摘要 |
<p>ABSTRACT A process is described for leaching a value metal from an ore containing said value metal, the process including the steps of leaching the ore in the presence of hydrochloric acid so as to form a soluble metal-chloride salt in a leach solution; adding sulphuric acid and/or sulphur dioxide to the leach solution; recovering a solid metal-sulphate or metal-sulphite salt from the leach solution; regenerating hydrochloric acid; and continuously transferring at least a portion of the regenerated hydrochloric acid in solution to the vapour phase. The vapourised hydrochloric acid is then captured and returned to the leaching step. The sulphuric acid and/or sulphur dioxide may be added to the leach solution during or after the leaching step. The value metal is typically selected from the group consisting of Zn, Cu, Ti, Al, Cr, Ni, Co, Mn, Fe, Pb, Na, K, Ca, platinum group metals and gold. The metal in the metal-sulphate or sulphite salt may be the value metal, or may be a metal of less value than the value metal, such as magnesium.</p> |