Application of the Rietveld Method to Quantify Mineral Phases in a Kaolin Mineral

Abstract

The applications of the mineral kaolin are varied, such as the ceramic industry, and the pharmaceutical industry, among others; although it is generally found in mining deposits accompanied by other mineral species considered contaminants. The above makes it necessary to apply qualitative and quantitative analysis techniques that determine the purity of the mineral, from its extraction, during its mechanical processing and kaolin recovery. In this work, a procedure for quantification of the majority species in the Kaolin mineral is proposed, according to the procedure proposed by Rietveld, from the diffractogram obtained by the x-ray diffraction technique, as well as the knowledge of the crystallographic characteristics of the mineral constituents. Three models are proposed based on the structural parameters of the phases present in the system: tridymite, cristobalite, and kaolinite. The experimental results show the total adjustment of the diffraction pattern in which it is observed that the weight percentage corresponds to 40.0% for tridymite, 39.5% for cristobalite, and 20.5% for kaolinite. These results were corroborated by specific semi-quantitative chemical analyses using scanning electron microscopy.