Study On Technology Optimization Of Fully Mechanized Caving Mining In Steeply Inclined Seam Of Wudong Mine

The main restricting factors for safe and efficient mining of steep seam in Wudong mine are horizontal segment height,coal caving parameter and mining pressure appearing in stope surrounding rock.Based on the Geological Survey,theoretical analysis,numerical calculation and field monitoring of Wudong mine,the optimization of top coal caving technology in steeply inclined seam is carried out.1 The stage height of horizontal sublevel fully mechanized caving face in inclined 45°steep seam is analyzed.Based on the index of top coal recovery rate,the change of top coal yield and the release rate of thickened top coal,the stage height of the horizontal sublevel fully mechanized caving face in inclined 45° steep seam is determined to be 25m.2 The main coal caving parameters are optimized.Taking the recovery of top coal as the index to optimize the use of multiple-wheel interval control method to discharge coal,the recovery effect of top coal after increasing stage height is ensured,and the coal caving step of two mining(coal caving step 1.2m)is determined by the relative recovery rate of top coal and the ratio of gangue of recycled particle.3 After comparing the height of the horizontal segment,the distribution characteristics of mine pressure and the transport characteristics of top coal,the existence of the upper section arch structure is unfavorable to the crushing of top coal,the stress of the roof side surrounding rock is not conducive to the stability of roof roadway,and the pressure on the face is not changed dramatically with the increase of stage height.4 The field monitoring and analysis shows that the influence of the forward support pressure in the coal wall is mainly in the vicinity of the roof side roadway,and the impact on the bottom side roadway is less than that of the inclined 45° steeply inclined seam after the increase of the stage height.It is necessary to strengthen the advanced support level of roof side roadway to ensure safety production in mine.This study can be used for reference in safe and efficient mining of inclined 45° steep and special thick seam.