综放工作面顶煤运移及煤矸界面演化规律研究

Research on the law of top coal movement and coal-gangue interface evolution in fully mechanized caving face

回采率低是放顶煤开采中存在的主要问题。通过PFC数值模拟软件对内蒙古查哈苏煤矿工作面顶煤颗粒运移规律进行模拟,获得了煤矸流场的运移及煤矸界面的演化规律。研究结果表明当采用低位放顶煤支架时,初采时顶煤易成拱,随着累计放煤步距的增加,顶煤冒落或滑移形成的放煤漏斗长轴逐渐向采空区偏转,且煤矸界面逐渐模糊并趋于平缓。其中,煤矸界面的趋缓是造成低位放顶煤采空区遗煤的主要原因。

The low recovery ratio of coal is an important problem in top coal caving. The re-search simulates the migration law of top coal particles by PFC in mining face of Chahasu CoalMine in Inner Mongolia, and the movement of coal-gangue flow field and the evolution law ofcoal-gangue interface are studied by the simulation. The research shows that the top coal is easyto arch during primary mining when using low integrated caving hydraulic supports. With the in-crease of coal drawing interval, the long axis of the funnel which is caused by top coal caving orsliding gradually deflects toward goaf, and the coal-gangue interface becomes blurry and begins toflatten. The flattening of coal-gangue interface is the main reason of residual coal in low integrat-ed caving goaf.