Oil sands, formerly referred to as tar sands, are sandy substrates that contain large deposits of bitumin, a kind of fossil fuel. Bitumen is a thick, viscous, black, sticky, tar-like form of liquid petroleum, but its physical consistency is comparable to that of cold molasses. Oil sands occurring at or near the surface can be mined using open-pit techniques. The bituminous materials are then extracted by heating and the hydrocarbons refined and manufactured into a synthetic petroleum product. Once the readily extractable, surface deposits are extracted, deeper bitumen may be mined using steam assisted, in situ techniques that decrease viscosity and allow the bitumen to flow so it can be pumped to the surface.

Mined oil sand typically contains 10-12% bitumen, 4-6% water, and 80-85% mineral sand and clays. About 2.2 tons (2 tonnes) of oil sand must be processed to produce one barrel (0.16 m³) of liquid petroleum...