Abstract
Abstract. The present study focuses on the structural and physicochemical characterization of brown coal samples using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX). The XRD results revealed a predominantly amorphous structure with minor crystalline inclusions of quartz, kaolinite, and illite. The FTIR spectra demonstrated a wide variety of oxygen-containing functional groups, including hydroxyl, carbonyl, and carboxyl moieties, indicating a high degree of oxidation and the presence of humic substances. The SEM micrographs showed a highly irregular, porous morphology with microcracks and aggregated lamellae, while the EDX analysis confirmed the dominance of carbon and oxygen, accompanied by trace amounts of Na, Mg, Al, K, and Fe. The integrated analytical approach provided a comprehensive understanding of the organic–mineral matrix of the studied brown coal, emphasizing its potential as a precursor for humate-based fertilizers and sorbent materials.