Sciencemadness Discussion Board

Can Magnesium be extracted from epsom salt easily

c-3h-8 - 3-5-2011 at 18:29

Can Magnesium be extracted from Epsom salt easily either by plating it on a metal or chemically somehow.

Neil - 3-5-2011 at 18:41

Magnesium is prepared by electrolysis of it's molten chloride. So I guess your answer would be no.


cyanureeves - 3-5-2011 at 18:50

i read here that it cannot because there is no magnesium metal in epsom salt rather a magnesium ion. i added ammonium hydroxide to epsom salt to supposedly get magnesium hydroxide precipitate and ammonium sulphate solution. sure as heck i got a white precipitate and a solution that when dried was also a white solid about 8 times more than the precipitate. they were both hard as heck to dry. maybe the magnesium hydroxide?

Neil - 3-5-2011 at 20:17

Yes... and if you calcine it you will have MgO or magnesium oxide. this can be chlorinated to make MgCl2 which can be electrolyzed to yield Mg metal. It might be possible to super heat MgO with Lithium or Sodium to recover Mg gas, you can react MgO with carbon at around 2000C° but then you would have 2000C° Mg gas, and good luck containing that.

but no, no Mg straight from MgSO4

symboom - 4-5-2011 at 00:08

electrolysis of magnesium oxide in molten calcium chloride then you don't have to worry about chlorine gas carbon dioxide when using a graphite gouging rod is evolved instead

-melting point of calcium chloride 1,421.6F
-melting point of magnesium metal 1202 °F
might be able to get away without argon which you can get from a welding supply then again you dont want a white hot raging fire

2 ways to magnesium hydroxide to eventually form magnesium oxide by pyrolysis of magnesium hydroxide to oxide.

-first electrolysis of magnesium sulfate to form magnesium hydroxide and sulfuric acid using an ion exchange resin(or mgso4 salt bridge)

-another simpler way
ammonium hydroxide reacts with magnesium sulfate
forming magnesium hydroxide and ammonium sulfate


ScienceSquirrel - 4-5-2011 at 03:34

Magnesium is readily and cheaply available as ribbon, turnings and powder in most places.
It is also used in pencil sharpeners, hard disc cases, survival fire lighters, etc.
It is very hard to make in a laboratory and will cost you a lot more than buying it.

c-3h-8 - 4-5-2011 at 04:10

So if I get some Magnesium Chloride at a fish store I could extract Magnesium by electrolysis and does anyone know how to do this what anode and cathode, temperature ,voltage, and would anything else be needed in the water MCl solution? Also was wondering can Magnesium be anodized?

blogfast25 - 4-5-2011 at 04:32

@ c-3h-8:

This is your answer.

Quote: Originally posted by ScienceSquirrel  
Magnesium is readily and cheaply available as ribbon, turnings and powder in most places.
It is also used in pencil sharpeners, hard disc cases, survival fire lighters, etc.
It is very hard to make in a laboratory and will cost you a lot more than buying it.


You're very obviously a beginner. Not one experimenter here, not even the most experienced, has ever tried the electrolysis of molten, anhydrous MgCl2 to obtain the metal (it doesn't work in solution).

Look up the process on the Tinkerwebs and by all means study it for your knowledge base (there's nothing on the subject that we could teach you that you can't find in basic web pages on it). But to try this at home lab level isn't just folly... it's also an UNNECESSARY folly!

[Edited on 4-5-2011 by blogfast25]

froot - 4-5-2011 at 07:05

You can obtain milk of magnesia at a local chemist.

Basically - (the principle, not the procedure)

Heat it above 400 deg C to dehydrate it leaving MgO.

Mix the MgO with carbon powder and heat it in a closed vented steel capsule to about 1000 Deg C.

MgO + C -> Mg + CO

Decant the molten Mg while it is above 700 deg C

If the molten Magnesium comes in contact with oxygen or water at any stage you may very well end up miamed for life. Think about that very carefully when you design the capsule and the decanting procedure.


Neil - 4-5-2011 at 07:50

Quote: Originally posted by ScienceSquirrel  
Magnesium is readily and cheaply available as ribbon, turnings and powder in most places.
It is also used in pencil sharpeners, hard disc cases, survival fire lighters, etc.
It is very hard to make in a laboratory and will cost you a lot more than buying it.


You can test to see if something is Mg or Al by preforming a spark test against a grinding wheel. Mg will spark, Al will not.

m1tanker78 - 4-5-2011 at 08:19

From experience, magnesium formed by molten electrolysis is very short-lived. You'll see a bright blue-white flash of light and be glad you were wearing protective gear (or possibly spend some time in your favorite hospital trying to rescue your eyesight if no protective gear). A fair bit of molten electrolyte is ejected in the process. I'm sure there's a way to tame the hot Mg some but it's not worth the time or effort IMO. Trying to do this in an inert environment puts it out of reach for most experimenters.

Mg fire starter: ~$2.49 (USD) for 25 grams or so. That's roughly 10 cents a gram. Even yours truly went out and bought a couple of Mg fire starter blocks for a rainy day. :P

Tank

blogfast25 - 4-5-2011 at 08:42

Quote: Originally posted by froot  

Mix the MgO with carbon powder and heat it in a closed vented steel capsule to about 1000 Deg C.

MgO + C -> Mg + CO

Decant the molten Mg while it is above 700 deg C

If the molten Magnesium comes in contact with oxygen or water at any stage you may very well end up miamed for life. Think about that very carefully when you design the capsule and the decanting procedure.



Please don’t give advice to people about procedures you’ve never carried out yourself. The MgO-C method is possibly even more dangerous and difficult to carry out in home lab circumstances, even more so by beginners.

This whole ‘let’s make some Mg at home’ lark is simply a nonsense.

The answer to 'Can Magnesium be extracted from epsom salt easily?' is a resounding 'NOOO'. It's pointless to encourage people to try and do the impossible...

Mixell - 4-5-2011 at 08:53

I support blogfast, this procedure is quite dangerous and hard to achieve at laboratory conditions (not to mention in a home lab setup). One thing to try to isolate very expensive and hard to get reagents/elements, but doing so for getting magnesium (which is cheap as crap in the USA and most of the modern world) is pointless and even can be called stupid, risking your eyesight, your body and even your life for a thing that you can buy everywhere is a something that should not be done.

Neil - 4-5-2011 at 09:05

Quote: Originally posted by froot  

Mix the MgO with carbon powder and heat it in a closed vented steel capsule to about 1000 Deg C.



Vented and closed?

The lit gives a temperature of 1800°C to 2000°C for this reduction at standard pressure. Or around 1200°C in a vacuum.



Magnesium can also be obtained free as sacrificial electrodes from water heaters, scrapped sacrificial anodes from ships/boats, transmission casings from certain vehicles, if you live near a Pratt and Whitney plant or any other high tech manufacture they often produce large amounts of Mg Mg/Al and Al scrap. Mg alloy tire rims are easily damaged and could be a possible source of large amounts of Mg.