Estudio químico de la presencia de montmorillonita en arcillas de la cuenca sedimentaria miocénica de Loja mediante técnicas de espectroscopía

Abstract

Seventeen clay samples from the polygon of the Miocene sedimentary basin of Loja were characterized chemically and by means of molecular spectroscopy techniques to determine if they contain any percentage of montmorillonite. The interest of establishing its existence lies in the fact that by knowing its chemical properties, applications can be potentiated. The samples were collected by geology and mining engineers (Universidad Técnica Particular de Loja, UTPL). A specific surface analysis was carried out, using the methylene blue test (MBT), after which organic matter was removed, silt (> 4 µm) and clay (= 4µm) fractions were separated and carbonates were removed (purification of the samples) in the Instrumental Analysis laboratories (Faculty of Sciences, ESPOCH) and in the departments of the University of Loja (UTPL), ESPOCH) and the Departments of Geology and Mines and Civil Engineering (UTPL). The purified samples were subjected to X-ray diffraction analysis to qualitatively and quantitatively define their phases (EVA and TOPAS software). X-ray fluorescence analyses were performed to determine their chemical and elemental composition. Using the values of specific surface area and clay fraction, the percentage of montmorillonite was estimated, which follows a similar trend to that established by X-ray diffraction, thus verifying the results.13 of the 17 samples analyzed were established to be montmorillonites, for each sample the corresponding polygon point was indicated and the percentage of clay and montmorillonite was compared, facilitating later analyses of exploitation efficiency. In conclusion, sample 1 from point 2 (P1M2) contains more clay and sample 2 from point 9 (P9M2) less. Sample 2 of point 4 (P2M4) has a higher percentage of montmorillonite and sample 1 of point 2 (P2M1) a lower one. In the case of material characterization, it is recommended to perform complementary analyses in order to verify the results.