Abstract: A method and plant for burning sludge or filter cakes during the cement clinker manufacture where the cement is manufactured in known manner by the cement raw meal being preheated, calcined and burned into clinker with subsequent cooling of the clinker and where the sludge is dried and finely divided prior to burning. The drying heat is provided by feeding hot raw meal from either the preheater or a separating cyclone installed in connection with the calciner to the drier unit, which may be a drier crusher. Applicable types of sludge include sewage sludge, beaching earth, paper sludge, fibre rejects, combustible chemical residues, e.g. waste derived from the manufacture of nylons and pesticides, and drill sludge resulting from oil exploration.

Abstract: In a process for the treatment of at least one mixture of solid and liquid waste substances which contains at least one metal such as Fe and/or compounds thereof, for example oxides, the mixture occurring in a condition in which it can be used at least only with difficulty, the mixture is at least extensively homogenised and mixed with at least one very fine-grain dry substance containing fly ash and/or coke. The resulting mixture is of such a nature, for example being at least predominantly in the form of agglomerates, that it can be fed to a thermal procedure, possibly after a grading operation.

Abstract: A concrete product which uses 100% of the melt slags and pulverizes the melt slags into aggregates and fine powders, grinds the aggregates so that the percentage of absolute volume of the aggregates is over 60%, mixes the aggregates, fine powders, water and cement, and forms the mixture into the concrete product by vibration or press molding.

Abstract: Acidic gases such as sulfur oxides are removed from a waste gas stream by passing it through a reverse jet scrubber in which a suspension of finely divided limestone is used as an absorption medium. The method is particularly adaptable for use in a cement manufacturing plant wherein the sulfur dioxides in the waste gases from the combustion of fossil fuels used for process heat are removed by passing them through a reverse jet scrubber that uses as an absorption medium a suspension of finely divided limestone derived from the powdered limestone feed to the cement-making process and wherein the calcium sulfate slurry formed by reaction of the sulfur oxides with the calcium carbonate in the absorption medium is returned to the limestone comminution step of the cement making process and thereby disposed of as an ingredient of the cement clinker.

Abstract: A process for forming an ash aggregate is provided. The process involves mixing a cellulose sludge material with an ash component. The ash component may comprise fly ash or sanitary waste ash in combination with fly ash. The sludge component preferably comprises paper mill sludge or pulp mill sludge. The hard lightweight aggregate may be utilized in a variety of manners, for example, to provide lightweight concrete and lightweight concrete mixes.

Abstract: A process for utilizing waste by combining of the waste with a mineral based solid material forming an additive. This additive is included as an ingredient in the manufacture of Portland cement with the additive being added to the cement clinker after heat treating of the raw material constituents producing the cement clinker.

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: Concrete compositions are provided which contain particulate rubber, preferably recycled rubber from such sources as automobile tires, in amounts between about 0.05 and about 20 percent by weight of the concrete composition. The concrete compositions further contain portland cement, water, and an aggregate material. Additional materials such as superplasticizers and fly ash can also be admixed with the concrete compositions.

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: A concrete mortar is formed by mixing together sand, cement, water and a sewage sludge ash. A foam is added to the mortar to form a foamed concrete composition.

Abstract: Rubber-crumb-reinforced cement-concrete structures (such as mortar (0), cement board (30), concrete masonry units (40), and concrete pipe (50)) provide resistance to cracking, increase resistance to acid rain, lower weight, improve shock wave absorption, lower heat conductivity and improve the acoustical environment. The structures preferably are made of concrete having a predetermined proportion (from about 1 to about 30 parts by weight per 100 parts by weight of cement) of recycled scrap rubber crumbs which are preferably undirectionally aligned in the cross-section of the structures.

Abstract: The present invention is an improved process for preparing a portland cement composition where the process comprises heat calcining a mixture comprising a source of calcium and a source of silicon to form clinker. The improvement comprises providing to the process a silicon containing product resulting from the hydrolysis of chlorosilicon by-product as at least a portion of the source of silicon.

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: 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: A process for producing cement, including preheating a mixture of ground raw materials (raw meal) in a preheating cyclone to form a preheated raw meal, calcining the preheated raw meal in a calciner to form a calcined raw meal, burning the calcined raw meal in a rotary kiln with the aid of a high-grade fuel to form a cement clinker, cooling the cement clinker in a rotary kiln and grinding the cooled cement clinker. The process is characterized by replacing 50 to 70% of the high-grade fuel with a low-grade fuel, gasifying the low-grade fuel in a fluidized bed to form a resulting fuel gas, supplying a first portion of the resulting fuel gas to a main burner of the rotary kiln, a second portion of the resulting fuel gas to the exhaust gas stream from the rotary kiln and a third portion of the resulting fuel gas to the calciner.

Abstract: A method is described for making concrete from an initially dry mixture including Portland cement, a fine aggregate, and a coarse aggregate. The method is effective for curing mixtures which contain rubble, as well as for mixtures which contain primarily virgin aggregate. In the method, substantially dry steam is introduced to the mixture at elevated temperature and pressure. Air injection may be utilized to further increase the pressure. An improved concrete is also described. The concrete exhibits unexpectedly high compressive strength.

Abstract: A waste sludge that contains water, oil and solids is subjected to filtration under vacuum or an applied inert gas pressure, preferably no more than 50 psia while utilizing a filter aid, to retain the maximum amount of oil in the filter cake. The filter cake is then dried at a relatively low temperature, slightly above the boiling point of water, to selectively remove water and produce a high heating value non-sticking solid. The product thus obtained in suitable for use as a solid fuel for a cement kiln or other combustion facilities. Depending on the amount of oil present in the original sludge, the applied pressure can be varied to retain different amounts of oil and to produce different heating values desired in the final solid fuel.

Abstract: A method of environmental cleanup by producing an autoclaved aerated cement building material (termed AAC) by a process that uses the available silica sand and other raw materials in mine tailings, in particular copper mine tailings from porphyry copper mines. The process minimizes the need for processed silica sand and other raw materials, normally used in the production of the AAC building material. The lightweight AAC building material produced from the mine tailings has excellent thermal insulation properties, sound absorption and other desirable construction qualities comparable to AAC building material produced using processed silica sand, i.e. from non-mine tailings raw material sources.

Abstract: A rotary cement kiln is operated with predried paper sludge in a secondary combustion period. The predrying of the paper sludge from a moisture content of about 50% by weight to a moisture content of about 30% by weight is effected with flue ga from the inlet end of the rotary kiln.

Abstract: Methods are disclosed for the use of inexpensive volatile fuels in the calcining zone of a cement kiln during the manufacture of cement clinker in a rotary vessel.

Abstract: Methods are disclosed for the use of inexpensive volatile fuels in the calcining zone of a cement kiln during the manufacture of cement clinker in a rotary vessel.

Abstract: A composition for use as a road base or levee fill. The composition comprises catalytic cracking catalyst particles in the size range of 1 to 200 microns and a binder the type and amount of which depend on the end use. Hydrated lime is employed as the binder in road base construction while hydrated lime, portland cement, fly ash or mixtures of fly ash and portland cement can be used in levee construction. The spent catalyst particles are present in amounts of 80% to 96% and the binder is present in amounts of 4% to 20%, both percentage ranges being determined according to the dry weight of the composition.

Abstract: A method for producing portland clinker which includes the steps of calcining a mixture of raw materials, at 1,350.degree.-1.450.degree. C. in a reducing gaseous medium containing more than 80 mass % of carbon monoxide, said mixture containing 59.7-65.05 mass % of limestone, 32.83-39.07 mass % of phosphoric slag and 1.07-6.21 mass % of additional materials containing not less than 40 mass % of iron oxide. The calcined product is then subjected to forced cooling.

Abstract: A method is shown for disposing of hazardous waste material without utilizing landfill or bulk incineration. The hazardous waste material is first fed to a shredder for shredding the waste material to pieces of a range of predetermined sizes. The solid hazardous waste material is intermixed with an inlet stream of recycled flammable fuel. The shredded material and combined fuel is then transported by means of a screw conveyor to a dissolving tank, the dissolving tank being provided with a mechanical agitator for agitating the shredded material and combined fuel to produce a homogeneous, flammable mixture. The contents of the dissolving tank are passes to a storage tank once a homogeneous, flammable mixture is achieved.