or sili¬ cate of sodium or potassium are particularly effective. Preferably, the inorganic compound is at least one < £ C0-. , NaOH, and a 2 Si0 3 -9H 2 0. In the case of Arizona coal, an alkali metal hydroxide, carbonate, or silicate may be used even in the absence of an organic surfactant to adequately deflocculate the coal-water slurry " containing at least 5% of minus 3 μm particles. The reason for this may be that the Arizona coal is already effectively wetted by natural surfactants, and addition of the inorganic compound serves to activate and enhance the dispersing effect of the natural material. When used in the presence of a syntheti surfactant, the alkali material preferably is added before the anionic organic surfactant is added to the slurry, but this order is not essential. Mixtures of the above alkali materials also can be used. It is to be understood that t combination of electrolyte and dispersing agent is used to bring the zeta potential of the coal particles to near maximum zeta potential in accordance with the invention as discussed above, and to disperse the coal particles, espec ially those of colloidal size. The amount of dispersing agents used can be determined by routine experiments to screen and select agents effective for a particular Alfred formula consist of coal and carrier water to convert it to a pipeline pump able coal-water slurry having the coal particles at near maximum zeta potential. The amount will vary, depending upon such factors as the concentration of the coal in the slurry, the particle size and particle size distribution, the amount of ash, i.e. clays and other minerals present, -the temperature of the slurry, the pH, the original zeta potential of the particles, and the particular electrolyte and/or dispersing agent(s) , e.g. a deflocculant anionic organic surfactant, and its concentration. In general, th dispersing agent, e.g. the above deflocculant, is present in the slurry at from 0.1 to 0.7 weight percent based on the weight of dry coal. Procedurally, in determining the amount of a specific dispersing agent needed, a series of measurements are made of viscosities versus shear rates versus zeta potential as described in Ex. 1 for a series o coal-water slurries containing a range of amounts of a par¬ ticular dispersing agent for a constant amount of coal-wate ^- EET - slurry. The data can be plotted as shown in Figs. 2-5 and13 and used as a guide to the optimum quantities of that agent to use to obtain near maximum zeta potential. The coordinate of the chart at which the viscosity and/or zeta potential is not decreased significantly by adding more agent is selected as an indication of the optimum quantity at maximum zeta po- tential, and the .amount is read from the base line of the chart. The viscosity and amount read from the titrationchart (Figs. 2-5 and 13) is then compared with an equivalent chart showing a correlation a orgviscosity, amount andmaximun zeta potential (Fig 2) . An amount of electrolyte and/cr dispersing agent(s) required to provi__ a nearmaximun zetapotential and a selected viscosity is then use! to male theAlfred coal-water slurry. Far example, in Fig. 2near maximun zetapotential, of (-) .50 to (-) 63.2 mv were obtained with 0.4 to 0.5 wgt. % of dispersing agent in a 55 wgt. %> Alfred coal-water slurry. Other methods for selecting the type and amount of dispersing agent needed to obtain a near maximum zeta potential in a coal consist made according to this invention will be apparent to those skilled in the coal-water slurry art. Fig. 3 shows semi-logarithmic plots of defloccula¬ tion curves obtained with varying amounts of sodium salt of condensed mono naphthalene sulfonic acid (Lomar PWA and Lomar PW) and of the ammonia salt of said sulfonic acid (Lomar D) dispersed in carrier water in parts of surfactant per 100 parts of ball milled W. Virginia coal (dry basis, 100 wgt. % 325 mesh ((-) 45 μ ) and having 10 wgt. % of particles minus 3 μm) in a coal-water-anionic organic sur- factant slurry containing 55 wgt. % of coal. From this data it is concluded that rheological plasticity will be provided and retained at near maximum zeta potential when about 0.4 to 0.7 gm of the anionic surfactant is present per 100 gms of dry W. Virginia coal in a dispersed coal- water slurry containing 55 wgt. %, of coal with the particle size distribution according to the Alfred formula. Fig. 4 similarly shows semi-logarithmic plots o deflocculation curves obtained with varying amounts of potassium salt of complex organic polyphosphate ester aci anhydride (Strodex V8 and Strodex PK-90) and of Hydrodyne- Aquadyne, a mixture of non-ionic wetting agents, disperse in water in ml. of surfactant per 100 parts of ball mille West Virginia coal (dry basis, 100 wgt. % minus 325 mesh ((-) 45 μm) , 10 wgt. % minus 3 μm) in a coal-water-anioni organic surfactant slurry containing 55 wgt. % of West Virginia coal slurry. From this data it is concluded tha rheological plasticity will be provided and retained when about 1 to 2 mis of liquid anionic surfactant or of non- ionic wetting agents are present per 100 gms of dry coal a dispersed coal slurry containing 55 wgt. % of coal with particle size distribution according to the Alfred formul Quantities of other dispersing agents to use ca be determined similarly. In general, the flow behavior o the slurry is controlled below the solids content or the dispersing agent addition level at which dilatency could begin to occur i.e. below the level at which viscosity in¬ creases as shear rate increases. Pumpability of the coal- water slurry is optimum under such rheological conditions but would decrease rapidly as dilatency is approached. As discussed above, certain electrolytes, such alkali inorganic compounds, can be added to the slurry to enhance the rheological plasticity of the slurry in the presence of an anionic organic surfactant. The effects o the addition of NaOH to 55% coal-water slurry wherein the coal particles were 100 wgt. % minus 325 mesh and 10 wgt. minus 3 um and containing varying amounts of an anionic organic surfactant, Lomar D, are shown in Table 6. TABLE 6 Brookfield Viscosity , cp NaOH, gms Lomar D at 60 rpm 0.4 1. . 15 450 1.2 0 . , 75 175 2.0 0. . 80 450 IJ • Table 6 shows a ratio of NaOH to Lomar D of 1.2:0.75 to provide an optimum low Brookfield viscosity of 176 cps at 60 rpm. From this data it is concluded that rheological plasticity will be provided and retained when the above ratio of amounts of NaOH to Lomar D are used to prepare an Alfred formula coal-water slurry. Fig. 5 shows deflocculation curves obtained using West Virginia bituminous coal-water slurry (wherein the coal particles were ball milled to provide 100 wgt. % minus 325 mesh and 10 wgt. % minus 3 pm) , 67.4 wgt. % solids, defloc- culated with from about 0.75 to 1.05 gms of Lomar D per 100 parts of coal (dry basis) and varying amounts of NaOH and K CO . The alkali materials were prepared as ION solutions in water and added in various amounts by volume to the slurry. In Fig. 5, 0 = 0ml; IN = 1 ml of lON-NaOH; 3N = 3 ml lON-NaOH; 5N = 5ml lON-NaOH; and IK = 1 ml 10N-K 2 C0 . ' It is concluded from the deflocculation curves that the use of 3 ml of lON-NaOH should provide optimum low viscosity at about 0.75 gm of Lomar D per 100 gms of coal in Alfred formula coal-water slurry. As each ml of lON-NaOH equals 0.4 gm of NaOH, dry basis, and each ml of 10N-K 2 CO 3 equals 0.69 gm of K 2 C0 3> the amount of alkali present in the slurries from which the data shown in the ■ curves was obtained ranged from 0.4 to 2.0 gm per 100 gm of coal. EXAMPLE 1 - PROCEDURE FOR SCREENING AND SELECTING DISPERSING AGENTS FOR USE IN MAKING ALFRED FORMULA COAL WATER SLURRY. A surfactant or combination of surfactants effective for use in practicing the invention may be found by either of the two following methods (a) or (b) as applied in (c) . (a) Zeta potential measurement. In general, a sample of coal is ground in a laboratory size porcelain ball mill with porcelain balls in water at ' 30 wgt. % solids for approximately 24 hours to insure that all the particles are<10 um. Small samples of this larger sample are then prepared in a known way by placing them in a vessel equipped with a stirrer with a sample of water to be- used as a carrier In the Alfred for¬ mula coal-water " slurry. Various acidic and basic salts are then added in incremental amounts to vary the ph, and various concentrations of various candidate dispersing agent organic surfactants likewise are added in incrementa amounts (e.g. grams per gram coal, both dry basis), alone or in combinations of two or more. These samples are then evaluated in any electrophoretic mobility, electrosomosis, or streaming potential apparatus to measure electrical po¬ tentials, from which the zeta potential is calculated in a known way. Plots of zeta potential vs. pH vs. concentra¬ tion may then be made to indicate candidate surfactants, or combinations thereof to be used to produce the optimum dis- persion of coal particles in the carrier water below the amount at which dilatency may be reached. A Pen Ke System 3000 apparatus wa-s used in the determination de¬ scribed and can process 40 samples in about 6 hours. (b) Alternate method for estimating equivalent zeta potential. A large sample of coal is ground in water as de cribed in (a) above at 50 wgt. % solids for about 2 to 4 hours to produce a slurry. This slurry Is found to have a Brookfield viscosity at 30 rpm of about 10,000 cps. Smaller samples, about 500 ml, of this slurry are then deflocculated by adding various candidate dis¬ persing agent surfactants and surfactant combinations to the sample of slurry, as above, dry or, preferably, in solution, dropwise, blending gently, and then measuring the viscosity at some constant shear rate (e.g., using a Brookfield LVT viscometer at 30 rpm) . A surfactant sys¬ tem which is found to produce an acceptably low, prefer¬ ably the lowest, viscosity at the lowest amount, e.g. in wgt. % of addition on a dry coal basis is thereby ident- ified as the most effective surfactant. (c) Reference may now be made to Figs. 2 and 13, which summarize the results obtained in screening tests carried out in accordance with (a) and (b) of this example using coal from an Eastern Kentucky mine at 55 wgt. % concentration and an anionic organic surfactant, sodium salt of an alkyl mono naphthalene sulfonic acid (Lomar D) , as a deflocculant dispersing agent. Referring to Fig. 13, and its inset, it is seen that as the-amount of deflocculant was increased from zero to 0.945 wgt. %, the zeta potential increased grad¬ ually with each incremental addition of Lomar D from (-) 15.4 v at 0.079 wgt. % to (-) 70.2 mv at 0.945%. Sim¬ ultaneously, as the shear rate (rpm) was increased during the time of presence of each incremental amount, the Brookfield viscosity is seen to decrease " until it reaches a minimum value at 30 rpm, while the rheology of the system is seen to change from pse odoplastic to dilatent at a rate between 30 and 60 rpm. Referring now to Fig. 2, it is seen that the chart line formed from the data from the inset of Fig. 13 forms a distinctive curve. The curve shows that as zeta potential increases from (-) 15.4 to (-) 67.7 v, the Brookfield viscosity falls from about 7000 cps to about 80 cps, and then levels off at about 75 cps at (-) 70. mv. From this data and chart, it is indicated that near max¬ imum zeta potential can be identified as being about (-) 63.2y_.rn, and the amount of Lomar D to use to make an Alfred formula coal-water slurry will be about 0.5 wgt. % based on the weight of coal, both dry basis. To be on the safer side, the amount of dispersing agent can be decreased slightly, e.g. to about 0.45 wgt. %, or less. While the above methods have been describedusing a preferred dispersing agent, Lomar D, it will be clear to one skilled in the art that any material can be similarly screened to find advantageous materials which can be used to practice the invention. EXAMPLE 2 - PREPARATION OF COAL SAMPLES FOR SI MEASUREMENTS. (a) Sieve analysis. Although any standard procedure may be use 5 measure particle sizes of coal particles from a coal and then to calculate the particle size distribution,, the pr cedure used in obtaining data discussed herein will be d cribed. A weighed sample, e.g. 50 grams dry wgt. o . 10 coal is dispersed in 400 ml of carrier water containing • v gt.%,Lomar D based on a weight of coal, dry basis, and t slurry is mixed for 10 minutes with a Hamilton Beach mix The sample is then allowed to stand quiescent for 4 hour or preferably, overnight. (This step usually is not nec 15 essary if the slurry was milled with surfactant) . The sample is then remixed very briefly. • is poured slowly on a stack of tared U.S. Standard sieves over a large vessel. The sample is carefully washed wit running water through the top sieve with the rest of the ' 20 stack intact until all sievable material on that sieve is washed through the sieve into the underlying sieves. Th top sieve is then removed and each sieve in the stack, as it becomes the top sieve, is successively washed and removed until each sieve has been washed. The sieves are 25 then dried in a dryer at 105°C and the residue on each is weighed In a known way. The sample which passed through the finest sieve was collected as a dilute slurry in a container for Sedigraph analysis. 30 (b) Sedigraph analysis. The sample finer than the smallest sieve si is carefully stirred and a representative sample (about 200 ml) is taken for analysis. The rest may be discarded. About 2 eyedroppers of the dilute slurry is 35 further diluted in 30 ml of distilled water with 4 drops Lomar D added. This sample Is stirred overnight witha ma tic stirrer. Measurement is theαmade with the Sedigraph 550 \- \ The Sedigraph 5500L uses photo extinction to measure particles*. It essentially measures projected shadows and due to diffraction effects around particles the data must be converted to mass-wgt.-%-finer-than. The data from the sieve and Sedigraph is combined with the D ς data obtained by SEM and used to prepare a CPFT chart. EXAMPLE 3 - PREPARATION OF BIMODAL BLENDED A 75 wgt. % coal-water slurry hereof is prepared using coal from the Black Mesa mine, as follows*. A fine(F.G..). grind portion is prepared by adding to a ball mill 30 parts " of carrier water, about 22.5 parts of pulverized coal (P.C.) and further adding, as electrolyte and dispersing agents, 0.075 parts of anionic surfactant, preferably Lomar D, and 0.075 parts of NaOH. The mixture is ball milled until the particle size distribution is about 45 wgt. % finer than 3 μ .- Also, about 52.5 parts of dry pulverized coal (P.C.) are milled until the coal has a particle size distribution in accordance with the Alfred consist formula where D- is 150 um (100 mesh), D g is<0.7um, and n is 0.8, as defined above, to obtain a pulverized coal (P.C.) fraction which ' is about 78 wgt. % (-) 79 um. A sufficient amount (47.35 parts) of the P.C. fraction is then added to the fine grind coal fraction to form the final 75 wgt. % coal-water slurry having an Alfred formula consist of 150 μm x 0. 2 μm with about 17.5 wgt. % minus 3 um. The total amount of ■ electrolyte and dispersing agent(s) used is predetermined by laboratory tests as described herein. It is effective to bring the entire compact of pulverized coal particles to near maximum zeta potential, and also, to maintain the particles in dispersed, or deflocculated, form in the carrier water of the slurry during pipeline pumping storage and pumping to an atomizer of a coal-water slurry burner or to other use means. The above method can easily be carried out whether using mono odal or multi odal distributions of particle sizes. For a mononodal distribution the electrolyte and dispersing agent preferably are added to the carrier water before it enters the pulverizing mill with the coal The coal is then ground in the presence of these agents. For ultimodal distributions the deflocculant dispersing agent preferably is added inwater asdescribed above, while grinding the fine fraction, and no dispersing agent needs to be added to the coarse pulverized (P.C.) fractions. T coarse dry P.C. fraction can then be added to the deflocc ted F.G. fraction, as described above. If a coal cleaning process including use ofafil press to recover solids is incorporated in the process, coarse P.C. grind having a coarse fraction ' consist suitab for preparing Alfred formula compact is first cleaned, th flocculated using appropriate flocculating chemicals prio to filter pressing and dewatering the coal, which removes these chemicals. An appropriate percentage of P.C. filte cake is then fine ground in the presence of all the deflo culant added as required to prepare the F.G. fraction. T resulting fine ground deflocculated slurry is then blende with an appropriate percentage of the P.C. filter cake in fine blunger or mixing tank to obtain Alfred formula coal water slurry ready for pipeline pumping or storage or for burning or otherwise using the coal-water slurry. EXAMPLE - INTEGRATED PROCESS WITH DEASHING AND BLENDING D τ = 300 μm. The practice of the invention in an integrated process for plant scale operation with de-ashing of West Virginia coal will now be described with reference to Fig 6 and 7 of the drawing. Bituminous coal from West Virginia, containing about 21% ash as mined or washed is introduced into a crusher 1 wherein it is crushed to about 2" size or less. The term "Ash" is used herein to define non-combustible c tent of the coal, such as clay and various minerals. The crushed coal is charged into a mill 2 , preferably a ball mill, where it is wet milled to a particle size of about 70%(-)200 mesh ((-)75 um) with about 7% (-) 3 μ to provi o a coarse fraction of coal particles suitable for preparing a coal compact in accordance with the Alfred consist for¬ mula with <1.0 um and n = 0.5, substantially as shown i en mixed with the fine grind portion made as described later herein. The particles of coarse milled coal are then charged to a slurry tank 3 containing carrier water in an amount sufficient to maintain a solids content of about 10% by weight. The pH of the mass in tank 3 is maintained at a pH of 10 or higher by addition of a solution of NaOH to cause deflocculation and separation of ash materials. Tank 3 is provided with a high intensity agitator 4 to effect dispersion of all particles. After about 20 minutes agita¬ tion, the slurry is continuously pumped by pump 3a through line 7 through the hydrocyclone 5 and hence back to tank 3. The hydrocyclone 5 removes the higher specific gravity minerals, preferably flocculated, and delivers them to scrap or reprocessing. After a suitable time of cycling the slurry through the hydrocyclone to maximize ash removal, the valve 3B is closed and valve 3C opened to filter, press 6 to filter the batch from tank 3. Filtrate from filter press 6 is recycled to tank 3. The pH of the water is ad¬ justed by addition of a solution of caustic soda. (NaOH)- The " partially ash-free coal thus obtained contains from about 0.5 to 10 wgt. % of ash. Treatment of the coal In tank 3 is, however, beneficial to remove at least gross amounts of the ash content of the coal, thereby increasing the net btu value of the coal-water slurry. A minor fraction of the filter cake from filter 6 containing filtered coal and about 25 wgt. %> water is dis¬ charged to a second slurry tank 8 where the cake may be diluted with water from line 8a, if water is needed and is agitated by means of a low speed agitator 9a operated as in tank 3. The filter cake is dispersed in tank 8 with suffi- cient water present to later make a final ' coal-water slurry of about 75 wgt. % solids after adding a first predetermined amount of deflocculant, further milling this minor fraction of coal to a fine grind and blending it with a major frac- tion of filtered coal from filter press 6 in a third slu tank 14. The coal-water slurry from tank 8 is discharge through line 15 into line 16 from which it is fed into l 17 and 18 leading to ball mills 19 and 20. A final predet mined amount of a solution of mixed deflocculants, usual making a total amount providing about 0.7 wgt. % of Loma and 0.7 wgt. % of NaOH and usually sufficient to adjust zeta potential of the particles to near maximum zeta pot tial and to disperse the particles, based on the totalam of dry coal in the final coal-water slurry to be made in tank 14, is added to the coal-water slurries in ball mil 19 and 20. The ball mills preferably are steel and are loaded with steel balls. The coal is milled to a fine g about 95 wgt. % (-) 40 μm x about 10 wgt. % (-) 3 u . T milled, fine grind ooal is discharged from ball mills 19 20 through lines 24 and 25 into tank 14 where it is blen and agitated by means of agitator 9 with the major fract of de-ashed coal from filter press 6. The coarse and fi grind coals are blended in proportions such that the ble has 75 wgt. % of coal, dry basis, and the coal particles have a substantially non-undulating Alfred formula coal sist having about 10 wgt. % of coal particles (-) 3 m p. the particles have a particle size range of about 300 u x 0.1 μm. The resulting final coal-water slurry product is a pipeline pumpable 75 wgt. % low viscosity Alfred formula coal-water slurry usually having a Brookfield viscosity of about 1000 to 2000 cps at 60 rpms. The deflocculated yield pseudoplastic coal-wat slurry is discharged from tankl4 to a storage tank 10. Successive charges of the slurry are blended continuousl in tank 10, preferably by pumping it continuously throug recycle pipeline 11 leading from the bottom of tank 10 to the top of tank 10. Uniformity of the slurry is thus mai tained and provides slurry of a substantially uniform btu content. The blended Alfred formula coal-water slurry is pumped from storage tank 10 through pipeline 27, which ma be a short pipeline or a long distance pipeline, and is f into an atomizer burner 12 of a furnace 13 used to generate heat energy to heat water in a steam boiler. Details of a typical atomizer burner for burning a coal-water-anionic organic surfactant are shown in Fig. 7. 5 Aqueous treatment of the coal for ash removal, deflocculation, and concentration also provides a suitable vehicle for sulfur removal. The amount of deflocculant or of a mixture of deflocculants , such as the anionic organic surfactant and NaOH, which must be used to obtain the bene- 10 fits and advantages of the invention using the Alfredformula consist can be readily predetermined in accordance with the procedures described in Examples 1-3. EXAMPLE 5 OF INTEGRATED PROCESS, WITH BLENDING BUT WITHOUT DEASHING, D L ' = 425 um ■15' Practice of the invention in an integrated process without deashing for plant scale operation with Black Mesa, Arizona, coal will now be described with further reference to Figs. 6 and 7 of the drawing. Sub-bituminous coal from Black Mesa coal fields 20 containing an average ash content of 9.8 wgt. %> (range of 6.5% to 17%) as mined or washed is introduced into crusher 1 and crushed to 2" size or less. The crushed coal is milled in about 10 wgt. % of carrier water to prepare pul¬ verized coal (P.C.) particles 50 to 70 wgt. % substantially 25 all finer than 425 m and suitable for preparing a coal consist in accordance with the Alfred formula with D, = 425 um, Dg=<1.0,. and n = about 0.45, substantially as shown in Fig. 11, when mixed with the fine milled portion made as described later herein. The P.C. coal is discharged 30 from mill 2 through line 16. Because of the low ash content of Black Mesa coal, it usually will not be necessary or or desirable to de-ash the coal. A minor fraction of the milled (P.C.) coal from line 16 is fed through lines 17 and 18 into ball mills 19 35 and 20. A solution of part of a predetermined amount of deflocculant materials is added to ball mills 19 and 20 and additional carrier water is added to each mill, for example, from line 8a, through tank 8, line 15 and lines 1 and 18, respectively. The amount of water added will depe on the amount of water present in the pulverized coal from ball mill 2. A major fraction of pulverized coal is fed through lines 16, 17, 18, 25 and 26 to tank 14. The total amount of minor and major fractions of pulverized coal wil amount to a final amount of coal which when diluted with t water added to ball mills 19 and 20 will make up to a 75 w % coal-water slurry and can readily be calculated ' .. The res of the predetermined amount of deflocculants needed to pro vide the colloidal particles of coal in the coal-water slurry with near maximum zeta potential is added to the ball mills 19 and 20 to provide a mixture of 1.0 wgt. % of Strodex V8 and 1.0 wgt. % NaOH, based on the total weight of dry coal in the final coal-water slurry to be made up in tank 14. The necessary amount of water needed in mills 19 and 20 is added also. The " mills are run for about 30 hours at 60 rpm or until a fine grind of Black Mesa coal is obtained which is 99 wgt. % minus 10 μm and about 46 wgt. % minus 3 sm. The milled, fine grind coal- water slurry is then discharged into tank 14 where it is blended with the major fraction of pulverized coal in proportions such that the blend has 75 wgt. % of coal, dry basis, and the coal particles have a substantially non- undulating coal consist in accordance with the Alfred formula as defined above with n = about 0.45 and particle size of about 7 wgt. % of coal particles minus 3 am. The resulting Alfred formula coal-water slurry usually will have a Brookfield viscosity of about 4000 cps at 60 rpm, substantially as shown in Fig. 1, A. The deflocculated, yield pseudoplastic 75 wgt. % coal-water slurry is discharged into tank 10, where it is blended as described in Example 4 , and pumped to a use site in short or long distance pipelines for burning in an atomizer burner furnace as described in Example 4. EXAMPLE 6 - INTEGRATED PROCESS , WITH OR WITHOUT DEASHING WITH BLENDING, D L = 75 m Using substantially the same method as describe in ' Examples 4 and 5, est Virginia or Eastern Kentucky coal, can be milled and dispersed in carrier water to prepare pipeline pumpable Alfred formula coal-water slurry with from about 65 to 77 wgt. % coal, with D-, - 75 μm , Dg =<1.0 μm , and n = 0.2 to 0.8 with about 6.6 to 29.3 wgt.% of particles of (-) 3 m. The slurry will usually have a Brookfield viscosity at 60 rpm of from 300 to 2400 cps. EXAMPLE 7 - INTEGRATED PROCESS, WITHOUT BLENDING, D L = 300 In view of the finding that West Virginia coal can be milled directly to prepare an Alfred formula coalcompact, this coal usually can be milled and used to make coal-water slurry without need to make a blend from a coarse fraction and a fine fraction as was done in Examples 4 - 6. Referring to Fig. 6, 75 wgt. % Alfred formulacoal- water slurry having an Alfred formula consist with D, — 300, ■ D s =<L0 and n = 0.2 to 0.6, substantially as shown in Fig. 12, can be made as follows: Crushed coal is charged into mill 2 and wet milled to a particle size of about 50 wgt.% (-) 200 mesh ((-) 75 Hn).. The coarse grind is discharged through line 16 into ball mill 19 or 20, alternately or simultaneously, as desired. Predetermined total amounts of electrolyte and/or dispersing agent(s) , e.g. 1.0 wgt. % of Lomar D and 1.0 wgt. % of NaOH, are added to each of mill 19 and/or 20 as needed fromdefloc¬ culant tank 21. The coal is then milled in mills 19 and/or 20 until a sample shows that the D τ , Dg and n values recited above have been attained and that there are at least 5 wgt. % of particles of (-) 3 um present. Usually the amount of (-) 3 um particles will be from about 20.5 wgt. % at n = 0.2 to about 5.0 wgt. % at n = 0.6. The coal-water slurry is tested to confirm that the zeta potential is" near maximum zeta potential (e.g. about (-) 50 mv as shown in Fig. 2), and that the Brookfield viscosity is about 1000 - 1500 cps. The slurry is then discharged into tank 14 for blending of batches. The slurry can be stored in tank 10 and charged from there into the atomizer burner 12 for burnins. EXAMPLE 8 - INTEGRATED PROCESS, WITHOUT BLENDIN WITH DEASHING, D L = 300 μm If the West Virginia coal is to be used in a de ashed form, the above process can be modified by dischar ing the 50 wgt. % (-) 200 mesh coal from mill 2 into tank for deashing substantially as described in connection wit Example 4. The deashed filter cake from filter press 6 c then be charged to tank 8 for dilution with carrier water and transferred to mills 19 and/or 20 as discussed above further milling and deflocculation to form the Alfredform coal-water slurry having the properties as described abov EXAMPLE 9 - INTEGRATED PROCESS - DIRECT MILLING WITHOUT DEASHING, D, = 1180 jum L ^ In a variation of Example 8, ' - crushed coal could be directly charged into ball mills 19 and 20 by me of charge lines (not shown) leading from the crusher to t ball mills. The electrolyte and/or dispersing agent then can be added directly into ball mills 19 and 20 in the pr determined total amounts with additional carrier water as described in Example 8 and milling carried out to obtain Alfred formula coal-water slurry with D, = 1180 um. The- finished slurry can then be further handled, as described above, in tanks 14 and 10 and burner 12. Net heat content of the Alfred formula 75 wgt. coal-water slurries of the above compositions made accord ing to the processes of Examples 1-9 are calculated to be about 105,000 btu/gallon of slurry when burned in the ato zer of a gas supported burner, compared to fuel oil which provides about 130,000 btu/gallon. The flame produced by the burning of the coal slurry can be radiation stabilized, although it may bepos ble for self-stabilization to occur at about 75% solids content in a properly designed burner. Cost calculations which have been made show th Alfred coal-water slurry of the Invention can be produce in large quantities to make the slurry competitive with oil on an equivalent heating value basis. Although the invention has been described in relation to use of the Alfred formula coal-water slurry for heat generation by direct combustion, it is also in¬ tended that the slurry of the invention be used in coal gasification or liquification processes to provide fuel gases and other coal byproducts. Besides being useful in conventional heat generating systems, this coal-water slurry may provide unique properties for use in MHD generators (magneto-hydro-dynamic) in as much as the slurry can be prepared to contain alkali ions needed in the combustion process in such generators. Furthermore, the Alfred formula can be used in preparing Alfred formula compacts of other solid materials which can be milled or otherwise provided in a particle size for preparing a solids compact characterized in that it comprises finely-divided solid particles of at least one solid material having a particle size in the range of about 1180^αm to 0.05 jam with at least 5 wgt. % of the particles being of colloidal size, e.g. (-) 3 um, and having a particle size distribution in accordance with the Alfred consist formula. The solid material can be any natural or synthetic material. Preferably it will be a mineral, or other similar natural material. Most pref¬ erably, the solid material will be an ore, for example, iron ore, or a precious metal ore, such as chromium, nickel, silver or gold ore. The Alfred formula compact of finely-divided solid material having an Alfred formula consist can be mixed with a fluid, which can be water, or a polar solvent, e.g. a ketone or an alcohol, or a hydrocarbon, e.g. fuel oil or naphtha, or a gas, for example, nitrogen, or inert combustion gases, to make a solids-fluid slurry. The amount of fluid used usually will be in an amount at least sufficient to transport the slurry in a pipeline, as is done with the coal-water slurry of the invention. When the solids-fluid slurry contains x^ater, and the solid material is not water soluble, electrolyte and/ or a dispersing agent can be used to disperse the solids in the fluid substantially in the way used to obtain th coal-water slurry having zeta potential at near maximum zeta potential. It is to be understood that the foregoing des cription and Examples are illustrative only and that changes can be made in the ingredients and their prop¬ ortions and in the sequence and combinations of process steps as well as other aspects of the invention discuss without departing from the scope of the invention as d fined in the following claims.

Claims: AMENDED CLAIMS (received by the International Bureau on 27 April 1981 (27.04.81)) 1. 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: 100, where CPFT =- cumulative weight percent, dry basis, of particles finer than a particle μ of stated size, D = diameter of particle μ, D, = diameter of largest particle in compact, sieve size or its equivalent, being from 38 to 1180 μm, Dg = diameter of smallest particle in compact, SEM size or Its equivalent, being from 0.05 to 3 um, n -= numerical exponent, with n being in the range of 0.2 to 0..7, and with all diameters sized in u , wherein, when said compact is admixed with dispersing agent and a sufficient amount of water to produce a suspension contain¬ ing 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. 2. A coal compact according to claim 1 character¬ ized in that said colloidal particles are of (-) 3 u size and said compact contains from about 5.0 to about 35.7 cumu¬ lative weight percent of particles finer than 3 μm. 3. A coal compact according to claim 1 characte ized in that said D- , D,-., n and the wgt. %> of particles of (-) 3 μm size are in accordance with said formula wherein: a) D L = about 425 μm, Dg = 0.1 to 1.0 μm, n= to 0.5, (-) 3 μm sized particles are. from 17.7 to "5.8 wgt. %, respectively, b) D, =■ about 300 μm, D g = 0.05 to 0.5, n = to 0.635, (-) 3 μm sized particles are fr 20.5 to 5.0 wgt. %, respectively, c) D L = about 1180 u , D g = 0.1 to 1.0, n = 0.12 to 0.4, (-) 3 μm sized particles are from 19.5 to 5.7 wgt. %, respectively, an d) D L = about 38 μ , D g = 0.1 to 1.0, n = 0. 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. 4. A stable, yield-pseudoplastic coal-water slur 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 p cent 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 fin ly-divided coal particles having a particle size in the ran of 1180 μm to 0.05 μm with at least 5 wgt. % ' of the particl being of colloidal size, said particles in said compact hav ing a particle size distribution substantially in accordanc with the following formula: 100, where CPFT = cumulative weight percent, dry basis, of particles finer than a particle μ of stated size, D = diameter of particle μ, D j = diameter of largest particle in compact, sieve size or its equivalent, and being from about 38 to about 1180 microns; D ς = diameter of smallest particle in compact, SEM size or its equivalent, and being from about 0.05 to about 3 microns; n = numerical exponent, with n being in the range of 0.2 to 0.7 and with all diameters sized in μm; and said coal particles having near maximum zeta potential in said coal-water slurry. 5. A coal-water slurry according to claim 4 charac¬ terized in that said slurry contains from 60- o 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. 6. A coal-water slurry according to claim 4 charac¬ terized 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. 7. A coal-water slurry according to claim 4 charac¬ terized in that said colloidal particles are of (-) 3 μm size and said compact contains from about 5.0 to about 35.7 cumu¬ lative weight percent of particles finer than 3 microns. ' 8. A coal-water slurry according to claim 4 charac¬ terized in that said D τ , D„, n and the wgt. % of (-) 3 μm size particles are in accordance with said formula wherein: a) D L = about 425 μm, D g = 0.1 to 1.0 μ , n = 0.2 to 0.5, (-) 3 μ sized particles are from 17.7 to 5.8 wgt. %, respectively, b) D L -= about 300 μm, D g = 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 g - 0.1 to 1.0, n = 0.12 to 0.4, (-) 3 μm sized particl are - - fro 19.5 to 5.7 wgt. %,, respectively, d) D-. = about 38 μm, D g = 0.1 to 1.0, n = to 1.0) (-) 3 um sized particles are f 35.7 to 7.0 wgt. %, respectively, said wgt. %> being based on total weightof coal in said compact, dry basis. 9. A coal-water slurry according to claim 4 characterized in that D,. - about 300 μm, Dg =<1.0 μm, n to 0.635 and (-) 3 μm size particles = 20.5 to 5.0 wgt. respectively, of the total weight of coal, dry basis. 10. A coal-water slurry according to claim 4 characterized in that D, = about 300 μm, D g =C0.5 μm, n about 0.4, and (-) 3 μm sized particles = about 9 wgt. % based on total weight of coal, dry basis. 11. A coal-water slurry according to claim 4, characterized in that the amount " of carrier water is suf cient to transport the slurry In a pipeline. 12. 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. 13. 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 anionic surfactant. 14. 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, (ϋ) 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. 15. A coal-water slurry according to claim 14 characterized in that the anionic surfactant is a sodium salt of an alkyl mononapthalene sulfonic acid. 16. A coal-water slurry according to claim 4 fur¬ ther comprising at least one electrolyte and characterized in that said electrolyte is present in an amount effective to modify the structure ofthe bound water layers of said coal particles and help to maintain said particles at said near maximum zeta potential. 17, 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. 18. 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 C0 3 , and a 2 Si0 3 .9H 2 0. 19. A coal-water slurry according to claim 18 characterized in that said electrolyte is NaOH. 20. A coal-water slurry according to claim 19 characterized in that said dispersing agent and said electro¬ lyte 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. 21. 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-CO , and 2 Si0 .9H 2 0. 22. A coal-water slurry according to claim 21 characterized in that said dispersing " agent is a sodium salt of an alkyl mononophthalene sulfonic acid and said electrolyte is NaOH. 23. A cόal-water slurry according to claim 4 characterized in that said near maximum zeta potential is less than about (-) 100 millivolts. 24. A coal-water slurry according to claim 4 characterized in that near maximum zeta potential is abou (-) 50 to (-) 60 millivolts. 25. A method for preparing a coal-fluid suspens with a Brookfield viscosity at 60 revolutions per minute less than 4000 centipoise, comprising the steps of: (a) providing the coal compact of claim 1, and (b) mixing said compact with dispersing age . and a sufficient amount of fluid to pro a suspension containing at " least about 6 . weight percent of said coal and at least about 20 weight-percent of said fluid. 26. The method as recited in claim 25, wherein s fluid is water. 27. 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 mainta the dispersed coal particles at near maximum zeta potentia in said coal-water slurry. 28. The method as recited in claim 26, wherein u to about 4 percent of dispersing agent, by weight of dry coal, Is mixed with said compact. 29. The method as recited in claim 28, wherein s suspension has a Brookfield viscosity at 60 revolutions pe minute of from about 300 to about 4000 centipoise. 1 30. ' The method as recited in claim 28, wherein said suspension has a Brookfield viscosity at 60 revolutio per minute of from about 200 to about 2400 centipoise. 31. The method as recited in claim 28, wherein said D, , Dg, n, and the weight percent of (-) 3 μm size particles are in accordance with said formula wherein: (a) D = about 425 μm, D g = 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 g = 0.05 to 0.5 μm, '5 n = 0.2 to 0.635, (-) 3 μm sized particles a e from 20.5 to 5.0 wgt. %, respectively, (c) D, = about 1180 μm, Dg = 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, 0 and (d) D. -=? • about 38 μ , D g = 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 com- 5 pact, dry basis. 32. The method as recited in claim 28 wherein D. = about 300 μm, D < - •= 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. 0 33. The method as -recited in claim 28, wherein D, = about 300 μm, D ς = 0.5 μm, n = about 0.4, and (-) 3 μ sized particles = about 9 wgt. % based on total weight of coal, dry basis. 34. The method as recited in claim 28, wherein 5 from about 0.05 to about 2.0 percent of said dispersing agent, by weight of dry coal, is mixed with said compact. 35. The method as recited in claim 34, wherein said dispersing agent is an anionic surfactant. 36. The method as recited in claim 35, wherein 0 said anionic surfactant is selected from the group consist¬ ing of: t (i) 2-ethylhexyl polyphosphoric ester acid anhydride and its potassium salt, (ii) complex organic polyphosporlc ester 5 acid anhydride and Its potassium salt, (iii) alkyl mononaphthalene sulfonic acid and its sodium and ammonium salts, and A- (iv) mixtures thereof. 37. The method as recited in claim 36 wherein s anionic surfactant is a sodium salt of an alkyl mononapht lene sulfonic acid. > 38. The method as recited in claim 28, wherein * to about 2 percent, by weight of dry coal, of electrolyte « Is mixed with said compact. 39. The method as recited in claim 38, wherein s electrolyte is an. inorganic compound. 10 40. The method as recited in claim 39, wherein said electrolyte is selected from the group consisting of NaOH, K 2 C0 3 , and a 2 Si0 3 .9H 2 0. EDITORIAL NOTE The claims amended by the applicant under Article 19 (1) of the PCT have not been renumbered in accordance with Section 205 of the Administrative Instructions under the PCT. The following information is given hereafter in order to facilitate the under¬ standing of the amended claims: Correspondence between original and amended claims: Original claims Amended claims 1 1 2 2 3 3 4 _ 4 5 (cancelled) 6 5 7 6 8 7 9 8 10 9 11 10 12 (cancelled) 13 (cancelled) 14 11 15 12 16 13 17 14 18 15 19 16 20 17 21 18 22 19 23 20 24 21 25 22 26 23 27 24 28-84 (cancelled) 25-40 (new)

Inventors: FUNK J
Applicants: UNIV ALFRED RES, ALFRED UNIV RES FOUND INC
Application year: 1980
Main classification: C10L1
IPC codes: B65G53, C10L1, C10L5, C21B5