Abstract: The method is used in processing raw meal such as cement raw meal, powdered limestone, alumina hydrate or the like including those having relatively high alkali chloride and/or sulfate content up to 2% Cl and/or 2.5% SO.sub.3 and includes the steps of metering the dry raw meal into a processing system, pumping the raw meal in the processing system to a separate combustion chamber, supplying fuel to the combustion chamber and igniting same therein to heat the dry raw meal in the combustion chamber to a temperature between 100.degree. and 600.degree. C. Further, the heated dry raw meal is pumped to a cyclone separator through which it is processed and then supplied to a long dry process alkali rich rotary kiln. In this way, problems due to alkali rich encrustations are reduced, and the thermal efficiency of the entire preheating system is increased.

Abstract: The method for processing cement raw meal and oil shale by combining them in a mixture with oil shale kerogen constituting 0.5 to 2% of the mixture by weight. This mixture is supplied to a separate heating chamber where it is preheated so as to heat the cement raw meal component and burn off the combustible component of the oil shale. The raw meal is heated in the chamber to a temperature between 100.degree. and 850.degree. C. The heated mixture is then fed to a preheater system having an output coupled to a rotary kiln. In one embodiment the preheater system includes four stages and the cement raw meal component, namely powdered limestone, is fed directly to the first stage unpreheated and the oil shale is fed separately to the combustion chamber where it is heated and the combustible constitutents thereof burned off and the heated oil shale component is then supplied to the second or third stage.

Abstract: The method is used in processing raw meal such as cement raw meal, powdered limestone, alumina hydrate or the like, and includes the steps of metering the dry raw meal into a processing system, pneumatically pumping the raw meal in the processing system to a separate combustion chamber, supplying fuel to the combustion chamber and igniting same therein to heat the dry raw meal in the combustion chamber to a temperature between 100.degree. and 500.degree. C. Further, the heated dry raw meal is pumped to a preheater system through which it is processed and then supplied to a rotary kiln. In this way, the preheater decarbonative capacity is increased, and the higher temperature of the gas exiting from the preheater system provides recoverable heat. The thermal efficiency of the entire preheating system is thus increased.