矸石充填料浆流变特性与颗粒级配相关性试验研究

Experimental study on correlativity between rheological parameters and grain grading of coal gauge backfill slurry

为了明确矸石充填料浆流变参数与颗粒级配指标的相关性,通过开展不同级配骨料、静置时间条件下的充填料浆流态变化规律试验,研究静置时间、颗粒级配对料浆流态变化的影响。以山西省孝义市新阳某矿矸石胶结充填采煤为工程背景,基于料浆流变特性,分析管道堵塞、磨损机理,得到最优的骨料颗粒级配（2号料浆骨料级配）;建立料浆不沉颗粒临界粒径公式,明确2号料浆中不沉临界粒径为14 mm。试验结果表明：料浆的初始剪切力和表观黏度均随着静置时间的延长而增加;料浆的流变特性是个多种模型复合特性的综合体现,随着剪切速率的增加,料浆流变曲线呈上凸状;粒径d10（即粒径累积分布中累积粒径含量达到10%时对应的粒径）、d30（即粒径累积分布中累积粒径含量达到30%时对应的粒径）与料浆的表观黏度和初始剪切力相关性最强,表明0~30μm粒径颗粒对料浆的流变性能影响最大;料浆静置时间越长,表观黏度与粒径d10,d30的相关性强度逐渐降低,而初始剪切力与之相关性则增强。

In order to investigate the correlation between grain grading and rheological parameters of high density concentration slurry, tests were conducted to study the effects of grain grading and static minutes on the rheological tendency variation law of backfill slurry at different grain grading and static minutes. Based on the engineering of Xinyang coal mine in Xiaoyi city Shanxi province with cemented backfill mining method, the mechanism of pipeline plugging and abrasion was analyzed on the basis of slurry rheological characteristic. And the optimal aggregate particle size grading of a coal mine in Xinyang City was gained. The formula for defining the critical diameter of non-subsidence aggregate in slurry was established, and the critical particle size in No.2 slurry was 14 mm. The results show that both the initial shear strength and apparent viscosity increase with the extension of time. The rheological curve of slurry is like a convex varying with shear rate, showing that the rheological model is pseudo plastic-Bingham-plastic. The apparent viscosity and initial shear are significantly relative to the grain diameter of d10 and d30 is strongest in all, indicating that the grain size of 0-30 μm proposes greatest influence on the rheological feature of slurry. The correlation level between apparent viscosity and grain diameter of d10 gradually reduces as time goes on, but oppositely the initial shear increases.