Removal of contaminants from materials
AssigneeCRI Recycling Service, Inc.
InventorsJohn W. Summerfield, John P. Markiewicz, John M. Moses, Randall L. Barcus
Life of this patent
Estimating the term…
Abstract
An improved approach for cleaning and recycling materials is based on pressurized solvents including liquid propane, butane, dimethyl ether, and supercritical carbon dioxide. The approaches are particularly suitable for cleaning sorbent materials. The approach allows for recycling of the sorbent materials, the solvent and the contaminents, typically oils and the like.
Claims11
A method of removing contaminants from a contaminated sorbent granular mineral material, said sorbant granular mineral material in virgin form having a contaminant absorbency within the structure of the granular particles of at least about 25 percent by weight of said virgin sorbent granular mineral material, said method comprising:
- contacting said contaminated sorbent granular mineral material in a pressure chamber with a pressurized solvent to form a solvent/contaminant mixture and cleaned sorbent granular mineral material, said solvent consisting essentially of a liquefied or supercritical form of ammonia, hydrocarbons or hydrocarbon substituted with functional groups including halogen atoms, oxygen atoms or nitrogen atoms, the solvent being a gas at standard temperature and pressure;
- and
- removing said cleaned sorbent granular mineral material from the pressurized chamber, wherein said cleaned sorbent granular mineral material has at least about 70 percent by weight of said contaminants removed;
- and
- distilling said solvent/contaminant mixture to recover at least a portion of said solvent.
Dependencies are inferred from the claim text.