| 摘要 |
<p>A process for recovering non- ferrous metal values from a sulphide concentrate containing at least one non-ferrous metal selected from zinc, copper, lead, cobalt, nickel, silver and gold, as well as iron, comprises leaching the sulphide concentrate in at least one leach stage including a primary leach stage in which the sulphide concentrate is leached under oxidising conditions with an acidic aqueous chloride solution containing calcium chloride, thereby to solubilise non-ferrous metal values in the material and to leave a residue comprising iron in oxide or hydrated oxide form and calcium sulphate, passing resulting non-ferrous metal- containing chloride leach liquor to an ion exchange stage in which non- ferrous metal values are recovered by cation exchange, maintaining pH conditions in the ion exchange stage favourable for cation exchange by addition of a pH control agent comprising a material selected from CaO, Ca(OH)2, CaCO3, and mixtures thereof, and recycling an aqueous calcium chloride-containing raffinate from the ion exchange stage to the primary leach stage.</p> |
