Processing of bituminous sands

Claim 1

IN A PROCESS FOR THE RECOVERY OF HYDROCARBON VALUES FROM CLAY-CONTAINING PETROLIFEROUS MINERAL SOLIDS WHEREIN (1) SAID SOLIDS ARE AGITATED WITH AN AQUEOUS ALKALI-METAL SILICATE SOLUTION AND A LIGHT HYDROCARBON DILUENT AT A MODERATELY ELEVATED TEMPERATURE FOR A PERIOD OF TIME SUFFICIENT TO REDUCE SAID SOLIDS TO A SUBSTANTIALLY HOMOGENEOUS PULP, (2) SAID PULP IS TREATED TO SEPARATE A SOLIDS PHASE, A LIQUID HYDROCARBON PHASE, AND AN AQUEOUS ALKALI-METAL SILICATE PHASE, (3) THE SEPARATED AQUEOUS ALKALI-METAL SILICATE PHASE IS RECYCLED TO THE AFORESAID STEP (1), AND (4) SAID SEPARATION TREATMENT IS SUCH THAT COLLOIDALLY DISPERSED CLAY ACCUMULATES IN SAID RECYCLED AQUEOUS ALKALI-METAL SILICATE, THE METHOD OF SUBSTANTIALLY REDUCING SAID ACCUMULATION WHICH COMPRISES ADDING TO SAID AQUEOUS ALKALI-METAL SILICATE SOLUTION A WATER-SOLUBLE POLYMER OF AN ALKYLENE OXIDE SELECTED FROM THE CLASS CONSISTING OF ETHYLENE OXIDE, THE PROPYLENE OXIDES AND THE BUTYLENE OXIDES, SAID POLYMER HAVING A MOLECULAR WEIGHT SUCH THAT A FIVE PERCENT BY WEIGHT AQUEOUS SOLUTION THEREOF HAS A VISCOSITY OF AT LEAST ABOUT 200 CENTIPOISES AT 20*C. AND SAID POLYMER BEING EMPLOYED IN AN AMOUNT SUFFICIENT TO EFFECT A SUBSTANTIAL REDUCTION IN THE AMOUNT OF CLAY COLLOIDALLY DISPERSED IN SAID AQUEOUS ALKALI-METAL SILICATE.