Use of precalciners to remove alkali from raw material in the cement industry. Quarterly technical progress report, November 1978-January 1979
The attached reports deal with the results of: (1) a literature survey on the general topics of alkali volatilization and heat transfer in cement manufacturing systems, (2) a survey of on-line gas analysis techniques for alkalies, sulfur and chlorine, and (3) a series of high-temperature burns of selected ground argillaceous minerals with various chloride-containing admixtures. Little further information regarding the volatility of alkalies in pure minerals was found. The survey of on-line gas analysis techniques for alkalies, etc., has shown that no techniques have as yet been developed to the stage where they can be used in cement kiln system. However, developments in this area might be expected to occur rapidly in the next few years. The experimental work has been successful in showing that the combined addition of CaCO/sub 3/ and CaCl/sub 2/ to several of the minerals enhances alkali volatility at 1000/sup 0/C relative to addition of CaCl/sub 2/ alone, although the degree of alkali loss rarely exceeds about 50%. The greatest success was achieved with the feldspars, which also performed well with additions of a MgCl/sub 2//NH/sub 4/Cl mixture. The illite and muscovite results generally were more difficult to interpret. The kaolin and montmorillonite actually showed gains in alkali content in many of the burns, probably due to a weakness in the experimental method. As a result, future experiments will, where possible, be conducted in a tube furnace, in a flowing gas stream, to avoid sample contamination. Further work will also include the use of FeCl/sub 3/ and HCl vapors in controlled atmospheres.
- Research Organization:
- Portland Cement Association, Skokie, IL (USA). Construction Technology Labs.
- DOE Contract Number:
- EM-78-C-02-4929
- OSTI ID:
- 5845696
- Report Number(s):
- COO-4929-2
- Country of Publication:
- United States
- Language:
- English
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Use of precalciners to remove alkalies from raw materials in the cement industry. Quarterly technical progress report, February--April 1979
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Related Subjects
CEMENT INDUSTRY
ENERGY CONSERVATION
KILNS
EFFICIENCY
ALKALI METALS
CALCINATION
RESEARCH PROGRAMS
VOLATILITY
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTS
INDUSTRY
METALS
PYROLYSIS
THERMOCHEMICAL PROCESSES
320303* - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Equipment & Processes