Marine polymetallic nodules or marine nodules are rocky bodies formed in the oceanic crust, where they are present in most oceans, at depths of 4,000 m. These mineral resources are characterized by having a high concentration of valuable metals such as Mn, Ni, Co, Cu, Fe, Te and rare earths. For the treatment of these, various investigations have been carried out in the recovery of metals such as segregation by roasting, ammonia and chlorinated leaching. From the exposed mechanisms, it is concluded that the most appropriate method for the treatment of marine nodules is acid leaching with iron reducing agents.