Pattern Fitting for Quantitative X-Ray Powder Diffraction Analysis of Portland Cement and Clinker.
Pattern Fitting for Quantitative X-Ray Powder
Diffraction Analysis of Portland Cement and Clinker.
Stutzman, P. E.
International Conference on Cement Microscopy, 18th.
International Microscopy Association. Proceedings.
April 21-25, 1996, Houston, TX, Intl. Cement Microscopy
Assoc., Duncanville, TX, Jany, L.; Nisperos, A.; Bayles,
J., Editor(s)(s), 18-28 pp, 1996.
portland cement; clinker; phase composition;
quantitative analysis; qualitative analysis;
whole-pattern fitting; x ray powder diffraction
X-ray powder diffraction is a direct method for
qualitative and quantitative phase abundance analysis of
fine-grained, crystalline materials. While the
application of powder diffraction for qualitative
analysis in the cement industry is well established, its
use in the determination of phase abundance is not as
common. Difficulty in measurement of peak intensity and
availability of suitable reference standards have
limited the application of x-ray diffraction in
quantitative analysis. Whole-pattern fitting offers a
means to address these problems by using all diffraction
peaks to estimate individual phase pattern intensities.
Dataplot, a graphics and data analysis language,
facilitates pattern-fitting and quantitative phase
abundance analyses by applying multivariate linear
least-squares regression based upon experimentally
derived x-ray diffraction reference patterns. Phase
abundance calculation by the internal standard method
uses the pattern scale factors calculated in the fit as
intensity values. Precision of replicate analyses by
pattern fitting show a distinct improvement over
measurement by peak profile fitting. Trials using known
mixtures of clinker interstitial phases indicate a very
good agreement with the known phase abundance values,
and absolute errors, based on the whole cement, of less
than 1 percent.