Effect of particle size distribution of tailings on pressure gradient and drag reduction characteristics of non-cemented paste considering wall slip
Effect of particle size distribution of tailings on pressure gradient and drag reduction characteristics of non-cemented paste considering wall slip
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DOI：
10.1016/j.cscm.2023.e02792
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发表时间：
2023-12
影响因子：
6.2
通讯作者：
Hongjiang Wang;Xi Zhang;Aixiang Wu
中科院分区：
文献类型：
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作者：
Hongjiang Wang;Xi Zhang;Aixiang Wu
膏体浆料在输送过程中表现出管壁滑移特性，从而有效降低管道输送阻力。为了研究具有壁滑移特性的膏体管道输送特性，建立了考虑壁滑移效应的管道压力梯度模型。为验证模型的准确性，以某铅锌矿溢流尾砂和分级尾砂为研究对象。根据二维压实理论，确定溢流尾砂混合比为8% ~ 39%，并相应配置5种不同级配的尾砂。进行了环试验、流变试验和沉降试验。以流变参数、极限体积浓度和平均粒径为基本参数，得到考虑壁面滑移效应的压力梯度值，并与环路试验实测压力梯度进行比较。结果表明，模型预测结果与实测值的相对误差为10%，具有较高的可靠性。压力梯度和质量浓度均呈二次函数增长趋势，与管道流量呈线性关系。随着-38µm颗粒比例的增加，压力梯度呈二次增长趋势。随着+ 38µm颗粒比例的增加，压力梯度呈二次函数递减趋势；滑移减阻率随质量浓度的增加而逐渐减小，不受管道流量的影响。当-38µm粒径比例为27.43% ~ 38.32%时，滑移减少率更为显著。考虑工程实际及运输成本，相应的溢流尾砂掺入比为16% ~ 31%。
The paste slurry exhibits pipe wall slip characteristics during transportation, thereby effectively reducing pipeline transportation resistance. In order to study the characteristics of paste pipeline transportation with wall slip characteristics, a pipeline pressure gradient model considering wall slip effect was applied. In order to verify the accuracy of the model, the overflow tailings and classified tailings of a lead-zinc mine were taken as the research object. According to the two-dimensional compaction theory, the mixing ratio of overflow tailings was determined to be 8% ∼ 39%, and five kinds of tailings with different gradations were configured accordingly. The loop test, rheological test and settlement test were carried out. Taking the rheological parameters, limit volume concentration and average particle size as the basic parameters, the pressure gradient value considering the wall slip effect is obtained and compared with the measured pressure gradient of the loop test. The results show that the relative error between the model prediction results and the measured values is 10%, which has high reliability. The pressure gradient and mass concentration show a quadratic function growth trend, and have a linear relationship with the pipeline flow rate. With the increase of the proportion of -38 µm particles, the pressure gradient shows a secondary growth trend. With the increase of the proportion of + 38 µm particles, the pressure gradient shows a quadratic function decreasing trend; The slip drag reduction rate gradually decreases with the increase of mass concentration, and is not affected by the flow rate of the pipeline. When the proportion of -38 µm particle size is 27.43% ∼ 38.32%, the slip reduction rate is more significant. Considering the actual project and transportation cost, the corresponding overflow tailings incorporation ratio is 16% ∼ 31%.