Silicates addition in bitumen froth treatment

Abstract

A method for processing a bitumen froth comprising bitumen, water and solids including fine solids for reducing the solids concentration in diluted bitumen is provided comprising diluting the bitumen froth with a hydrocarbon diluent to form a dilfroth; adding a sufficient amount of a silicate to the dilfroth to cause a substantial amount of fine solids to associate with the water instead of the diluted bitumen; and allowing the diluted bitumen to separate from the water containing the substantial amount of fine solids to produce a dilbit having less than 3 percent by weight solids.

1 . A method for processing a bitumen froth comprising bitumen, water and solids including fine solids for reducing the solids concentration in diluted bitumen, comprising:
 diluting the bitumen froth with a hydrocarbon diluent to form a dilfroth;   adding a sufficient amount of a silicate to the dilfroth to cause a substantial amount of fine solids to associate with the water instead of the diluted bitumen; and   allowing the diluted bitumen to separate from the water containing the substantial amount of fine solids to produce a dilbit having less than 3 percent by weight solids.   
     
     
         2 . The method as claimed in  claim 1  wherein the produced dilbit comprises less 1 percent by weight solids. 
     
     
         3 . The method as claimed in  claim 1  wherein the hydrocarbon diluent is naphtha. 
     
     
         4 . The method as claimed in  claim 1  wherein the silicate is sodium silicate. 
     
     
         5 . The method as claimed in  claim 1  wherein hydrocarbon diluent is added to the bitumen froth to give a diluent to bitumen ratio of about 0.5:1 to about 1:1. 
     
     
         6 . The method of  claim 1  wherein the diluted bitumen is separated from the water and fine solids in a gravity settler vessel. 
     
     
         7 . The method of  claim 1  wherein the diluted bitumen is separated from the water and fine solids in at least one scroll centrifuge, at least one disc centrifuge or at least one sequence of scroll and disc centrifuges. 
     
     
         8 . The method of  claim 1  wherein the diluted bitumen is separated from the water and fine solids in at least one inclined plate separator. 
     
     
         9 . A method for processing a bitumen froth comprising bitumen, water and solids including fine solids for reducing the solids concentration in diluted bitumen, comprising:
 diluting the bitumen froth with a hydrocarbon diluent to form a diluted bitumen froth;   adding a sufficient amount of a silicate to the diluted bitumen froth to cause a substantial amount of fine solids to associate with the water instead of the diluted bitumen;   subjecting the diluted bitumen froth to gravity separation in a first gravity settler vessel to produce a first diluted bitumen overflow having less than 3 percent by weight solids and a solids underflow; and   subjecting the first diluted bitumen overflow to gravity separation in a second gravity settler vessel to produce a second diluted bitumen overflow having less than 1 percent by weight solids.   
     
     
         10 . The method as claimed in  claim 9  wherein the hydrocarbon diluent is naphtha. 
     
     
         11 . The method as claimed in  claim 9  wherein the silicate is sodium silicate. 
     
     
         12 . The method as claimed in  claim 9  wherein hydrocarbon diluent is added to the bitumen froth to give a diluent to bitumen ratio of about 0.5:1 to about 1:1. 
     
     
         13 . The method as claimed in  claim 9 , further comprising:
 diluting the solids underflow from the first gravity settler vessel with hydrocarbon diluent and subjecting the diluted solids underflow to gravity separation in a third gravity settler vessel to produce a third diluted bitumen overflow.   
     
     
         14 . The method as claimed in  claim 9 , further comprising:
 adding a silicate to the diluted solids underflow prior to adding it to the third gravity settler vessel.