Production
Zinc is the fourth most common metal in use, trailing only iron, aluminium, and copper with an annual production of about 10 million tonnes. Worldwide, 95% of the zinc is mined from sulfidic ore deposits, in which sphalerite (ZnS) is nearly always mixed with the sulfides of copper, lead and iron. Zinc metal is produced using extractive metallurgy. Roasting converts the zinc sulfide concentrate produced during processing to zinc oxide: For further processing two basic methods are used: pyrometallurgy or electrowinning. Pyrometallurgy processing reduces zinc oxide with carbon or carbon monoxide at 950 °C (1,740 °F) into the metal, which is distilled as zinc vapor. The zinc vapor is collected in a condenser. Electrowinning processing leaches zinc from the ore concentrate by sulfuric acid: After this step electrolysis is used to produce zinc metal.
Cadmium is a common impurity in zinc ores, and it is most isolated during the production of zinc. Some zinc ores concentrates from sulfidic zinc ores contain up to 1.4% of cadmium. Cadmium is isolated from the zinc produced from the flue dust by vacuum distillation if the zinc is smelted, or cadmium sulfate is precipitated out of the electrolysis solution.
The richest mercury ores contain up to 2.5% mercury by mass, and even the leanest concentrated deposits are at least 0.1% mercury, with cinnabar (HgS) being the most common ore in the deposits. Mercury is extracted by heating cinnabar in a current of air and condensing the vapor.
Super-heavy elements such as copernicium are produced by bombarding lighter elements in particle accelerators that induces fusion reactions. Whereas most of the isotopes of rutherfordium can be synthesized directly this way, some heavier ones have only been observed as decay products of elements with higher atomic numbers. The first fusion reaction to produce copernicium was performed by GSI in 1996, who reported the detection of two decay chains of copernicium-277.
- 208
82Pb + 70
30Zn → 277
112Cn + n
In total, approximately 75 atoms of copernicium have been prepared using various nuclear reactions.
Read more about this topic: Group 12 Element
Famous quotes containing the word production:
“The production of obscurity in Paris compares to the production of motor cars in Detroit in the great period of American industry.”
—Ernest Gellner (b. 1925)
“The heart of man ever finds a constant succession of passions, so that the destroying and pulling down of one proves generally to be nothing else but the production and the setting up of another.”
—François, Duc De La Rochefoucauld (1613–1680)
“Constant revolutionizing of production ... distinguish the bourgeois epoch from all earlier ones. All fixed, fast-frozen relations, with their train of ancient and venerable prejudices are swept away, all new-formed ones become antiquated before they can ossify. All that is solid melts into air, all that is holy is profaned, and man is at last compelled to face with sober senses, his real conditions of life, and his relations with his kind.”
—Karl Marx (1818–1883)