Abstract:

Currently, in Quang Ninh coal Basin, coal production mines from steep thick coal seams account for about 10÷12% of the total underground mining coal output; among them, coal production mines by the sublevel top coal caving system account for significant proportion. However, until now, there are no study on the effectiveness of sublevel top coal caving in Quang Ninh coal Basin. Geological and technical factors significantly impact on the effectiveness and safety for underground coal mining. In this study, the author used the physical model of experiments to define the main factors affecting the effectiveness of the sublevel top coal caving for underground mining of steep thick coal seams in Quang Ninh coal Basin such as slope of coal seam, top coal caving span, sublevel height, structure of hydraulic supports, top coal caving process. The research results have clarified the movement process of coal, rocks on the roof and pointed out the cause of the loss of coal in the sublevel top coal caving. On that basis, the paper proposed suitable technical solutions, mechanization equipment, structure of hydraulic supports and top coal caving process for sublevel top coal caving system in the underground mines with steep thick coal seams in Quang Ninh Coal Basin