International
Tables for
Crystallography
Volume H
Powder diffraction
Edited by C. J. Gilmore, J. A. Kaduk and H. Schenk

International Tables for Crystallography (2018). Vol. H, ch. 3.9, p. 370

Section 3.9.11. Summary

I. C. Madsen,a* N. V. Y. Scarlett,a R. Kleebergb and K. Knorrc

aCSIRO Mineral Resources, Private Bag 10, Clayton South 3169, Victoria, Australia,bTU Bergakademie Freiberg, Institut für Mineralogie, Brennhausgasse 14, Freiberg, D-09596, Germany, and cBruker AXS GmbH, Oestliche Rheinbrückenstr. 49, 76187 Karlsruhe, Germany
Correspondence e-mail:  ian.madsen@csiro.au

3.9.11. Summary

| top | pdf |

The value in using diffraction-based methods for the determination of phase abundance arises from the fact that the observed data are derived directly from the crystal structure of each phase. Knowledge of phase abundance is valuable in many fields including (i) mineral exploration, where the type and amount of major minerals serve as indicators for valuable minor minerals, (ii) mineral extraction, where the performance of the process line is governed by the mineralogy, not the commonly used elemental compositions, (iii) in situ studies, where the mechanism and kinetics of phase evolution resulting from the application of an external variable can be examined and (iv) the optimization of production conditions for advanced materials.

The methodology of QPA is fraught with difficulties, many of which are experimental or derive from sample-related issues. Hence, it is necessary to verify diffraction-based phase abundances against independent methods. This should include calculation of the expected sample element composition (using the QPA and an assumed or measured composition of each phase) and comparing these values with the measured element composition. In those circumstances where this is not possible, the QPA values should be regarded only as semi-quantitative. While such values may be useful for deriving trends within a particular system, they cannot be regarded as an absolute measure.

References

Hill, R. J. & Howard, C. J. (1987). Quantitative phase analysis from neutron powder diffraction data using the Rietveld method. J. Appl. Cryst. 20, 467–474.Google Scholar
Knorr, K. & Bornefeld, M. (2013). Proceedings of Process Mineralogy '12, 7–9 November 2012. Cape Town, South Africa, pp. 651–652. http://www.proceedings.com/16755.html.Google Scholar
Knudsen, T. (1981). Quantitative X-ray diffraction analysis with qualitative control of calibration samples. X-ray Spectrom. 10, 54–56.Google Scholar
Madsen, I. C., Scarlett, N. V. Y., Cranswick, L. M. D. & Lwin, T. (2001). Outcomes of the International Union of Crystallography Commission on Powder Diffraction Round Robin on Quantitative Phase Analysis: samples 1a to 1h. J. Appl. Cryst. 34, 409–426.Google Scholar
O'Connor, B. H. & Raven, M. D. (1988). Application of the Rietveld refinement procedure in assaying powdered mixtures. Powder Diffr. 3, 2–6.Google Scholar
Scarlett, N. V. Y., Madsen, I. C., Cranswick, L. M. D., Lwin, T., Groleau, E., Stephenson, G., Aylmore, M. & Agron-Olshina, N. (2002). Outcomes of the International Union of Crystallography Commission on Powder Diffraction Round Robin on Quantitative Phase Analysis: samples 2, 3, 4, synthetic bauxite, natural granodiorite and pharmaceuticals. J. Appl. Cryst. 35, 383–400.Google Scholar
Webster, N. A. S., Madsen, I. C., Loan, M. J., Knott, R. B., Naim, F., Wallwork, K. S. & Kimpton, J. A. (2010). An investigation of goethite-seeded Al(OH)3 precipitation using in situ X-ray diffraction and Rietveld-based quantitative phase analysis. J. Appl. Cryst. 43, 466–472.Google Scholar
Webster, N. A. S., Pownceby, M. I. & Madsen, I. C. (2013). In situ X-ray diffraction investigation of the formation mechanisms of silico-ferrite of calcium and aluminium-I-type (SFCA-I-type) complex calcium ferrites. ISIJ Int. 53, 1334–1340.Google Scholar
Zevin, L. S. & Kimmel, G. (1995). Quantitative X-ray Diffractometry. Springer-Verlag New York, Inc.Google Scholar








































to end of page
to top of page