Since zinc
is also less reactive than carbon, zinc is also extracted using a similar
method to iron.
The main ore of zinc
is zinc blende (zinc sulfide).
The first
step in its extraction after the ore is mined is concentration (or purification),
separation of the ore from the gangue, impurities.
–Crushed
ore is fed into tanks of water containing an oil-detergent mixture and air blown through the
mixture while being stirred.
–Heavier
contaminants sink to the bottom, while the oil coated lighter mineral particles rise to the
surface of the oily froth.
–The
oily mineral particles are then skimmed off with the froth, cleaned and dried.