Flocculation Efficiency and Spatial Distribution of Water in Oil Sands Tailings Flocculated with a Partially Hydrophobic Graft Copolymer.

This work investigates the effect of partially hydrophobic grafted polymers on flocculation and dewatering of oil sands mature fine tailings. Here, we combine confocal microscopy and rheology to investigate how the graft density of ethylene-propylene-diene grafted with hydrolyzed poly(methyl acrylate) (EPDM--HPMA) affects its dispersion in water and flocculation efficiency in terms of sediment solids content and long-term dewatering of oil sands tailings. Increasing the graft density from 30 to 50% makes the flocculant easier to disperse, increases the rate of initial dewatering, and also enhances the viscoelastic response of the flocculated sediments.