A plant for recovering metals and/or metal oxides from industrial process waste, in particular oil product refining waste, comprises a furnace; a feed line connected to a main inlet of the furnace and configured to feed the furnace with a solid waste containing metals, in particular in oxide form; an outlet line, connected to a solid phase outlet of the furnace and configured to draw a metal-enriched solid phase out of the furnace; the furnace is a belt conveyor furnace having a belt conveyor closed in a loop with a substantially horizontal configuration and having a top face, which receives the waste to treat and conveys it between two longitudinal opposite ends of the belt conveyor furnace respectively provided with the main inlet and the solid phase outlet.