Nickel

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Nickel
Chemical formula Ni
Atomic Number 28 
OTP appearance silver solid 
Molar Mass(g/mol) 58.7 
Melting Point(°C) 1455 
Boiling Point(°C) 2730 
Density(g/cc) 8.9 
Coefficient of Thermal Expansion(×10-6 °C-1) 13.3
NFPA 704
NFPA704.png
4
2
1
 

Uses

Primary

Secondary

  • As an alloy with chrome (nichrome) for electrical heating elements
  • -carbonyl can be used to nickel-plate metals

Natural Occurrence

  • Elemental nickel occurs in meteorites, but rarely.
  • -sulfide in pentlandite
  • minority constituent (1-3%) goethite

Hazards

  • -carbonyl is toxic
  • Many nickel salts are carcinogenic

Production

Extraction

Elemental Nickel

  • from -sulfide via calcining and carbothermic reduction
    2 NiS + 3 O2 NiO + 2 SO2
    NiO + C Ni + CO

Purification

Typically, Nickel occurs with problematic amounts of iron and/or cobalt.

  1. Repeat
    1. Treat powdered impure nickel oxides with hydrogen at 200°C to reduce the oxides to nickel.
      NiO(s) + H2(g) Ni(s) + H2O(v)
    2. Expose the impure metal to carbon monoxide forming -carbonyl gas
      FeCoNi(s) + 4 CO(g)
      {
      60-220°C}
      Ni(CO)4(g) + FeCo(s)
    3. Separate the -carbonyl gas from the solid impurities
    4. Decompose the -carbonyl at 250°C, leaving carbon monoxide to be reused
      Ni(CO)4(g)
      {
      ≥250°C}
      Ni(s) + 4 CO(g)
  2. Until the powder is no longer yielding -carbonyl

Testing

Storage

Disposal

See Also

References