A process is disclosed for the recovery of valuable metals from oxidic ores, in particular from polymetallic nodules. The process is suitable for the recovery of Cu, Co, Ni, Fe, and Mn, which are the main metals of interest in such polymetallic nodules. The present process is, among others, characterized by the handling of Fe, which is dissolved and kept in solution until the step of crystallization rather than removed at an earlier stage. A mixed Mn—Fe residue is obtained, which, after thermal treatment, provides a Mn—Fe oxide that is suitable for the steel or for the manganese industry. Excellent Cu, Co and Ni yields are obtained, while Fe is leached and valorized together with Mn.