Neutron and X-ray Rietveld quantitative phase analysis of industrial Portland cement clinkers

O. Pritula¹, Ľ. Smrčok¹, D. M. Többens², V. Langer³

¹Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 36 Bratislava, Slovak Republic

²BENSC, Hahn-Meitner Institute, Glienickerstrasse 100, D-14109 Berlin, Germany

³Department of Environmental Inorganic Chemistry, Chalmers University of Technology, S-412 96 Gothenburg, Sweden

Weight fractions of four dominant phases (C₃S, C₂S, C₄AF and C₃A) present in five industrial clinkers were estimated by a series of neutron and X-ray Rietveld refinements. Calculated powder patterns were derived from the structural data for triclinic and monoclinic C₃S, monoclinic C₂S, orthorhombic

C₄AF and cubic C₃A. Neutron diffraction data were collected with the high resolution E9 diffractometer (BENSC) using the wavelengths of 1.797Å and 2.816Å, X-ray diffraction data with a high resolution transmission diffractometer using CoKα₁ radiation. Elemental composition of the samples obtained by ESEM/EDX technique were in a good agreement with the data delivered by the producers. Convergence of the refinements was remarkably different for X-ray and for neutron data. Several refinements were not completed due to numerical instabilities. Neutron refinements were found to be more stable than X-ray, but there was not any notable difference in the final estimated phases' compositions. Calculated absolute deviates of phases' weight fractions were mostly within ±10%, which for the less abundant phases corresponded to relative deviations within ±50%.

Acknowledgement

This work was supported by the European Community under the Access to Research Infrastructures Action of the Human Potential Programme - contract number HPRI-CT-2001-00138. We also thanks the producers for kindly providing us with the samples of clinkers and their chemical analyzes ň.