面向残煤复采的煤泥基注浆充填材料机械活化机理研究

Research on the mechanical activation mechanism of coal slime based19 grouting filling materials for residual coal remining

为便于复采后煤炭资源的回收利用,设计充填材料时,需充分考虑充填材料的可洗选性和来源广泛性,减少洗选工序和运输成本。因此,本研究提出以机械力活化煤泥代替部分水泥作为胶结材料,煤粒作为骨料的注浆材料的研究思路,煤泥和煤粒材料来源广泛,且可以减少采用水泥胶结充填材料混入原煤后增加的洗选成本。基于此,开展活化煤泥注浆材料坍落扩展度、泌水率和抗压强度的研究,分析机械力活化参数对注浆材料性能影响规律,结果表明:采用活化煤泥作为注浆材料时,可使原煤泥料浆浓度由74%降低至65%,活化煤泥替换原煤泥质量对注浆材料的坍落扩展度和抗压强度的影响远远大于活化煤泥时间。活化煤泥料浆浓度65%,活化时间2h,替代原煤泥80%时,注浆材料黏度最大增加约30倍,注浆材料的抗压强度由0.92MPa提高到1.915MPa。活化煤泥改性注浆材料力学特性和流动特性的原因为机械能输入增加煤泥内能,破坏煤泥中高岭土层间结构并生成胶凝材料,激发了煤泥潜在胶结性能,增强注浆材料力学性能。

To facilitate the recovery of coal resources after re-mining,the design of the filling material needs to fully consider the washability and wide range sources of the filling material to reduce the washing process and transportation costs. Therefore,this study proposes the research idea of using mechanically activated coal slime instead of partial cement as the cementitious material and coal particles as the aggregate for the grouting material,where coal slime and coal particle materials come from a wide range of sources,solving the problem of increasing washing cost due to cementitious filling material mixed into raw coal. Based on this,research is conducted on collapse extension,bleeding rate,and compressive strength of activated coal slime grouting materials,and the influence of mechanical force activation parameters on the performance of grouting materials is analyzed. The results show that activated coal slime works as grouting material,the concentration of raw coal slurry can be reduced from74% to65%. Besides,the mass ratio of activated coal slime has a much greater effect than that of activated time in terms of the property of collapse extension and compressive strength. When concentration of activated slime grouting slurry of65% and replaced mass ratio of80% by activated slime(time of2h)are used,the maximum increase in viscosity of the slurry material reaches about30times,and the compressive strength of the grouting material increased from0. 92MPa to1. 915MPa. The mechanical property and flow characteristics of activated grouting material change,which is caused by that mechanical energy input increases the internal energy of slime. The energy destroys the interlayer structure of kaolinite and generates hydrous calcium zeolite,which stimulates the potential cementing properties of coal slurry and enhances the mechanical properties of the grouting material.