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Aqueous and Surface Chemistry of Calcium - Metal Hydroxides in High pH Environments

Published online by Cambridge University Press:  10 February 2011

David L. Cocke
Affiliation:
Gill Chair of Analytical Chemistry, Lamar University, Beaumont, TX 77710, [email protected]
M. Yousuf
Affiliation:
Gill Chair of Analytical Chemistry, Lamar University, Beaumont, TX 77710, [email protected]
A. Mollah
Affiliation:
Gill Chair of Analytical Chemistry, Lamar University, Beaumont, TX 77710, [email protected]
Thomas R. Hess
Affiliation:
Gill Chair of Analytical Chemistry, Lamar University, Beaumont, TX 77710, [email protected]
Tien-Chih Lin
Affiliation:
Gill Chair of Analytical Chemistry, Lamar University, Beaumont, TX 77710, [email protected]
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Abstract

Mixed hydroxides of calcium, zinc, cadmium and lead have been recently identified in the high pH environments of hydrating cement. FTIR, XRD, SEM, and SPM have been used to characterize these systems. A chemical equilibrium model of the early hydration of a zinc-doped cement/water system, Na-K-Ca-Zn-H-SO4-OH-Zn(OH)2-Zn(OH)3-Zn(OH)4-H2O, has been developed to better understand the mechanism of the surface formation of calcium hydroxyzincate (CHZ). The model is based on Pitzer's semi-empirical method for calculation of ion-activity coefficients at high ionic strength. The Pitzer parameters for Na+-Zn2+,Na+-Zn2+- and have been evaluated, and the results successfully predict the equilibria (solubilities) of Na2SO4-ZnSO4-H2O, NaOH-Zn(OH)2-H2O and KOH-ZnO-H2O systems. The chemical model clearly demonstrates that the formation of CHZ on the calcium-silicahydrate (C-S-H) surface is critically controlled by the Ca2+ ion concentration as well as pH of the pore water system. The results of this study suggest that the growth of CHZ is preceded by surface complex formation. Sequential charge control and sequential structure development have been used to discuss the surface selectivity of these compounds and their control of cement hydration.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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References

1. Conner, J. R., Chemical Fixation and Solidification of Hazardous Substances (Van Nostrand Reinhold, New York, 1990).Google Scholar
2. Wiles, C. C. in Standard Handbook of Hazardous Waste Treatment and Disposal, edited. by Freeman, Harry M. (McGraw Hill, New York, 1989).Google Scholar
3. Cocke, D. L. and Mollah, M. Y. A. in Chemistry and Microstructure of Solidified Waste Forms, edited by. Spence, Roger D. (Lewis Publishers, Boca Raton:, 1993) pp 187242.Google Scholar
4. Mollah, M. Y. A., Parga, J. R. and Cocke, D. L., J. Environ. Sci. Health, A27, 1503 (1992).Google Scholar
5. Lieber, W. and Gebauer, J., Zement-Kalk-Gips, 22, 161 (1969).Google Scholar
6. Arliguie, G., Ollivier, J. P. and Grandet, J., Cemt. Concr. Res., 12, 79 (1982).Google Scholar
7. Arliguie, G. and Grandet, J., Cemt. Concr. Res., 20, 517 (1990).Google Scholar
8. Lieber, W., Zement-Kalk-Gips, 20, 91 (1967).Google Scholar
9. Mollah, M. Y. A., Vempati, R., Lin, T-C.. and Cocke, D., Waste Management, 15, 137 (1995).Google Scholar
10. Pitzer, K. S. in Activity Coefficients in Electrolyte Solutions edited by. Pytkowicz, R. M. (CRC Press, Boca Raton, 1979).Google Scholar
11. Plummer, L. N. and Parkhurst, D. L., U.S. Geological Survey Water-Resources Investment Report, 884153 (1989).Google Scholar
12. Harvie, C. E. and Weare, J. H., Geochimica et Cosmochimica Acta, 44, 981 (1980).Google Scholar
13. Harvie, C. E., Møller, N. and Weare, J. H., Geochimica et Cosmochimica Acta, 48, 723 (1984).Google Scholar
14. Pitzer, K. S., J. Phys. Chem., 77, 268 (1973).Google Scholar
15. Huang, H., J. Sol. Chem., 18, 1069 (1989).Google Scholar
16. Kuester, J. L. and Mize, J. H., Optimization Techniques with Fortran, (McGraw-Hill, New York, 1973).Google Scholar
17. Lin, T-C., “Chemical Modeling of the Zinc-Doped Cement/Water System and Characterization of Calcium hydroxyzincate.” M.S. thesis, Lamar University, Texas, (1994).Google Scholar
18. Filippov, V., Nokhrin, V. and Muzalevskaya, A., Russian J. Inorg. Chem., 30, 1372 (1985).Google Scholar
19. Sharma, R. A., J. Electrochem. Soc.: Electrochem. Sci. Tech, 113, 2215 (1986).Google Scholar
17. Pitzer, K. S., Roy, R. N. and Silvester, L. F., J. Am. Chem. Soc., 99, 4930 (1977).Google Scholar
18. Wagman, D. D., Evans, W. H., Parker, V. B., Schumm, R. H., Halow, I., Bailey, S. M., Churney, K. L. and Nuttall, R. L., J. Phys. Chem. Ref Data, 11, suppl.2 (1982).Google Scholar
19. Gartner, E. M., Tang, F. J. and Weiss, S. J., J. Am. Cer. Soc., 68, 667 (1985).Google Scholar
20. Michaux, M., Fletcher, P. and Vidick, B., Cemt. Concr. Res., 19, 443 (1989).Google Scholar
21. Stumm, W., in Chemistry of the Solid-Water Interface (John Wiley, New York, 1992).Google Scholar