Abstract: A method of recovering steel plant waste revert materials including blast furnace flue dust and sludges involves mixing the revert materials with water to provide a total moisture content of about 14-20% by weight, then adding Portland cement as a sole binder, mixing, and, when the water content is limited to about 18 to 20%, casting the mixture onto the ground in the form of a slab or, when the water content is limited to about 14 to 16% and an accelerator for curing the cement is used, casting the mixture onto a conveyor in the form of preformed streams, curing the cast mixture and breaking it up to provide 1/2 inch to 5 inch agglomerate particles that can be recycled to the blast furnace.

Abstract: Improved concrete or mortar materials wherein cement in the precursors for these is replaced by electric arc furnace dust in amounts from 0+% to 4% or more based on the amount of cement by weight. In addition, the electric arc furnace dust can be used as an additive to obtain the same effect.

Abstract: From about 25% to about 50% but not more than about 200 lbs of the Portland cement of a general purpose concrete mix which contains for each cubic yard of the concrete to be produced in generally homogeneous admixture about 400-750 lbs. portland cement, about 1600-2000 lbs. coarse aggregate of a size of at least about 3/8 inch, and sufficient fine aggregate of a size less than 3/8 inch and up to minor amounts of conventional additives to yield one cubic yard when the admixture is combined with water in an amount equal to about 40-70% by weight of said portland cement, is replaced with a) Class F fly ash having a calcium oxide content up to about 6% and b) cement kiln dust (CKD) in a weight ratio of fly ash to CKD of about 2:3-3:2. Preferably, 30% or more of the Portland cement is replaced.

Abstract: A cementitious composition for oil well cementation able to prevent fluid migration comprises water, hydraulic cement, surfactant or organic dispersant, and carbon black.

Abstract: A homogeneous dry particulate cement mixture in ready-to-use form is provided, which comprises ground blast-furnace slag having a specific surface area of 500-750 m.sup.2 /kg and ground fly ash having a specific surface area of 500-750 m.sup.2 /kg, in a weight ratio in the range of 20/80-70/30, and further comprises the following components in the amounts indicated, calculated on the total mixture: at least 2% by weight of portland cement clinker and 2-12% by weight of sodium silicate (calculated as Na.sub.2 O+SiO.sub.2). When processed, the cement mixture yields a mortar or a concrete having improved strength properties as well as a good resistance against an acidic environment.

Abstract: The present invention relates to a novel composition which is useful for forming construction blocks and encapsulating hazardous materials, a process for producing blocks and encapsulating the material, and blocks made of the material. This composition is a mixture of klin dust or volcanic fly ash and aggregate. The process comprises the steps of (a) blending a dry mixture comprising the kiln dust or volcanic fly ash mixture with water; (b) transferring the blended mixture into a compression zone and (c) compressing the blended mixture in the compression zone to form a brick of the desired size.

Abstract: A hydraulic composition comprising (a) a cement composition prepared by subjecting size-adjusted cement having its particle size distribution adjusted to have a 50% pass particle diameter of from 2 to 7 .mu.m and a ratio of a 90% pass particle diameter to a 10% pass particle diameter of from 25 to 40 to a water-spraying treatment to increase the loss on ignition thereof by 0.5 to 2.0% by weight and (b) a water reducing agent; and a process for producing a concrete pile by using a mixture of the hydraulic composition and from 18 to 25% by weight of water based on the hydraulic composition. A mortar or concrete mixture of the hydraulic composition exhibits sufficient fluidity and provides a hardened product having a greatly improved compressive strength. The concrete pile produced by using the hydraulic composition has a compressive strength of 800 kgf/cm.sup.2 or higher at one day age.

Abstract: The invention relates to a method for preparing a hydraulically settable cement base material starting from steel slags formed in a steel-making process, which method comprises the formation, in steel slags in the liquid state, of a ferrite gradient by adding a ferrite-precipitating compound, the separation, if required, of the high-ferrite fraction formed, the separation of at least the low-ferrite fraction formed, the cooling and the comminution thereof to obtain a hydraulically settable material. The ferrite-precipitating compound used has preferably acid components, and can expediently generate silicic acid. At least before the cooling of the low-ferrite fraction, the aluminum content of the liquid slag material is regulated by the addition of an aluminate-containing material, such as bauxite. The high-ferrite fraction separated can be returned to the steel-making process to reduce or remove the addition of a flux in the production of steel.

Abstract: An alkali-activated silicate based cement or binder has a cure characteric which is modified by a phosphate additive which retards the set time of the cement or binder. The phosphate allows a longer set time than conventional alkali-activated silicate glass cements.

Abstract: The invention provides a novel, environmentally stabilized formed product and to a method of producing a hard, dry, e.g., agglomerated or formed, environmentally stabilized product useful as a construction material, e.g., as pellets, panels, bricks, etc. comprising: a) ash such as RDF or coal ash (typically stack scrubber solids or bottom ash obtained from the burning of coal), b) an oxidizer and c) water. The amount of water present is selected to render the product plastic so that it can be molded to the desired shape. The oxidizer is provided in a sufficient amount to oxidize unstable compounds and to convert potassium, calcium or magnesium bisulfite to the sulfate form. Following the addition of the oxidizer, the admixture is exposed to electromagnetic energy, preferably ultraviolet light, to help drive the oxidation reaction to completion.

Abstract: A low cost cement composition that can be admixed with water and hydrothermally closed cured to give acid-resistant products of high compressive strength consisting essentially of, in parts by weight, 1 to 1.5 parts of a calcium oxide material containing at least about 60% CaO, 10 to 15 parts of pozzolanic material containing at least about 30% by weight amorphous silica, and 0.025 to 0.075 parts by weight of an alkali metal catalyst and building materials made therefrom as well as the method of making such building materials by closed curing.

Abstract: Cementitious compositions useful as lightweight aggregates are formed from a blend of spent bed material from fluidized bed combustion and fly ash. The proportions of the blend are chosen so that ensuing reactions eliminate undesirable constituents. The blend is then mixed with water and formed into a shaped article. The shaped article is preferably either a pellet or a "brick" shape that is later crushed. The shaped articles are cured at ambient temperature while saturated with water. It has been found that if used sufficiently, the resulting aggregate will exhibit minimal dimensional change over time. The aggregate can be certified by also forming standardized test shapes, e.g., cylinders while forming the shaped articles and measuring the properties of the test shapes using standardized techniques including X-ray diffraction.

Abstract: The method of the invention provides a geopolymeric binder in powder, used for the ultra rapid treatment of materials, soils or mining tailings, containing toxic wastes. The geopolymeric binder has a setting time equal to or greater than 30 minutes at a temperature of 20.degree. C. and a hardening rate such as to provide compression strengths (Sc) equal to or greater than 15 MPa, after only 4 hours at 20.degree. C., when tested in accordance with the standards applied to hydraulic binder mortars having a binder/sand ratio equal to 0.38 and a water/binder ratio between 0.22 and 0.27. The preparation method includes the following three reactive constituents:a) an alumino-silicate oxide (Si.sub.2 O.sub.5,Al.sub.2 O.sub.2) in which the Al cation is in (IV-V) coordination as determined by MAS-NMR analytical spectroscopy for .sup.27 Al;b) a disilicate of sodium and/or potassium (Na.sub.2,K.sub.2)(H.sub.3 SiO.sub.4).sub.

Abstract: Compositions particularly suitable for use in preparation of concrete and mortar products comprising at least one cement and from about 5% to about 30% by weight of the cement of siliceous ash from crop residue, wherein the ash is from about 60% to about 95% by weight silica, at least about 90% of the silica is amorphous, at least about 75% of ash particles are in a size range of from about 4 to about 75 micrometers, and the ash particles have a mean particle diameter measured by laser-light scattering of at least 6 micrometers and a B.E.T. surface area of at least 20 m.sup.2 /g. The cement employed is a portland cement or a blended portland cement. Concrete and mortar products prepared from these compositions are characterized by exhibiting after 28 days a compressive strength of at least 2500 psi and chloride permeabilities of less than 2000 coulombs when measured in accordance with AASHTO T-277.

Abstract: According to the method fly ash is pre-hydrated using cold water and the mixture is then treated in a receptacle under pressure from superheated or saturated steam at a temperature lying between 130.degree. C. and 250.degree. C. The method is applicable to any substance containing quicklime that is to be slaked.

Abstract: A method for installing piles in offshore waters using a drill and grout technique. The method utilizes a drilling fluid for drilling the borehole for the pile that forms a cementitious filter cake on the borehole wall and a cement for grouting the pile that is compatible with both the filter cake and salt water.

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: A low-permeability barrier for waste disposal sites such as landfills and waste lagoons, and a method for constructing the same, includes a waste material. The waste material is stabilized to decrease the permeability characteristics of the waste material and may be further processed to improve the structural characteristics of the waste material and to prevent leaching of any leachable components. A method is provided for applying the waste material to the waste disposal site as a liner, interim cover, and/or final cover.

Abstract: An unground, fine pozzolan having a sulphur content determined as wt. % SO.sub.3 of 5 to 25 wt. % is employed in admixture with Portland cement to provide a blended hydraulic cement which has increased compressive strength characteristics as well as extended retardation time without the need for separate addition of gypsum; the pozzolan may also be admixed with fly ash to provide a pozzolan blend for use with Portland cement with reduced Portland cement content and use of Class C fly ash; the pozzolan is derived by reaction of coal flue gases with an atomized vapor of slaked lime.

Abstract: The process is the type wherein the solid portions of waste materials of all origins are crushed and ground to a granulometry of under 5 mm and then are heated to between 750.degree. C. and 1,350.degree. C. According to the invention, after the addition, if applicable, of liquid waste to obtain a pasty mass, a reagent is added to the latter, in pulverulent form having granules of under 500 microns based with calcium carbonate, silicium oxide and, possibly, aluminum and iron oxides in quantities to produce the following ratio after incineration: ##EQU1## Application to the treatment of all types of waste by combustion.

Abstract: A low density aggregate product and method for making the same utilizing coal ash slag resulting from a typical coal gasification system wherein the resulting aggregate product has a lower density than the initial coal ash slag. The coal ash slag is combined with a small amount of a binder and then fired for a predetermined time and temperature to produce the aggregate. Also, by heating the coal ash slag and binder, a gaseous efflux is emitted to form interlaced channels throughout the aggregate which have a characteristic length and diameter.

Abstract: Described is the process for forming a hardenable mixture of a coal ash comprising free CaO and free CaSO.sub.4.0 H.sub.2 O.In order to remove all free CaO the coal ash is mixed with a fly-ash comprising essentially no free CaO and no free CaSO.sub.4.0 H.sub.2 O and water and subsequently subjected to a heat treatment.By removal of free CaO it is found that the strength of hardened granules formed from such ash mixture does not deteriorate as is the case from granules formed with a coal ash comprising free CaO.Also a process for forming hardened granules and a building component formed with use of a hardenable mixture according to the invention are described.

Abstract: The subject invention relates to a rapid-setting self-hardening backfill composition and method of installation. The composition comprising a minor amount of Class C fly ash as a primary constituent and other filler materials such as Class F fly ash in major amount. When such materials are combined with water in controlled amount, they produce a backfilling material which is flowable and self-leveling for easy installation in utility trenches and similar excavations in street and roadway surfaces to support relatively heavy compressive loads within relatively short periods of time without settling. The self-hardening initially flowable mixtures attain considerable strength for withstanding traffic loads without undue settling in time periods of about 4 hours.

Abstract: The present invention relates to processes for producing a material usable as a suitable civil engineering and construction material by treating a combustion ash formed by the combustion of a fluidized bed comprising a coal as the fuel and limestone as a desulfurizing agent. In this process, quick lime contained therein is sufficiently slaked at first by addition of water and heat thus generated is released to prevent disintegration of the product, and then the product is subjected to atmospheric pressure steam treatment to obtain a product of high strength in a short time.

Abstract: For a treatment of the residues which become available as dry dust in the purification of exhaust gas and contain, inter alia, 5 to 12% by weight CaO and have a conductance in excess of 6000 .mu.S/cm, a process is proposed in which the residues are fluidized with purified exhaust gas in a circulating fluidized bed system consisting of a fluidized bed reactor, separator and recycling line and the CaO contained in the residues is reacted with the CO.sub.2 contained in the exhaust gases to form CaCO.sub.3.

Abstract: A low density aggregate product and method for making the same utilizing coal ash slag resulting from a typical coal gasification system wherein the resulting aggregate product has a lower density than the initial coal ash slag. The coal ash slag is combined with a small amount of a binder and then fired for a predetermined time and temperature to produce the aggregate. Also, by heating the coal ash slag and binder, a gaseous efflux is emitted to form interlaced channels throughout the aggregate which have a characteristic length and diameter.

Abstract: A cement based on blast-furnace slag and fly ash, characterized in that the cement is a homogeneous dry particulate mixture in ready-to-use form, which comprises blast-furnace slag having a specific surface area of 500-650 m.sup.2 /kg and fly ash in a weight ratio in the range of 20/80-60/40, and further comprises the following components in the amounts indicated, calculated on the total mixture: at least 2% by weight of portland cement clinker and 2-12% by weight of sodium silicate (calculated as Na.sub.2 O+SiO.sub.2).

Abstract: The advantages of high alumina cement (early strength, resistance to sulphate attack) are preserved and its disadvantage (weakens with age) is solved by mixing it 50:50 with silica fume, gasifier slag, fly ash or other pozzolanic or latently hydraulic material. This encourages formation of gehlenite octahydrate in preference to the harmful `conversion` (weakening) reaction.

Abstract: Described is the process for forming a hardenable mixture of a coal ash comprising free CaO and free CaSO.sub.4 .OH.sub.2 O.In order to remove all free CaO the coal ash is mixed with a fly-ash comprising essentially no free CaO and no free CaSO.sub.4.OH.sub.2 O and water and subsequently subjected to a heat treatment.by removal of free CaO it is found that the strength of hardened granules formed from such as mixture does not deteriorate as is the case form granules formed with a coal ash comprising free CaO.Also a process for forming hardened granules and a building component formed with use of a hardenable mixture according to the invention are described.

Abstract: Disclosed is a method of improving the quality of a structure to be prepared from mortar or concrete, the method being characterized in that when the mortar or concrete is kneaded, a water-soluble amino resin is admixed therewith, or a water soluble amino resin and at least one of a higher fatty acid metal salt and a nonionic surfactant are admixed therewith.

Abstract: The invention concerns a method for producing a hardened mineral product, especially concrete. The method utilizes a hydration reaction with water for at least 1 hour, preferably for 4 to 40 hours, by producing a water/binding agent paste containing components for retardation of binding agent crystallization together with other possible admixtures, e.g., accelerators. When the binding agent reaches an appropriate degree of hydration, preferably 10 to 90%, the unset paste is complemented with fillers for producing the desired mineral mix, after which the end product is shaped as desired and hardened. The water/binding agent paste is agitaged in order to promote the hydration reaction, and when required, admixed with an additional amount of the retarding component of the binding agent crystallization. Furthermore, the invention includes an apparatus for hydrating the binding agent with a facility for subjecting the paste to compacting pressurization in order to improve hydration.

Abstract: A heat-curing cement composition comprising 60 to 75% by weight of 3CaO.SiO.sub.2, in which the total content of 3CaO.Al.sub.2 O.sub.3 and 4CaO.Al.sub.2 O.sub.3.Fe.sub.2 O.sub.3 is lower than 10% by weight, the alkali content is lower than 0.2% by weight as the Na.sub.2 O equivalent, the balance is composed mainly of 2CaO.SiO.sub.2 and gypsum, and the Blain specific surface area is 3500 to 5500 cm.sup.2 /g. This cement composition provides a hardened body when heat-cured under a high temperature of 35.degree. to 85.degree. C.

Abstract: For the disposal of salt-containing dusts of incinerator plants, with addition of water the salt-containing dusts are intensively mixed with other waste materials, such as ashes and fly ashes from thermal power plants fired with hard coal or brown coal, waste materials from foundries containing quartz sands and waste materials from calcium carbide production, the mixture containing at least 8% hydrothermally reactive calcium oxide or equivalent amounts of other hydrothermally reactive calcium compounds and the water addition being so rated that an optimum compacting is possible and the mixture is thereafter processed by compacting to give stable firm compacts and the compacts subsequently hardened in an autoclave by saturated steam at a pressure of at least 1 bar.