Characterization of Kazakhstan’s Clays by Mössbauer Spectroscopy and X-ray Diffraction

Abstract

Studies of the mineralogical composition were carried out, and the features of the clays from the deposits of Kazakhstan were established using Mössbauer spectroscopy (MS) and X-ray diffraction analysis (XRD). According to the XRD results, all the samples were mixed-layer clays of the kaolinite–illite type. The lattice parameters of the kaolinite were determined, and it was shown that its structure was disordered and contained a certain amount of impurity in some of the clay samples. A special feature of two of the samples was the additionally identified muscovite polytype 2M1. The spectra of the iron-containing clays were amenable to being resolved into separate components, with similar Mössbauer parameters of the kaolinite, muscovite, illite, and glauconite. The oxidation state of the iron was determined using MS. The predominant part of paramagnetic iron in most samples was in the trivalent state. The primary minerals contributing to Fe2+ were illite and muscovite. The results obtained during the study of the clay samples with complex mineralogical compositions using MS and XRD methods both complemented one another and were found to be in good agreement.