防治俯采工作面煤自燃稠化浆体的流变特性研究

Rheological Characteristics of Thickened Slurry for Preventing and Controlling Spontaneous Combustion of Coal in Underhand Working Face

针对大倾角俯采工作面煤自燃防治过程中不易灌浆、漏风强度大、浆液无法向高处堆积等问题,以高分子聚合材料、表面活性剂、固相材料为原始材料,制备出不同水土比、稠化剂浓度的浆体并进行悬浮稳定试验,研究稠化浆体的悬浮特性,通过对不同浓度的稠化浆体进行流变特性试验,拟合出流变本构方程,从而研制出一种性能优异、适用于大倾角俯采工作面的稠化浆体材料,最后采用Fluent软件模拟稠化浆体在采空区内的扩散特征。研究结果表明:黄土为稠化浆体最适合的固相材料;当水土质量比为8∶1、稠化剂质量浓度为0.3%时,稠化浆体悬浮性能较好,且屈服应力最小,具有更好的流动性;在采空区内稠化浆体的流动速度与扩散半径成反比,在浆体注入6 h后扩散半径达最大值。

In response to the problems of difficulty in grouting,high air leakage intensity,and inability to pile up slurry at high altitudes during the prevention and control process of coal spontaneous combustion in steep dip underhand working face,a slurry with different water to soil ratios and thickening agent concentrations was prepared using polymer material,surfactant,and solid phase materials as raw materials,and suspension stability experiments were conducted to study the suspension characteristics of thickened slurry.By conducting rheological characteristic tests on thickened slurry of different concentrations and fitting the rheological constitutive equation,a thickened slurry material with excellent performance and suitable for steep dip underhand working face was developed.Finally,Fluent software was used to simulate the diffusion characteristics of thickened slurry in the goaf.The research results indicate that loess is the most suitable solid phase material for thickened slurry.When the water to soil mass ratio is 8∶1 and the mass fraction of thickening agent is 0.3%,the suspension performance of thickened slurry is good,and its yield stress is the smallest,indicating better flowability.The flow velocity of thickened slurry in the goaf is inversely proportional to the diffusion radius,and the diffusion radius reaches its maximum value after 6 h of slurry injection.