(246a) Squeeze Flow Rheometry of Paste and Slurry

A squeeze flow analysis method of sticking viscoplastic fluids as mud, mineral pastes or slurry is developed. This method allows an equivalent flow curve to be extracted from squeeze data. For this purpose, it is assumed that the fluids stick on both plates and the flow field is essentially extensional around the plane of symmetry. Furthermore, we consider a Bingham model to describe the squeeze flow of any fluids and specify an equivalent stress-strain state at any time. For this, we have calculated an instantaneous average strain rate. This average strain rate is defined by means of a dimensional analysis coupled with energy balance. The constitutive parameters of the Bingham model are evaluated by confronting squeeze data and analytical solution of the Bingham squeeze force which included the outcoming sample effects. This provides also the average strain rate value and one point of the equivalent flow curve. In consequence, we developed an algorithm that enables the construction of an equivalent flow curve with step-by-step computation. The algorithm, preliminary tested and validated on simulated data of complex fluids in sticking squeeze flow, is applied on experimental squeeze data. It is finally shown that the equivalent flow curve obtained from squeeze data are in agreement with conventional shear flow curve.