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Bitumen recovery from tar sands

  • US 4,470,899 A
  • Filed: 02/14/1983
  • Issued: 09/11/1984
  • Est. Priority Date: 02/14/1983
  • Status: Expired due to Term
First Claim
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1. A process for recovering bitumen from tar sands, the process comprising the step of:

  • obtaining bitumen-containing tar sands;

    pretreating the tar sands with a diluent so as to lower the viscosity of the bitumen such that the viscosity is in the range of from about 5 to about 20 poise at a digestion temperature of from about 40°

    C. to about 70°

    C.;

    digesting the tar sand in a slightly basic solution at a temperature in the range of from about 40°

    C. to about 70°

    C. to disengage the bitumen from said particles in the tar sand;

    mixing the tar sand during the digestion step so as to create a shear stress force field in the range of from about 20 to about 100 dynes per square centimeter; and

    separating the tar sand into a bitumen-rich concentrate and tailings by flotation.

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