Capillary Suction for Dewatering Oil Sands Mature Fine Tailings: Experimental and Modeling Results

Abstract

The main challenge to the efficient processing of surface-mined oil sands is the generation of large volumes of slow-settling mature fine tailings (MFT). Tailings pose a significant environmental risk, including failure of storage facility, air-borne emissions, and surface and groundwater contamination. There is no practical mechanism to economically, technically, and ecologically dewater tailings to sufficiently dry MFT for reclamation. In this work, we leverage the natural mechanism of capillary action over filter paper to increase the area available for evaporation. The filter paper accelerated the evaporation of ∼35% of the MFT water, leading to an ∼20% increase in solidification and 33–55% reduction in reclamation time. The thermodynamics of water evaporation and mass transfer are modeled to estimate the rate of evaporation. Model fitting shows good accuracy in estimating dewatering for both nonporous and porous substrates using one and two fitted parameters, respectively.