Effect of Mineral Surface Properties on Water Behaviors in Pores Constructed by Calcite and Silica Particles

Water confined in the pore space has different behaviors than bulk water, and the minerals constructing the pores will affect water properties. In this paper, the relaxation characteristics of water filling in the pores of calcite and silica powders (45-74 mu m) at various saturation levels are studied by a low-field nuclear magnetic resonance instrument. Results show that water in calcite and silica powders has different T-2 relaxation behaviors. Based on the results of X-ray computed tomography scanning of pore structures, contact angle measurement, and time-of flight secondary ion mass spectrometry analysis of surface functional clusters, this phenomenon is ascribed to the different status of hydroxyl groups as the interstitial hydroxyl ion because of the formation of the bicarbonate ion by either the interaction of water with the carbonate ion or bounding with -Si at the silica surface. Such differences lead to water behaving differently in the pores constructed with calcite and silica particles.