Sciencemadness Discussion Board

Magnesium Nitrate

Mr.O-Nitrate - 29-11-2003 at 18:48

I just ordered some Magnesium Nitrate and wondered if I could use that instead of KNO3 for black powder?

If I did would this give off white sparks as it deflagrates?

I am looking around for information but it's looking slim.

[Edited on 30-11-2003 by Mr.O-Nitrate]

[Edited on 30-11-2003 by Mr.O-Nitrate]

Magnesium nitrate

Magpie - 29-11-2003 at 20:58

I have a little practical experience (on-the-job) with what we believe is magnesium nitrate in an aqueous waste stream of mixed salts. When we tried to dry the mixed salts we would get a gummy mass which screwed everything up. We guessed that magnesium nitrate was staying as a hydrate at the dryer temperature (360 F) since as IIRC it is strongly deliquescent. We dealt with the problem by ppt the Mg with NaOH. So - are you getting a hydrate? I suspect so, and if not, I'm guessing it will pull water from the air agressively to form a hydrate. So I'm suspecting this might not be too practical as an oxidant. I will be interested to see what you find out in experimentation.


JDP - 29-11-2003 at 21:42

Mg(NO3)2 is an extremely hygroscopic nitrate; if you leave it out overnight expect to comeout the next morning to a nice puddle of solution. I once made a decent quantity of the nitrate by desolving 5g of Mg into 100mls of HNO3 the reaction was very vigorus and vaporised half the HNO3, when cooled the solution quickly precipitates large quantitys of cristals to whitch 50mls of water were added and it was boiled down to drive off all the water/acid, then I was satisfyed that the nitrate wasnt hygroscopic, boy was I wrong. I believe if you are to try makeing a BP type of explosive out of it you will have to keep the mix very dry at all times.

Microtek - 30-11-2003 at 04:22

Do any of you know at what temperature Mg(NO3)2 gives off all its water of crystallization ? I want to experiment with using it to dehydrate 62% HNO3 ( ie, as a substitute for H2SO4 in HNO3 concentration ).

vulture - 30-11-2003 at 06:17

100C. Be wary of your vessel though, like MgSO4 it rapidly forms a solid rock hard block when crystallizing anhydrously. I ruined some glassware that way.

1 more thing...

Mr.O-Nitrate - 30-11-2003 at 08:49

How sensitive is Magnesium Nitrate after it has been mixed with a fuel?

Is the sensitivity like KNO3 or like Potassium Chlorate?

[Edited on 30-11-2003 by Mr.O-Nitrate]

[Edited on 30-11-2003 by Mr.O-Nitrate]

Uh oh..

Mr.O-Nitrate - 30-11-2003 at 10:22

I read on the msds sheet for Mag Nitrate that...
Dimethyl formamide, combustible, organic and oxidizable materials."

Does this mean when I add somthing like powdered sugar, it will spontaneously ignite?

trinitrotoluene - 30-11-2003 at 12:24

How much did you buy the magnesium nitrate for?
If your planning to use it as an oxidizer its definately not worth it as its a hydrate, which means nearly half of its weight is water, so after it's dried you only going to nearly half the amount you started with.

Haggis - 30-11-2003 at 12:37

Most oxidizers have that labeling on it so they do not burn violently if a spark happens to reach them while mixed with a fuel. This is exactly what you want it to do. No, it shouldn't spontaneously ignite with simple sugar.


Mr.O-Nitrate - 30-11-2003 at 13:28

I dont plan on mixing with water anymore.

I plan on using a mortar and pestle. I have about 30 grams but I can't remember how much it was.

I think i can grind it all I want because there are no metals with the Mg(NO3) and powdered sugar. The only concern would be heat build up from friction.

flash powder

tom haggen - 30-11-2003 at 14:35

could anyone point me in right direction on searching for a complete list of flash powder compostions. I have been limited to using aluminum as my only fuel. i'm also looking for flash powders using magnesium nitrate as a oxidizer

[Edited on 1-12-2003 by tom haggen]

[Edited on 1-12-2003 by tom haggen]

unionised - 30-11-2003 at 15:33

WTF has that got to do with this thread?
Anyway, I looked in Bretherick to see what it said about mag nitrate/ DMF. It says that a possible cause of the reaction is" hydrolysis of the hexahydrate above its melting point (90C) to liberate nitric acid"
That is about as close as I have found to any data on the dehydration temp of mag nitrate; it hydrolyses and loses acid above 90C. Of curse, it won't do this at the same temp in the presence of nitric acid.

Microtek - 1-12-2003 at 07:27

I tried diluting technical nitric acid ( 62 % ), with distilled water and neutralised with MgCO3. The clear solution was placed in an oven at 200 C for several hours. No HNO3 was given off, but on cooling, a solid mass of white material solidified in the glass container. It was incredibly hard and I had to dissolve it again to remove it.