Method for extracting oil from oil-contaminated soil

A method for extracting oil from oil-contaminated sludge comprising the steps of:

• (a) mixing the oil-contaminated sludge with a solvent to form a slurry of oil-contaminated sludge particles suspened in the solvent;
• (b) injecting the oil-contaminated sludge into the upper end of a vertically disposed, hollow chamber of uniform cross-section and substantially simultaneously injecting fresh solvent into the lower end of the hollow chamber that flows upwardly through the hollow chamber at a controlled rate so that the oil-contaminated sludge particles fall by gravity through the the upwardly flowing fresh solvent;
• (c) subjecting the oil-contaminated sludge particles and solvent in the hollow chamber to sonic energy in the frequency range of about 0.5 to 2.0 kHz without cavitation of the solvent whereby the oil on the sludge particles is displaced therefrom and dissolved by the solvent;
• and
• (d) recovering the substantially oil-free sludge particles from the bottom of the hollow chamber.

A method for extracting oil from oil-contaminated drill cuttings comprising the steps of:

• (a) mixing the oil-contaminated drill cuttings with a solvent to form a slurry of oil-contaminated drill cuttings suspended in the solvent;
• (b) injecting the oil-contaminated drill cuttings into the upper end of a vertically disposed, hollow chamber of uniform cross-section and substantially simultaneously injecting solvent into the lower end of the hollow chamber that flows upwardly through the hollow chamber at a controlled rate so that the oil-contaminated drill cuttings fall by gravity through the upwardly flowing fresh solvent;
• (c) subjecting the oil-contaminated drill cuttings and solvent in the hollow chamber to sonic energy in the frequency range of about 0.5 to 2.0 kHz without cavitation of the solvent whereby the oil on the drill cuttings is displaced therefrom and dissolved by the solvent;
• and
• (d) recovering the substantially oil-free drill cuttings from the bottom of the hollow chamber.

A method for extracting oil from oil-contaminated soil particles comprising the steps of:

• (a) injecting the oil-contaminated soil particles into the upper end of a vertically disposed, hollow chamber of uniform cross-section containing a solvent and substantially simultaneously injecting fresh solvent into the lower end of the hollow chamber that flows upwardly through the hollow chamber at a controlled rate so that the oil-contaminated soil particles fall by gravity through the upwardly flowing fresh solvent;
• (b) subjecting the oil-contaminated soil particles and solvent in the hollow chamber to sonic energy in the frequency range of about 0.5 to 2.0 kHz without cavitation of the solvent whereby the oil on the soil particles is displaced therefrom and dissolved by the solvent;
• and
• (c) recovering the substantially oil-free soil particles from the bottom of the hollow chamber.

A method for extracting oil from oil-contaminated sludge particles comprising the steps of:

• (a) injecting the oil-contaminated sludge particles into the upper end of a vertically disposed, hollow chamber of uniform cross-section containing a solvent and substantially simultaneously injecting fresh solvent into the lower end of the hollow chamber that flows upwardly through the hollow chamber at a controlled rate so that the oil-contaminated sludge particles fall by gravity through the upwardly flowing fresh solvent;
• (b) subjecting the oil-contaminated sludge particles and solvent in the hollow chamber to sonic energy in the frequency range of about 0.5 to 2.0 kHz without cavitation of the solvent whereby the oil on the sludge particles is displaced therefrom and dissolved by the solvent;
• and
• (c) recovering the substantially oil-free sludge particles from the bottom of the hollow chamber.

A method for extracting oil from oil-contaminated drill cuttings comprising the steps of:

• (a) injecting the oil-contaminated drill cuttings into the upper end of a vertically disposed, hollow chamber of uniform cross-section containing a solvent and substantially simultaneously injecting fresh solvent into the lower end of the hollow chamber that flows upwardly through the hollow chamber at a controlled rate so that the oil-contaminated drill cuttings fall by gravity through the upwardly flowing fresh solvent;
• (b) subjecting the oil-contaminated drill cuttings and solvent in the hollow chamber to sonic energy in the frequency range of about 0.5 to 2.0 kHz without cavitation of the solvent whereby the oil on the drill cuttings is displaced therefrom and dissolved by the upwardly flowing solvent;
• and
• (c) recovering the substantially oil-free drill cuttings from the bottom of the hollow chamber.