Ambient froth flotation process for the recovery of bitumen from tar sand

Claim 1

A froth flotation method suitable for recovery of bitumen from tar sands comprising: (a) admixing raw tar sand with a fluid medium effective to selectively wet and disperse the sand grains to produce a tar sand slurry; (b) milling said tar sand slurry to liberate the bitumen from the tar sand grains; and (c) admixing with the tar sand slurry from about 0.35% to about 1.8% by weight of a collector oil based on a unit of raw tar sand feed; (d) separating the tar sand slurry by ambient froth flotation into a product slurry of bitumen enriched tar sand and a tailing of waste sand slurry substantially free of bitumen; and (e) treating said waste sand slurry with an effective amount of hydrated lime and an organic flocculant to cause flocculation, thereby settling out the suspended sand; and recycling the fluid above the precipitated sand to step (a) or step (b).