Characterization of clay mineral from Kolubara mining basin, Serbia, with a determined layered structure

Abstract

The clay minerals deposit from the mining basin Kolubara, Serbia, is a natural sediment material with high economic potential in many fields. The chemical composition of starting clay determined by inductively coupled plasma spectrometry shows that its main composition of SiO2 is 88.00 wt.%. Organic impurities from clay have been removed by heat treatment at 600 °C for 2 h in air. After thermal treatment, an aqueous solution of HCl sedimentary mineral was chemically treated. Surface properties of starting clay and thermally and chemically treated clay (treated clay) were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size distribution method. The XRD analyses of the starting and treated clay confirmed that quartz is a significant phase, followed by the appearance of feldspar and smectite clays. The SEM method showed impressively layered microstructure on various magnifications for both groups of investigated materials. The average particle diameter value for starting clay was about 23 μm and about 53 μm for treated clay. These methods showed that the starting clay changed the surface properties during thermal and chemical treatment, resulting in the merging of clay layers.