充填开采是煤矿绿色开采技术体系关键环节之一,针对充填过程中的矸石−粉煤灰基充填料浆的输送技术问题,设置了不同质量浓度、粉煤灰掺量、养护温度和时间等参数,开展了温-时耦合效应下矸石-粉煤灰充填料浆流变测试试验,探究各参数对料浆流变特性的影响。通过正交极差分析温度和静置时间对料浆屈服应力影响权重,并建立温-时耦合效应下流变参数回归模型。试验结果表明:质量浓度对料浆的流动性能影响显著,随质量浓度的增加,料浆剪切应力与剪切速率线性相关性降低,质量浓度为78% 时兼具较好的流动性和稳定性;粉煤灰掺量增加会提高料浆的剪切应力和剪切增稠的程度,粉煤灰掺量为85% 时料浆屈服应力最大,粉煤灰掺量75% 次之,粉煤灰掺量65% 最小;高温加速了料浆的水化反应速率和增强了粉煤灰的火山灰反应活性,静置120 min 时养护温度50 ℃ 时屈服应力较20、35 ℃ 增幅分别为44.5%、37.5%。静置时间对料浆屈服应力的影响程度强于温度,粉煤灰掺量为75% 时,温度20 ℃ 条件下料浆静置120 min 后屈服应力比静置0 min增加了133.7%;不同温度条件下,料浆屈服应力随静置时间均呈线性增长趋势,拟合度均在0.9 以上;最后,建立温−时耦合效应下料浆的屈服应力演化模型。通过理论模型计算结果与试验结果对比,平均误差在5%,拟合效果较好,可为煤矿充填管道输送阻力计算提供参考。

Filling mining is one of the key links in the green mining technology system of coal mines, in view of the transportation technologyof the gangue-fly ash based filling slurry during the filling process, parameters such as different mass concentrations, fly ash content,curing temperature and time were set. The rheological tests of the gangue-fly ash based filling slurry under the temperature-time couplingeffect were carried out to explore the influence of various parameters on the rheological properties of the slurry. Through orthogonal rangeanalysis, the influence weight of temperature and standing time on the yield stress of the slurry was analyzed, and the rheology under thetemperature-time coupling effect parametric regression model was established. The test results show that the mass concentration has a significanteffect on the fluidity of the slurry. With the increase of the mass concentration, the linear correlation between the shear stress ofthe slurry and the shear rate decreases. When the mass concentration is 78%, it has both good fluidity and stability; The increase of the flyash content will increase the shear stress and the degree of shear thickening. When the amount of fly ash is 85%, the yield stress of theslurry is the largest, followed by the amount of fly ash of 75%, and the amount of fly ash 65% is the smallest; High temperature acceleratesthe hydration reaction rate of the slurry and enhances the pozzolanic reactivity of fly ash. The curing temperature at 50 ℃ increased by44.5% and 37.5% respectively compared with 20 ℃ and 35 ℃ when the fly ash was kept for 120 minutes; The setting time has a stronger influence on the yield stress of the slurry than that of temperature. When the fly ash content is 75%, the yield stress of the slurry afterstanding for 120 minutes at a temperature of 20 ℃ increases by 133.7% compared with that of standing for 0 min; Under different temperatureconditions, the yield stress of the slurry increases linearly with standing time, and the degree of fitting is above 0.9. Finally, the yieldstress evolution model of the slurry under the temperature-time coupling effect is established. By comparing the calculation results of thetheoretical model with the test results, the average error is about 5%, and the fitting effect is good, which can provide a reference for thecalculation of the pipeline transportation resistance of the filling pipeline in the coal mine.