一种考虑固相浓度作用的改进泥浆流变模型

A rheological model of slurry considering the influence of solid concentration

泥浆流变特性决定其运动形态和过程,并受固相浓度/含水率影响显著。本研究基于泥浆流体运动的纳维-斯托克斯方程和浆体固-液相互作用,推导了泥浆稠度系数随固相浓度变化的三参数简化表达式,并在H-B流变模型基础上建立了改进的四参数泥浆流变模型。通过与不同源地、不同固相浓度/含水率的泥浆流变测试结果比较,验证了稠度系数简化表达式的合理性和改进流变模型的适用性。研究表明,所构建的稠度系数表达式可合理描述固相浓度对稠度系数的规律性作用;利用改进流变模型,可实现对不同固相浓度泥浆流变特性变化的预测;随泥浆固相浓度的上升/含水率的降低,颗粒间的引力和絮网连接程度增加,流变稠度系数逐渐增大;此外,稠度系数的变化具有显著阶段性:泥浆固相浓度在达到临界浓度之前,稠度系数增速较小;在达到临界浓度之后,稠度系数随固相浓度上升而迅速增大。

The rheological properties of slurry determine the pattern and process of its movement,which are significantly influenced by the solid concentration/moisture content.This paper derived a simplified three-parameter expression of the consistency coefficient of the slurry which is a function of the solid concentration,based on the Navier-Stokes equations for fluid and the interaction between the liquid phase and the solid phase.Thereafter,an improved H-B rheological model was established and followed by comparison with the experimental results of slurry,characterized by different origins and solid concentration/moisture content for validation.The study indicates that the established model can adequately depict the dependence of the rheological properties of slurry on the water content.The consistency coefficient gradually increases with the increase of the solid concentration,as a results of the enhanced particle adsorption.The variation of the consistency coefficient can be divided into two stages,a i slow increase with the increasing solid concentration before reaching the critical value and a rapid increas afterwards.