Abstract
Abstract Humic acid obtained from coal mining waste from the Lenger deposit was studied. Potassium humates were extracted from the raw material using potassium hydroxide. Hydrochloric acid at various concentrations was used for acid sedimentation of humic acids. Experimental data were obtained describing the effect of the HCl concentration and the sedimentation time on the organogenic composition of humic acid and on its acidic characteristics. Organogenic elements, carboxyl groups, and acid values were determined. Fourier transform infrared spectrometry with absorption bands in the range of 4000–600 cm−1, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and X‐ray diffraction analysis were used to characterize the feedstock and the obtained products.