magnesium powder

[hermanntrude]

I have some magnesium turnings but i want magnesium powder. do you think it's safe to grind it in a mortar and pestle? do you think it'd work?

[person]

I wonder if magnesium is brittle onough ..

Mabe if you cooled it with liquid nitrogen:D

[UC]

I have some magnesium turnings but i want magnesium powder. do you think it's safe to grind it in a mortar and pestle? do you think it'd work?

 

It'd be safe to try a mortar and pestle, but I can almost guarantee you that it wont work. You're going to mash all the bits of metal together and not much else.

 

You could try the magnesium in light mineral oil in a blender for a while, then repeated washings with hexane. I've made very fine aluminum powder with the standard ball-mill method, but I suspect that Mg is far too reactive to be ground for a week and a half and not be all oxide. A little oil in there with it would impede proper grinding by making the powder clump.

 

What is the powder for?

[hermanntrude]

i want to try this reaction

 

Ive done it once with magnesium turnings and it was OK but i didnt get a fireball, just pop pop pop. i think it was the silane that was popping and the magnesium that was fizzing.

[UC]

If that's the case, you may want to put quartz sand and the turnings in the mortar and pestle and see if you can grind it directly together. The sand should be a nice abrasive and will probably help get the magnesium much finer.

[person]

Would that reaction work the same with aluminium powder ??

[hermanntrude]

Would that reaction work the same with aluminium powder ??

 

in theory, yes, but the trouble with aluminum is is creates aluminum hydroxide on its surface which is almost impenetrable. Perhaps a drop of mercury might start it off, but i wouldnt want to try it like that.

 

I tried it today with the turnings and it kind of works, but it's not as spectacular. One thing that i didn't foresee which i should have done is that the magnesium reacts with the test-tube itself, since that's essentially made of silica too. Don't expect to keep the test-tube afterwards :0) I also allowed the mixture to cool to very close to room temperature before tipping it into the acid, just to minimise the risk since the article didn't say whether they cooled it or not.

 

I'll upload the video to youtube.

[UC]

Would that reaction work the same with aluminium powder ??

 

Essentially a silicon thermite then. It will take a lot of heat to start. Look at how close the electronegativites are as well. I think it would be more of an intermetallic/semimetallic than an actual silicide capable of forming silane upon acidification.

 

You would still produce silicon, just mixed with alumina and possibly dissolved/alloyed with excess aluminum.

[hermanntrude]

that's basically what happens with magnesium too. you don't get anything like a complete reaction.

 

here's the video :0) enjoy