| 摘要 |
<p>PROCESS FOR RECOVERING PLATINUM GROUP METALS FROM ORES ALSO CONTAINING NICKEL, COPPER AND IRON A process is described for the separation of platinum group metals (PGM) from ores also containing iron, nickel and copper as sulfides. The minerals in the ore are first concentrated by flotation and the ore concentrate is melted in an electric furnace to form a matte containing at least 95% of the precious metals. The matte is granulated while molten to granules of a mean size not greater than about 210 micrometers (.mu.m) and then pressure leached with sulfuric acid and oxygen to separate the nickel, iron and copper as their respective sulfates, while recovering the PGM as a residue. Concentration of the leach residue by roasting and subsequent acid leaching yields a final PGM product containing the major portion of the precious metals in the ore and substantially all (i.e., at least about 95%) of the precious metals in the ore concentrate and which contains less than 1% total nickel, iron and copper. The iron, nickel and copper in the leach solution can be subsequently recovered and/or discarded as, respectively, natrojarosite, nickel or copper metal or various compounds such as sulfides, hydroxides, or oxides, as appropriate to the specific application.</p> |
