Patent ID: 6312528
Filing Date: 2001-11-06
Classification: B08B,C09K,C11D,Y02P

Abstract:
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; andremoving 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; anddistilling said solvent/contaminant mixture to recover at least a portion of said solvent.