Chen Qiusong, Zhou Hailong, Wang Yunmin, Li Xiaoshuang, Zhang Qinli, Feng Yan, Qi Chongchong
School of Resources and Safety Engineering, Central South University, Changsha 410083, China.
Sinosteel Maanshan General Institute of Mining Research Co., Ltd., Maanshan 243000, China.
Materials (Basel). 2022 May 6;15(9):3339. doi: 10.3390/ma15093339.
Cemented paste backfill (CPB), a technology placing the solid waste into mined-out stopes in the mine through pipeline transportation, has been widespread all over the world. The resistance loss is an important parameter for pipeline transport, which is significantly affected by the slurry characteristics. However, the coupling effect of inlet velocity (IV), particle mass concentration (PMC), and particle size (PS) has not been well evaluated and diagnosed. Hence, the CFD-based three-dimensional network simulation of CPB slurry flow in an L-shaped pipe at different combinations of the three parameters was developed using COMSOL Multiphysics software, and the findings were validated through a loop experiment. The results show that increasing IV and reducing PS will contribute to the homogeneity of the slurry in the pipeline, while the PMC presents little effect. The pipe resistance loss is positively correlated with IV and PMC and negatively correlated with PS. The sensitivity to the three parameters is IV > PS > PMC. In particular, the resistance loss is minimal at IV of 1.5 m/s, PMC of 72%, and PS of 1000 um. The calculation model of resistance loss regressed from simulation presented a high accuracy with an error of 8.1% compared with the test results. The findings would be important for the design of the CPB pipeline transportation and provide guidance in the selection of transfer slurry pumps, prepreparation of backfill slurry, and pipe blockage, which will improve the safety and economic level of a mine.
胶结膏体充填（CPB）是一种通过管道输送将固体废物放入矿山采空采场的技术，已在全球广泛应用。阻力损失是管道输送的一个重要参数，它受料浆特性的显著影响。然而，入口速度（IV）、颗粒质量浓度（PMC）和颗粒尺寸（PS）的耦合效应尚未得到很好的评估和诊断。因此，利用COMSOL Multiphysics软件对CPB料浆在L形管道中不同参数组合下的流动进行了基于计算流体力学（CFD）的三维网络模拟，并通过回路实验对结果进行了验证。结果表明，提高入口速度和减小颗粒尺寸有助于料浆在管道中的均匀性，而颗粒质量浓度的影响较小。管道阻力损失与入口速度和颗粒质量浓度呈正相关，与颗粒尺寸呈负相关。对这三个参数的敏感性为入口速度>颗粒尺寸>颗粒质量浓度。特别是，当入口速度为1.5 m/s、颗粒质量浓度为72%、颗粒尺寸为1000μm时，阻力损失最小。从模拟中回归得到的阻力损失计算模型具有较高的精度，与试验结果相比误差为8.1%。这些研究结果对CPB管道输送的设计具有重要意义，并为输送料浆泵的选择、充填料浆的预制备和管道堵塞提供指导，这将提高矿山的安全性和经济水平。
