Abstract: Aspects of the invention include a method of producing a cement material comprising step of: first reacting a calcium-bearing starting material with a first acid to produce an aqueous first calcium salt; second reacting the aqueous first calcium salt with a second acid to produce a solid second calcium salt; wherein the second acid is different from the first acid and the second calcium salt is different from the first calcium salt; and thermally treating the second calcium salt to produce a first cement material. Preferably, but not necessarily, during the second reacting step, reaction between the first calcium salt and the second acid regenerates the first acid.

Abstract: A method for treating cement kiln dust is provided. The method includes the steps of receiving cement kiln dust (CKD) from a kiln; heating the collected CKD; forming a gas stream of vaporized metal and CKD by sufficient heating to separate at least one heavy metal from the collected CKD stream to create a cleaned CKD stream and a metal stream; providing a water soluble alkaline-earth metal polysulfide; combining the heavy metal stream with the water soluble alkaline-earth metal sulfide to create a combined stream; and removing at least a portion of one heavy metal from the combined stream.

Abstract: In a method for processing and utilizing bypass dust obtained during the production of cement, it is proceeded as a) contacting the bypass dust with an aqueous phase and mixing the same to obtain a homogenous slurry, with water-soluble components of the bypass dust being dissolved in the aqueous phase, b) carrying out a solid-liquid separation to separate the solids contained in the slurry so that a brine is remaining, c) separating heavy metals present in the brine and precipitating calcium as poorly soluble calcium salts, e.g. CaCO3, to obtain a processed brine, and d) subjecting the processed brine to a fractional crystallization.

Abstract: To provide a low price industrial salt by reducing facility and operation costs without electro-deposition and crystallization and through reduction in quantity of chemicals used. An industrial salt S obtained by the steps of: extracting a part of combustion gas from a kiln exhaust gas passage running from an inlet end 12b of a cement kiln 12 to a bottom cyclone 13; recovering dust D from the extracted gas G2 and washing recovered dust; and drying a filtrate L1 after the washing in a gas stream. The industrial salt can be obtained by removing a calcium component from the filtrate and drying the filtrate from which the calcium component is removed in a gas stream. Further, from the filtrate can be removed sulfate radical, and drying the filtrate from which the calcium component is removed in a gas stream to obtain the industrial salt. For the drying can be used an exhaust gas discharged from a clinker cooler 12a and a spray drier 43 may be used for the drying.

Abstract: Methods and compositions are disclosed that comprise interground perlite and hydraulic cement. An embodiment provides a method of cementing comprising: providing a settable composition comprising perlite, hydraulic cement, and water, wherein the perlite and hydraulic cement are interground prior to combination with the water to form the settable composition; and allowing the settable composition to set.

Abstract: An embodiment of the present invention comprises a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising unexpanded perlite, cement kiln dust, and water; and allowing the settable composition to set. Another embodiment of the present invention comprises a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising ground unexpanded perlite, Portland cement interground with pumicite, and water; and allowing the settable composition to set. Yet another embodiment of the present invention comprises a settable composition comprising: ground unexpanded perlite; cement kiln dust; and water.

Abstract: The present invention is directed to plug-and-abandon operations that use plugging compositions comprising cement kiln dust, pumicite, and/or lime. An embodiment includes a method of plugging a well bore for abandonment comprising: placing a plugging composition in the well bore, the plugging composition comprising: cement kiln dust in an amount of about 5% to about 100% by weight of cementitious components, pumicite in an amount of about 5% to about 100% by weight of cementitious components, 0% to about 24% of Portland cement by weight of cementitious components, and water; and allowing the plugging composition to set and form a plug.

Abstract: Methods and compositions are disclosed that comprise cement kiln dust having a mean particle size that has been altered. An embodiment discloses a subterranean treatment method comprising: introducing a treatment fluid into a subterranean formation, wherein the treatment fluid comprises cement kiln dust having a mean particle size that has been altered from its original size by grinding, separating, or a combination thereof. Another embodiment discloses a subterranean treatment method comprising: introducing a treatment fluid into a subterranean formation, wherein the treatment fluid comprises cement kiln dust having a mean particle size that has been reduced from its original size.

Abstract: The present invention provides settable compositions and methods of using settable compositions that comprise a hydraulic cement; a partially calcined kiln feed comprising SiO2, Al2O3, Fe2O3, CaO, MgO, SO3, Na2O, and K2O; metakaolin; and water. The location to be cemented may be above ground or in a subterranean formation.

Abstract: Method and system for a cement burning facility. When exhaust gas in a part of a preheater or a kiln inlet of a cement kiln is extracted, a cement material is dispersed. The dispersed amount of the cement material is adjusted to maintain the temperature of the extracted gas between 950° C. and 1,150° C. The extracted gas is cooled to at most the melting point of a chlorine compound. A solid-gas separation device adjusts classification particle size to between 15 ?m and 30 ?m. A dust trap removes fine powder dust with a particle size equal to or smaller than the classification particle size. The amount of fine powder dust collected by the dust trap is maintained between 50 g/m3N and 150 g/m3N, with the concentration of chlorine in the collected fine powder dust set to between 5% and 20%.

Abstract: An exhaust gas treatment method and system of a cement burning facility, wherein a chlorine concentration of the collected fine powder dust is set in a range of 5 to 20% in such a manner that when a part of exhaust gas is extracted as extracted gas from a lowermost part of a preheater, or a kiln inlet part of a cement kiln, a cement raw material is dispersed and the temperature of the extracted gas is held in a range of 950° to 1150° C. By adjusting the dispersion amount of the cement raw material, the extracted gas is cooled to a melting point or less of a chlorine compound, and a classification particle size in a solid-gas separator is then adjusted in a range of 12 ?m to 30 ?m, to separate for removal and collection fine powder dust.

Abstract: A cement kiln chlorine/sulfur bypass system wherein the equipment cost is suppressed and the sulfur included in a combustion gas bled from a cement kiln is separated and effectively utilized. The cement kiln chlorine/sulfur bypass system comprises an air bleed means for bleeding a kiln exhaust gas passage, which runs from the end of the cement kiln to a bottom cyclone, of a part of the combustion gas, a separating means for separating dust in the gas bled by the air bleed means into coarse particles and fine particles, and a wet dust collector for collecting dust from the gas containing the fine particles separated by the separating means. The separating means is preferably a classifier in which the cut size is changeable. The wet dust collector is preferably a mixing scrubber.

Abstract: A method to efficiently reduce lead content of cement without exerting influence upon quality of the cement. The method comprises the steps of: controlling O2 concentration of combustion gas in an inlet end of a cement kiln to 5% or lower and/or CO concentration thereof 1000 ppm or more; extracting a part of combustion gas from the cement kiln and collecting dust contained in the combustion gas; and collecting lead from the dust collected. With this, the area where raw material temperature in the cement kiln is between 800° and 1100° can be turned into reducing atmosphere to sharply increase volatilization rate of lead, and collection of lead from the dust allows lead content of cement to efficiently be reduced without exerting influence upon quality of the cement.

Abstract: An object of this invention is to provide an exhaust gas treatment method and system for a cement burning facility which allows the handling property of collected powder dust to be improved and which enables smooth removal of hydrogen chloride that may result from burning of organic sludge. When part of exhaust gas in a lowermost part of a preheater 3 or a kiln inlet part 2 of a cement kiln 1 is extracted to obtain extracted gas, a cement material is dispersed, and the disperse amount of the cement material is adjusted so as to maintain the temperature of the extracted gas between 950° C. and 1,150° C. The extracted gas is cooled to at most the melting point of a chlorine compound. Then, solid-gas separation device 12 adjusts a classification particle size to between 15 ?m and 30 ?m. Dust trap 13 collects and removes fine powder dust with a particle size equal to or smaller than the classification particle size.

Abstract: An embodiment of a method of cementing comprises: introducing a cement composition into a subterranean formation, wherein the cement composition comprises cement kiln dust, a natural pozzolan, and water; and allowing the cement composition to set. Another embodiment of a method comprises: introducing a cement composition into a subterranean formation, wherein the cement composition comprises a cement, a natural pozzolan, and water, wherein the cement comprises Portland cement interground with burned shale; and allowing the cement composition to set. Another embodiment includes a cement composition comprising at least one additive selected from the group consisting of cement, cement kiln dust, Portland cement interground with burned shale, and a combination thereof; a natural pozzolan; and water.

Abstract: Of the many compositions and methods provided herein, an embodiment of a method comprises introducing a foamed cement composition into a subterranean formation, wherein the foamed cement composition comprises: a cementitious component; a foaming and stabilizing surfactant; an oil-swellable particle; gas; and water; and allowing the settable composition to set in the subterranean formation. Another embodiment of a method comprises introducing a foamed cement composition into an annulus between a pipe string and a subterranean formation, wherein the foamed cement composition comprises comprising: a cementitious component; a foaming and stabilizing surfactant; an oil-swellable particle; gas; and water; and allowing the settable composition to set in the annulus. An embodiment of a foamed cement composition comprises a cementitious component, a foaming and stabilizing surfactant, a swellable particle, gas, and water.

Abstract: A method of making cement clinker in a wet rotary kiln that includes providing raw material at the front of the kiln and adding a second group of materials for processing at an intermediate location along the kiln. This second group may include materials that improve the clinker and requires less energy to produce. A kiln system that employs this method and a cement clinker made by the method.

Abstract: The present invention provides settable compositions that comprise water and cement kiln dust. The settable compositions optionally may comprise an additive that comprises at least one of the following group: fly ash; shale; slag cement; zeolite; metakaolin; and combinations thereof. The settable compositions optionally may be foamed with a gas. Methods of cementing also are provided that comprise: providing the settable composition; introducing the settable composition into a location to be cemented; and allowing the settable composition to set therein. The location to be cemented may be above ground or in a subterranean formation.

Abstract: Exemplary embodiments include settable spotting compositions that comprise cement kiln dust and associated methods of use. Exemplary embodiments also include methods that comprise providing a settable spotting composition comprising cement kiln dust; introducing the settable spotting composition into a well bore that penetrates the subterranean formation so as to displace at least a portion of a second fluid from the well bore.

Abstract: Cementing compositions are provided that comprise water, cement kiln dust, vitrified shale, zeolite, and/or amorphous silica, that utilize a packing volume fraction such that the solid particulate materials of the fluid are in a hindered settling state. Methods of cementing are provided that utilize compositions comprising water, cement kiln dust, vitrified shale, zeolite, and/or amorphous silica, that utilize a packing volume fraction such that the solid particulate materials of the fluid are in a hindered settling state.

Abstract: A dry cementitious composition which when slurried with water produces an economical hydraulic cementitious slurry for closing abandoned wells. The dry cementitious composition is a cement/CKD blend as the major component with a weight ratio of parts cement to parts of CKD between about 2/3 and about 3/1. Hydraulic cementitious slurries when cured can produce hard cementitious bodies which will meet or exceed the API specification for a competent hard plug. A process for blending the cement and CKD during transit from the cement source to the off-load site without requiring further blending after off-loading. Methods are provided for determining the formulation having the cheapest cost per unit volume of hydraulic cementitious slurry thereby enabling competitive quotes based on cf of hydraulic cementitious slurry required.

Abstract: A method of recycling cement kiln dust (CKD) generated during the direct manufacturing of cement. The recycling process utilizes the creation of a flowable slurry comprising CKD, a process aid, optionally other raw materials and water. The process aid is selected from the group consisting of sucrose, raffinose, lignin, methylglucopyranoside, lactose, fructose, sodium polyphosphate, trehalose and mixtures thereof, and is added to increase the flowability of the slurry and thereby simplifying recycling. The slurry is reintroduced into the cement kiln, wherein it is burned to create cement clinkers, that are subsequently ground to the fineness required for hardening when reacted with water.

Abstract: A method and apparatus for recovering calcium sulfate di-hydrate (gypsum) from a precipitation reaction between cement kiln dust and commercial, spent or waste grade sulfuric acid solution. The gypsum recovered from this process acts as a necessary functional additive for use in the production of hydraulic Portland cement. The invention advantageously provides for a method of producing a fertilizer as a byproduct of the gypsum production process. The invention also provides a method of producing Portland cement using the gypsum derived from the cement kiln dust.

Abstract: Methods for recycling cement kiln dust are described and involve heating a mixture containing at least one additive, water, and cement kiln dust for a sufficient time and at sufficient temperatures to form cement clinker. The additive contains an organic polyacid, a hydroxy carboxylic acid, a polycarboxylic acid, a saccharide, a carbohydrate, a salt thereof, or combinations thereof. A cement slurry containing water, cement kiln dust, and the above-described additive is also described as well as apparatus for recycling the cement kiln dust.

Abstract: Fresh or stockpiled cement kiln dust is moistened with sufficient water so that the amount of total free and combined water relative to dust is about 3 parts water to 1 part dust by mass, or less. The wet solids are treated with carbon dioxide to convert compounds, such as calcium hydroxide, to carbonates, such as calcium carbonate. The degree of carbonation is controlled so that the solubility of calcium becomes minimum for the dust being treated; this is also when hydroxyl and bicarbonate ions in solution are about at their minima. As the carbonation reactions occur, the water combined in hydroxides is released as free water so that the mixture becomes a slurry and the potentially soluble alkalies and sulfate (and any chlorides present) are released to the liquid phase. The solids are separated from the liquid, and the solids, which may be washed, provide a material suitable for return as feed to the kiln.

Abstract: A process of treating dust from a cement manufacturing operation. The process comprises adding carbon bearing material to the dust catch from a cement manufacturing operation to form a mixture, which is formed into nodules and sizing the nodules to obtain a feed material having a selected size range. The nodules are directed as feed material to a fluidized bed which is maintained by passing air for combustion upwardly through a bed of material. The material is thermal processed within the fluidized bed in a reducing atmosphere by supplying fuel for combustion in the fluidized bed to maintain temperatures sufficient to volatilize alkali and sulfur compounds in the feed material and produce a product having an increased concentration of cement forming compounds and reduced alkali and sulfur compounds as compared to the feed material. The reduced clinker is then re-oxidized to minimize/reverse adverse color and mineralogy.

Abstract: Processes for making cement which when used to make concrete can stabilize the concrete against alkali-silica reactivity (ASR) from alkali containing components. The process includes adding lithium containing materials in the front of a cement kiln along with the cement starting materials in an amount sufficient to minimize ASR.

Abstract: With the present invention, a feed preparation system for producing cement includes mixing raw materials with a source of potassium. The mixture is conveyed to feed preparation system where it is placed in condition for treatment in a fluidized bed reactor for thermal processing to produce cement clinker. The potassium combines with the SO.sub.2 generated in the process to form potassium sulfate solids that are filtered from the process gas stream before emission to the atmosphere to thereby reduce sulfur emissions from the fluid bed cement process. The starting material may include white cement raw meal, grey cement raw meal and cement kiln dusts.

Abstract: In general purpose concrete compositions, from about 10% but less than about 25% by wt of the usual amount of portland cement for such compositions is replaced with Class F fly ash and cement kiln dust, both abundant and inexpensive waste products, in the weight ratio of such fly ash to cement kiln dust of about 3:1-1:1 with a minimum of about 5% of the replaced portland cement being cement kiln dust. General purpose concrete prepared from these mix compositions exhibit early strength characteristics, especially from day 1 to day 3, generally equal to or better than those exhibited by comparable all portland cement mix compositions.

Abstract: In a kiln plant for burning clinker from mineral raw materials, such as cement raw materials, and comprising a kiln (1), a precalciner (4), a preheater (6, 7, 8) and a flue gas filter (31), part of the kiln flue gases is diverted from the precalciner and the preheater via a bypass (20-30), the bypassed amount of flue gas being subjected to a preceding quenching in a chamber (21), humidified with water and cooled in a reactor (23), thereby causing the chlorides and alkalis in the bypassed gas to deposit upon dust particles which together with material dust in the gases are precipitated from the latter in a separator (25). The bypassed flue gas thus being almost purified of harmful compounds is then fed to the filter (31) or recirculated to the bypass in such manner that at least part of the precipitated compounds and material dust from the reactor (23) and the separator (25) is returned to the reactor for renewed treatment in same.

Abstract: A composition, suitable for use as a base in the construction of roads, parking lots, and other areas, is formulated from an ash aggregate comprising municipal solid waste incinerator ash, MSWIA, mixed with an aggregate material; upon addition of cement, compaction and curing, a volumetrically stable solid is formed. The incinerator ash is combined with an aggregate material, crushed, and sifted to remove particles having a size greater than three eights (3/8") inch prior to the addition of cement. The moisture content of the ash aggregate mixture and ash aggregate/cement mixtures are carefully adjusted to achieve maximum compressive strength. When ash aggregates containing less than 50 percent MSWIA are combined with at least 5 percent cement by dry weight, volumetrically stable solids are formed within seven days that have compressive strengths in excess of 300 psi.

Abstract: A cement-type binding material suitable as a building material for use in the manner of a Portland cement including for underground work, or as a curing accelerating additive in mortar cement or masonry cement or in concrete or as a basic material for producing building components, is produced by mixing flue dust or flue ash with a product obtained by desulfurizing flue gases. The quantity of flue dust or ash is so measured than any free lime and lime being freed during an oxidizing and calcining treatment is completely bound to aluminates and silicates capable of reacting with water. The so produced intermediate multi-phase product is milled to a certain fineness and mixed with slag sand also milled to a certain fineness. The so obtained product is suitable for use in all instances where gypsum could not be used heretofore or could be used only under expensive protective measures.