Caracterización y Evaluación de un Depósito de Caolín de "Los Azufres" Michoacán, México, para su Uso Industrial

Abstract

In this work a kaolin ore from the region of Los Azufres, state of Michoacan, Mexico, was characterized and evaluated in order to assess its use in the industry. A powder fraction less than 45 μm were studied by X-ray fluorescence (XRF), x-ray diffraction (XRD) and infrared spectroscopy (IR). The results showed high silica content of ~70%, associated with minerals such as cristobalite, tridymite and quartz followed by kaolinite and a small amount of alunite. The distribution, morphology and surface area of the particles were obtained by Laser Diffraction, Scanning Electron Microscopy (SEM) and Brunauer Emmett Teller technique (BET). Thermal characterization was performed by differential thermal analysis (DTA), thermal gravimetric analysis (TGA) and dilatometric analysis. The thermal characterization results displayed a strong mineral thermal expansion from room temperature to 300 °C, followed by an abrupt contraction a temperatures between 580 °C to 920°. This could be associated with phase transformations of the polymorphs of silica, the dehydroxylation of the alunite and kaolinite and the desulfatation of alunite. The physical properties such as mineral color, degree of whiteness, plasticity, linear shrinkage and density were also determined. Finally whit the results obtained in this work, it can be concluded that the investigated ore is highly recommended for the cement industry and plastic.