METHODS FOR THE EXTRACTION OF LATERITE METALS AND OCEANIC MANGANESE NODULES

摘要

The selective leaching of metal ions from various iron oxide and manganese oxide containing ores employs intermediary solutions. The leaching processes are based upon a redox acid leach step employing stabilized cuprous ions and, in one instance, a combination thereof with ferrous ions. Leaching is conducted at low temperatures, up to about 90 DEG C. and low pressures, up to about 1.5 MPa and at a pH of about 1.5 to 2.5. Nickel and cobalt recoveries from the ores, employing these processes, will usually equal or exceed 90 percent. The intermediary solutions comprise stabilized acidic cuprous ions Cu+L wherein L is a stabilizing ligand selected from the group consisting of CO, XRCN and Cl-, X being -H or -OH and R being aliphatic having from one to about four carbon atoms. In at least one process, ferrous ions are introduced for a separate leaching step. Additional steps include regeneration of the lixiviant cuprous ion solutions and removing a portion of the copper ions from the copper ion solution before or after the step of regenerating. Several processes for the regeneration are possible employing quinolic compounds, H2, CO or syngas as reductants.