Sciencemadness Discussion Board

Ball milling Black Powder with ceramic media

Bimseby - 13-12-2014 at 06:21

Hello all mad scientists out there!

I would like to know if anyone has any experience with ball milling Black Powder with alumina balls and whether it is hopeless to attempt to, or not?
The reason I ask is that I am a bit in doubt whether this particular type of ceramics are sparking or not.

from skylighter.com
"Ceramic is hard, does not wear out quickly, but some types of ceramic do spark."
http://www.skylighter.com/fireworks/how-to/choose-ball-milli...

Please do share if you have any knowledge to contribute with :D

[Edited on 13-12-2014 by Bimseby]

blogfast25 - 13-12-2014 at 06:25

'BP'?

Please, we may be hobby scientists but we're not mind readers.

Concise communication is a hallmark of good science.

Bimseby - 13-12-2014 at 06:29

BP is a contraction for Black Powder, sorry I should have made it clear :)

Bert - 13-12-2014 at 07:08

Start here:

Ian von Maltitz: Black Powder

Then look at this:

Lloyd E. Sponenburgh: Ball Milling Theory and Practice

And finally, you could read this short post regarding how NOT to mill the complete ingredients, just the separate components:

Some Guy: posting about black powder
Quote:


One more time:


Making powder is DANGEROUS!


All commercial powder mills are built with the EXPECTATION THEY WILL BLOW UP. Because they will, if used long enough.

Look at the history of the DuPont family. Notice all the dead (mangement level!) people, and blown up mills?

http://www.historypin.com/attach/uid32851/tours/view/id/945/...

Google the names of any black powder maker, historical or modern along with "explosion", "deaths", etc. You will find plenty.

After Du Pont sold the last powder mill in the USA to GOEX, there were a series of problems. A lot of you know about the GOEX production moving out of PA, then moving again- The meaty part starts at page 10.

http://www.laflinandrand.com/madmonk/history.pdf

This link is instructive on how NOT to run a BP manufacturing operation.
Never hurry. Never cut corners.


[Edited on 13-12-2014 by Bert]

[Edited on 13-12-2014 by Bert]

hissingnoise - 13-12-2014 at 07:12

Quote:
Please, we may be hobby scientists but we're not mind readers.

Ah come on, Gert ─ what else could it be?
Quote:
Please do share if you have any knowledge to contribute with

I use AH lead shot (UN) and have safely ground dry BP in an unattended mill.


Fulmen - 13-12-2014 at 07:47

Go ahead, just be sure to stand waaaay back and don't be surprised if it blows up. There is more to this than the presence of sparks or not, imagine the energy released in the impact between two balls. With ceramic media there is no deformation, meaning the impact will be focused on a very small area. And as I'm sure you know, if you give any energetic material a big enough whack it will go off.
Lead is safer because it's softer. At every impact the balls will deform, spreading the energy over a much larger surface. This also makes the mill more efficient as you don't need the huge pressures that ceramic balls will produce. The larger contact area of lead means that more material will be crushed for each impact.

hissingnoise - 13-12-2014 at 08:05

Quote:
Go ahead, just be sure to stand waaaay back and don't be surprised if it blows up.

Indeed Fulmen, the mill should be operated remotely and shouldn't be approached while running!

It does seem though, to produce fast powder faster . . . ?


Fulmen - 13-12-2014 at 08:24

If anything ceramic media would probably be slower. Now if you're milling hard materials ceramic would be better, but for BP the hardness isn't needed and comes at a cost. Lead has a higher density, which means more kinetic energy for a given volume.

blogfast25 - 13-12-2014 at 08:55

Quote: Originally posted by hissingnoise  
Ah come on, Gert ─ what else could it be?



Errmmm... just about anything really.

I hope you're not opposed to people expressing themselves understandably.

hissingnoise - 13-12-2014 at 10:54

Kinda associate BMs, CM and AHLS with BP, myself . . . ;)

Bimseby - 13-12-2014 at 12:59

Thank you guys for your replys, I learned a few things.

I will be running the mill at some point later, mixing the nitrate with the milled charcoal and sulphur. My plan is to grab my longest wires and place the mill on a field far away. :P

Amos - 13-12-2014 at 13:14

Would there be any downside to grinding the black powder wet, either with water or a solvent?

Bimseby - 13-12-2014 at 13:28

How would you make sure you have as small kno3-crystals as possible when you dry it?

Amos - 13-12-2014 at 13:34

Quote: Originally posted by Bimseby  
How would you make sure you have as small kno3-crystals as possible when you dry it?


So far as I've heard about black powder on forums and videos and such, you DON'T want the finest crystals as possible. That's why people make granulated gunpowder.

http://en.wikipedia.org/wiki/Gunpowder#Corning

Fulmen - 13-12-2014 at 14:43

Don't know about wet, but there should be some moisture when milling. The impacts will produce heat, and due to the solubility properties of potassium nitrate it should quickly dissolve and precipitate out again. I believe this is key to a good product, it ensures every bit of fuel is thoroughly covered with a layer of fine oxidizer.

IrC - 13-12-2014 at 19:10

Anyone try using lead antimony balls? You will not have as much Pb contamination but they are so much harder I wonder if impact becomes a problem. Has anyone tried using 91 percent rubbing alcohol to moisten the powder while milling?

TheAlchemistPirate - 13-12-2014 at 20:16

Actually, using hot water/rubbing alcohol is a very common way of coating the sulfur/charcoal with the oxidizer. Normally it is done when you don't have a ball mill, and need smaller amounts of black powder. Basically the charcoal,sulfur, and oxidizer(ground to a tolerable level separately)are dissolved in hot water, then the solution is poured into a shallow basin. Rubbing alcohol is added, and this forces the black powder to crystallize out as a single material (if that makes any sense). The crumbly substance is then sieved/recrystallized until it is the desired grain size. This makes corned powder, which burns faster and more powerfully, and when packing for a salute/cannon you don't need to allow air space, since it already has it between the grains. Now if the OP is wanting fine powder for a rocket engine, I don't know if corned powder will work as well.
Another thing, when pressing the milled black powder(to break it with a hammer to make corned powder) if you so choose that method, moisture is always added, both for safety and the integrity of the "puck" of black powder produced.
Also, (almost done) it is very possible to safely mill the whole black powder mixture(unattended)using lead media (even with antimony added, which is commonly practiced), in the right ball mills (normally lined with hardened rubber). I somehow doubt that some critics saying these things have read much about BP manufacture. However, as Bert said, never cut corners, or do things without reading everything you can about it.
Sources: Reading MANY books/reputable sites about pyrotechnics production, especially about black powder.

[Edited on 14-12-2014 by TheAlchemistPirate]

The_Davster - 13-12-2014 at 20:47


IrC: Used to mill BP with lead antimony balls for many years. No issues. Usually with a few percent water added.




[Edited on 14-12-14 by The_Davster]

Fulmen - 14-12-2014 at 01:03

Correct, hardened lead will work fine. If you want to learn more about milling BP, do a search for "Lloyd Sponenburg". He was the one who popularized ball mills back in '95 or so, and he was quite active on usenet rec.pyrotechnics at the time. Maybe his book is still available?

Fulmen - 14-12-2014 at 03:09

Yup, that's the one. Although I do not condone the copying of his material, he's just a bloke like the rest of us not a company with deep pockets. Pay the man if you can, I feel he's deserved it. I never bought the book myself, but then again I could just ask him back when he was on rec.pyro. Those were the days...

IrC - 14-12-2014 at 04:39

Quote: Originally posted by Fulmen  
Yup, that's the one. Although I do not condone the copying of his material, he's just a bloke like the rest of us not a company with deep pockets. Pay the man if you can, I feel he's deserved it. I never bought the book myself, but then again I could just ask him back when he was on rec.pyro. Those were the days...


You are right of course so I deleted the post. I put the title you mentioned in google and a pdf link came right up. Posted it without thinking as it sounded like you were unable to find a copy. It would irritate me to have my work tossed online for free. Most often I do not agree with causing someone not to get paid for their work. One exception being one of the 'Evil Genius' books. The author contacted me and asked if one of my articles could be a chapter in his up and coming book in the series. I agreed merely asking for a copy in print or PDF in exchange. Never heard from him again and about a decade later found a PDF online. Downloaded it out of curiosity to see if he used my work. He had, so I figured it was fair if I had a copy for free. After all I am sure he made good money on the book and all I had asked for was a copy in exchange.

greenlight - 14-12-2014 at 06:01

I am getting a ball mill in the next week or so and was going to order some proper pyrotechnic grinding media online. In the meantime will medium size lead fish sinkers work well as non-sparking media for milling black powder, are they safe to use?

hissingnoise - 14-12-2014 at 07:39

Ceramic media will work well if the oxidiser is ground separately and the components mixed by running the mill without media . . .

If you intend compressing and granulating, the powder should be moistened by ethanol to avoid formation of larger KNO3 crystals!

http://unitednuclear.com/index.php?main_page=index&cPath...



[Edited on 14-12-2014 by hissingnoise]

TheAlchemistPirate - 14-12-2014 at 09:38

Quote: Originally posted by hissingnoise  
to avoid formation of larger HNO3 crystals!

http://unitednuclear.com/index.php?main_page=index&cPath...


HNO3?!
Anyways, yes, lead fishing weights should work fine. I have even heard of them being more efficient than spherical media.

Bert - 14-12-2014 at 11:39

Quote: Originally posted by Fulmen  
Correct, hardened lead will work fine. If you want to learn more about milling BP, do a search for "Lloyd Sponenburg". He was the one who popularized ball mills back in '95 or so, and he was quite active on usenet rec.pyrotechnics at the time. Maybe his book is still available?


Look at the above posts ? Sponenburgh book is linked on 3rd reply... Also Ian von Maltitz.

[Edited on 14-12-2014 by Bert]

hissingnoise - 14-12-2014 at 11:54

Quote:
Anyways, yes, lead fishing weights should work fine. I have even heard of them being more efficient than spherical media.

Ooops!

They won't stay efficient for very long, however ─ non-spheroidal lead media will fairly quickly deform, and the lozenge form is probably least useful . . .

IrC - 14-12-2014 at 13:19

Quote: Originally posted by Bert  
Look at the above posts ? Sponenburgh book is linked on 3rd reply


What I get when I skim through threads. I saw the post asking about the title and entered it in google. Never even noticed it was already linked and searching for it was not required.

Fulmen - 14-12-2014 at 14:43

Damn, missed that one completely. Oh well, it's worth mentioning twice.