煤矿开采覆岩离层注浆浆液配比优化试验研究

覆岩离层注浆充填技术是一种煤矿绿色开采新技术，能有效控制离层上方的地表沉陷，对保护地表建筑物安全及生态环境稳定具有重要意义。为了探究离层注浆浆液最优配比，选取水固比、固相比、水玻璃掺量和悬浮剂掺量4个浆液性质的主要影响因素，采用正交试验和单因素试验的方法探究各因素对浆液的相对密度、黏度、析水率和结石率的影响。试验结果表明，水固比是控制浆液性质的主控因素。其他影响因素中，固相比对黏度影响较大，水玻璃掺量对析水率、结石率影响较大。单因素实验中，各电厂粉煤灰浆液随水固比减小，浆液析水率减小，结石率增加，黏度增加，即浆液中粉煤灰质量比越大，浆液稳定性和填充效果越好，但扩散半径越小。随着水固比减小，达到某一水固比值后，浆液黏度将显著增大。不同电厂粉煤灰浆液性质不相同，因此在注浆前对拟用粉煤灰进行试配是必要的。

Experimental study on optimization of overburden separation layer grouting slurry mixture ratio

In order to improve the abscission layer of overburden rock grout properties, explore the optimal ratio of abscission layer grouting slurry, this article compared to water solid ratio, solid, and the dosage of sodium silicate and suspending agent dosage four main factors influencing the performance of slurry, the method of orthogonal test and single factor test were adopted to explore the factors of the proportion of grout, viscosity, the effects of drainage rate and the rate of stone. The results show that the ratio of water to solid is the main factor controlling the properties of the slurry, the ratio of solid has a great influence on the viscosity, and the content of sodium silicate has a great influence on the rate of water evolution and the rate of stone. The wet ash of power plant cannot be mixed into a single phase, so it is not recommended to use untreated wet ash as grouting material. The properties of fly ash slurry in different power plants are different, so it is necessary to test mix the fly ash before grouting. As the water-solid ratio of fly ash in each power plant decreases, the water extraction rate of the slurry decreases, the stone rate increases, and the viscosity increases. In other words, the larger the mass ratio of fly ash in the slurry, the better the slurry stability and filling effect, but the smaller the diffusion radius. With the decrease of the water-solid ratio, the slurry viscosity will increase significantly after reaching a certain water-solid ratio.