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The chemistry and mineralogy of some granulated and pelletized blastfurnace slags

Published online by Cambridge University Press:  05 July 2018

P. W. Scott
Affiliation:
Department of Geology, University of Hull, Hull HU6 7RX
S. R. Critchley
Affiliation:
Department of Geology, University of Hull, Hull HU6 7RX
F. C. F. Wilkinson
Affiliation:
Department of Geology, University of Hull, Hull HU6 7RX

Abstract

Samples of granulated slag from Scunthorpe, Humberside, collected over several years, vary somewhat in chemical composition reflecting differences in iron-making practice. All contain some melilite and oldhamite crystals and minor amounts of iron along with the glass. Granulated slag from Usinor, Dunkirk, France, has a little more CaO than the Scunthorpe material with crystals of merwinite and oldhamite. Pelletised slag from Redcar, Teeside, is much more vescicular than the granulated material and contains melilite and oldhamite.

The melilite crystals contain many inclusions of oldhamite and iron. They span a wide range within the akermanite-gehlenite series and are non-stoichiometric in composition. The merwinite may have formed largely by quench crystallization. Oldhamite is probably the first phase to form in all the slags. The silicate mineralogy can be explained in terms of the phase relationships within the CaO-SiO2-Al2O3-MgO quaternary system. The small difference in composition of the French slags is sufficient for them to fall into the primary phase field of merwinite rather than melilite. Assuming that only a minor proportion of crystals is acceptable in slags for use in Portland Blastfurnace Cement, the present low Al (< 11 % Al2O3) British and French slags are approaching an optimum composition.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1986

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References

Butler, B.C.M. (1977) Mineral. Mag. 41, 493-9.CrossRefGoogle Scholar
Critchley, S.R. (1983) The chemistry and mineralogy of some granulated blastfurnace slags.Unpubl. M.Sc. thesis, University of Hull. 74 pp.Google Scholar
Dunham, A.C. and Wilkinson, F.C.F. (1978) X-ray spectrom. 7, 50-6.CrossRefGoogle Scholar
Emery, J.J. (1978) Proceedings 3rd ‘Industrial Minerals' International Congress, Paris, 127-42.Google Scholar
Hooton, R.D., and Gupta, R.P. (1977) Silicates Industriels. 42, 111-20.Google Scholar
Gutt, W. (1972) Chemistry and Industry, 1972,439-447. Building Research Station, Current PaperCP14/72.Google Scholar
Nixon, P.J., Smith, M.A., Harrison, W.H., and Russell, A.D. (1974) Building Research Station, Current PaperCP19/74, 81 pp.Google Scholar
Kunicki, M., and Roussel, M. (1977) Silicates Industriels. 42, 183-91.Google Scholar
Lee, A.R. (1974) Blastfurnace and steel slag: production, properties and uses. Edward Arnold, London. 119 pp.Google Scholar
Levin, E.M., Robbins, C.R., and McMurdie, H.F. (1964) Phase diagrams for ceramists. American Ceramic Society, Columbus, Ohio. 601 pp.Google Scholar
Levin, E.M., Robbins, C.R., and McMurdie, H.F. (1969. Ibid. 1969 Supplement. 625 pp.Google Scholar
Norrish, K., and Hutton, J.T. (1969) Geochim. Cosmochim. Acta. 33, 431-53.CrossRefGoogle Scholar