Abstract: A process for treating coal includes contacting the coal with a leaching agent configured to remove a mineral from the coal; forming a wastewater stream comprising water and a concentration of a contaminant; and contacting the wastewater stream with a first side of a reverse osmosis membrane under pressure, wherein a permeate stream comprising a reduced concentration of the contaminant permeates the reverse osmosis membrane and flows from a second side of the reverse osmosis membrane, and a concentrate stream comprising an increased concentration of the contaminant is retained on the first side of the reverse osmosis membrane.

Abstract: In drying coal to be used as fuel for a coal-fired boiler, the coal is dried at a temperature of 80 to 150° C. by using combustion exhaust gas having passed through an air heater for the coal-fired boiler. Moreover, after medium-quality or low-quality coal is heated to a temperature of 300 to 500° C. at a heating rate of not less than 100° C. per minute and then cooled to a temperature of 250° C. or below at a cooling rate of not less than 50° C. per minute, the resulting reformed coal is cooled to a temperature of 70° C. or below and stored for 1 month or more in a state of isolation from the atmosphere. In producing the aforesaid reformed coal, the medium-quality or low-quality coal is heated by using combustion exhaust gas obtained at the outlet of an economizer included in the coal-fired boiler equipment or at the outlet of a denitrator included therein.

Abstract: The present invention relates to a flotation agent comprising a collector hydrocarbon composition comprising more than 80 wt % of iso and normal paraffins, less than 1 wt % aromatics, less than 5 ppm sulphur and less than 1 ppm nitrogen, and having a density of between 0.65 and 0.8 g/cm3 at 15° C., and at least one frothing agent, and to a process for the froth flotation of non-metal and metal ores and sludges.

Abstract: A method of reducing mercury emissions using a combustion device including at least a combustion zone. The method includes receiving a flow of fuel including mercury at the combustion device assembly; injecting a first mercury oxidizer flow including MgCl2 on the fuel upstream of the combustion device assembly; and oxidizing the mercury using a mercury oxidizer flows and the combustion device assembly.

Abstract: A method of processing coal to remove sulfur and other contaminants by mixing coal in a solution of aqueous ammonia having a selected concentration range (preferred range of 3%-5%) of ammonia to water in a reaction vessel. The mixing causes the solution to be brought into contact with the surfaces and pores of the coal. The process is monitored to detect when the concentration of aqueous ammonia in the reaction vessel has fallen below the selected range, and aqueous ammonia with an ammonia concentration in or above the selected range is fed into the reaction vessel to return the solution to within the selected range. The cleaned coal may be rinsed and dried, or dried without rinsing to form an ammonia coating on the coal surfaces and pores. Several plant layouts to practice the method are described.

Abstract: Methods for pretreating and improving coking coal quality for producing blast-furnace coke by: (a) rapid-heating the coal charge in a fluidized-bed to a temperature range between not lower than 300° C. and not higher than the temperature at which the coal charge begins to soften, at a rate of 30 to 103 ° C./min., (b) classifying the rapid-heated coal charge to fine- and coarse-size coal, and then (c-1) briquetting the fine-size coal or (c-2) rapid-heating the fine- and coarse-size coal individually in a pneumatic preheater to a temperature range between not lower than 300° C. and not higher than the temperature at which the coal charge begins to soften, at a rate of 103 to 105 ° C./min., and (d) forming the fine-size coal.

Abstract: Chemical looping combustion of coal utilizing a rotating regenerative assembly to expose coal particles to alternating conditions of oxidation and regeneration.

Abstract: A system for refining carbonaceous material including a carbonaceous material feedstock unit including a first vibratory screen unit for sizing the carbonaceous material; a digestion unit including a digestion unit in communication with the carbonaceous material feedstock unit; and an acid feedstock unit in communication with the digestion unit for providing an acid mixture solution to the digestion unit including a source of H2O; a source of HF; a source of H2SiF6, wherein the these compounds may be mixed together in ratios prior to being provided to the digestion unit; a separation unit in communication with the digestion unit for separating the digested carbonaceous material from the acid mixture solution; and a dryer unit in communication with the separation unit for drying the digested carbonaceous material and separating the carbonaceous material based on density.

Abstract: Processes and compositions are provided for decreasing emissions of mercury upon combustion of fuels such as coal. Various sorbent compositions are provided that contain components that reduce the level of mercury and/or sulfur emitted into the atmosphere upon burning of coal. In various embodiments, the sorbent compositions are added directly to the fuel before combustion; are added partially to the fuel before combustion and partially into the flue gas post combustion zone; or are added completely into the flue gas post combustion zone. In preferred embodiments, the sorbent compositions comprise a source of halogen and preferably a source of calcium. Among the halogens, iodine and bromine are preferred. In various embodiments, inorganic bromides make up a part of the sorbent compositions.

Abstract: An organically complexed nanocatalyst composition is applied to or mixed with coal prior to or upon introducing the coal into a coal burner in order to catalyze the removal of coal nitrogen from the coal and its conversion into nitrogen gas prior to combustion of the coal. This process leads to reduced NOx production during coal combustion. The nanocatalyst compositions include a nanoparticle catalyst that is made using a dispersing agent that can bond with the catalyst atoms. The dispersing agent forms stable, dispersed, nano-sized catalyst particles. The catalyst composition can be formed as a stable suspension to facilitate storage, transportation and application of the catalyst nanoparticles to a coal material. The catalyst composition can be applied before or after pulverizing the coal material or it may be injected directly into the coal burner together with pulverized coal.

Abstract: An improved biodiesel production process includes the steps of processing a feedstock to produce biodiesel, cooling the biodiesel so as to form sediment, and filtering the biodiesel to remove the sediment. The resulting biodiesel from the cold filtration process avoids problems of sediment formation during storage and transportation.

Abstract: Carbonaceous materials are thermally upgraded in a pressurized steam environment to remove moisture and other byproducts. A variety of water/solid separation devices may be employed in a process vessel to maximize moisture removal from the upgraded charge. Heating media inlet nozzles and process chamber vents are strategically positioned at the process vessel wall to minimize short circuiting of heating media to vessel outlet vents and to continuously separate hot water removed from the charge and condensed steam, such that the upgraded material removed from the process vessel is not discharged with accompanying free moisture. After upgrading, the charge may be rehydrated to improve its stability during shipping and storage.

Abstract: A microbiological method of desulfurization (MDS) of hydrocarbon fuels such as coal, coal tar and petroleum uses an aqueous microbial biocatalytic agent which is not significantly reproducing but is still capable of oxidizing inorganic sulfur compounds and/or of selectively cleaving sulfur-carbon bonds in organic compounds, thereby removing sulfur with insignificant losses in fuel value. Microorganisms are selected according to the type of fuel sulfur present and the environment in which the desulfurizing process is to take place. One embodiment allows droplets of highly concentrated cell-water suspensions to pass from the top surface of the fuel through to the bottom, desulfurizing along the way and removing the sulfur products of the process as well. This MDS method can be used during hydrocarbon fuel production, storage, transport, and/or processing conditions, thereby also providing an added benefit in corrosion protection of the vessels used for these functions.

Abstract: A coal transformation system comprises an ecological coal production unit for transforming raw coal into ecological coal. The production unit has an exhaust for carrying in a storage unit combustible, gaseous, waste by-products generated during the transformation of raw coal. A control system is provided for allowing the combustible, gaseous, waste by-products to be withdrawn and subsequently used as an additional source of energy when the system energy demand reaches a predetermined value, thereby contributing to reduce the energy costs during peak power needs.

Abstract: The invention provides a method treating acid raw water including the step of neutralising the water by adding calcium carbonate to it in a neutralising stage. The neutralised water is then rendered alkaline or more alkaline by adding an alkali thereto selected from calcium hydroxide, calcium oxide and mixtures thereof in a lime treatment stage. The alkaline water is then treated with carbon dioxide in a carbon dioxide treatment stage, with the carbon dioxide reacting in the carbon dioxide treatment stage with calcium hydroxide dissolved in the water.

Abstract: Coal beneficiation is achieved by suspending coal fines in a colloidal suspension of microscopic gas bubbles in water under atmospheric conditions to form small agglomerates of the fines adhered by the gas bubbles. The agglomerates are separated, recovered and resuspended in water. Thereafter, the pressure on the suspension is increased above atmospheric to deagglomerate, since the gas bubbles are then re-dissolved in the water. During the deagglomeration step, the mineral matter is dispersed, and when the pressure is released, the coal portion of the deagglomerated gas-saturated water mixture reagglomerates, with the small bubbles now coming out of the solution. The reagglomerate can then be separated to provide purified coal fines without the mineral matter.

Abstract: A process and system for recovering fine coal having a size at or below 400 mesh. The process and system includes a series of cyclone separators, a vibrating screen, a centrifuge and a flow path to clean, recover and dewater fine coal having a nominal size of 3 mm down to 400 mesh or below. The process and system includes the use of commercially available components arranged in a novel manner to efficiently recover fine coal for use in various energy supplying systems.

Abstract: Process for treating coal to enhance its rank, wherein the temperature of the material is gradually increased in a controlled set of atmospheres, to allow for the reduction of surface and inherent moisture and the controlled reduction of volatile matter while maintaining the coal's natural structural integrity. The process reduces the time, capitalization, and production costs required to produce coal of enhanced rank, thus substantially increasing the cost effectiveness and production rate over prior processes.

Abstract: An improved process for removing mercury and other trace elements from coal containing pyrite by forming a slurry of finely divided coal in a liquid solvent capable of forming ions or radicals having a tendency to react with constituents of pyrite or to attack the bond between pyrite and coal and/or to react with mercury to form mercury vapors, and heating the slurry in a closed container to a temperature of at least about 50.degree. C. to produce vapors of the solvent and withdrawing vapors including solvent and mercury-containing vapors from the closed container, then separating mercury from the vapors withdrawn.

Abstract: A method for recovering coal from a mixture containing fine particles of coal, the mixture including fine coal particles, water, and impurities, the method including feeding the mixture to a first liquid/solid separator that removes relatively large pieces of material from the mixture producing a first stream containing recoverable fine coal particles, and pumping the first stream from the first liquid/solid separator to at least one second liquid/solid separator, the at least one second liquid/solid separator separating recoverable fine coal particles from the first stream producing a product flow containing fine coal particles and a discharge stream containing, e.g., water and impurities. In one aspect, the coal in the product flow is then dried and/or pelletized. In one aspect fine coal particles in the product flow have a largest dimension of less than 100 microns. In one aspect, fine coal particles in the product flow have a largest dimension of at least about 40 microns.

Abstract: A method is provided for reducing the nitrogen oxide content of a flue gas produced by the combustion of fuel by introducing a nitrogen oxide removal agent into either the nitrogen oxide contaminated flue gas or the fuel to be combusted. The nitrogen oxide removal agent is the reaction product of a carbon compound in a pyrolysis liquor and a nitrogen compound such as ammonia, ammonium hydroxide or urea. The carbon compound is selected from carboxylic acids, phenols, esters, aldehydes and ketones. The pyrolysis liquor is derived from a feed stock containing cellulose, lignin or starch.

Abstract: The present invention relates to various apparatuses and processes for treating carbonaceous materials to remove by-products therefrom. More particularly, the present invention relates to the treatment of carbonaceous materials by injecting an inert gas into the carbonaceous material under a vacuum or injecting steam into the carbonaceous material either with or without the vacuum being applied in a controlled manner to more consistently treat the charge of carbonaceous material.

Abstract: The invention described herein relates to a process for treating carbonaceous material wherein the resulting product is resistant to undesired combustion. According to the process, carbonaceous material is treated with a gaseous mixture comprising a major amount of inert gas and a minor amount of oxygen either during or subsequent to carrying out the upgrading step to at least partially oxidize the carbonaceous material.

Abstract: The invention relates to a method of removing metals from a fossil fuel comprising the steps of contacting the fossil fuel with a biocatalyst selected from the group consisting of an enzyme which degrades porphyrin molecules under conditions suitable for the removal of the metals from the fossil fuel; and separating the metals from the fossil fuel. Preferred embodiments of the biocatalyst include heme oxygenase and cytochrome C reductase, such as cytochrome C reductase from Bacillus megaterium, Catharanthus roseuse, Escherichia coli, animal cells, plant cells or yeast cells. The cytochrome C reductase can be contacted with the fossil fuel in an aqueous medium as a substantially cell-free preparation or cell preparation. In one embodiment of the invention, the metals are recovered from the resulting metal containing stream.

Abstract: A coal preparation plant separates a low specific gravity clean coal fraction from a high specific gravity refuse fraction, and separately processes those fractions. Run of mine coal having particle sizes up to about 4 inches is mixed with a slurry of water and magnetizable particles, and is introduced into a heavy media cyclone to separate the high and low specific gravity fractions. The high specific gravity refuse fraction is delivered to a first magnetic separator to extract the magnetizable particles, while the low specific gravity clean coal fraction is delivered to a second magnetic separator to remove the magnetizable particles. The system is highly efficient and has a high processing capacity.

Abstract: In a process for detoxifying a coal-tar deposit, effective amounts of carbon and a calcium oxide containing substance are added at a mixing station to at least a portion of the coal-tar deposit. The reaction mixture thus formed is mixed at a temperature of about 70.degree. F. to 130.degree. F. for a time sufficient to detoxify it and convert it into a non-hazardous reaction product. The coal-tar deposit may be either a substantially homogeneous coal-tar or a heterogeneous coal-tar contaminated substrate. The mixing station site may be either subsurface or surface and may include a container. The non-hazardous reaction product may be separated into small particles, suitable as fuel, and large particles, suitable as safe fill.

Abstract: The invention relates to electrostatic separation of coal from toxic and pyritic elements and ash compounds. More particularly this invention relates to separation of coal from refuse material by imparting opposite electrostatic charges to coal and refuse particles, passing them between oppositely charged electrodes and mechanically separating the electrostatically attracted diverging coal and refuse particles. The electrostatic attraction and divergent separation process is maximized by performing the charging and separation functions within a continuously vacuum reduced atmosphere. The use of a vacuum exhaust to continuously remove water and water vapor can prevent charge dissipation of the coal particles through charge transfer to water and water vapor. Additionally, the vacuum reduced atmosphere can prevent impairment of electrostatic influence due to gas turbulence.

Abstract: A method for dewatering mineral slurries employing a copolymer of diallyldimethlylammonium halide and a vinyl alkoxysilane, which is preferably a copolymer of diallyldimethylammonium chloride and vinyltrimethoxysilane as a coagulant is disclosed. The method for dewatering mineral slurries containing water comprising the steps of: feeding said mineral slurry into a thickener, treating said mineral slurry with an effective amount of a coagulant which comprises a copolymer of halide and a vinyl alkoxysilane; allowing the water to separate from the mineral slurry, withdrawing the water from said thickener and discharging said mineral products from said thickener. Mineral slurries which can be effectively treated are copper and taconite. The above-mentioned method may also include treatment with a flocculant in conjunction with the coagulant.

Abstract: The present invention provides for a fuel coal processing system having a centrifugal type coal pulverizer and an electrostatic type coal purifier and an optional fuel coal size classifier all combined into one integral, cooperatively acting fuel coal preparation device in one embodiment, and a centrifugal type coal pulverizer and fuel coal size classifier combined in a second embodiment. The centrifugal type coal pulverizer may be a counter rotating cup and ring assembly for breaking apart the coal particles and impurities. The coal particles and impurities leave the pulverizer in flat, radiating, sheet pattern which passes through the electrostatic purifier or separator. The electrostatic separator has a pair of plates which are oppositely charged and arranged next to the pulverizer. The top plate is negatively charged to attract the positively charged pure coal particles and repel the negatively charged pyritic particles.

Abstract: Thermal treated coal which has a water content of not more than 10%, which has pores with an oil adsorbed onto and impregnated into the pore surface, and which is decarboxylated and dehydrated to have a reduced porosity is provided. In its manufacture, porous coal and an oil are mixed to prepare a slurry, and the slurry is heated for effecting slurry dewatering. During the slurry dewatering, oil is adsorbed onto the surface of the pores of the porous coal. Subsequently, the slurry is heated for refining, followed by a solid-liquid separation at the final stage.

Abstract: The invention disclosed relates to a method for drying low-quality solid carbonaceous fuels such as lignite and sub-bituminous coal to reduce the moisture content substantially to zero, and to minimize re-adsorption of moisture during storage and transporation. The method involves drying the solid fuel in a mildly reducing atmosphere at a temperature in the range of 150.degree.to 300.degree. C., preferably 200.degree.to 210.degree. C. The mildly reducing atmosphere may be provided by a gaseous lower-alkane e.g. propane and methane. In some cases, the coal may beneficiated by agglomeration with small amounts of oil.

Abstract: A process for producing low mercury coal during precombustion procedures by releasing mercury through discriminating mild heating that minimizes other burdensome constituents. Said mercury is recovered from the overhead gases by selective removal.

Abstract: An improved process is described for agglomerating ground coal in which a bridging oil is used as the agglomerating vehicle. This bridging oil is a mixture of a heavy gas oil obtained from coal/oil coprocessing and a heavy hydrocarbon oil, such as bitumen or heavy oil, preferably mixed in the proportion of about 23-40% heavy hydrocarbon oil and 60-77% heavy gas oil. The agglomerated product is mixed with additional heavy oil or bitumen and it becomes the feedstock to a coal/oil coprocessor, with heavy gas oil being formed as one of the product streams. At least part of this heavy gas oil product stream is recycled to the agglomeration stage as the heavy gas oil component of the bridging oil. This agglomeration procedure has the advantage of providing an agglomerate of excellent quality, while carrying out the agglomeration in a short time at ambient temperature and using less than 10% by weight of bridging oil.

Abstract: 3-acrylamido-3-methylbutanoic acid copolymers of acrylamide or acrylic acid are selective flocculant for coal present in coal refuse slurries.

Abstract: Fine particle coal is beneficiated in specially designed dense medium cyclones to improve particle acceleration and enhance separation efficiency. Raw coal feed is first sized to remove fine coal particles. The coarse fraction is then separated into clean coal, middlings, and refuse. Middlings are comminuted for beneficiation with the fine fraction. The fine fraction is deslimed in a countercurrent cyclone circuit and then separated as multiple fractions of different size specifications in dense medium cyclones. The dense medium contains ultra-fine magnetite particles of a narrow size distribution which aid separation and improves magnetite recovery. Magnetite is recovered from each separated fraction independently, with non-magnetic effluent water from one fraction diluting feed to a smaller-size fraction, and improving both overall coal and magnetite recovery.

Abstract: The separation density of a dense media comprising a slurry of magnetite and water in a cyclone for beneficiating coal containing refuse is maintained within predetermined limits by: (a) measuring the total solids in an overflow of the cyclone; (b) comparing the total solids with a predetermined correlation with separation density; and (c) changing the relative proportions of the feed flow of magnetite and water to the cyclone when the separation density as determined by the correlation is outside the predetermined limits.

Abstract: A process for the selective removal or chemical modification of minerals contained in carbonaceous materials, comprising treating with an aqueous solution of a compound selected from ammonium salts, polyhydroxy alcohols, organic acids, organic complexing agents and polysaccharides. The process may be used to increase coal recovery, improve coal quality and enhance coal ash fusion characteristics.

Abstract: In the present invention, iron sulfate is added in the form of an aqueous wash solution to coal agglomerates after separation of ash from the agglomerated coal. As the agglomerates remain in a continuous water phase, a good dispersion of the iron sulfate solution throughout the agglomerate matrix occurs. At this stage an unexpectedly strong adsorption of Fe ions onto the coal surfaces occurs without any adverse effects on agglomerate integrity and the ability to separate it selectively by floatation. Furthermore, this good dispersion also results in over 94% of the iron sulfate in the wash solution being transferred to the agglomerates. This manner of addition of iron sulphate to coal has been shown to elevate advantageously the lowest temperature at which coke formation occurs during coprocessing.

Abstract: Method and apparatus for treating sulphur bearing coal comprising pulverizing the coal, mixing it with water, a reagent and free air and pumping the resulting mixture to a classifier to separate the coal from sulphur and clay, all at the mine site. The resulting pure coal slurry is then pumped to a plant site where it is mixed with acid and bacteria. The resulting slurry is pumped to a bacteria digester wherein it is recirculated to provide maximum contact of bacteria and coal, completing the removal of sulphur. The resulting slurry is introduced into a mixer wherein the bacteria is neutralized by a reagent, raising the pH above 7 to destroy the bacteria and simultaneously aerating the mixture to treat the effuent. The desulphurized coal is treated by drying apparatus to provide a final purified coal product.

Abstract: In a process for reducing the sulfur and ash contents of coal, coal is sequentially contacted with fused alkali metal caustic, wash water, and acid. Contacting the coal with the caustic produces water-soluble compounds. Sufficient wash water is used to reduce the temperature of the caustic treated coal and dissolve the bulk of the water-soluble compounds before the water-soluble compounds convert to water-insoluble compounds that precipitate on the caustic-treated coal. Caustic removed from the coal by the water is recovered as anhydrous caustic for again contacting coal.

Abstract: An apparatus and process of steam treating carbonaceous materials under a controlled temperature and pressure. The feed material is introduced into an autoclave or similar vessel and injected with steam at a high pressure and temperature for a controlled period of time to effect thermal restructuring of the carbonaceous material and to effect a conversion of the moisture and a portion of the volatile organic constituents therein to a gaseous phase. Water, wax and tar are recovered during this process and the water may be used as a source of pre-heating feed material in another vessel while the tar may be used as a heating source since it has a high heating value. The upgraded product is allowed to cool and then removed from the reaction vessel. The invention alternatively contemplates use of a separate pre-heating chamber for the carbonaceous feed material.

Abstract: A method and apparatus for removing light hydrocarbons, such as heptane, from coal agglomerates includes an enclosed chamber having a substantially horizontal perforate surface therein. The coal agglomerates are introduced into a water bath within the chamber. The agglomerates are advanced over the surface while steam is substantially continuously introduced through the surface into the water bath. Steam heats the water and causes volatilization of the light hydrocarbons, which may be collected from the overhead of the chamber. The resulting agglomerates may be collected at the opposite end from the surface and subjected to final draining processes prior to transportation or use.

Abstract: In a process for reducing the sulfur and ash contents of coal, coal is sequentially contacted with fused alkali metal caustic, water, carbonic acid, and a strong acid. Caustic removed from the coal by the water and the carbonic acid is recovered as anhydrous caustic for again contacting coal.

Abstract: A method of cleaning particulate coal which is fed with a dense medium slurry as an inlet feed to a cyclone separator. The coal particle size distribution is in the range of from about 37 microns to about 600 microns. The dense medium comprises water and ferromagnetic particles that have a relative density in the range of from about 4.0 to about 7.0. The ferromagnetic particles of the dense medium have particle sizes of less than about 15 microns and at least a majority of the particle sizes are less than about 5 microns. In the cyclone, the particulate coal and dense-medium slurry is separated into a low gravity product stream and a high gravity produce stream wherein the differential in relative density between the two streams is not greater than about 0.2. The low gravity and high gravity streams are treated to recover the ferromagnetic particles therefrom.

Abstract: The invention concerns a process for the preparation of demineralized coal, comprising the steps of:(a) forming a slurry of coal particles, preferably at least 50% by weight of which particles have a maximum dimension of at least 0.5 mm, with an aqueous solution of an alkali, which solution has an alkali content of from 5 to 30% by weight, such that the slurry has an alkali solution to coal ratio on a weight basis of at least 1:1;(b) maintaining the slurry at a temperature of from 150.degree. to 300.degree. C., preferably 170.degree. C. to 230.degree. C., for a period of from 2 to 20 minutes substantially under autogenous hydrothermal pressure and rapidly cooling the slurry to a temperature of less than 100.degree. C.

Abstract: A process is disclosed for the beneficiation of coal by selective caking, in which process a caking mixture is employed consisting of:one or more solvents selected from among light hydrocarbons having boiling points not higher than 70.degree. C.;a non-ionic, oil-soluble additive obtained from controlled propoxylation of the phenolic fractions derived from cake-oven tars;and possibly one or more heavy co-caking agents selected from among coal-derived oils having boiling points between 200.degree. and 400.degree. C., or the residual products of petroleum refining or mixtures of the same.

Abstract: A process for removing mineral impurities such as metal oxides from coal and shale oil structures is disclosed. The process is carried out by subjecting crushed coal or shale to a hydrocarbon fluoride leaching solution, separating the HF leach liquor from the coal or shale, washing the coal or shale with water, leaching the washed coal or shale with hydrogen chloride solution, separating the HCl leach liquor from the coal or shale, washing the coal or shale with water, and removing residual impurities from the treated coal or shale by heating under a vacuum. The process allows for the recovery of carbons and hydrocarbons of high purity from coal or shale which do not require expensive emission control equipment when combusted.

Abstract: A process particularly suited for producing anthracite coal having an ash content greater than about 20 percent. In the process, an aqueous feedstock slurry composed of raw input and a heavy medium having a magnetic component is subjected to a particular type of cyclonic separating action which produces a coal product having a specific gravity of at least about 1.9 while the specific gravity of the heavy medium is maintained at least about 0.4 units below the specific gravity of the coal product. The configuration of the cyclones and composition of heavy medium is such as to enable separation to occur at a relatively high specific gravity with a medium of relatively low specific gravity and viscosity, thereby minimizing magnetite ore losses and energy required to effect separation.

Abstract: A process for treating carbon to reduce the ash content therein. The process involves treating the carbon with a fluorine acid solution which consists of an aqueous solution of hydrofluorosilicic acid and hydrogen fluoride, such that the available metal oxides are converted to metal fluorides and/or metal fluorosilicates and separating the treated carbon from the metal fluorides and/or metal fluorosilicates produced by the treatment.

Abstract: A coal or similar carbonaceous fuel is selectively freed of sodium by water washing it and ion exchanging the washed coal with a strong aqueous electrolyte solution which is substantially free of sodium ions and contains a kind and concentration of ions which are correlated with the composition of the coal to cause a selective removal of ion-exchangeable sodium from the coal.