Removal of suspended mineral matter from asphaltic petroleum oils

Claim 1

A METHOD OF PRODUCING LOW-ASH ASPHALT FROM THE HIGH-VISCOSITY ASPHALTIC NATURAL TAR SEPARATED FROM TAR SANDS BY ANY WATER-WASHING METHOD FOLLOWED BY DEHYDRATION OF THE SEPARATED TAR, AND WHICH RETAINS SILT AND CLAY OF COLLOIDAL OR NEAR-COLLOIDAL SIZE WHICH WILL NOT SETTLE OUT OR FILTERED OUT AT TEMPERATURES UP TO COKING TEMPERATURE; COMPRISING THERMALLY CRACKING THE DEHYDRATED TAR, AT ATMOSPHERIC PRESSURE OR UNDER A SLIGHT VACUUM AT FROM ABOUT 650*F., UP TO A MAXIMUM OF ABOUT 830*F. UNTIL ABOUT 0.2 TO ABOUT 3 WEIGHT PERCENT OF FREE CARBON HAS BEEN FORMED BASED ON THE ORGANIC MATERIAL IN THE FEED DURING A RESIDENCE TIME OF ABOUT 40 MINUTES TO ABOUT 6 HOURS WHEREBY SAID SILT AND CLAY BECOME FILTERABLE, SEPARATING FILTERABLE SOLIDS BY FILTERING FROM THE RESIDUAL ASPHALTIC MATERIAL AT ELEVATED TEMPERATURES BELOW THOSE CAUSING APPRECIABLE THERMAL CRACKING AND RECOVERING (AS FILTRATE) COMMERCIAL QUANTITIES OF LOW-ASH ASPHALT WITH AN ASHCONTENT NOT SIGNIFICANTLY GREATER THAN APPROXIMATELY 0.12% CONTAINING ONLY METAL IMPURITIES IN ACTUAL CHEMICAL COMBINATION WITH THE ORGANIC MATERIALS AND AN ASH-CONTAINING RESIDUE.

Claim 2

A METHOD OF PRODUCING LOW-ASH ASPHALT FROM THE HIGH-VISCOSITY ASPHALTIC NATURAL TAR SEPARATED FROM TAR SANDS BY ANY WATER-WASHING METHOD FOLLOWED BY DEHYDRATION OF THE SEPARATED TAR, AND WHICH RETAINS SILT AND CLAY OF COLLOIDAL OR NEAR-COLLOIDAL SIZE WHICH WILL NOT SETTLE OUT OR FILTERED OUT AT TEMPERATURES UP TO COKING TEMPERATURE; COMPRISING THERMALLY CRACKING THE DEHYDRATED TAR, AT ATMOSPHERIC PRESSURE OR UNDER A SLIGHT VACUUM AT FROM ABOUT 650*F., UP TO A MAXIMUM OF ABOUT 830*F. UNTIL ABOUT 0.2 TO ABOUT 3 WEIGHT PERCENT OF FREE CARBON HAS BEEN FORMED BASED ON THE ORGANIC MATERIAL IN THE FEED DURING A RESIDENCE TIME OF ABOUT 40 MINUTES TO ABOUT 6 HOURS WHEREBY SAID SILT AND CLAY BECOME FILTERABLE, SEPARATING FILTERABLE SOLIDS BY FILTERING FROM THE RESIDUAL ASPHALTIC MATERIAL AT ELEVATED TEMPERATURES BELOW THOSE CAUSING APPRECIABLE THERMAL CRACKING AND RECOVERING (AS FILTRATE) COMMERCIAL QUANTITIES OF LOW-ASH ASPHALT WITH AN ASHCONTENT NOT SIGNIFICANTLY GREATER THAN APPROXIMATELY 0.12% CONTAINING ONLY METAL IMPURITIES IN ACTUAL CHEMICAL COMBINATION WITH THE ORGANIC MATERIALS AND AN ASH-CONTAINING RESIDUE.