Аннотация
The article presents the results of oxygen addition effect at the low-rank coal drying in the coal heat treatment technology. Drying, as one of the stages of the technology, is carried out by diffusion method, using an oxygen addition in a quantity of 2%. The results of the study show the possibility of intensifying moisture removal by the proposed method at the expense of intensifying oxidation processes in diffusion conditions of porous body. Coal has effective and closed porosity. The increased concentration of oxygen in air creates conditions for intensifying oxidation reactions in the effective porosity. In the matrix of the porous body of coal, heat is emitted and temperatures rise. Quantity of the heat produced by the low-temperature reaction of oxygen in coal elements (1.24‧1025 W) allows to increase the temperature of the total mass of coal approximately to the 60°C. Due to the increase in temperature, the dynamic pressure in the flow through the open porosity increases ( 6.18‧10-3Pа). As a sequence, the static pressure is reduced to negative value (down to negative 100 Pa) in closed pores. The reduction of external pressure alters the gas equilibrium, which leads to the effect of destruction of capillary condensate and promotes moisture release. The final mass fraction of H2O as a result of diffusion method of drying when the oxygen content of the air is raised during the drying process for 1 hour in a range from 2.9 to 5.8 %.