Nickel is a soft, silvery-white metallic element that is used in a wide variety of industrial and consumer products. Among the most popular applications are stainless steel, magnets, coinage, and special alloys.
The bulk of nickel mined comes from laterites and magmatic sulfide deposits. Nickeliferous limonite [Fe,Ni)O(OH)] and garnierite (a hydrous nickel silicate) are the primary minerals found in laterites. Pentlandite [Ni,Fe)9S8] is the main mineral in magmatic sulfide deposits.
Natural nickel has a small content of nickel 62, about 3.59%. It is enriched to 98% using the radiochemical method, which involves the transfer of metallic nickel of a natural isotopic composition to nickel tetrafluorophosphine — Ni (PF 3 ) 4. This compound is then sent to a cascade of centrifuges where it is irradiated in a nuclear reactor.
Processes and Applications
A variety of nickel-containing enzymes are present in living cells, including a class of carbon monoxide dehydrogenases. Another class of superoxide dismutase is also present.
Other nickel-containing enzymes include glyoxalase and superoxide anion exchangers. In many bacteria, there is a nickel-tetrapyrrole coenzyme that forms a translocation intermediate between porphyrin and corrin.
Physicochemical and Physical Properties of the Elements
The main physical properties of nickel are its low specific heat capacity, high thermal conductivity, and strong magnetic properties. It has a low melting point, making it useful for forming insulating materials. It is a component of many chemical compounds and alloys. It is also a very corrosion-resistant metal, making it useful for armor plates and burglar-proof vaults.