dangerous amateur
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Ballmilling AN mixtures
Hi,
I wonder if AN mixtures can safely be ball milled.
I found AN to cake very fast after drying and milling, even when sealed.
For optimal results with very small charges and also as small blasting caps as possible I need a high quality very intimate mixture.
Mostly Ammonal.
In pyrotechnical sence were talking about some "nitrate flashpowder", however I found AN with 4% dark flake Al barely ignitable.
2% would be sufficient, the rest in form of coarser stuff can be added later.
How would you feel about that?
Can you suggest some kind of anticake to keep the AN airfloat for some time, enabling me to shake it together with the AL afterwards?
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hissingnoise
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Despite their shock insensitivity I would be wary of milling ignitable AN mixtures . . .
If you need finely divided AN mill it separately and mix the components by hand!
Of course, the extreme hygroscopicity of AN will always present problems in pyrotechnics!
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VladimirLem
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ive seen ammonal-b that was not ignited by a 0.8g MHN detonator...im pretty sure that there are much more danergous things than milling
ANC-compounds...
BUT sure, hissingnoise is right, better save than sorry^^
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dangerous amateur
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I often used AN coming straight out of a coffee grinder and mixed that with dark al by shaking it together. But mostly I got the impression that this
method does not get the most intimate mix possible.
Ammonal B is a good idea maybe. I could mill AN and a little charcoal, with the charcoal hopefully prevent caking and help it to stay airfloat. Then
shake it with the Al...
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ive seen ammonal-b that was not ignited by a 0.8g MHN detonator. |
I bet there was only atomized Al in it. That would be useless for me, as I want to work with small charges about 30-50g.
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virgilius1979
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At least you could imagine a remote control and a blast screen to protect against accidental ignition.
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Fantasma4500
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if you want to mix AN very well with aluminium i can say i have mixed up to 50 grammes of AN SU Al (ammonium nitrate, sucrose, aluminium) in a coffee
grinder, nothing happened at all, also i have tried mixing freshly dried AN with a small amount of MgAl, more Al, SU in a 1.5 litre bottle, shaken
together very well.. nothing happened, the 1.1 kg of ammonal wasnt even able to be ignited.. at all..
based on this i would say there wouldnt be MUCH of a chance it self igniting, at the coffee grinder i used aluminium foil, and basically this was for
getting aluminium powder (a video showed how this made it easier)
the idea with this was to prevent the aluminium dust from settling inside the coffee grinder, so it has been done alot.
But if you want to be completely safe just stick with shaking it around well in a container..
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hissingnoise
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Freshly-milled aluminium powder has been known to ignite catastrophically in mill jars when these have been opened!
During milling, the oxygen-content of the air within the jar is used up as fresh aluminium is exposed and passivated.
When the jar is opened after the milling, the inrush of fresh oxygen can cause reaction at such rate that a sudden deflagration can ensue!
Couple that with a potent oxidiser and . . .
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alancain
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Hissingnoise is exactly correct. New faces are still experimental.
[Edited on 31-1-2013 by alancain]
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