| abstract |
A process is described for leaching a value metal from an iron-containing ore, the process including the steps of leaching the ore in an acidic sulfate solution so as to form an iron-sulfate salt in a leach solution; adding sulfur dioxide to the leach solution during and/or after the leaching to regenerate acid; and recovering the iron-sulfate salt from the leach solution. The value metal is typically Zn, Cu, Ti, Al, Cr, Ni, Co, Mn, Fe, Pb, Na, K, Ca, Ag, Au or a platinum group metal. The leaching solution can also include chlorides. One or more value metals, such as nickel and/or cobalt, may be recovered with the iron sulfate salts and can subsequently be separated from the iron sulfate salts. The recovered iron sulfate salts can be decomposed to iron oxides without decomposing the sulfate salts of the other metals or whilst also decomposing the sulfate salts of the other metals, those other metals being recovered by posttreatment of the iron oxide calcine. The regenerated acid is typically recycled within the leach process. |