摘要 |
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 DEG and 850 DEG 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. The apparatus for carrying out the method includes one or two hoppers, pneumatic pumps, metering devices for metering a cement raw meal-oil shale mixture or the cement raw meal and oil shale separately to the pumps, the combustion chamber, the preheater system and a rotary kiln.
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