Lafarge Canada Inc.

Lafarage Canada Inc.

Donald Stephen Hopkins

David Bridson Oates

Kevin Moire Cail

Paul Lehoux

Robert Kim Ungar

Michael Ritch

James Edward Cross

David B Oates

Rayburn R Anderson

Paul H Lehoux

Philip De Zacarias

Michael David Thomas

Paul Honore Lehoux

The yield of cement clinker recovered from a kiln assembly is enhanced by feeding a particulate material comprising silica and an oxide of at least one of calcium and aluminum, for example, fly ash into contact with hot cement clinker; the fly ash melts to a partially fused material which chemically reacts with the hot clinker to produce a pyroprocessed cement clinker of crystalline hydraulic silicates; the extruder is added to the hot cement clinker downstream of the formation of the cement clinker, and suitably is added to the hot cement clinker at the upstream end of the cooler of the kiln assembly, or within the kiln, downstream of the burning zone, and more especially in the initial cooling zone at the discharge end of the kiln.

Enhancement of cement clinker yield

A combination of a class C fly ash having a high analytical content of CaO, and a silica fume, with a hydraulic cement, such as Portland cement, produces concrete with alkali-silica reactive aggregate having acceptable low expansion such as by ASTM C 1260; and also produces sulphate resistance with mineral aggregates generally.

Cement composition for alkali-reactive aggregate and for sulphate

Ground bottom ash, a waste material derived from combustion of coal, which presents a disposal problem, replaces part of the cement in a cementitious material useful in concretes and mortars and provides compressive strengths in concretes comparable with or better than corresponding cements in which there is no replacement of cement by ground bottom ash and cements containing fly ash.

Cementitious composition containing bottom ash as pozzolan and concretes

A cement mix based on an inorganic hydraulic cement, for example, Portland Cement, an air-cooled blast furnace slag and silica fume produces concretes having strength characteristics superior to those achieved by the cement alone; furthermore this cement mix is superior to a corresponding mix based on the inorganic hydraulic cement, and the air-cooled slag without the silica fume, and to a corresponding mix based on the cement and silica fume without the slag; additionally a cost saving in the expensive Portland Cement is achieved by use of the air-cooled slag which is a waste material and cheaper than granulated or pelletized slag.

Cement with air-cooled slag and silica fume

An unground, fine pozzolan having a sulphur content determined as wt. % SO.sub.3 of 5 to 25 wt. % is employed in admixture with Portland cement to provide a blended hydraulic cement which has increased compressive strength characteristics as well as extended retardation time without the need for separate addition of gypsum; the pozzolan may also be admixed with fly ash to provide a pozzolan blend for use with Portland cement with reduced Portland cement content and use of Class C fly ash; the pozzolan is derived by reaction of coal flue gases with an atomized vapor of slaked lime.

Pozzolan blends

Growing community of inventors

Thornhill, Canada

Donald Stephen Hopkins