A Particle Size Study of Natural Mineral Compounds in Lignite

The particle sizes of main mineral compounds in the structure of lignite were determined using physical methods (SAXS, TEM, and XRD analysis) and chemical processes of selective dissolution. It has been shown that calcium and magnesium compounds in the structure of lignite were present in the form of small nanoparticles with sizes of about 10 nm. Particles consisting of aluminum and iron compounds had larger sizes of about 20–35 nm. Silica-containing particles in the structure of lignite had sizes of 100 nm or greater.