Defining outburst-free zones in protective mining with seam gas content-method and application

It is one of the technical problems how to scientifically, rapidly and accurately determine the scope of outburst elimination after the protective layer extraction in multiple-seam mining. A seam with less outburst proneness is often extracted prior to its overlying or underlying seams with high outburst proneness to mitigate the risk by de-stressing and de-gassing of the seams. A number of indices are used to define outburst-free zones or protected zones in the seams. However, these indices are not quite consistent in theory and their practicality is sometimes limited. To address these issues, a trial was conducted to measure and use seam gas content in a de-stressed and de-gassed seam for defining outburst-free zones in the seam at Pansan Mine, Huainan, China. This paper describes the field trial and presents its results.