Magnesium

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Magnesium
Chemical formula Mg
Atomic Number 12 
OTP appearance silver grey solid 
Molar Mass(g/mol) 24.3 
Melting Point(°C) 650 
Boiling Point(°C) 1091 
Density(g/cc) 1.8
NFPA 704
NFPA704.png
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0
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Uses

Justification Questioned

Other

  • structural material
  • high temperature deflagration
  • Key component of Grignard reactions.

Natural occurence

Production

Extraction

from magnesium chloride

A patent[1] covers this process

  1. Produce a saturated solution of magnesium chloride
  2. Add liquid mercury
  3. Run 4-5V through the solution and mercury, amalgamating the magnesium and freeing the chlorine.
    N.B. Good operating percentage is 2-4%Mg (w/w) in HgMg amalgam, which is 15-30% (molar)
    MgCl2(aq) + Hg(l)
    {
    4-5V, 80°C}
    HgMg(l) + Cl2(g)
  4. Flow the mercury out of the tube and cool it, producing a solid and liquid phase
    HgMg amalgam
    {
    0°C}
    Hg5Mg2(s) + Hg(l)
  5. Recycle the liquid mercury into the cell
  6. Heat the solid, boiling the mercury and melting the magnesium
    Hg5Mg2
    {
    ≥ 650°C}
    5 Hg(v) + 2 Mg(l)
  7. Condense the vaporous mercury and recycle
  8. Accumulate liquid magnesium until you have enough
  9. Solidify magnesium

Purification

The most common adulterant is calcium. Magnesium oxalate is soluble in water and calcium oxalate is not.

Testing

Storage

Disposal

See Also

References

  1. US patent 3074861
    Link courtesy Google