EXTRACTION OF COPPER FROM ORES AND CONCENTRATES

摘要

1496852 Copper recovery DEXTEC METALLURGICAL PTY Ltd 27 Jan 1976 [14 Feb 1975] 03180/76 Heading C1A [Also in Division C7] Cu is leached or recovered from an ore or concentrate containing Cu and Fe by immersion thereof in an acidic electrolyte containing chloride in an amount between that needed to dissolve any Cu+ present and saturation, with intimate admixture of the mixture with air or an oxygen bearing gas, at a temperature of 50‹ C. to boiling, at pH controlled to 1À5-7À0, and at substantially atmospheric pressure. Fe solubilized in the process precipitates as Fe 2 O 3 , any sulphide is reduced to elemental form and the Cu goes into solution. The pH may be maintained with HCl addition or by anodic oxidation of water, in the latter case in the anode compartment of a diaphragm cell on the cathode of which the Cu is recovered. The Cu is alternatively recovered by cementation. A pulsating air stream may be supplied via a porous graphite plate. The electrolyte may be the chloride of NH 4 , Na, Mg, Zn or Mn to which Cu ions may be initially added. The soluble Fe content during operation may be kept below 5 g/l. The extraction of chalcopyrite is best effected at pH 2-2À5 above 70‹ C. Malachite or azurite may be treated.