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
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—State of Utah, U.S. public relief program (1935-1943)
“I really know nothing more criminal, more mean, and more ridiculous than lying. It is the production either of malice, cowardice, or vanity; and generally misses of its aim in every one of these views; for lies are always detected, sooner or later.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)
“The problem of culture is seldom grasped correctly. The goal of a culture is not the greatest possible happiness of a people, nor is it the unhindered development of all their talents; instead, culture shows itself in the correct proportion of these developments. Its aim points beyond earthly happiness: the production of great works is the aim of culture.”
—Friedrich Nietzsche (1844–1900)