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Abstract In fact，coal and gas outburst is mechanical destabilization and damage to gassy coal induced by mining under tridimensional stresses，seriously threatening safe production for coal mine. Taking the moulding coal powders of typical high-gassy coal mines，Sunjiawan coal mines in Fuxin as research object，the experiments of coal and gas outburst were made to detect rule by home-made device under tridimensional stresses including axial pressure，confining pressure and pore pressure to simulate －600 m mining. The outburst features were reproduced such as that the size of jet mouth is smaller than the radius of jet hole and the distribution of jet coal powders has sorting feature. The reliability of device was verified. According to the results，six outburst zones were divided and new understandings were presented. The mass distribution of coal powders had zone feature and existed extremal zone and mean zone. A new idea was presented to study outburst mechanism based on the jet features of gas-coal two-phase reflected in experiments. The maximum zone of mass of coal powders was located in medium long zone which was the energy dissipation zone of jet outburst of gas-solid two-phase gassy coal. The remarkable wave character was observed by the distribution of coal powders on different particle sizes. The coal powders of smaller size were main part in maximum zone of mass. The coal powders of rather large size were main part in minimum zone of mass. The coal powders of smaller size were main part in the ending of outbursting zone. It was presented that high-pressure gas is not only outbursting power but also damage power for powdered coal. The energy releasing has wave character in the process of coal and gas outburst. The conclusions can offer references to mechanism understanding of coal and gas outburst.
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Received: 18 December 2012
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2013, Vol. 32 
