Synchrotron Radiation Measurements of Degree of Saturation in Porous Matrix

Abstract

An experimental technique is developed using synchrotron radiation to determine changes in the degree of saturation in a drying porous matrix. Analyses of the drying characteristics of two synthetic slurries, kaolin and graphite, are made after dewatering. The radiation technique is also able to measure the dynamics of the consolidation of the filter cake prior to drying. Desaturation initially takes place as gas displaces pore liquid. Further changes in the degree of saturation occur due to evaporative losses as dry nitrogen gas flows through the cracks in the porous medium. Differences in pore evacuation and evaporation between graphite and kaolin porous matrices are due to differences in the pore structure of the cake as it initially dewatered. The highly collimated, high-energy X-rays produced at the Cornell High Energy Synthrotron Source allow exceptional spatial (0.5 mm) and temporal (0.5 s) resolution of changes in the degree of saturation throughout the drying porous matrix.