Hostname: page-component-8448b6f56d-qsmjn Total loading time: 0 Render date: 2024-04-19T19:09:31.462Z Has data issue: false hasContentIssue false

Mineralogical Transformations and Microstructure After Disposal of Cementitious Advanced Coaltechnologyby-Product

Published online by Cambridge University Press:  21 February 2011

G.J. McCarthy
Affiliation:
Department of Chemistry, North Dakota State University, Fargo, ND 58105
R.D. Butler
Affiliation:
Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND 58202
D.W. Brekke
Affiliation:
Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND 58202
S.D. Adamek
Affiliation:
Department of Chemistry, North Dakota State University, Fargo, ND 58105
J.A. Parks
Affiliation:
Department of Chemistry, North Dakota State University, Fargo, ND 58105
H.J. Foster
Affiliation:
Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND 58202
J. Solc
Affiliation:
Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND 58202
Get access

Abstract

By-products from two advanced coal technologies, Fluidized Bed Combustion (FBC) and Limestone Injection Multistage Burner (LIMB), were found to be cementitious when mixed with water and compacted. However, exposure to natural conditions in test cells resulted in losses of strength and increases in permeability over a period of years. Changes in mineralogy and microstructure with time in recovered core samples have been characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Up to 80 wt% of the core materials had converted to crystalline hydrate phases by the end of two years. Ettringite, gypsum and portlandite were the initial hydration products. In the LIMB materials, formation of thaumasite in microfractures, channels and voids was detected after one year, and in the FBC material after two years. Thaumasite formation was accompanied by reductions in gypsum and portlandite; it did not appear to be forming at the expense of ettringite. EDS examination of many ettringite and thaumasite crystals showed that the former always contained some Si and the latter some Al, which is evidence for ettringite-thaumasite solid solution. Thaumasite formation accompanied marked losses in strength and increases in permeability.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Weinberg, A., Petrini, R.H. and Butler, R.D., Advanced Coal Technology Waste Disposal, draft final report prepared for U.S. Department of Energy, Morgantown Energy Technology Center (1993); A. Weinberg, B.J. Coel and R.D. Butler, Field Study for Disposal of Solid Wastes from Advanced Coal Processes: Ohio LIMB Site Assessment. Final Report, DCN 94-218-044-31, RCN 218-044-03-30, Radian Corporation, Austin Texas, October 1994.Google Scholar
2. Butler, R.D., Brekke, D.W., Foster, H.J. Solc, J. and McCarthy, G.J., “Mineral Diagenesis in Buried FBC Ash and Effects on Long-Term Physical and Chemical Behavior,” in Proc. Seventeenth Biennial Low-rank Fuels Symposium, St. Louis, MO (UND-Energy and Environmental Research Center, Grand Forks, ND, 1993) pp. 515530.Google Scholar
3. Solem, J.K. and McCarthy, G.J., in Advanced Cementitious Systems, (Mater. Res. Soc. Proc. 245, Pittsburgh, PA, 1992) pp. 7179.Google Scholar
4. Solem-Tishmack, J.K., Use of Coal Conversion Solid Residuals in Solidification-Stabilization Technology. M.S. Thesis, Department of Soil Science, North Dakota State University, Fargo, ND, 173 pp. (1993).Google Scholar
5. Bender, J.A., Solem, J.K., McCarthy, G.J., Oseto, M.C. and Knell, J.E., in Adv. X-Ray Anal., Vol. 36, (Plenum Publ. Corp., New York, 1993) pp. 343353.Google Scholar
6. McCarthy, G.J., Bender, J.A., Solem, J.K. and Eylands, K.E., in Proc. Tenth Intern. Ash Use Symp, EPRI TR-101774s (Electric Power Research Institute, Polo Alto, CA, 1993), pp. 58/1–14.Google Scholar
7. McCarthy, G.J. and Solem-Tishmack, J.K., in Advances in Cement and Concrete, ed. by Grutzeck, M.W. and Sarkar, S.L. (Am. Soc. Civil Engineers, New York, NY, 1994) pp. 103122.Google Scholar
8. McCarthy, G.J., Solem, J.K., Manz, O.E. and Hassett, D.J., in Fly Ash and Coal Conversion ByProducts: Characterization, Utilization and Disposal VI, (Mater. Res. Soc. Proc. 178, Pittsburgh, PA, 1988) pp. 333.Google Scholar
9. McCarthy, G.J., Johansen, D.M., Steinwand, S.J. and Thedchanamoorthy, A., in Adv. X-Ray Anal., Vol. 31 (Plenum Publ. Corp., New York, 1988) pp. 331-343; G.J. McCarthy and D.M. Johansen, Powd. Diff. 3, 156-161 (1988); A. Thedchanamoorthy and G.J. McCarthy, in Adv. X-Ray Anal., Vol. 32 (Plenum Publ. Corp., New York, 1989), pp. 565-572; G.J. McCarthy and A. Thedchanamoorthy, in Fly Ash and Coal Conversion By-Products: Characterization. Utilization and Disposal V, (Mater Res. Soc. Proc. 136, Pittsburgh, 1989) pp. 67-76; G.J. McCarthy and J.K. Solem, in Adv. X-Ray Anal., Vol. L4 (Plenum Publ. Corp., New York, 1992) pp. 387-394.Google Scholar
10. Mattigod, S.V. and Rai, D., in Advanced Cementitious Systems, (Mater. Res. Soc. Symp. Proc. 245, Pittsburgh, PA, 1992), pp. 6570.Google Scholar
11. Berry, E.E. and Anthony, E.J. (1987), in Fly Ash and Coal Conversion By-Products: Characterization, and Disposal III, (Mater. Res. Soc. Proc. 86, Pittsburgh, PA, 1987), pp. 159170.Google Scholar
12. Berry, E.E., Hemmings, R.T., Cornelius, B.J. and Anthony, E.J., in Fly Ash and Coal Conversion By-Products: Characterization, and Disposal III, (Mater. Res. Soc. Proc. 136, Pittsburgh, PA, 1989), pp. 922.Google Scholar
13. Berry, E.E., Hemmings, R.T. and Cornelius, B.J. (1991). Commercialization Potential of AFBC Concrete: Part 2. Mechanistic Basis for Cementing Action, Report GS-7122, Electric Power Research Institute, Palo Alto, CA, Vol. 2 (1991).Google Scholar
14. Bickley, J.A., Hemmings, R.T., Hooton, R.D. and Balinski, J., in V. Mohan Malhotra Symposium: Concrete Technology Past. Present. and Future, ACI SP-144, Mehta, P.K., Ed. (Am. Concrete Institute, Detroit, 1994), pp. 159175.Google Scholar
15. Coal and Synfuels Technology, Vol. 15, No. 42, October 31, 1994, p. 1.Google Scholar