Removal of fine solids from bitumen by hetero-aggregation and magnetic separation using surface-modified magnetite nanoparticles. Part 1: Proof of concept

•Magnetite nanoparticles were functionalized by stearylamine acetate.•The functionalized magnetite captured fine solids from a 2:1 cyclohexane:bitumen solution.•The magnetite-fine solids aggregates were removed by magnetic field-assisted filtration.•Fine solids content in the 2:1 cyclohexane:bitumen solution was lowered to 300–400 ppm.