MINERAL UTILIZATION
In
preparation for the smelting process, the ore is crushed
and concentrated by a flotation method. The concentrated ore
is melted in a smelting furnace where impurities are either
burned-off as gas or separated as molten slag. This step is
usually repeated several times to increase the purity of the
metal.
For
the electrowinning method ore or mine tailings are
first leached with a weak acid solution to remove the desired
metal. An electric current is passed through the solution
and pure metal is electroplated onto a starter cathode made
of the same metal. Copper can be refined from oxide ore by
this method. In addition, copper metal initially produced
by the smelting method can be purified further by using a
similar electrolytic procedure.
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