Abstract: An improved lightweight cementitious product made up of an aqueous cementious mixture that can incorporate fly ash, portland cement, sand, lime, and the weight saving component, which is micronized polystyrene particles having particle sizes in the range of 50 to 2000 microns, and characterized by having very low water contents, in the range of from about 0.5% to 5% v/v. The ultra low water compositions can be extruded and can be molded under high pressure.

Abstract: An process for manufacturing a admixture for concrete, mortar or asphalt out of paint sludge is discussed; The preferred embodiment utilizes the chemical drying of paint sludge through the addition of lime. The resulting powder contains a mixture of slaked lime and paint solids and can be used in the formation of concrete, mortar or asphalt.

Abstract: A slurry composition for stabilizing the upper layers of the earth comprising a lime and a fly ash having a calcium oxide content of less than 18% and water.

Abstract: The invention includes methods and compositions relating to calcium phosphate cements, which self-harden substantially to hydroxyapatite at ambient temperature when in contact with an aqueous medium. More specifically the cements comprise a combination of one or more sparingly soluble calcium phosphates other than tetracalcium phosphate with an aqueous solution adjusted with a base to maintain a pH of about 12.5 or above and having sufficient dissolved phosphate salt to yield a solution mixture with phosphate concentration equal to or greater than about 0.2 mol/L.

Abstract: A method is shown for improving the properties of hot mix asphalt by treating the aggregate which is combined with bituminous binder with lime. A hot quicklime slurry is produced by slaking quicklime with water at the site of the hot mix asphalt plant using a portable mixing tank. The hot quicklime slurry is then applied to the aggregate, the aggregate is dried and combined with the binder to produce the hot mix asphalt.

Abstract: A process and apparatus by which blast-furnace slag can be added to the feedstock materials fed into the feed-end of a rotary cement kiln to form cement clinkers. The blast-furnace slag is crushed and screened to provide blast-furnace slag particles having particles with a predominant size of up to a maximum diameter of substantially 2" or less.

Abstract: A cementitious mixture includes hydraulic cement, fly ash, and an effective amount of unfired nature finely divided material, such as a clay, containing at least about 35% alumina, to accelerate the early strength of a mix. A method of accelerating early strength in a cementitious mix comprises the adding of alumina in the form of an unfired raw material, such as clay, in an effective amount in such mix.

Abstract: Cuttable concrete capable of being cut and sculpted with traditional tools and process for the manufacture and moulding thereof. The concrete consists of a mixture of a volume V of mineral material essentially in the form of crushed oolitic limestone, a volume V1, less than V, of a carbonated binder, preferably lime and/or cement based, and excess water. The cuttable concrete is useful in the building industry, interior decoration, urban fittings and the manufacture of casting moulds.

Abstract: A process and apparatus by which steel slag can be added to the feedstock materials fed into the feed-end of a rotary cement kiln to form cement clinkers. The steel slag is crushed and screened to provide steel slag particles having a maximum diameter of 2".

Abstract: Disclosed is a method and an apparatus for the heat treatment of lime sludge (CaCO.sub.3) to form burnt lime (CaO). In the method of the present invention a lime sludge feed is entrained in and thereafter dried in a gas flash dryer means to produce a dried lime sludge. The dried lime sludge is separated from the gases and thereafter is fed to a rotary kiln in which the dried lime sludge is converted to active burnt lime. In order to maintain the flow of gas in the flash dryer means at a predetermined velocity in order to entrain all the lime sludge feed in the gas flow, an adjustable portion of the separated gases are recycled through the flash dryer means.

Abstract: Disclosed is a method and an apparatus for the heat treatment of lime sludge (CaCO.sub.3) to form burnt lime (CaO). In the method of the present invention lime sludge is dried in a gas dryer means, to produce a dried lime sludge. The dried lime sludge is separated from the gases and thereafter is first fed to a compacting means wherein it is compacted into a plurality of substantially uniform bodies which are thereafter fed to a shaft kiln in which the compacted dried lime sludge is converted to active burnt lime.

Abstract: A method and composition for the preparation of calcium silicate bounded shaped articles comprising mixing SiO.sub.2 containing powder, unslaked or slaked lime, calcium hydroxide, with a waste paper pulper slurry containing cellulosic particle of less than 1.1 mm in length is described. Additionally, Portland cement, alumina cement, calcium sulfate anhydride, plaster of Paris, a foam, and a thermally activated accelerator may also be added to the mixture which is then shaped into blanks, and autoclaved.

Abstract: An invention is shown in which a quicklime is hydrated in the presence of a special chemical modifier to produce a controlled temperature hydrate having improved plastic properties and greater surface areas.

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 process for the production of a water-insoluble, abrasion-resistant, synthetic solid article or aggregate, as well as the products produced thereby. Fly ash, lime, water and FGD sludge are mixed intimately and formed at pressures exceeding 1,000 psi, preferably 4000-8000 psi. The product is cured for at least the equivalent of 28 days at 73.degree. F., and crushed and sized to produce a commercial aggregate, for example, for concrete, asphalt, concrete masonry units, etc.

Abstract: Smoke purification waste materials (SPW), rich in lime, are mixed with a product containing at least 60% silica and/or aluminum to bring the pH to a value of between 7 and 11.5 and with a quantity of water of between 15% and 160% of the weight of the waste materials and said product. In practice, the ratio of SiO.sub.2 and Al.sub.2 O.sub.3 over CaO must be at least equal to 0.8. Solid compounds are obtained that are virtually insoluble in water and that are non-pollutant.

Abstract: A waste material which contains chromium and/or lead impurities is treated by mixing the waste material with diatomaceous earth and/or sodium borate and then heating the mixture in a free oxygen containing gas at about 500.degree.-1500.degree. C., preferably in the presence of steam.

Abstract: A hydrous calcium silicate based material prepared according to a wet method employing a specific liquid to solid phase ratio and pressures. The resulting hydrous calcium silicate based material comprises predominantly 11.3 .ANG. tobermorite and minor amounts of inorganic or organic fibers. This material has good insulating properties and good mechanical strength.

Abstract: The present invention provides a cement setting accelerator comprising 100 parts by weight of a sintered body, 5 to 70 parts by weight of an alkali metal carbonate powder and at most 170 parts by weight of a lime powder and a method of manufacturing the same. The sintered body contains a predetermined ratio of 3CaO.2Na.sub.2 O.5Al.sub.2 O.sub.3, Na.sub.2 SO.sub.4 and Na.sub.2 O.Al.sub.2 O.sub.3. Alternatively, a predetermined ratio of 3CaO.2Na.sub.2 O.5Al.sub.2 O.sub.3, Na.sub.2 SO.sub.4 and 4CaO.3Al.sub.2 O.sub.3.SO.sub.3 are contained in the sintered body. Further, a raw material mixture, which is not sintered and equal in the chemical composition to the sintered body noted above, may be used in place of the sintered body. Setting and hardening of a cement paste is markedly promoted by adding a small amount of the cement setting accelerator of the present invention to the cement paste.

Abstract: A liquid aqueous sludge is transferred into a cylindrical-conical tank and gitated by blowing in air through a downwardly extending tube. A closed circulation of sludge is established between this main tank and a reagent tank by means of a recycling pump. The reagent tank overflows into the main tank. Chalk is added to the reagent tank and a pozzolanic material is added to the main tank. When the mixture of dilute sludge, chalk and possolanic material is homogeneous, it is transferred to a filter press by means of a further pump. The filter cake is collected for final storage or discharged to set slowly.

Abstract: An aqueous fluid for treating underground, carbon dioxide-containing formations penetrated by casing regions of a wellbore, prior to the cementing of casings into the wellbore, comprises: (i) water, (ii) an agent which substantially increases (preferably by at least about 50 percent) the solubility of lime in water, and (iii) lime in an amount at least about saturating the water in the fluid. The lime in the treatment fluid reacts with carbon dioxide in penetrated formations to produce insoluble calcium carbonate, which blocks pores in the formations. Insoluble calcium hydroxide, formed by reaction of the lime with the water in the treatment fluid, deposits as an insoluble filter cake on the walls of the borehole where the fluid penetrates formations. The calcium hydroxide filter cake may react with the carbon dioxide to form additional calcium carbonate which helps the filter cake form a tight, impermeable barrier at the borehole.

Abstract: During use in hydrocarbon conversion processes, sorbents, e.g. for carbon and metals, and catalysts become contaminated with metals, e.g. heavy metals such as vanadium, nickel and sodium. Leaching of heavy metals can be sharply reduced by treatment of such spent particulate materials with alkaline earth metal compound, e.g. lime, calcium fluoride, calcium sulfate, and barium chloride. Surprisingly, calcium chloride, calcium carbonate, sodium bicarbonate are relatively ineffective.

Abstract: A method and composition are provided for creating smooth surfaces on building structures, particularly concrete structures. A first constituent is prepared by mixing together quantities of acrylic mortar admix, concrete plaster adhesive, joint compound, hydrated lime and water. The first constituent is mixed with Portland cement at the construction site. The resultant mixture is smoothed onto concrete or wooden surfaces of a building structure, and dries in about an hour to produce a smooth, hard surface.

Abstract: A method for forming strong and durable pellets from dust collected from stack gases. The dust includes CaSO.sub.3, CaSO.sub.4 and unreacted CaD. A portion of water required for total hydration with the dust is blended in a mixer. The moistened powder is stored in a conditioning container wherein the moistened powder is chemically reacted and heated to form a hydroxide with the oxides in the powder. Water is added to the hydrates and the wetted hydrates are subjected to an intense second mixing. The wetted hydrates are then pelletized in a pelletizer.

Abstract: A method of producing cement or concrete, comprising the step of adding fly ash to the cement or concrete at the production stage, the fly ash containing lime and reaction products from the reaction occurring between lime and sulphur oxides in connection with the desulphuration of flue gases. To avoid the disadvantageous effects of calcium sulphite and entringite reactions and to increase the used amount of fly ash containing desulphuration waste, the calcium sulphite is oxidized by hydrogen peroxide either before the production of cement or concrete or during the production.

Abstract: A durable structure can be easily and safely demolished by using a demolition-facilitating agent comprising, as an effective principal component 50% to 100% by weight of quick lime particles having an apparent density of 2.0 or more, a weight per unit volume of 1.0 kg/l or more, a particle size of 15 mm or less, and an average particle size of 0.1 mm or more, and optionally, additional solid particles, for example, sand particles, which are inert to water, rigid, porous inorganic grains, for example, hydrated zeolite grains, or a water-absorbing organic material, for example, acrylonitrile-grafted starch in a manner such that the demolition-facilitating agent in the dry state is fed into holes formed in a durable structure to be demolished and then water is fed into the holes to allow the quick lime particles to react with water and thus expand, to demolish the durable structure.

Abstract: A method of treating solid hazardous waste containing unacceptable levels of leachable metals such as lead and cadmium includes mixing the solid waste with lime and an agent selected from the group consisting of carbon dioxide and bicarbonate. After the solid waste and agent are mixed under conditions which support reaction between the agent and metals, the metals will be converted to nonleachable forms which are relatively stable under normal environmental conditions. If the solid waste material and agent are both dry when mixed, it may be beneficial to add water to facilitate the mixing of the solid waste and agent and the conversion of the metals into nonleachable forms.

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.

Abstract: Parts subject to wear, which come into contact with metal melts, are formed with a hydraulically setting high-alumina refractory concrete having a compression strength when cold, measured on dried crude product, of at least 400 kp/cm.sup.2. The compression strength is at least 700 kp/cm.sup.2 after firing at 1400.degree. C. The refractory concrete has a dimensional stability at 1400.degree. C. of at least plus or minus 0.2%. The refractory concrete contains corundum and active alumina as aggregates, an alumina .[.concrete.]. .Iadd.cement .Iaddend.containing less than 22% lime and, as required, a thinning agent. Up to 5% of the aggregates can be replaced by a spinel-forming substance preferably MgO or MgO-yielding compounds; or up to 5% of the aggregates can be replaced by carbon black, pitch or graphite; or up to 7% of the aggregates can be replaced by chromium oxide. Aggregates under 0.5 mm can be present in the refractory concrete as round grains.