Methods for the complex thermoanalysis of these solid fuels are discussed. The following processes were studied: moisture evaporation, emission of volatile products (separate evaluations of pitch and gas emission), reaction of non-volatile fuel residue with the oxygen in air. The data bank on the reactivity of Beresovsky deposit brown coal oxidatively aged to different extents was gathered. The results of the work can be used in mathematical simulation of processes for the coal processing using the power technology.