The effect of temperature on the yield stress of mineral suspensions

The response of the yield stress of suspensions of zirconia to changes in temperature was investigated using direct measurement with the vane technique. The objective of the study was to both probe the nature and origins of the temperature-related changes in the static structure present in the suspensions. The measurements showed that the yield stress of zirconia increased by up to 50% with an increase in temperature from 298 to 318 K. The yield stress-temperature data was modelled using a theoretical framework incorporating interparticle force considerations. In contrast to the experimental data, the model indicated that only a very Small increase in yield stress with temperature would be expected. However, the analysis of the model inputs implied that the yield stress increase could most likely be attributed to a very small change in interparticle spacing from 26.5 to 23.5 angstrom over the temperature range Studied. The physical likelihood of such a change is discussed. (C) 2008 Elsevier Inc. All rights reserved.