温度对磷石膏充填料浆流变参数影响分析

Effect of Temperature on Rheological Parameters of Cemented Phosphogypsum Backfill Slurry

采用恒温水浴箱与旋转流变仪测试不同温度以及质量浓度下磷石膏充填料浆的流变参数,研究发现,磷石膏充填料浆流变曲线符合Hershel-Bulkley模型特征,低温条件下,屈服应力随着充填料浆质量浓度的增加而增加,但在低浓度区域(固体质量分数55%～58%)增长缓慢。另外,随着温度的升高,充填料浆屈服应力与实测黏度稳定值也随之增长,说明温度的升高使得浆体内部结构得以增强,同时低浓度浆体屈服应力对质量浓度的敏感性也有所提高。温度的变化不但会影响磷石膏充填料浆的流变参数,而且通过计算层流状态下不同温度充填料浆水平直管流动阻力损失值,发现温度升高也会增长浆体阻力损失值,并且随着浆体平均流速的增加,增长值会逐渐增高,但是相对增长率却逐渐下降。

The rheological parameters of cemented phosphogypsum backfill slurry under different temperature and mass concentration were tested by temperature-controllod water bath and rheometer.It was found that the rheological curve of phosphogypsum backfill slurry conformed to the characteristics of Hershel-Bulkley model.Under low temperature conditions,the yield stress increased with the increasing mass concentration of the backfill slurry,but increased slowly in the low concentration region(solid mass concentration between 55% and 58%).In addition,with the increase of temperature,the yield stress of the backfill slurry and the measured stable viscosity value also increased,indicating that the increase of temperature made the internal structure of the backfill slurry enhanced,and the sensitivity of the low-concentration slurry yield stress to mass concentration also improved.The change of temperature not only affected the rheological parameters of the phosphogypsum filling slurry,it was also found that the slurry resistance loss value would be increased with the increasing of the temperature when the phosphogypsum backfill slurry flowing through the houizontal straight pipes under the laminar flow state.As the average flow rate of the slurry increased,the growth value gradually increased,but the relative growth rate gradually decreased.