Process for the removal of organic contaminants from solids

Claim 1

A process for the decontamination of solid materials contaminated with hydrophobic organic compounds, the process comprising the steps of: a. providing a mixture of solids with water and contaminant including hydrophobic organic compounds; b. leaching the solids with solvents to obtain contaminated solvent and water and a mixture of decontaminated solids and solvent by: i. removing water from the mixture of step (a) with a hydrophilic solvent to obtain a first liquid steam of water, hydrophilic solvent and contaminant and a first solid steam of solids, hydrophilic solvent and contamininant; ii. removing contaminant form the first solid steam with a comixture of the hydrophilic solvent and a hydrophobic solvent to obtain a second liquid steam of the two solvents and contaminant and a second solid steam of the solids, the two solvents and the remaining contaminant, and iii. removing hydrophobic solvent and remaining contaminant from the second solid steam with hydrophilic solvent to obtain a third liquid steam of the two solvents and the remaining contaminant and a decontaminated third solid steam of solids and hydrophilic solvent; c. stripping contaminant from at least two of the liquid steams with the hydrophobic solvent to obtain an output of decontaminated hydrophilic solvent and an output of hydrophobic solvent and concentrated contaminant; and d. stripping the hydrophilic solvent from the third solid steam to obtain decontaminated solids and decontaminated hydrophilic solvent.