Paramagnetic properties of brown coal from the Kiyaktinskoe deposit before and after mechanical treatment and electron irradiation

Results of a study of the paramagnetic characteristics of brown coal from the Kiyaktinskoe deposit (Kazakhstan) in a native state and after mechanical treatment and electron irradiation are reported. The effects of these actions on changes in the paramagnetic properties of the test coal and on the intensification of a coal hydrogenation process are discussed. It was found that the concentration of free radicals changed only slightly after mechanical treatment in a ball mill at room temperature in an atmosphere of air, whereas the concentration of Fe3+ ions noticeably increased. Upon the electron irradiation of coal, the dose dependence of the concentration of free radicals passed through a maximum at a dose of 100 kGy. At the same radiation dose, the yield of a kerosene-gas oil fraction upon the hydrogenation of Kiyaktinskoe coal increased, and the total yield of liquid products increased upon the irradiation of coal and a catalyst (bauxite 094) to a dose of 100 kGy. It was hypothesized that Fe3+ ions, which were additionally formed upon coal grinding and irradiation, can serve as an internal catalyst in the course of coal hydrogenation.