F.Sereshki - School of Civil, Mining and Environmental Engineering, University of Wollongong, NSW, ۲۵۰۰, Australia
N.I. Aziz
I. Porter

An outburst in a coalmine may be defined as the violent projection of coal and gas away fbm the freshly exposed coal in mining operations. A number of factors influence influence outbursts, some of which are easily controllable while others, have proven to be more difficult to control. Significant progress has been made in understanding the influence of coal permeability on gas drainage for preventing outburst. The gas permeability of a coalbed, is influenced by gas desorption because of the changes in the volumetric strain of the coal matrix. The volumetric changes of the coal matrix has been examined in various gas environment including methane, carbon dioxide, nitrogen and 50% / 50% mixture of methandcarbon dioxide. Two types pf coal samples were studied, and these included samples from North Goonyella mine , Queenstand, Australia and Tabas codmine in Iran. The samples were saturated with different gases at pressure up to 5 MPa and the volumetric strains were measured during sorption process and the shrinkage coefficients were determined. The shrinkage coefficients were found to be influenced by the type of gas in coal and the applied gas pressure.

as, methane, outburst, shrinkage coefficient, Tabas coal basin and North Gooneyella coalmine