全尾砂料浆流变特性试验

Experiment on Rheological Properties of Full Tailings Slurry

利用尾砂进行胶结充填,不仅可以有效避免尾砂堆存引起的环境、土地等问题,还可以有效保障矿区人员的人身和财产安全。充填尾砂的强度和流变特性对采空区的稳定性及料浆输送过程的难易程度有重要影响。在对某铁矿全尾砂物理化学性质研究的基础上,通过控制剪切速率的方法(CR法)研究不同灰砂比、不同质量浓度充填料浆的流变特性。结果表明:料浆流变曲线适合用宾汉塑性体的流变特征来描述;料浆的屈服应力随着料浆浓度的增加而增大,在灰砂比一定时,屈服应力与料浆浓度之间呈指数关系;在同一质量浓度条件下,充填料浆的屈服应力值变化不大;灰砂比为1∶6,1∶8和1∶10的充填料浆,当其浓度由72%增加到74%时,料浆的屈服应力呈现大幅度的增长;料浆的粘度系数随着质量浓度的不断增加而增大,粘度系数随着灰砂比的增大基本呈现增大的趋势,但是灰砂比对其影响不显著。

Cemented filling with tailings can not only effectively avoid the environmental and land problems caused by tailings stockpiling,but also effectively guarantee the personal and property safety of mining personnel.The strength and rheological properties of filling tailings have an important influence on the stability of goaf and the difficulty of slurry transportation.Based on the study of physical and chemical properties of tailings from an iron mine,the rheological properties of filling slurries with different cement-sand ratios and different mass concentrations were studied by controlling shear rate(CR method).The results were concluded as follows.Firstly,the rheological curve of slurry was suitable to be described by the rheological properties of Bingham plastic body.Secondly,the yield stress of slurry increased with the increase of slurry concentration,and there was an exponential relationship between the yield stress and slurry concentration at a certain cement-sand ratio.Thirdly,under the same mass concentration,the yield stress of filling slurry had little change.Fourthly,when the cement-sand ratio of filling slurry was 1∶6,1∶8 and 1∶10 and its concentration increased from 72%to 74%,the yield stress of slurry increased greatly.Finally,the viscosity coefficient of slurry increased with the increase of mass concentration,and basically showed an increasing trend with the increase of lime-sand ratio,but the influence of cement-sand ratio was not significant.