| 摘要 |
<p>1502986 Iron and nickel oxides INCO Ltd 20 March 1975 [26 March 1974] 11551/75 Heading C1A [Also in Division C7] Ferronickel is produced from a nickeliferous iron-bearing sulphide material by roasting the sulphide at 500-1200‹ C. in a gas containing free oxygen to a calcine containing less than 0À5 wt. per cent S, and reduction smelting the calcine to Fe-Ni. The sulphide material may be ore, ore concentrate, or sulphided scrap, and contains at least 1 wt. per cent N. Suitable ores are pyrrhotite, pentlandite and chalcopyrite which may be crushed, concentrated by a flotation process, dewatered, agglomerated and fed to a fluidized bed roaster at a temperature sufficient to remove As, Sb, Bi, Pb, Se, Te, Sn and Zn by volatilization. If after roasting, the ratio of Ni: Cu is less than 75: 1, the calcine may be chlorinated with a gas containing a small amount of Cl 2 . The calcine may be prereduced prior to smelting with, e.g. coke, anthracite or charcoal, in an electric arc furnace.</p> |
