Methods for removing bitumen from tar sands

Abstract

Methods are provided for removing bitumen from tar sands. One method may include contacting the tar sands with a hydrocarbon. The method may also include contacting the tar sands including the hydrocarbon with a water soluble silicate. The method may further include separating the tar sands into a liquid portion and a solid portion, the liquid portion including the water soluble silicate and the bitumen. The method may also include separating the water soluble silicate from the bitumen.

We claim: 
     
         1 . A method for removing bitumen from tar sands, comprising:
 contacting the tar sands with a hydrocarbon;   contacting the tar sands including the hydrocarbon with a water soluble silicate;   separating the tar sands into a liquid portion and a solid portion, the liquid portion including the water soluble silicate and the bitumen; and   separating the water soluble silicate from the bitumen.   
     
     
         2 . The method of  claim 1 , wherein the water soluble silicate is selected from sodium silicate, zirconium silicate, magnesium silicate, and potassium silicate. 
     
     
         3 . The method of  claim 2 , wherein the water soluble silicate is a sodium silicate. 
     
     
         4 . The method of  claim 1 , further comprising crushing the tar sands. 
     
     
         5 . The method of  claim 1 , wherein the hydrocarbon is selected from condensate, diesel, and gasoline. 
     
     
         6 . The method of  claim 1 , wherein the hydrocarbon is diesel. 
     
     
         7 . The method of  claim 1 , wherein contacting the tar sands with the water soluble silicate further includes contacting the tar sands with at least a portion of the water soluble silicate separated from the bitumen. 
     
     
         8 . The method of  claim 1 , further comprising excavating the tar sands from a tar sand deposit located proximal the surface of the earth. 
     
     
         9 . A method for removing bitumen from tar sands, comprising:
 crushing the tar sands in a crusher to form a crushed tar sand;   contacting the crushed tar sand with a hydrocarbon to form a first mixture;   contacting the first mixture with a water soluble silicate at ambient temperature to form a second mixture;   separating the second mixture into a first liquid portion, a second liquid portion, and a solid portion; and   contacting the first mixture with the first liquid portion.   
     
     
         10 . The method of  claim 9 , wherein the first liquid portion is the water soluble silicate, and the second liquid portion includes the hydrocarbon and the bitumen. 
     
     
         11 . The method of  claim 10 , wherein separating the second mixture into the first liquid portion, the second liquid portion, and the solid portion further comprises:
 separating the solid portion from a mixture of the first liquid portion and the second liquid portion in a first separator;   feeding the mixture of the first liquid portion and the second liquid portion to a second separator; and   separating the first liquid portion and the second liquid portion in the second separator.   
     
     
         12 . The method of  claim 10 , wherein the water soluble silicate is selected from sodium silicate, zirconium silicate, magnesium silicate, and potassium silicate. 
     
     
         13 . The method of  claim 9 , wherein separating the second mixture into the first liquid portion, the second liquid portion, and the solid portion is carried out in a three-phase separator. 
     
     
         14 . The method of  claim 9 , wherein the hydrocarbon is selected from condensate, diesel, and gasoline. 
     
     
         15 . The method of  claim 9 , further comprising:
 directing the first liquid portion to a storage tank containing the water soluble silicate; and   directing the water soluble silicate from the storage tank to a mixer containing the first mixture.   
     
     
         16 . A method for removing bitumen from tar sands, comprising:
 crushing the tar sands in a crusher to form a crushed tar sand;   conveying the crushed tar sand to a first mixer;   contacting the crushed tar sand with a hydrocarbon in the first mixer to form a first mixture;   conveying the first mixture to a second mixer;   contacting the first mixture with a water soluble silicate at ambient temperature in the second mixer to form a second mixture;   separating the second mixture into a first liquid portion, a second liquid portion, and a solid portion; and   feeding the first liquid portion to the second mixer.   
     
     
         17 . The method of  claim 16 , wherein separating the second mixture into the first liquid portion, the second liquid portion, and the solid portion further comprises:
 separating the solid portion from a mixture of the first liquid portion and the second liquid portion in a first separator;   feeding the mixture of the first liquid portion and the second liquid portion to a second separator; and   separating the first liquid portion and the second liquid portion in the second separator.   
     
     
         18 . The method of  claim 16 , wherein separating the second mixture into the first liquid portion, the second liquid portion, and the solid portion is carried out in a three-phase separator. 
     
     
         19 . The method of  claim 16 , wherein:
 the water soluble silicate is selected from sodium silicate, zirconium silicate, magnesium silicate, and potassium silicate;   the first liquid portion is the water soluble silicate, and the second liquid portion includes the bitumen and the hydrocarbon; and   feeding the first liquid portion to the second mixer further comprises
 feeding the first liquid portion to a storage tank including the water soluble silicate; and 
 feeding the water soluble silicate including the first liquid portion to the second mixer. 
   
     
     
         20 . The method of  claim 16 , wherein the solid portion includes a clean sand having a greater crush strength than a crush strength of the tar sand prior to the removal of the bitumen therefrom.