不同粒径煤矸石浆液的流变性能试验

煤矸石浆液的流变性能影响注浆的可泵性，可通过调节粒径和水矸比对流变性能进行调控。本文测试了新鲜煤矸石浆液的流变性能、流动度及流动时间，研究了不同粒径(100目、150目、200目、250目、300目，分别对应150μm、106μm、74μm、58μm和48μm)及水矸比(1.0、1.5、2.0)对煤矸石浆液流变性能的影响，探讨了流变参数、流动度及流动时间的变化规律，并提出了注浆建议。结果表明：水矸比是煤矸石浆液流变性能的主控因素，煤矸石浆液在水矸比为1.0时，符合Herschel-Bulkley模型，颗粒粒径会影响浆液的屈服应力和塑性黏度，屈服应力为2.5～3.6 Pa;在水矸比为1.5、2.0时，符合Bingham模型，颗粒粒径只影响浆液的屈服应力，屈服应力为0.1～0.7 Pa。不同粒径煤矸石浆液的流动度均不低于365 mm,流动时间在27～31 s。为提高浆液的可泵性，可考虑采用较大的水矸比(≥1.5)和较长的搅拌时间(>800 s)。

Rheological Properties Test of Coal Gangue Slurry with Different Particle Sizes

The pumpability of coal gangue slurry is affected by its rheological properties, which are regulated by particle size and water/gangue ratio. The rheological properties, degree of fluidity and flow time of fresh coal gangue slurry were tested in this paper, and the effects of different particle sizes (100 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, corresponding to 150 μm, 106 μm, 74 μm, 58 μm and 48 μm, respectively) and water/gangue ratio (1.0, 1.5, 2.0) on the rheological parameters were discussed.The variation rules of rheological parameters, degree of fluidity and flow time were discussed as well, and some grouting suggestions were put forward. The results show that the water/gangue ratio is the main controlling factor of rheological properties of coal gangue slurry. When the water/gangue ratio is 1.0, the coal gangue slurry conforms to the Herschel-Bulkley model, and the particle size affects both the yield stress and plastic viscosity of coal gangue slurry, and the yield stress is between 2.5 Pa and 3.6 Pa. When the water/gangue ratio is 1.5 and 2.0, the coal gangue slurry conforms to the Bingham model, and the particle size only affects the yield stress of coal gangue slurry, and the yield stress is between 0.1 Pa and 0.7 Pa. In addition, the degree of fluidity of coal gangue slurry with different particle sizes is more than 365 mm, and the flow time is in the range of 27 s to 31 s. Based on these test results, grouting suggestions are put forward that a larger water/gangue ratio (≥1.5) and a longer stirring time (>800 s) are recommended to improve the pumpability of coal gangue slurry.