Abstract: Lightweight aggregate for use in the building industry is produced by pelletizing or granulating pulverized fuel ash or other siliceous material with a binder comprising lime in an amount less than 5% by weight based on the weight of the mixture of lime and siliceous material and curing the pellets or granules at a temperature within the range of from 35.degree. C. to 100.degree. C. in an atmosphere saturated with water vapor. The amount of lime added as binder is preferably within the range of from 1 to 4.5% by weight and curing temperature is preferably within the range of from 50.degree. to 85.degree. C. Preferably the pelletizing process is also carried out at an elevated temperature within the range of from 35.degree. C. to 100.degree. C.

Abstract: In order to produce mineralic bodies of high porosity, usable inter alia as adsorbers, purifiers and catalyst carriers, a predominantly mineralic mass with organic admixtures--both preferably obtained from industrial waste products--are subjected to a three-phase treatment. In a first phase, the mass is heated in an inert or reducing atmosphere to a sintering temperature between about 1000.degree. C. and 1350.degree. C. whereby the organic constituents are carbonized and partly penetrate the consolidating mineralic structure. In a second phase, still under the same nonoxidizing atmosphere and at the sintering temperature referred to, the mineralic structure is sintered into a coherent matrix. In a third phase, with reduction of the temperature to a lower level between about 600.degree. and 1000.degree. C. and exposure to the atmosphere, the carbonaceous substances occluded in the mineralic skeleton are burned off to increase its porosity.

Abstract: A method and apparatus is provided for reducing and measuring carbon content in fly ash. The invention employs microwave energy as the method of heating for inducing combustion of the carbon in a fly ash sample. Measurement of the carbon content can be accomplished in accordance with the present invention by measuring temperature differential of an excess energy absorber in the form of water before and after the fly ash is exposed to microwave radiation.

Abstract: A method of recovering fuel from coal ash containing non-combusted carbon in particulate form discharged from a pulverized coal fired boiler, a fluidized bed boiler or a coal gasification furnace together with exhaust gases. In this method, water and a binder and surfactant, if necessary, are added to the ash collected by the dust collecting device, and the mixture is agitated to form coarse particles of high carbon content. Then fine particles of high ash content are separated from the coarse particles, allowing the coarse particles separated from the fine particles to be dehydrated while tailing ash is turned white in color and the ash is put to use.

Abstract: A method of treating scrubber sludge removed from a gas scrubbing apparatus of the type adapted to reduce SO.sub.x content in the treated gas, is provided. The method comprises collecting the spent residue from a fluidized combustion bed of the type wherein lime or calcium carbonate particles are suspended in a fluidized medium and wherein a carbonaceous fuel is ignited proximate said fluidized medium to absorb therein substantial amounts of SO.sub.x which is generated upon ignition of said carbonaceous fuel. The fluidized bed combustion residue is then subjected to a separating treatment wherein a slurry of residue is mechanically agitated. The supernatant liquor from the slurry is separated therefrom, leaving a precipitate material which latter material is mixed with sludge. The novel composition comprises a combination of scrubber sludge and fluidized bed combustion residue precipitate, as above mentioned.

Abstract: A method of preparing a snow and ice control composition to improve traction on ice and snow covered surfaces. The composition comprises coal ash, binder, a melting depressant and enough water to form a dough-like mixture with said mixture pelletized by extrusion through a die and cured to form particles ranging in size from 1/16 th to 11/2 inches. The resulting said pellets have excellent strength and can be formulated to be environmentally acceptable.

Abstract: A method of manufacturing shaped rigid articles comprises preparing a mixture of thermally stable particulate material and a liquid resin having a viscosity of less than about 10 Stokes to form a thin coating of resin on the particles, at least a major portion of the particulate material comprising fly ash spheres, and forming the resulting mixture into a preselected shape with the resin bonding the particles together to form a rigid article having the preselected shape and containing less about 15% by weight resin. A rigid article also preferably has a cold tensile strength of at least about 125 psi.

Abstract: A fire retardant coating composition useful as a paint or as a mastic is composed of ultrafine pulverized fly ash, a low viscosity vinyl acrylic type emulsion polymer as a binder and water. The composition also preferably contains one or more of a dispersant, a defoamer, a plasticizer, a thickener, a drying agent, preservative, a fungicide and an ingredient to control the pH of the composition and thereby inhibit corrosion of any metal surface to which the composition is applied.

Abstract: A method for the strengthening of glasses, glazes, cement, gypsum board, wood fiber board, mineral fiber board, lime or gypsum by adding fly or filter dust to the starting material after which the mixture is heated or not heated depending upon the product being manufactured. For glasses, glazes and other vitreous products (besides porous ceramic products) and cement the starting material is heated to above 1000.degree. C. For gas concrete, gypsum board, wood fiber board and mineral fiber board the starting material is heated to from 100.degree.-1000.degree. C. For cement, lime and gypsum it is possible that no heating take place to the starting material.