Document Type

Conference Paper

Publication Date


Publication Details

X. Choi, Application of a numerical model for outburst prediction, control and management, 12th Coal Operators' Conference & The Australasian Institute of Mining and Metallurgy, 2012, 286-293.


The basic underlying mechanism for outburst initiation involves the expulsion of coal at a pressure gradient above a critical value which is directly related to the strength and porosity of the coal at the current state, and the composition (degree of gas saturation) of the pore fluid. Coal strength, porosity, stress, gas pressure and pressure gradient are important for outburst initiation. Permeability and rate of desorption can be important for outburst evolution by controlling the amount of gas that would become available to drive an outburst. The severity of an outburst depends on gas pressure, the hydrodynamic force, the strength and toughness of the coal, and the amount of free gas that becomes available during an outburst. For the same pressure gradient, the degree of violence is greater for weaker and more friable coal. Outburst propensity can be reduced by changing the method of mining, mine geometry, and the preventive and control measures adopted by the mines. The relative importance of the various factors and parameters will depend on the conditions of individual mines. As the interaction among the various processes and factors leading to outburst can be very complex, it is necessary to treat the coal-rock-stress-structure-gas interaction as a system. For outburst prediction, one approach is to use a numerical model that can model the individual processes and their interactions. This paper lists some of conclusions that have been derived from the results of the laboratory experiments and the modelling studies conducted to date and describes how the model can be used to help a particular mine assess outburst proneness and the potential risks, and to identify the critical factors for the purpose of outburst control and management. Based on the assessed risk and the degree of uncertainty, one may choose complete prevention or suitable control and management measures, without undermining safety which is one of the most important considerations.