The object of the program was to investigate the rates at which a variety of coals change their properties when subjected to drying and mild gas-phase oxidation, and to correlate the effective uses of such treatment on the agglomerative properties of the coals. Seven coals from different sources were oxidized at various temperatures and pressures, in fixed-bed reactors under a range of flow rates and for various particle sizes. The coals pretreated in this manner were evaluated by a thermo-mechanical expansion test for correlation to the oxidative changes. Interpretative models were developed that can be used to explain, predict, and interpret kinetic results for a wide range of coals. The rates at which a variety of coals undergo mild gas phase oxidation were measured in a fixed-bed reactor for various reaction temperatures (150 to 300/sup 0/C), coal particle sizes (-6 5 US mesh), and oxygen concentrations (16 to 35 mol percent). Total oxygen consumption, CO/sub 2/, CO, and H/sub 2/O production, and oxygen deposition rates were determined from gas chromatographic analysis of reactor effluent gases. The experiments identify conditions under which oxidation rate is determined by the rate of gaseous diffusion within the coal particle, or the intrinsic rate of chemical reaction. Model equations were developed for both regimes. The rate at which gasses are evolved during coal drying under an inert atmosphere were also measured in a fixed bed reactor. The effects of drying severity on subsequent oxidation rates were also measured.