颗粒粒径对尾砂膏体触变性的影响  

Study of the effect of particle size on the thixotropy of tailings pastes

作　　者：张连富 王洪江[2] 吴爱祥[2] 杨科[1] ZHANG Lian-fu;WANG Hong-jiang;WU Ai-xiang;YANG Ke(School of Mining Engineering,Anhui University of Science and Technology,Huainan 232001,China;School of Civil and Resources Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]安徽理工大学矿业工程学院,淮南232001 [2]北京科技大学土木与资源工程学院,北京100083

出　　处：《工程科学学报》2023年第1期1-8,共8页Chinese Journal of Engineering

基　　金：国家自然科学基金重点资助项目(51834001);国家留学基金委资助项目;安徽理工大学引进人才科研启动资金资助项目(2022yjrc59)。

摘　　要：高浓度尾砂料浆具有复杂的触变性,颗粒粒径是影响料浆触变性的重要因素,颗粒粒径对触变性影响的定量研究尚不丰富.为探究高浓度尾砂膏体的颗粒粒径对触变性的影响,使用同种尾砂制备了不同平均粒径的样品并制成膏体,开展恒剪切速率实验.结果表明,尾砂膏体具有显著的触变性,恒剪切速率条件下呈剪切稀化.稳态条件下,料浆静态屈服应力、动态屈服应力、宾汉姆黏度均与颗粒平均粒径平方的倒数呈线性正相关.瞬态条件下,颗粒平均粒径和相应瞬态拟合参数呈线性关联.推荐的稳态和触变性模型均表现出较高的适用性.通过数据拟合构建了稳态剪切应力和瞬态剪切应力的预测模型,定量表征颗粒平均粒径对触变性料浆稳态和瞬态流变行为的影响.High-concentration tailings pastes are commonly encountered in the surface deposition and underground cemented paste backfill.It is necessary to forecast the pressure loss along the pipe and the flow behavior in the mined-out area when tailings pastes are transported in a pipeline or stored up in goaf.Traditionally,thixotropy has often been overlooked while designing tailings paste transport and disposal systems due to the complexity of thixotropy characterization.However,thixotropy plays an essential role in the rheology of tailings pastes.To achieve the accurate representation of thixotropy,a suitable constitutive model has to be selected in advance.Unfortunately,there is no current available thixotropic model for tailings pastes up to date.Moreover,tailings pastes exhibit complex thixotropy that is significantly affected by the particle size of tailings,though the relevant studies are not abundant.It is important to analyze quantitively the relationship between particle size and thixotropic parameters based on an appropriate constitutive model.In this work,the constitutive thixotropic model for tailings pastes proposed by Zhang et al.was adopted.To reveal the influence of particle size on the thixotropy of tailings pastes,samples of various mean particle sizes prepared from the same tailings were applied to constant shear rate experiments.Results show that the target tailings pastes display significant thixotropy,leading to shear thinning under steady shear rates.In the steady state,the static yield stress,dynamic yield stress,and Bingham viscosity appear to correlate linearly to the reciprocal of the square of the mean particle size.As for the transient state,the corresponding fit parameters show a strong linear dependence on the mean particle size.The proposed equilibrium and thixotropic models are valid.The forecasting models for equilibrium and transient shear stress are established based on data fit,which is attributed to the quantitative characterization of steady-state and transient rheology for thixotr

关 键 词：颗粒粒径 尾砂膏体 触变性 流变参数 预测模型 

分 类 号：TG142.71[一般工业技术—材料科学与工程]