Richard A Marshall

US Patent:

59222778, Jul 13, 1999

Filed:

Jul 22, 1997

Appl. No.:

8/898706

Inventors:

Ron Donhoff - Alhambra CA
Thomas W. Robertson - San Pedro CA
Richard Marshall - Arroyo Grande CA

International Classification:

B03B 900

US Classification:

422 1

Abstract:

A recycling system treats petrochemical types of hazardous waste for disposal. Such waste typically includes in large part, a mixture of hydrocarbons, water, solids (soil particulate), and metals. The recycling system separates the water, solids, hydrocarbons, and metals from one another. The recycling system includes the following processing steps: (1) mixing the hazardous waste with a water-miscible washing medium, and agitating the mixture for separating water and some hydrocarbons from solids; (2) removing hydrocarbons from solids by mixing the solid/hydrocarbons with a washing medium that is nonmiscible with water, and agitating the mixture for dissolving hydrocarbons in the solids; (3) removing metals from the separated solids by mixing the separated solids with an acidic washing medium, and agitating the mixture for dissolving metals from the separated solids into liquid solution; and (4) subjecting the separated solids to an alkaline washing solution for neutralizing acidity in the separated solids, and thereafter drying the separated solids for removal of moisture for disposal of the separated solids. Processing in accordance with the invention, provides separated water and soil particulate substantially free of contamination by hydrocarbons and/or toxic/RCRA metals, and thus may be reintroduced into the environment, the water sewered, and the metals recycled.