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A study of calcium hexaluminate

Published online by Cambridge University Press:  14 March 2018

D. S. Buist*
Affiliation:
Central Research Laboratories, General Refractories Limited, Worksop, Notts

Summary

Calcium hexaluminate has recently been confirmed as a stable phase occurring within the system CaO-Al2O3. In the present investigation, this aluminate has been synthesized from the constituent oxides and its X-ray, optical, and physical (microhardness and reflectivity) properties determined. Similar data have also been obtained on the ferrian phase from the immediate hot-face zone of high-alumina bricks that had been in service in electric arc furnace roofs. An electron-probe microanalysis study revealed that between 12 and 13 % atomic replacement of Al by Fe had occurred in this ferrian calcium hexaluminate. The melting behaviour of the pure compound has been studied by firing pellets in a specially-constructed vacuum furnace. Results show the incongruent melting point to be 1870°C (±10° C), while the liquidus temperature is 1970° C (±10° C). These points were determined by examining polished sections of compacts heated within the range 1820 to 2000° C. A revised phase diagram of the high-alumina portion of the system CaO-Al2O2 is presented.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1968

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References

Auriol, (A.), Hauser, (G.), and Wurm, (J. G.), 1964. Phase Diagrams for Ceramists (American Ceramic Society), fig. 232, p. 102.Google Scholar
Buist, (D. S.), Jackson, (B.), Stephenson, (I. M.), Ford, (W. F.), and White, (J.), 1965. Trans. Brit. Ceram. Soc., vol. 64, p. 173.Google Scholar
Buist, (D. S.) and Gelsthorpe, (J. R.). Science of Ceramics, vol. 4 (to be published).Google Scholar
Burdese, (A.) and Brisi, (C.), 1961. Annali Chim., vol. 41, p. 564.Google Scholar
Dayal, (R. R.) and Glasser, (F. P.). Science of Ceramics, vol. 3 (to be published).Google Scholar
[Filonenko, (N. E.)], 1949. (Compt. Rend. Acad. Sci. URSS), vol. 64]; cited by Filonenko and Lavrov (1949).Google Scholar
[Filonenko, (N. E.)] and Lavkov, (I. V.)], 1949. Ibid., vol. 66, p. 673.Google Scholar
Gentile, (A. L.) and Foster, (W. R.), 1963. Journ. Amer. Ceram. Soc, vol. 46, p. 74.Google Scholar
Hayhukst, (A.) and Webster, (R.), 1964. I.S.I. Spec. Rep. 87, p. 171.Google Scholar
Hughes, (H.), 1967. Internal report, The United Steel Companies, Limited, Research & Development Department, Swinden Laboratories, Rotherham.Google Scholar
Langenberg, (F. C.) and Chipman, (J.), 1956. Journ. Amer. Ceram. Soc., vol. 39, p. 432.CrossRefGoogle Scholar
Nichol, (I.) and Phillips, (R.), 1965. Min. Mag., vol. 35, p. 200.Google Scholar
Osborn, (E. F.) and Muan, (A.), 1964. Phase Diagrams for Ceramists (American Ceramic Society), Fig. 630, p. 219.Google Scholar
Perry, (G. S.), 1966. Paper presented at the Eighth Electromagnetic Window Symposium, Georgia Institute of Technology, Atlanta, Georgia, 1-3 June 1966.Google Scholar
Rankin, (G. A.) and Weight, (F. E.)., 1915. Amer. Journ. Sci., ser. 4, vol. 39, p. 1.Google Scholar
Shepherd, (E. S.), Rankin, (G. A.), and Weight, (F. E.), 1909. Ibid., vol. 28, p. 293.Google Scholar
Wisnyi, (L. G.), 1955. High Alumina Phases in the System Lime-Alumina. Doctoral dissertation, School of Ceramics, Rutgers, the State University.Google Scholar