Can you help me make home brewed magnesium?

December 3, 2006 10:35 PM

Can you help me make home brewed magnesium?

To be specific, the form of magnesium used in survival kit fire starters.

I've been on this little survival kick lately after watching some TV shows and began wondering if you could produce magnesium in the wild..

My original question was going to ask if it might be possible when stranded on an island with a downed plane (for parts), to somehow make magnesium for flares and such using electrolysis of sea water. After doing a bit of research now I just want a recipe for making it here in civilization.

From what I understand the most common way of deriving magnesium is from electrolysis of magnesium chloride produced from sea water. You end up with magnesium chloride after removing the sodium chloride from the water and letting the water evaporate.

I'm not really sure what the ratio of magnesium is in sea water. One of my sources claims it's 0.13% but the sodium/magnesium chloride ratios seem to depend on location. The Dead Sea for instance has only 8% sodium chloride and 53% magnesium chloride.

That's about as far as I got.

Basically what I want is to visit the hardware store and the beach and start making some magnesium. Possible?

Take it away hive!

posted by sipher to science & nature (6 comments total)

You're aware you can obtain magnesium powder and magnesium ribbon quite easily, right? You're just interested in learning to purify it at home?
posted by ikkyu2 at 10:38 PM on December 3, 2006

Right. I just want to make it myself.
posted by sipher at 10:53 PM on December 3, 2006

well, you have to melt the salt, which means you need to get it above 700 C, then stick in some wires (i'd go with tungsten, prolly) and attach a current source, and off you go! you'll end up with magnesium-plated tungsten. you can then melt the magnesium off at ~1000 C. do the electrolysis in a well-ventilated area since Cl₂ gas is pretty bad for you.
posted by sergeant sandwich at 11:09 PM on December 3, 2006

http://www.magspecialties.com/students.htm
http://www.gcsescience.com/ex7.htm
posted by farmersckn at 12:14 AM on December 4, 2006

An alternate process.

Please don't try to make magnesium at home. You will need to deal with high temperatures and toxic chemicals. The finished product burns easily and is difficult to extinguish.
posted by b1tr0t at 12:27 AM on December 4, 2006

My original question was going to ask if it might be possible when stranded on an island with a downed plane (for parts), to somehow make magnesium for flares and such using electrolysis of sea water.

Not an answer, and it's probably already occured to you, but since you would be essentially applying energy to undo the combustion process of magnesium in order to put it back in it's high-energy pure state, it will require you to put in more energy to make the magnesium than will be released when you burn the finished product. Therefore, your survival strategy would be greatly enhanced by cutting out the middle man (the magnesium) and instead appling all that energy directly to the problem (be it creating a signal flare, starting a fire, whatever).
posted by -harlequin- at 12:40 PM on December 4, 2006