Sciencemadness Discussion Board

Aluminum Powder

elementcollector1 - 2-9-2012 at 21:07

What can I use for thermite?
-Aluminum foil, ball milled until fine powder: Failed every time for me so far, don't know why.
-Powdered metal lumps: Haven't tried, will probably work better.
-Official source (e.g. Elemental-Scientific, etc.)

hyfalcon - 3-9-2012 at 00:53

http://alphachemicals.com/aluminum_powder

Works quite well with all my regular thermite reactions I've tried. I'm going to start working on the TiO2 thermites next.

siegfried - 3-9-2012 at 14:51

Use 3 parts by weight of Technical grade Ferric(ous)Oxide Fe3O4 and 2 parts by weight of Aluminum powder 100 mesh for the best results. Ignite by magnesium ribbon or KClO4/Mg mix using a fuse (flash powder). Can be stored dry in a glass bottle for many years.

Example: 60g Fe3O4 + 40g Al = 100g Thermite

elementcollector1 - 3-9-2012 at 15:20

Well, I'm not so much interested in the classical iron thermite as in the other possible thermites, like chromium, or manganese. I want to know either if there's something wrong with my existing stock, or if I'm igniting it wrong.

triplepoint - 3-9-2012 at 17:58

So, you're interested in exotic thermites? Perhaps you should take alook at the exotic thermite thread: http://www.sciencemadness.org/talk/viewthread.php?tid=10249&...

platedish29 - 3-9-2012 at 18:43

Thats much mote way liker exodia o0
..
seems proud of blender volcano

elementcollector1 - 3-9-2012 at 21:31

I guess I'll try cutting through some aluminum scrap I have, then. Aluminum should be able to ignite on its own, correct?

Poppy - 3-9-2012 at 22:07

Drop iron oxide inside molten aluminum. You don't have to put your head right above the demonstrating reaction.
It's denser, and will submerge.
Bro tip: add coating to the oxide.

hyfalcon - 4-9-2012 at 02:36

You trying to get someone hurt?! Don't EVER drop anything into molten aluminum! As far as ignition goes, I just use a common sparkler. A lot cheaper than Mg ribbon.

elementcollector1 - 4-9-2012 at 09:02

Well, with a proper heat sink mixed in, you could do it the other way around and drip molten aluminum into the crucible.
Molten aluminum isn't scary. It's like gallium, only painfully hot to touch. No sputtering, splashing, sloshing, etc.

What kind of coating?

Poppy - 4-9-2012 at 09:20

Some coating to make sure the dripped oxides won't clump like chocolate powder in milk when they reach the molten aluminium.

In fact I think its suicidade, but as you working with chromium that would be somehow slow and controllabe. o0?

Blogfast gave me a good idea in the neodymium thread. Use some low heat of formation Cr3+ compound other than the oxide, this will slow even more the process. Choose a suitable anion as to proceed to the reaction with vigorous heating, sufficient to melt elemental chromium, but low enough to evade explosions/ boiling

Just use ropes and hooks to stay very much away from it

[Edited on 9-4-2012 by Poppy]

Ignition

MadHatter - 4-9-2012 at 10:12

I've used cheap sparklers to ignite thermite. Use a propane or MAPP gas torch to ignite
the sparkler. You'll wear out a butane. If it's warm enough I suggest potassium
permanganate with a couple drops of glycerine. That's more than hot enough to get
the reaction started. KMnO4 is still available at some Sears stores for use in iron
water filters. Won't be cheap but it was a convenient source and you don't need too
much.

ItalianChemist - 5-9-2012 at 07:35

Only powder works well for thermite! You can buy it from ebay!

Poppy - 5-9-2012 at 08:44

Why don't you start making your own aluminium powder?
Make a high melting point metallic cilinder, plug a pressurizing on top, nozzle at bottom. Open nozzle valve: you should get aluminium spray. collect in a closed container filled with CO2. Let cool
Find a way to separate it according to mesh size.

zed - 8-9-2012 at 11:16

Well, you could try using Al from a different source, just until you get your bearings.

The folks at http://www.firefox-fx.com/ would probably be happy to sell you anything the law allows.

elementcollector1 - 11-9-2012 at 19:20

Uh, Poppy, I have no idea how to build one of these, and even if I got all that, the Al produced would be pyrophoric.

Poppy - 11-9-2012 at 20:52

Yea. It wouldn't be THAT expensive. Just find a proper workshop to prepare the fittings for you.
As for the Al being pyrophoric, the powder should be allowed to form an oxide layer which passivates the action of the enviroment preventing it from burn, melt furthermore explode. The process of passivation must be slow and cold, controllabe.

Does water bring you anything into mind?
Ever experienced dripping molten lead into water?

Again, use pulley and belts to stay behind the walls! Good luck!

Best regards, Poppy.

[Edited on 9-12-2012 by Poppy]

elementcollector1 - 11-9-2012 at 21:05

Ever reacted aluminum with water? I'm pretty sure it reacts.
So, it would be like an extruder with a fine particle size mesh, made entirely of stainless steel?

triplepoint - 11-9-2012 at 21:19

Quote: Originally posted by elementcollector1  
I want to know ...if I'm igniting it wrong.


What are you using as your ignition method?

Ball milled foil should be fine enough to give reliable results.

elementcollector1 - 12-9-2012 at 09:29

Blowtorch. Don't have any reliable chemical methods on hand, and just somehow lost my newly made stock of sodium nitrate.

Poppy - 12-9-2012 at 15:40

Quote: Originally posted by elementcollector1  
Ever reacted aluminum with water? I'm pretty sure it reacts.
So, it would be like an extruder with a fine particle size mesh, made entirely of stainless steel?


Sorry I couldn't get to the point of yours.

elementcollector1 - 12-9-2012 at 16:39

Aluminum reacts with water when fine enough, forming aluminum hydroxide and hydrogen. This ruins the powder as it builds up more oxide than actual aluminum.