固体充填开采中的矸石粒径级配优化试验

Experimental on optimization of gangue particle size gradation in solid filling mining

针对原生矸石级配较差、在固体充填过程中压缩量大、充实率低等问题,采用理论计算、实验室试验和数值模拟等研究方法,对固体充填开采中矸石粒径级配优化进行了研究。通过分析应变随级配系数的变化规律,得到4种变形最小的级配组合。进一步分析压实破碎前后粒径变化规律和变形模量与应力之间的关系,得出级配组合为D=30 mm,n=0.3时,压实破碎程度最高,变形模量最大。分析数值模拟的固体充填效果得出:以优化级配后的矸石做充填体可以提供更好的围岩应力场和位移场;当D=30 mm,n=0.3时,基本顶下沉量最小,其值比原始级配下降25.3%,煤壁应力峰值最小,充填体支撑效果最好。河沙对细矸有替代性,可有效降低矸石破碎成本。

For the problems of poor grade of primary gangue,large compression and low filling rate in solid filling process,the optimization of gangue grain size grade in solid filling mining is studied by using theoretical calculations,laboratory tests and numerical simulations.By analyzing the variation law of strain with gradation coefficient,four gradation combinations with the smallest deformation are obtained.Further analysis of the particle size change before and after compaction and the relationship between deformation modulus and stress suggests that when the gradation combination is D=30 mm and n=0.3,the degree of compaction and crushing is the highest,and the deformation modulus is the largest.The numerical simulation of the solid filling effect revealed that the optimized graded gangue as the filling body can provide a better stress field and displacement field of the surrounding rock.When D=30 mm and n=0.3,the basic roof subsidence is the smallest,which is 25.3%lower than the original gradation,the peak stress of the coal wall is the smallest,and the filling body support effect is the best.River sand has substitution for fine gangue,which can effectively reduce the cost of gangue crushing.