Decomposition of gas and coal solid solutions.pdf

Journal of Mining Science, Vol. 30, No. 3, 1994 D E C O M P O S I T I O N O F G A S A N D C O A L S O L I D S O L U T I O N S A. D. Alekseev, A. T. Airuni, I. V. Zverev, V. V. Sinolitskii, and Yu. F. Vasyuchkov UDC 622.537.86 In many of the worlds coal deposits mining is carried out at considerable depths under conditions of high natural gas- bearing coal and mine pressure which increases the danger of sudden gas and coal outbursts. In the coal mines of the Donbass the measured methane pressure at depths of 900-1100 m exceeds 10-12 MPa [1]. Worsening of natural development conditions for coal seams at considerable depths and an increase in the frequency and force of sudden gas and coal outbursts (SGCO) has given rise to the requirement of developing and applying reliable methods for predicting SGCO and effective means of overcoming them. The most promising way of providing a physical basis for predicting SGCO is establishment of features of the transformation of gas-bearing coal material at higher structural levels, i.e., atomic, molecular, and submolecular structures, with the aim of revealing the interconnection of the level of the coal material structure with macroscopic properties and the gas dynamic condition of seams critical with respect to SGCO. Use of data for the higher levels of coal material structure in solving engineering problems in the coal industry is only possible by establishing the connection between the higher organization levels for coal material elements constituting the gas-bearing coal mass and the macroscopic properties of this mass. In coal seams undisturbed by technogenic effects diffusion transfer of gas predominates which hardly changes the homogeneous state of the natural coa l -gas -mois tu re system. Under natural conditions in the post-inversion period this system may be represented by a broad spectrum of states; from limiting homogeneous to maximum heterogeneous inherent in mainly tectonic and techn