To treat organic sludge while keeping facility costs, cement production efficiency, and a reduction in clinker production amount to a minimum. An organic sludge treatment device includes: a fractionation device 7 that fractionates a preheated raw material R2 from a preheater cyclone 4C excluding a bottommost cyclone of a cement burning device 1; a mixing device 8 that mixes an organic sludge S with the fractionated preheated raw material, and that dries the organic sludge using sensible heat of the preheated raw material; and a supply device (mixture chute 12, double-flap damper 13, shut damper 14) that supplies a mixture M from the mixing device to a calciner furnace 5 of the cement burning device or to a duct disposed between a kiln inlet portion of a cement kiln 2 and the calciner furnace. The treatment device may be provided with an introduction device for introducing an exhaust gas G2 including dust, odor and water vapor from the mixing device to a gas outlet of a bottommost cyclone 4A of the cement burning device.

Aqueous cementitious slurries including predominantly Type I Portland cement containing an aluminate additive. The aluminate additive is an aluminate salt other than calcium aluminate or calcium sulfoaluminate, preferably sodium aluminate. Cementitious reactive powders of the slurry include the Type I Portland cement and 0.1-10 wt. % of the aluminate additive as an accelerator. The slurries may have a set time of about 10 minutes or less. Due to the short set time, the cementitious reactive powders may facilitate cement board fabrication by continuous manufacturing processes. Methods for making cement boards may include disposing the aqueous cementitious slurry including the cementitious reactive powders in a continuous layer, preferably upon a porous support, and setting the aqueous cementitious slurry with a set time of about 10 minutes or less.

A method for preparing low-background cement includes: uniformly mixing a seed crystal of cement, C.sub.4AF whiskers, and high-magnesium raw material to yield a first mixture, calcining the first mixture at 1400-1500 C., to yield a low-background clinker, the first mixture including 1.0-5.0 wt. % of the seed crystal of cement, 1.0-5.0 wt. % of the C.sub.4AF whiskers, and the balance is the high-magnesium raw material; and grinding a second mixture of the low-background clinker and gypsum, to yield low-background cement. The seed crystal of cement is a high-magnesium and low hydration heat clinker, has a specific activity of Ra-226 radioactive nuclides within 50 Bq/kg, and the MgO content of the clinker is between 4.0 wt. % and 5.0 wt. %, with 50 wt. % <C.sub.3S <55.0 wt. %; and the high-magnesium raw material has a MgO content between 2.5 wt. % and 3.0 wt. %.

A process for producing fly ash in a fluidized bed boiler includes combusting a fuel in a fluidized bed combustor in the presence of limestone particles, recovering fly ash, and recovering bottom ash. The fuel contains hydrocarbons and sulfur. A majority of the sulfur from the fuel is recovered from the bottom ash. The fly ash may contain less than 5% by weight of sulfur oxides. This may be achieved by using limestone particles having certain properties and/or narrowing an inlet from the boiler into a cyclone.

A method for the preparation of industrial-scale concrete installations with improved compression strength, curling, cracking and cracking characteristics, the method comprising the addition of nanosilica particulate, and more preferably, colloidal amorphous silica, having specific size and surface area characteristics to a concrete mix after water has been added to the mix and the mix has been agitated.

An apparatus and method to efficiently recover noble metals such as gold, silver and copper and aluminum from incineration ash, and effectively use ash after recovering the noble metals and others. An incineration ash treatment apparatus 1 including: a crusher for crushing an incineration ash A1 to be less or equal to 5 mm in maximum particle diameter, or/and a classifier for classifying an incineration ash to obtain an incineration ash whose maximum particle diameter is less or equal to 5 mm; an eddy current separator 8 for separating an incineration ash whose maximum particle diameter is less or equal to 5 mm discharged from the crusher or/and the classifier into a conductor E and a nonconductor I; a specific gravity separator for separating a conductor discharged from the eddy current separator 8 into a high gravity material H2 and a low gravity material L2. The specific gravity separator can be an air table 10. A classifier for classifying a crushed material C, classifying point of which is 5 mm or less, can be mounted, and fine particles P whose particle diameters are 5 mm or less discharged from the classifier can be fed to the eddy current separator 8. Rotation speed of a drum of the eddy current separator 8 can be 4000 rpm or more.

An apparatus and method to efficiently recover noble metals such as gold, silver and copper and aluminum from incineration ash, and effectively use ash after recovering the noble metals and others. An incineration ash treatment apparatus 1 including: a crusher for crushing an incineration ash A1 to be less or equal to 5 mm in maximum particle diameter, or/and a classifier for classifying an incineration ash to obtain an incineration ash whose maximum particle diameter is less or equal to 5 mm; an eddy current separator 8 for separating an incineration ash whose maximum particle diameter is less or equal to 5 mm discharged from the crusher or/and the classifier into a conductor E and a nonconductor I; a specific gravity separator for separating a conductor discharged from the eddy current separator 8 into a high gravity material H2 and a low gravity material L2. The specific gravity separator can be an air table 10. A classifier for classifying a crushed material C, classifying point of which is 5 mm or less, can be mounted, and fine particles P whose particle diameters are 5 mm or less discharged from the classifier can be fed to the eddy current separator 8. Rotation speed of a drum of the eddy current separator 8 can be 4000 rpm or more.

Methods and composition are provided for deriving cement and/or supplementary cementitious materials, such as pozzolans, from one or more non-limestone materials, such as one or more non-limestone rocks and/or minerals. The non-limestone materials, e.g., non-limestone rocks and/or minerals, are processed in a manner that a desired product, e.g., cement and/or supplementary cementitious material, is produced.

A raw meal for a cement clinker, a cement clinker made from that raw meal and a process for producing a cement clinker are provided. The clinker contains mainly the hydraulically activate alphaH-belite polymorph and calcium sulfoaluminate (ye'elimite or C.sub.4A.sub.3?), at the low firing temperature of 1050? C., using a combination of fluoride and boron oxide.

Various examples related to portland cement manufacturing using municipal solid waste incineration (MSWI) ash are provided. In one example, a method includes providing a raw kiln feed including MSWI to a kiln, forming ash-amended clinker (ACK) by heating the raw kiln feed in the kiln, and preparing ash-amended cement (AAC) from the ACK. The MSWI bottom ash can make up about 5% by mass or less of the raw kiln feed. The ACK can have a chemical composition that meets ASTM C150/ASTM C595, and the AAC can include arsenic, barium, copper, and lead consistent with defined Soil Cleanup Target Levels. In another example, a system includes a kiln, a kiln feed system that supplies raw kiln feed including MSWI bottom ash to the kiln, and a finish mill that grinds ACK formed by heating the raw kiln feed in the kiln to form AAC.