| 摘要 |
Cu, Ag, Ni, Co and/or Zn are recovered from their sulphide ores by leaching with a 30-50 vol.% HNO3 soln., heating the soln. to a temp. at or above the m.pt. of sulphur while the soln. is held under pressure in a relatively inert atmos., controlling the temp. of the soln. to ppte. sulphur, separating the sulphur and recovering metal values from the acid soln. Using a leaching time of as little as half an hour, 99+% metal recoveries are obtd.; the leaching operation selectively insolubilities iron or sulphur in the ore so that these can be readily separated as a commercially valuable by-product; the leach soln. lends itself to known preferential pptn. metal recovery techniques; the metal values can be solvent extracted without the problems of lasting pptes. forming in the leach soln. and fouling the extn. process; iron can be economically removed from the leach soln. without addn. of large amts. of acid neutraliser. |
