Abstract: The present invention relates to a method for treating of oil contaminated, metal-containing solids, in particular spent catalysts. The solids are cleaned with a dense phase gas and then metal is recovered from the cleaned solids.

Abstract: A method for cleaning objects is disclosed. The method includes placing the objects into a cleaning chamber and contacting them with a dense phase gas. After draining the dense phase gas from the cleaning chamber, the pressure in the cleaning chamber is changed at a rate of at least 1 bar per minute, preferably at a rate of 5 bar per minute, more preferably at a rate of 10 bar per minute.

Abstract: A method for cleaning objects in a cleaning fluid is disclosed. The cleaning fluid initially includes a dense phase gas and water and in a subsequent cleaning step at least part of the water is filtered out of the cleaning fluid.

Abstract: A method is provided for processing parts in more than one bath of dense phase carbon dioxide wherein the processing includes transferring dense phase carbon dioxide from a storage tank to a cleaning chamber, processing said parts in said cleaning chamber with said dense phase carbon dioxide, withdrawing at least a part of said dense phase carbon dioxide from said cleaning chamber, distilling said withdrawn dense phase carbon dioxide, and transferring said distilled carbon dioxide back to said storage tank, wherein said distilled carbon dioxide is cooled prior to being transferred to said storage tank and said cooling is carried out depending on the temperature and/or the pressure in the storage tank and/or the cleaning chamber.