A process for recovering bitumen, or heavy petroleum, from admixture with sand and similar inorganic materials wherein said bitumen-sand mixture is mixed with an aqueous solution of an ammonium salt selected from ammonium sulfite, ammonium bisulfite and mixtures thereof to form a second mixture comprising...http://www.google.com.au/patents/US4250016?utm_source=gb-gplus-sharePatent US4250016 - Recovery of bitumen from tar sand
