How is zinc mined?

Answer 1

Zinc is mined either by underground or open-pit mining or a combination of both.
Underground mining is done when the rocks, minerals, or gemstones are too far underground to get out with surface mining.Open-pit mining is a kind of surface mining. Mining companies choose this way to get rocks and minerals out of the ground because it is the easiest and cheapest way to do it. Open-pit mining is only used if the rocks or minerals are close to the surface of the land or if a normal tunnel-type of mine isn't possible

Answer 2

There are zinc mines throughout the world, with the largest producers being Australia, Canada, China, Peru and the U.S.A. Mines and refiners in Europe include Umicore in Belgium, Tara, Galmoy and Lisheen in Ireland, and Zinkgruvan in Sweden. Zinc metal is produced using extractive metallurgy. Zinc sulfide (sphalerite) minerals are concentrated using the froth flotation method and then usually roasted using pyrometallurgy to oxidise the zinc sulfide to zinc oxide. The zinc oxide is leached in several stages of increasingly stronger sulfuric acid (H2SO4). Iron is usually rejected as Jarosite or goethite, removing other impurities at the same time. The final purification uses zinc dust to remove copper, cadmium and cobalt. The metal is then extracted from the solution by electrowinning as cathodic deposits. Zinc cathodes can be directly cast or alloyed with aluminium.

Electrolyte solutions must be very pure for electrowinning to be at all efficient. Impurities can change the decomposition voltage enough to where the electrolysis cell produces largely hydrogen gas rather than zinc metal.

There are two common processes for electrowinning the metal, the low current density process, and the Tainton high current density process. The former uses a 10% sulfuric acid solution as the electolyte, with current density of 270–325 amperes per square meter. The latter uses 22-28% sulfuric acid solution as the electrolyte with current density of about 1000 amperes per square meter. The latter gives better purity and has higher production capacity per volume of electrolyte, but has the disadvantage of running hotter and being more corrosive to the vessel in which it is done. In either of the electrolytic processes, each metric ton of zinc production expends about 3900 kW·h (14 MJ) of electric power