Abstract: Apparatus is disclosed for the thermal decomposition or pyrolysis of shredded vehicle tires. Interially of a pyrolysis chamber is mounted a hollow shaft which carries on at least a portion of its outer surface, a conveyor flight and a plurality of partial flights which compact, mix and stir the rubber shreds during the decomposing cycle. Undecomposed rubber, fiberglass, carbon and metal products are collected at the end of the decomposition chamber and the gaseous products of decomposition are separately collected and sent through a fractionator. Externally of the decomposition chamber is a screen type magnetic separator which removes the magnetic susceptible metal particles and the carbon passes through the rotating cylindrical screen. Undecomposed rubber, fiberglass and the like are removed from the screen and separately treated.