Аңдатпа
Abstract The chemical composition and the temperature dependences of the electrical characteristics (electric capacity, electrical resistance, and dielectric constant) of the ash of Bogatyr coal in its original form and after electromagnetic and electric discharge treatments in a range of 293–483 K were studied, and the procedures of these coal ash treatments were specified. Temperature ranges in which the materials exhibited semiconductor properties and metallic conductivity were determined. The band gaps (ΔE) were calculated for the test samples. The results of measurements showed that the ash after electric discharge treatment has the highest values of electric capacity and permittivity and the lowest electrical resistance, as compared with those of the initial ash and ash after electromagnetic treatment. Coal ash after electric discharge treatment seems a promising prepared raw material for its further thermochemical processing with the extraction of valuable components such as rare metals, silica, and alumina.