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Rare metals

  1. Oct 19, 2005 #1
    Is there any way that i can extract magnessium from magnessium sulfate and sodium metal from salt Inside the house.
  2. jcsd
  3. Oct 19, 2005 #2


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    To exactract Na from NaCl, it will require a lt of energy, but it can be done.
    A common was to do it is to melt the salt (NaCl) ad then pass an electric current through the liquid, breaking it apart into Na metal and Cl2 gas. However, since NaCl is an ionic compound, it has a high melting point, 801 degrees C (1474 degrees F), and this is not easily (or safely) achieved in the common home. Not to mention the electrical energy required to split it up and the fact that your producing chlorine gas in your house.
    So this is probably not an inside activity to say the least.

    MgSO4 is an ionic compount too, so the same set of dificulties apply. I suppose you could use the electrolytic method of breaking apart the compound, but the problem is that Magnesium Sulfate melts at an even higher temperature than NaCl (1124 degree C).

    Mg is relitively easy to obtain without making it yourself, but Sodium Metal, not so much.
    Using NaOH instead of NaCl makes the process easier to electrolytically produce sodium metal, but it is still not a good thing to do inside or without the proper safety precautions.
  4. Oct 19, 2005 #3
    Actually magnesium sulfate decomposes at 1124C into sulfur trioxide and magnesium oxide. So you'll be working with the oxide which has a much higher melting point of 2800C.

    Electrolysis of molten magnesium hydroxide would be a better bet. As stated above, there's no real reason (other than for fun) to do this because magnesium can be commonly found (try firestarters).

    Commericially, most reactive metals are derived from the fused chlorides (NaCl, MgCl2), but this can hardly be performed at home. The melting point of NaCl can be reduced significantly by forming a eutectic with CaCl2. Still, I would not try this. Chlorine may be fine to handle in the lab at room temperature, but I would NOT want to have to deal with it at 600+ C!

    Sodium hydroxide here would give you the best shot. If you DO manage to do this successfully you'll have flying burning molten metal on your hands which is quite dangerous to say the least.
  5. Oct 20, 2005 #4
    how much degrees are we talking about here? :smile:
  6. Oct 20, 2005 #5
    To around 600 C. Significant for an industrial operation but not for the home chemist. :frown: Compare that with NaOH's melting point of 318C.
  7. Oct 20, 2005 #6
    2 questions. will CaCl2 lower the melting point of Magnessium sulfate and Is there any way to manufacture NaOH at home?
  8. Oct 20, 2005 #7


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    You sure like to do things the hard way dont you, making your own NaOH.Not that I can blame you, I have been known to do this too all to often.
    But NaOH is even easier to get than Mg, it is sold as "lye" in the form of drain cleaner.
    You could, possible (I am not sure), make it electrolytically, but even if true, it would be much much more trouble than it is worth.
  9. Oct 20, 2005 #8
    The lowest mixtures for magnesium sulfate that I could find did not involve CaCl2, but were:
    K2SO4-MgSO4-Na2SO4 31%-29%-40% 634 C
    MgCl2-MgSO4 81%-19% 657 C
    Ya so basically forget about making magnesium from magnesium sulfate. But, you could react MgSO4 with that NaOH that you want to make :smile:, and make magnesium from the resulting Mg(OH)2 precipitate which melts at 350C. I might just try this sometime for fun. (Note: you can also buy a suspended solution of Mg(OH)2 as a laxative)

    Now for your NaOH...

    1) Where do you live? In the U.S. there are tons of drain cleaners and other cleaning products that are either pure NaOH or a solution of it. This would definently be your best source.

    2) You could make it by reacting quicklime (CaO) with baking soda (NaHCO3).
    CaO + H2O --> Ca(OH)2
    Filter out any excess CaO.
    Ca(OH)2 + NaHCO3 --> NaOH + H2O + CaCO3(s)
    Filter out CaCO3.

    3) Industrially, NaOH is made by elecyrolysis of NaCl with special membranes (see chloro-alkali process).
  10. Oct 20, 2005 #9
    The more things you can make on your own, the more rewarding the whole process seems when you finally reach your goal :biggrin: .
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