Powder X-Ray Diffractometry (P-XRD)
The Helmholtz Institute Freiberg for Resource Technology uses the Powder X-Ray Diffractometry (P-XRD) complimentary to the Mineral Liberation Analysis (MLA) for the mineralogical phase analysis of rocks and synthetic mixtures that result from processing or recycling. Such analyses are needed not only for the exploration of new deposits, but also for the characterization of technological processes. Qualitative as well as quantitative data analyses are possible, depending on sample amount and preparation.
How does it work?
A primary, monochromatic X-ray hits a flat surface of a sample made of crystalline powder. The X-ray is scattered by the atoms in the crystals. Since the atoms are arranged in a very regular manner the scattered X-rays will be extinguished or enhanced in a similar regular manner. The resulting angle dependent diffractogram follows Bragg’s law and is characteristic for every different phase.
The Rietveld method is used for the quantification of phases in mixtures. This method compares theoretical single-phase diffractograms with the current measured data. Additionally it is possible to take several effects like microabsorption, preferred orientation into account. The result is the proportion of the phases in the analyzed mixture.