Please use this identifier to cite or link to this item:
Title: Thermal behaviour of kaolinitic raw materials from San José (Oruro, Bolivia)
Author: Alfonso Abella, María Pura
Penedo, L.A.
Garcia Vallès, Maite
Martínez Manent, Salvador
Martinez, A.
Trujillo, J.E.
Keywords: Mineralogia
Issue Date: 1-Feb-2022
Publisher: Springer
Abstract: Kaolin is widespread as a result of the alteration in the San José Sn-Ag deposit located in Oruro, Bolivia. This study presents a chemical, mineralogical and thermal characterization of the San José kaolinitic deposit, which is necessary to determine their optimal applications. Mineral phases of these white silty kaolinitic materials were determined by X-ray diffraction (XRD) and are quartz, kaolinite, K-feldspar, muscovite, illite and minor halloysite, dickite, plagioclase, jarosite, rutile, alunite and gypsum. The fraction < 63 µm contains 20-27 mass% of kaolinite. Differential thermal analysis (DTA) shows an endothermic peak at 520 °C associated with the dehydroxylation of kaolinite and an exothermic peak at ~ 980 °C related to the crystallization of mullite. TG curves show a total mass loss up to 1300 °C of about 8 mass%. The dilatometric curves show a shrinkage at about 890 °C produced by the collapse of metakaolinite into a spinel-like structure, and another shrinkage starts at 1010 °C, at the beginning of the sintering, when the spinel-like phase is transformed to mullite and amorphous SiO2. Lightness L* is 80-92, but only the mined materials have b* < 4, suitable for paper filling applications.
Note: Reproducció del document publicat a:
It is part of: Journal of Thermal Analysis and Calorimetry, 2022, vol. 147, num. 9, p. 5413-5421
Related resource:
ISSN: 1388-6150
Appears in Collections:Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)

Files in This Item:
File Description SizeFormat 
728102.pdf1.13 MBAdobe PDFView/Open

This item is licensed under a Creative Commons License Creative Commons