Method of Processing Tailings from Solvent-Based Hydrocarbon Extraction

Abstract

Described is a method of processing a bituminous feed. The bituminous feed is solvent extracted to form a bitumen-rich stream and a bitumen-lean stream. Solvent is recovered from the bitumen-rich stream to form a bitumen product. Solvent and water are recovered from the bitumen-lean stream to form dry tailings with a moisture content of less than 40 wt.%. The dry tailings are separated into at least two streams, each stream having a moisture content of less than 40 wt. %, based on at least one physical or chemical property. At least one of the at least two streams is then used at an oil sands mine site. In this way, the dry tailings may be used more effectively.

1 . A method of processing a bituminous feed, the method comprising:
 a) solvent extracting the bituminous feed and forming a bitumen-rich stream and a bitumen-lean stream;   b) recovering solvent from the bitumen-rich stream to form a bitumen product;   c) recovering solvent and water from the bitumen-lean stream to form dry tailings with a moisture content of less than 40 wt. %;   d) separating the dry tailings into at least two streams, each stream of the at least two streams having a moisture content of less than 40 wt. %, based on at least one of a physical property and a chemical property; and   e) using at least one of the at least two streams at an oil sands mine site.   
     
     
         2 . The method of  claim 1 , wherein the at least one of the physical property and the chemical property comprises one of size, density, dipole moment, permeability, shape, magnetism, adhesiveness, wettability, attrition, strength, solubility, inductiveness, and electric charge. 
     
     
         3 . The method of  claim 1 , wherein step d) comprises separating the dry tailings with a separator, wherein the separator comprises one of a screen, a sieve, a blower, a cyclone, a centrifuge, a gravity settler, filtration, electrostatic precipitation, magnetism, a shaker, a grinder, milling, and rolling. 
     
     
         4 . The method of  claim 1 , wherein step d) comprises separating the dry tailings into a coarser particles stream having coarser particles and a finer particles stream having finer particles. 
     
     
         5 . The method of  claim 4 , further comprising adding water to the coarser particles stream and pumping the coarser particles stream into place for construction of a mine form at the oil sands mine site, wherein the mine form comprises one of a dyke and a road. 
     
     
         6 . (canceled) 
     
     
         7 . The method of  claim 4 , wherein the finer particles stream is an impermeable layer at the oil sands mine site. 
     
     
         8 . The method of  claim 4 , further comprising depositing the coarser particles stream over the finer particles stream to control dusting. 
     
     
         9 . The method of  claim 1 , wherein step e) comprises depositing the at least one of the at least two streams in an oil sands mine pit. 
     
     
         10 . The method of  claim 1 , wherein step e) comprises using at least one of the at least two streams for drainage, as foundation, for reclamation at the oil sands mine site. 
     
     
         11 . (canceled) 
     
     
         12 . The method of  claim 1 , further comprising, prior to step d), reducing a moisture content of the dry tailings by drying, extraction or agglomeration. 
     
     
         13 . (canceled) 
     
     
         14 . The method of  claim 1 , further comprising mixing at least one of the at least two streams with an additive comprising one of a polymer, gypsum, alum, and a resin. 
     
     
         15 . The method of  claim 1 , further comprising recovering at least one heavy metal from at least one of the at least two streams, wherein the heavy metals comprise at least one of titanium, strontium, and vanadium. 
     
     
         16 . (canceled) 
     
     
         17 . The method of  claim 1 , further comprising grinding at least one of the at least two streams. 
     
     
         18 . The method of  claim 1 , further comprising recycling at least one of the at least two streams into the solvent extraction of step a). 
     
     
         19 . The method of  claim 1 , further comprising combining at least one of the at least two streams with tailings generated from an aqueous-based bitumen extraction process. 
     
     
         20 . The method of  claim 1 , wherein the dry tailings have a water: solids mass ratio of less than 0.15:1. 
     
     
         21 . The method of  claim 1 , wherein the oil sands mine site is one of a mine site employing aqueous-based bitumen extraction and a mine site employing solvent-based bitumen extraction. 
     
     
         22 . (canceled) 
     
     
         23 . The method of  claim 1 , wherein one of step a) comprises:
 contacting the bituminous feed with a bridging liquid comprising water, and an extraction liquor comprising a solvent; and separating water from the bitumen-rich stream; and   agitation to form agglomerates comprising solids and water, wherein the agglomerates are in the bitumen-lean stream.   
     
     
         24 . (canceled) 
     
     
         25 . The method of  claim 23 , wherein at least 80 wt. % of the agglomerates of step c) are less than 2 mm. 
     
     
         26 . The method of  claim 1 , wherein the solvent comprises one of an organic solvent and a mixture of organic solvents. 
     
     
         27 . (canceled)