By‐Product of Sulfur Recovery from Phosphogypsum as Concrete Aggregate
Publication: Journal of Materials in Civil Engineering
Volume 6, Issue 4
Abstract
A sulfur‐recovery process from phosphogypsum produces a by‐product slag that can potentially be used as aggregate in portland cement concrete. The phase composition and microstructure of samples of slag from a bench‐scale (Florida Institute for Phosphate Research [FIPR]) and a pilot‐scale (campaign 5) run of the process were characterized. Both slags have a frothy appearance. The FIPR slag consists of elongate, and often radiating crystals of gehlenite , enclosing larnite . Some amounts of iron sulfide and magnetite are also present. Campaign 5 slag does not contain gehlenite since quartz is present. Its microstructure is also different, consisting of an intimate, heterogeneous mixture of calcium silicates and opaque phases. Residual gypsum is present in both slags but in greater amounts in campaign 5; the latter also contains some ettringite and native sulfur. The FIPR bench‐scale run produced a completely burned residue while the pilot‐scale run residue was underburned. However, mineralogically, both are suitable as aggregate in concrete as long as the amount of sulfate phases is not too high (<4.5%).
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References
1.
Alonzo, A. A. (1989). Microscopical examination and X‐ray diffraction analysis of phosphogypsum slab aggregate. Construction Technology Laboratory, Inc., Skokie, Ill.
2.
Campbell, D. H., and Tang, F. J. (1990). Microscopy and X‐ray diffraction of phosphogypsum based slag aggregate. Construction Technology Laboratory, Inc., Skokie, Ill.
3.
Chatterjee, A. K. (1983). “Role of volatiles in cement manufacture.” Advances in cement technology, S. N. Ghosh, ed., Pergamon Press, Oxford, England, 203–263.
4.
Deer, W. A., Howie, R. A., and Zussman, J. (1986). Disilicates and ring silicates. Longman Scientific and Technical, Essex, England.
5.
DeHayes, S. M., Grady, J. M., and Vidergar, D. M. (1986). “Clinker microstructure—a comparison of dry process, preheater and precalciner kilns.” Proc. VIII Int. Conf. on Cement Microscopy, J. Bayles, G. R. Gouda, and A. Nisperos, eds., Orlando, Fla.
6.
Drever, J. I. (1982). The geochemistry of natural waters. Prentice‐Hall, Inc., Englewood Cliffs, N.J.
7.
Gillot, J. E. (1987). Clay in engineering geology. Elsevier, Amsterdam, the Netherlands.
8.
Insley, H., and Frechette, V. D. (1955). Microscopy of CERAMICS and CEMENTS including glasses, slags, and foundry sands. Academic Press, New York, N.Y.
9.
Lea, F. M. (1971). The chemistry of cement and concrete. Chemical Publishing, New York, N.Y.
10.
Lloyd, G. M, Marten, J. H., and Kendron, T. J. (1985). Phosphogypsum: a source of sulfur dioxide. Proc. Am. Chemical Soc. Meeting, American Chemical Society, Chicago, Ill.
11.
Meyer, B. (1977). Sulfur, energy, and environment. Elsevier Scientific Publishing Company, Amsterdam, the Netherlands.
12.
Ott, E. (1993). “Investigation of the technical feasibility of using phosphogypsum‐based slag aggregate in portland concrete mixtures,” MSc thesis, Louisiana State University, Baton Rouge, La.
13.
Ott, E., Foxworthy, P. T., and Seals, R. K. (1993). “Utilization of phosphogypsum‐based slag aggregate in portland cement concrete mixtures.” Rep. No. I‐93‐5, Inst. for Recyclable Materials, Baton Rouge, La.
14.
Powder diffraction file. (1986). Joint Committee for Powder Diffraction Standards, International Center for Diffraction Data, Swarthmore, Pa.
15.
Samarai, M. A. (1976). “The disintegration of concrete containing sulphate‐contaminated aggregates.” Mag. Concr. Res., 28, 130–142.
16.
Taha, R. A., and Seals, R. K. (1992a). “Engineering properties of phosphogypsum‐based slag aggregate.” Transp. Res. Rec., 1345, 106–112.
17.
Taha, R. A., and Seals, R. K. (1992b). “The use of phosphogypsum‐based slag in hot mix asphaltic concrete.” Proc. Utilization of Waste Mater. in Civ. Engrg. Constr., Materials Engineering Division, American Society of Civil Engineers, New York, N.Y., 202–216.
18.
Taha, R. A., Seals, R. K., and Tittlebaum, M. E. (1991). “Engineering properties of phosphogypsum‐based slag aggregate.” Rep. No. I‐91‐1, Inst. for Recyclable Mat., Baton Rouge, La.
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Copyright © 1994 American Society of Civil Engineers.
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Received: Sep 29, 1993
Published online: Nov 1, 1994
Published in print: Nov 1994
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