Abstract
The hydration products of CrVI-doped tricalcium silicate (C3S)⊛ have been investigated. C3S is the main constituent of Portland cement responsible for the strength and stability of hardened Portland cement paste. Chromium trioxide (CrO3), added as a dopant to C3S, simulates hexavalent chromium waste that may be stabilized in ordinary Portland cement. X-ray diffraction was used to monitor the development of the hydration reaction products from the early stages to the late reaction stages. Leaching studies were carried out to evaluate the stability of the CrVI-containing phases in the hydrated C3S matrix.
In monolithic waste forms containing hexavalent chromium, CaCrO4·2H2O was found to form within a few minutes of the hydration reaction. With increasing concentration of Ca2+ in the pore solution, Ca2CrO5·3H2O became the stable species. The chromium in this phase was found to be very mobile in a standard acetic acid leaching test.
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References
F. P. Glasser, in “Proceedings of the Chemistry and Microstructure of Solidified Waste Forms”, edited by R. D. Spence (Lewis Publishers, Boca Raton, Florida, 1993) p. 1.
J. L. Means, L. A. Smith, K. L. W. Nehrig, S. E. Brauning, A. R. Gavaskar, B. M. Sass, C. C. Wiles and C. I. Mashni, “The application of solidification/stabilization to waste materials” (Lewis, Boca Raton, Florida, 1995).
C. Tashiro, H. Takahashi, M. Kanaya, I. Hirokida and I. Yoshida, Cem. Concr. Res. 7 (1977) 288.
N. L. Thomas, D. A. Sameson and D. D. Double, Cem. Concr. Res. 11 (1981) 143.
C. S. Poon, A. I. Clark, C. J. Peters and R. Perry, Yaste Manag. Res. 3 (1985) 127.
C. S. Poon, A. I. Clark, R. Perry, A. P. Barker and P. Barnes, Cem. Concr. Res. 16 (1986) 161.
P. L. Bishop, Hazardous Yaste Hazardous Mater. 5 (1988) 129.
R. B. Heimann, D. Conrad, L. Z. Florence, M. Neuwirth, D. G. Ivey, R. J. Mikula and W. W. Lam, J. Hazardous Mater. 31 (1991) 39.
D. G. Ivey, R. J. Mikula, W. W. Lam, M. Neuwirth, D. J. Conrad and R. B. Heimann, in “Proceedings of the Chemistry and Microstructure of Solidified Waste Forms”, edited by R. D. Spence (Lewis, Boca Raton, Florida, 1993) p. 123.
A. Kindness, S. A. Macia and F. P., Glasser, Yaste Manage. 14 (1994) 3.
H. Poellman, ST. Auer, H. J. Kuzel and R. Wenda, Cem. Concr. Res. 23 (1993) 315.
H. F. W. Taylor, “Cement chemistry” (Academic Press, London, 1990).
J. Bensted and S. P. Varma, Silicates Industriels 37 (1972) 315.
K. B. Wilberg, “Oxidation in organic chemistry”, Part IV (Academic Press, New York, 1965).
R. Keller, “Basic tables in chemistry” (McGraw-Hill, New York, 1967).
E. E. Pressler, S. Brunauer, D. L. Kantro and C. H. Weise, Anal. Chem. 33 (1961) 877.
W. A. Gutteridge, Brit. Ceram. Proc. 35 (1984) 11.
H. P. Klug and L. E. Alexander, “X-ray diffraction procedures for polycrystalline and amorphous materials” (Wiley, New York, 1974).
Environmental Protection Agency, Federal Register 51 (1986) 21 685.
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Omotoso, O.E., Ivey, D.G. & Mikula, R. Hexavalent chromium in tricalcium silicate: Part I Quantitative X-ray diffraction analysis of crystalline hydration products. Journal of Materials Science 33, 507–513 (1998). https://doi.org/10.1023/A:1004304820952
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DOI: https://doi.org/10.1023/A:1004304820952