Method for recovery of hydrocarbons form contaminated soil or refuse materials

Claim 3

A method according to claim 1 wherein said feedstock comprises oil-contaminated soil, said solid inert organic fraction comprises soil and said organic matter comprises said oil.

Claim 4

A method according to claim 2 wherein in said step (a) said first mixture comprises said oil-contaminated soil at a solids concentration in the range of about 25-90% in water at a temperature in the range of about 60°-95° C., and said particulate coal; wherein said ratio of oil to dry coal is in the range of about 1.0:10 to about 4.0:10; in said step (b) said first mixture is tumbled for about 5-15 minutes; then screened to separate particles therefrom of average diameter greater than about 1.0 mm; in said step (c) said frothing agent is selected from the group consisting of polymeric, anionic and cationic surfactants and is added to said resultant mixture in an amount of about 0.01-0.10% by weight based on the total amount of said coal; in said step (d) said agitation is accomplished by injecting air to said second mixture with mechanical mixing at a temperature in the range of about 40°-60° C.; and subsequent to said step (e), further comprising the steps of allowing the remaining portion after removal of said froth of said second mixture to resettle to form cleaned soil and supernatant water, and separating said clean soil from said supernatant water.

Claim 5

A method according to claim 3 wherein said particulate coal in said first mixture consists essentially of particles which pass through sieves having opening of 600 microns in size.

Claim 6

A method according to claim 1 wherein said feedstock comprises tar wastes, said solid inert inorganic fraction comprises sand and said organic matter comprises tar.

Claim 7

A method according to claim 5 wherein in said step (a) said first mixture comprises said tar wastes combined with an aqueous slurry of water and particulate coal which is maintained at a temperature in the range of about 60°-85° at a pH in the range of about 7-9, wherein the ratio of said tar to dry coal and said first mixture is in the range of about 1.0:10 to 4.0:10; wherein in said step (b) said first mixture is tumbled for about 5-15 minutes, then screened to separate the particles therefrom of average diameter greater than about 3 mm; and further comprising the steps subsequent to step (b) of step (b)(1) agitating said first mixture with high shear force for about 2-5 minutes to form agglomerates; and step (b)(2) adding sufficient water at a pH of 7-7.5 to the agglomerate-containing mixture from step (b)(1) to obtain a concentration of about 5% by weight total solids; then proceeding according to said step (c), wherein said frothing agent is selected from the group consisting of polymeric, cationic and anionic surfactants is added to said resultant mixture in an amount of about 0.01-0.1% by weight based on the total amount present of said coal; and in said step (d) said agitation is accomplished by injecting air to said second mixture with mechanical mixing of said second mixture; and subsequent to said step (e), further comprising the steps of (e)(1) washing said froth over screens with 300-400 micron openings and collecting the resulting cleaned agglomerates; and step (e)(2) collecting the washing from step (e)(1) and combining same with the remaining portion of said second mixture from step (e) to form a third mixture; and step (e)(3) cycloning said third mixture to separate sand contained therein from said third mixture.

Claim 8

A method according to claim 6 wherein said particulate coal in said first mixture consists essentially of particles passing through sieves having size openings of 600 microns.