运动状态下全尾砂胶结料浆流变参数时变性研究

Study on time-dependent rheological parameters of unclassified tailings cemented slurry under motion state

全尾砂胶结料浆在管路输送过程中流变参数具有时变性。以连续搅拌方式模拟料浆在输送过程中的运动状态,借助Brookfield流变仪研究了不同质量浓度和灰砂比条件下,搅拌时间对料浆流变参数的影响规律及作用机理。研究结果表明:1)当搅拌时间逐渐增加时,灰砂比1∶5,质量浓度分别为72%、74%和76%的全尾砂胶结料浆其屈服应力和黏性系数均随之增大,且料浆质量浓度越高,搅拌时间对料浆流变参数的影响越显著;2)质量浓度74%,灰砂比分别为1∶5、1∶10和1∶15的全尾砂胶结料浆屈服应力和黏性系数也随搅拌时间的增加而增大。料浆流变参数增大的主要原因为:料浆中水泥水化反应产生的具有凝聚网络结构的凝胶成分含量随时间的增加而不断增加。

Rheological parameters of unclassified tailings cemented slurry are time-dependent during pipeline transportation.The motion state of the slurry during pipeline transportation was simulated by continuous stirring a method of continuous stirring was used.Using Brookfield rheometer,effects of stirring time on rheological parameters of slurry and its mechanism were analyzed under different mass concentrations and cement-sand ratio.The results indicated that∶1)with the cement-sand ratio of 1∶5,the yield stress and viscosity coefficient were increased with the increase of stirring time as the concentration of slurry was 72%,74% and 76%,and the higher the concentration was,the more significant of the stirring time on the rheological parameters of the slurry;2)with the mass concentration of 74%,the yield stress and viscosity coefficient were also growth with the increase of stirring time as the cement-sand ratio was 1∶5,1∶10 and 1∶15.The increase of rheological parameters of slurry was mainly attributed to that the content of gel component which had coherency network structures generated by cement hydration reaction in slurry increased continuously with the hydration time.