| 摘要 |
The method of winning metals, esp. Cu, from sulphide ores comprises (a) roasting the ore under oxidising conditions at 400-1400 degrees C to remove elemental S; (b) treating the S-free roasted material in a furance at 400-1400 degrees C to reduce the oxidised material or change the structure of the roasted product; (c) leaching the product in a first soln. contg. a ligant to extract the main fraction of metal; (d) sepg. the solids by filtering; and (e) leaching in a second soln. contg. a ligand. Pref the ore is roasted under oxidising conditions at 650-1000 degrees C and then treated under reducing conditions at 750-950 degrees C using as reducing gas a mixt. of CO/CO2 or H2/H2O. The CO/CO2 ratio is such that Zn- and Cu cpds. are formed, the Zn cpds. being leached without extracting the Cu compd. The leaching soln contains Cu (II) sulphate, water and a ligand such as acetone nitrile, acrylonitrile or allyl alcohol. The sulphuric gases formed are utilized for producing sulphuric acid and other waste gases are removed by treating with aq. lime sludge. The starting material may be an oxide ore in which case the oxidising roasting step is not applied, or may be a metal. |
