A method for processing material comprising combinations of aluminum and plastic, such as aluminum bottle caps having a plastic coating, comprising the steps of: pyrolyzing the plastic in an inert atmosphere, cracking or gasifying the gases or vapours which are released in the course of pyrolysis, afterburning the coke which remains behind on the aluminum in the course or pyrolysis. The gases or vapours released are recirculated and are used, during pyrolysis, as an inert, oxygen-free medium.