Abstract: A process and apparatus is disclosed for removing volatile contaminants from scrap metal. The process is carried out in a furnace maintained at a relatively constant temperature having a first zone in which volatiles contained on the surface of the metal are vaporized and a second zone in which carbon contained on the surface of the metal is pyrolyzed. The furnace also has a vibrating conveyor for transporting metal therethrough at a specific speed. The process includes the step of vaporizing and fluidizing the volatiles to produce fumes containing unburned hydrocarbons without oxidizing the metal. The hydrocarbon fumes are then burned to produce hot gas which is recirculated to the furnace so as to contact new incoming scrap metal.

Abstract: A control system controlling the movements of a pneumatic percussion tool for breaking crust away from anode butts in an electrolysis cell. The system comprises a control arm extending through first and second plates connected to respective first and second valve stems. In a preferred embodiment, the first valve stem operates a hydraulic scissors jack for extending and retracting the tool, and the second valve stem operates a hydraulic rotator motor for radially rotating a mast supporting the tool. A preferred system also comprises a pneumatic control valve connected to the control arm for positioning and energizing the percussion tool.