Determination of amorphous matter in industrial minerals with X-ray diffraction using Rietveld refinement.

PDF FIG.1 FIG.2
Published: Feb 17, 2020
DOI: https://doi.org/10.12681/bgsg.20940
Keywords:
Amorphous matter X-ray diffraction particle size internal standard Rietveld refinement
George Christidis
Technical University of Crete,
https://orcid.org/0000-0002-2302-0296
Katerina Paipoutlidi
Technical University of Crete
https://orcid.org/0000-0001-7488-2091
Ioannis Marantos
Institute of Geology and Mineral Exploration (IGME)
Vasileios Perdikatsis
Technical University of Crete
Abstract

A great variety of fine grained industrial rocks, which are valued by the industry contain variable amounts of amorphous or poorly crystalline matter, which is not easily detectable by the conventional mineralogical analysis methods based on X-ray diffraction (XRD). The quantification of amorphous matter in industrial rocks is a major task because it provides a thorough characterization of the raw materials and assists to interpret their reactivity. Among the most reliable methods used for quantification of amorphous matter, are those which are based on Rietveld refinement. In this study we prepared 1:1 mixtures of synthetic or natural calcite and quartz with 5-80% glass flour and added corundum (α-Al2O3) internal standard and applied the Autoquan2.80 © software based on the BGMN computer code to quantify the amorphous matter content. The mixtures with synthetic minerals yielded results with minimum absolute error due to the similar particle size of the minerals, the internal standard and the glass. By contrast, the mixtures with natural minerals displayed greater relative error due to the particle size difference between the minerals on the one hand and the internal standard and the glass on the other, due to the microabsorption effect. Moreover, preferred orientation was important in the case of natural calcite, due to perfect  cleavage plane. Mixtures containing up to 25% amorphous matter did not display the characteristic hump at 20-30 °2θ, suggesting that the lack of the hump is not a safe criterion for the recognition of amorphous matter.

Article Details
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  • Petrology and Mineralogy
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Author Biography
George Christidis, Technical University of Crete,

Technical University of Crete,

School of Mineral Resources Engineering 

73100 Chania

Greece

References
Barker, J.M., Santini, K., 2007. Perlite. In: Elzea Kogel, J.E., Trived, N.C., Barker, J.M., Trukowski S.T (Eds) Industrial Minerals and Rocks, Commodities, Markers and Uses 7th Ed), SME, Littleton CO, 685-702pp.
Bell, F. G., 1996. Lime stabilisation of clay minerals and soils. Engineering geology, 42, 223-237.
Benito, R., Garcia-Guinea, J., Valle-Fuentes, F.J., Recio, P., 1998. Mineralogy, geochemistry and uses of the mordenite–bentonite ash-tuff beds of Los Escullos, Almería, Spain. Journal of Geochemical Exploration, 62, 229-240.
Bish, D.L. & Plötze, M., 2011. X-ray powder diffraction with emphasis on qualitative and quantitative analysis in industrial mineralogy. in: G.E. Christidis (Ed) Advances in the characterization of Industrial Minerals. EMU Notes in Mineralogy vol 9, Mineralogical Society of Great Britain and Ireland, London, 35-76 pp.
Blanco Valera, M., Martínez Ramírez, S., Ereña, I., Gener, M., & Carmona, P., 2006. Characterization and pozzolanicity of zeolitic rocks from two Cuban deposits. Applied Clay Science, 33, 149–159.
Breese R.O.Y., Bodycomb, F.M., 2007. Diatomite. In: Elzea Kogel, J.E., Trived, N.C., Barker, J.M., Trukowski S.T (Eds) Industrial Minerals and Rocks, Commodities, Markers and Uses 7th Ed), SME, Littleton CO, 333-450 pp.
Christidis, G.E., 2001. Formation and growth of smectites in bentonites: a case study from Kimolos Island, Aegean, Greece. Clays and Clay Minerals, 49, 204-215
De La Torre, A.G., Bruque, S. & Aranda, M.A.G., 2001. Rietveld quantitative amorphous content analysis. Journal of Applied Crystallography, 34, 196-202.
Guidobaldi, Cambi, C., Cecconi, M., Deneele, D., Paris, M., Russo, G., Vitale, E., 2018. Multi-scale analysis of the mechanical improvement induced by lime addition on a pyroclastic soil. Engineering Geology, 221, 193-201.
Hill, R.J., 1991. Expanded use of the Rietveld method in studies of phase abundance in multiphase mixtures. Powder Diffraction, 6, 74-77
Massazza, F., 1993. Pozzolanic cements. Cement and Concrete Composites, 15, 185-214.
Mertens, G., Snellings, R., Van Balen, K., Bicer-Simsir, B., Verlooy, P., & Elsen, J., 2009. Pozzolanic reactions of common natural zeolites with lime and parameters affecting their reactivity. Cement and Concrete Research, 39, 233–240.
Post, J.E. & Bish, D.L., 1989. Rietveld refinement of crystal structures using powder X-ray diffraction data. in: Bish, D.L., Post, J.E (eds): Modern Powder Diffraction. Reviews in Mineralogy, 20, 277-308.
Rietveld, H.M., 1969. A profile refinement method for nuclear and magnetic structures. Journal of Applied Crystallography, 2, 65-71.
Snellings R., Machiels L., Mertens G. & Elsen J., 2010. Rietveld refinement strategy for quantitative phase analysis of partially amorphous zeolitised tuffaceous rocks. Geologica Belgica, 13, 183-196.
Suherman, P.M., Van Riessen, A., O’Connor, B., Li, D., Bolton, D. & Fairhurst, H., 2002. Determination of amorphous levels in Portland cement clinker. Powder Diffraction, 17, 178-185.