基于L管实验的全尾砂膏体流变特性研究

Rheological Properties of Unclassified Tailings Paste Slurry based on L-tube Pipeline Test

膏体的流变特性是影响膏体管道输送的重要因素。为获取膏体充填料浆真实的输送流变特性,利用L管实验装置,基于宾汉塑性模型获得膏体料浆的屈服应力及塑性粘度,得到不同料浆浓度和灰砂比条件下的管道输送阻力和充填倍线。结果表明:料浆浓度和灰砂比的上升都会导致剪切应力的增加,充填倍线的降低,其中,料浆浓度是影响充填体流动特性的最关键因素,而灰砂比是影响膏体强度的关键因素,但是膏体浓度的影响也不能忽视。根据L管和强度特性实验结果以及一二步骤采场的强度和输送需求,分别推荐了采场最佳膏体配比。

The rheological properties of the slurry is the key factor that affecting the tube transportation of the paste backfill.The L pipeline test devices were adopted to investigate the real rheological properties of the paste backfill slurry.Based on the Bingham plastic model,the yield stress and plastic viscosity of the slurry were obtained,and the pipeline transportation resistance and stowing gradient under different concentration and different cement-sand ratio were further calculated.The results show that:the increase of slurry concentration and the cement/sand ratio will lead to a raise of shear stress and a decline of stowing gradient.Moreover,the slurry concentration is the most important factor affecting the flow characteristics of the paste backfill,while the cement/sand ratio is the key factor that affecting the strength,but the effect of slurry concentration cannot be ignored.According to the experimental results of L-tube and strength characteristics,and based on the strength and conveying requirements of the stope in the first and second steps,the optimal composition of paste is recommended.