Abstract: The cementitious material comprises an initial mixture of portland cement clinker and a modifier ranging in weight from approximately 0.5% to 5%, preferably 1%, of the weight of the clinker. The modifier is selected from a group comprising (a) a melamine formaldehyde-sodium bisulfite copolymer, and (b) sodium naphthalene sulfonate. The portland cement clinker and the modifier are intimately mixed and caused to react together in a solid state reaction by energetically grinding them together in a highly energetic ball-and-tube grinding mill to a high degree of fineness of at least approximately 5000 Blaine. Modified cementitious materials are produced by providing an additional constituent in the initial mixture comprising a hard, dense, substantially inert mineral material ranging up to 70% of the mixture by weight. The percentages of the portland cement clinker and the modifier are correspondingly reduced. The modified initial mixture is ground as before.

Abstract: A method for manufacturing cement is described, by which gypsum is added to the clinker in the clinker cooler (3). Hereby it is obtained that the gypsum is dried in a safe, simple and inexpensive manner without substantial additional costs for establishment and operation.

Abstract: The invention relates to a method of producing cement clinker from fine-grained cement raw material which after preheating and calcining is burnt in a clinker burning zone divided into two stages and is then cooled. Optimum process conditions, particularly in the clinker burning zone, are achieved in that the calcined material is first of all heated to a temperature up to the region of the sintering temperature in a stage formed by a fluidized bed or spouted bed so that a build-up granulation of the material is brought about, whereupon the material thus heated is heated to the sintering temperature in a second stage of the clinker burning zone which acts as the finish-burning stage and tempered to the finishing burn.

Abstract: Processes and systems for producing cementitious materials from ferrous blast furnace slags. Processes comprise mixing of a source of CaO with molten slag flowing from at least one slag tap hole of a blast furnace. Sufficient CaO is mixed with the molten slag to raise the ratio of CaO to SiO.sub.2, the C/S Ratio, of the slag to between about 64 1.06 and 1.25, while maintaining the Base Number of the molten slag less than about 1.55. The slag is then water granulated and ground to a predetermined degree of fineness. An activator then is added to the ground granulated slag. The C/S Ratio of the granulated slag determines the degree of fineness to which the granulated slag must be ground to achieve a desired hydration rate in the resultant cementitious material. Cementitious materials with C/S Ratios in this range may be ground less finely, yet possess the same hydration rates, as other more finely ground cementitious materials.

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: The present invention pertains to a portland cement clinker containing the following amounts of clinker phases, in wt. %:C.sub.3 S: 30 to 80,C.sub.4 A.sub.3 S: 5 to 30,C.sub.4 AF: <30,C.sub.2 S: <40,C.sub.3 A: <20,and an SO.sub.3 content between 2 and 8 wt. %, obtained by calcining a raw material mixture containing CaO, SIO.sub.2, AL.sub.2 O.sub.3, and Fe.sub.2 O.sub.3 in the presence of an additive containing SO.sub.3 and an additive containing fluorine at temperatures between 1,150.degree. C. and 1,350.degree. C.

Abstract: Method for eliminating the dangerous alkali-aggregate reaction in concretes which contain hydrated cement obtained by the alkaline activation of Portland cement. The formation in this concrete of a compound which can generate a soluble alkali aluminate is prevented by reacting a mineral composition by alkaline activation, the said compound consisting of a hydrated alumino-silicate whose Nuclear Magnetic Resonance .sup.27 Al MAS-NMR spectrum shows a resonance at 66.+-.5 ppm corresponding to a (Q.sub.3)(3Si)-type (AlO.sub.4) tetrahedron. The above-mentioned mineral composition contains:a) 100 parts by weight of the said calcium alumino-silicate;b) 10 to 30 parts by weight of powdered synthetic alumino-silicate belonging to the class of silicates whose mineralogical structure is lamellar and whose MAS-NMR for .sup.27 Al has at least one main resonance at 20.+-.5 ppm and/or 50.+-.5 ppm in relation to AlCl.sub.3.c) 0 to 10 parts by weight of a hydrated disilicate Ca(H.sub.3 SiO.sub.4).sub.2 whose (SiO.sub.

Abstract: This invention relates generally to dredging under harbors and waterways and fabricating building materials and more particularly to an apparatus for dredging that produces no waste and uses the dredged material for useful building products. Furthermore, all off the equipment that is used for the dredging and fabricating building materials from the dredged materials placed upon at least one floating badge.

Abstract: A suspension shaft furnace and process for producing clinkers from discrete pellets of cement-forming batch materials, the furnace having a top vertical shaft section comprising a pellet-feeding and preheating zone, an intermediate fluidized bed section containing fuel inlet conduits for clinkering of the pellets in a fluidized bed, an air-permeable clinker-impermeable support for supporting the pellets as a fluidized bed, and a lower clinker-cooling section beneath the fluidized bed section. Clinker-discharge means permit the gravity flow of clinkers from the top of the fluidized bed down into a cooling zone in the cooling section. Air inlet means supply a combustion-supporting cooling gas up through the cooling zone, to cool the clinkers therein, and upstream through the fluidized bed section to support the combustion of fuel at the fuel inlet conduits.

Abstract: A flux composition for cement comprises mainly wollastonite. One of the compositions of the flux is wollastonite 99%, fluorite 5-15% and gypsum 30-35%. The flux is added during the preparation of the cement raw materials and comprises 1-10% of the admixture. Thus, the firing temperature firing time may be shortened, the consumption of coal may be decreased and manufacturing productivity of the cement may be improved. In addition, the compression strength and the binding strength of the cement are also improved.

Abstract: A composition for treating toxic metals in solid waste, sludge or slurry is provided. The composition includes a reducing agent such as ferrous sulfate or sodium sulfite and a fixative containing solid calcium oxide or solid magnesium oxide. The composition may also include an acid such as sulfuric acid.

Abstract: This invention isolates in separate furnaces the three thermochemical processes required in manufacturing Portland cement and sulphur dioxide from a calcium sulfate source so as to yield improved pyrometallurgical treatment for each individual process. Separating these processes facilitates selection of the most kinetically suitable reactions by enabling the maintenance of optimum conditions for each process without compromising the thermal or kinetic efficiencies of the other processes.Only one fourth of the calcium sulfate is reduced to calcium sulfide in a separate ad hoc reduction furnace specifically designed for achieving enhanced reduction parameters which results in minimized reduction equipment size. Treating most of the calcium sulfate elsewhere works to avoid side reactions and allows Portland cement raw mix components to have an enhanced synergistic catalytic effect on reduction kinetics.