Kuznetsov, Oleksandr (Baker Hughes) | Mazyar, Oleg (Baker Hughes) | Agrawal, Devesh (Baker Hughes) | Suresh, Radhika (Baker Hughes) | Feng, Xianhua (Baker Hughes) | Behles, Jackie (Baker Hughes) | Khabashesku, Valery (Baker Hughes)
Oil sand ore flotation is a primary method of bitumen recovery from mined Athabasca tar sands. In bitumen flotation, suspended biwettable ore fines, such as clays, tend to migrate to oil-water interfaces, creating slime coating on liberated bitumen droplets. Slime coating significantly reduces the efficiency of the flotation process and overall oil recovery. Ultra-dispersed hydrophilic silica nanoparticles were found to stabilize biwettable ore fines in an aqueous phase by adsorbing onto fines surfaces, even at concentrations as low as 50 ppm. As a result, fine solids move away from oil/water interfaces, reducing the slime coating and increasing bitumen recovery during flotation of low-grade ore by more than 5%. The addition of nanoparticles has no negative effect on froth quality or oil, water and solid separation in naphthenic and paraffinic froth treatment processes. Detailed molecular dynamics (MD) simulations revealed mechanisms that improve bitumen liberation from mined oil sands in a flotation process. The studies demonstrated that colloidal nanoparticles affect many stages of the bitumen extraction process from bitumen separation to clay wettability alteration.