Use of precalciners to remove alkalies from raw materials in the cement industry. Quarterly technical progress report, February--April 1979
Laboratory tests designed to evaluate the volatility of alkalies in finely-ground argillaceous minerals are reported. A method used to determine the sintering points of these minerals is described. In addition to six pure minerals which were studied, argillaceous materials which are more typical of cement-plant raw feed components were studied. The conclusions of this report are: at 1000/sup 0/C, a combination of CaCO/sub 3/ and CaCl/sub 2/ additives enables volatilizion in one-half hour up to about 50% of the total alkali from high-alkali feldspars. However, much less alkali was lost from the typical cement plant raw materials under the same conditions; the atmosphere in which the experiment was conducted may have a significant effect on the results, especially if there is S present in the system. Absence of O can lead to decomposition ofnormally involatile alkali sulfates. Fe Cl/sub 3/, may be lost from the sample. Losses are greatest in the absence of CaO and water vapor; sintering points of the pure minerals are above 1200/sup 0/C. Therefore, there is little danger of their sintering at 1000/sup 0/C, the presence of fluxing agents such as CaCl/sub 2/ may cause some sticking: and the use of vapor-phase compounds such as FeCl/sub 3/ and HCl is not an effective means of volatilizing alkalies under test conditions of (1000/sup 0/C for 30 minutes).
- Research Organization:
- Portland Cement Association, Skokie, IL (USA)
- DOE Contract Number:
- EM-78-C-02-4929
- OSTI ID:
- 6102925
- Report Number(s):
- COO-4929-3
- Country of Publication:
- United States
- Language:
- English
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Use of precalciners to remove alkali from raw material in the cement industry. Quarterly technical progress report, May-June 1979
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Related Subjects
CEMENTS
HYDROXIDES
CALCIUM CHLORIDES
EVAPORATION
CALCIUM OXIDES
CARBON OXIDES
IMPURITIES
IRON CHLORIDES
MINERALS
OXYGEN
SINTERING
SULFATES
SULFUR
ALKALINE EARTH METAL COMPOUNDS
BUILDING MATERIALS
CALCIUM COMPOUNDS
CALCIUM HALIDES
CARBON COMPOUNDS
CHALCOGENIDES
CHLORIDES
CHLORINE COMPOUNDS
CRYOGENIC FLUIDS
ELEMENTS
FABRICATION
FLUIDS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
IRON COMPOUNDS
MATERIALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360601* - Other Materials- Preparation & Manufacture