EPR INVESTIGATION OF OXIDIZED ANTHRACITE

The influence of thermooxidative treatment at various temperatures on the paramagnetic properties of oxidized anthracite and the relation be tween the change of anthracite paramagnetism and formation of stable o xygen groups is investigated. It is established that the number of par amagnetic centers determined in initial and oxidized anthracite at 100 and 200-degrees-C is nearly equal. The quantity of paramagnetic cente rs for anthracite oxidized at 400-degrees-C is three times lower. The decrease of PMC concentration up to 400-degrees-C depends on the incre ase of the temperature, as well as on the oxidized process. The data o btained in vacuum show the same dependence decrease of PMC with enhanc ement of oxidation temperature as those obtained in air atmosphere. An increase of the g-factor with the increase of the oxygen adsorption h as been found. A relation between the linewidth of the spectrum of ant hracite and the extent of oxidation of anthracite has been established .