振动放顶煤技术原理与实践

TECHNICAL PRINCIPLE OF TOP-COAL CAVING WITH VIBRATION AND ITS PRACTICE

综放开采顶煤放出率低始终是困扰厚煤层开采的一大技术难题,系统介绍历时5 a进行的振动放顶煤的机构设计、实验室试验、离散元数值模拟和工业试验研究的方法与结果。室内试验研究结果表明,振动最大影响范围为0.65 m,振动频率选择1.0 Hz效果较佳。离散元数值模拟结果表明:由于增加水平运动的动力,振动水平力与垂向力共同作用下,使顶煤实现分层逐层放落,从而降低混矸率,提高顶煤放出率。在潞安王庄煤矿5209工作面进行工业试验,激振机构安装在掩护梁上,激振油缸推动力为200 kN,振动频率为0.8～1.0 Hz,经6个月的现场试验与观测,由于振动机构的作用,使顶煤放出率平均提高3%。系统研究结果表明,振动放顶煤技术可以较大幅度提高块裂顶煤放出率,降低混矸率,是放顶煤开采的一项很有前景的技术。

Low recovery ratio of top-coal in the fully-mechanized coal mining is a hot technical problem.A series of investigation methods and results of mechanical design,laboratory experiments,DEM numerical simulation,and in-situ practice of the vibration top-coal caving are described.The experimental results demonstrated that the vibration effect range can reach 0.65 m far from the roof of mining space;and it is also found that vibration frequency 1.0 Hz is the optimum choice.The numerical simulation results illustrated that the top coal could be caved layer by layer,with the effect of vertical weighty and horizontal vibration forces working together.Consequently,the waste stone ratio in mined coal was decreased and the recovery ratio of top coal was increased.The results of 6 months in-situ practice in Wangzhuang mine,Lu′an Coal Industry Company,demonstrated that the recovery ratio of top coal was increased by 3% in average with the vibration mechanism.The systematical investigations have demonstrated that the vibration top-coal caving is an advantageous and profitable technique,which can greatly increase the recovery of top-coal and decrease the waste stone ratio.