Really wet BP ball-milling-- any problems?

Retrieved: 12/28/2014
Last Post: 01/21/2002

clark kromer
1/3/02

A few months ago I bought a ball mill from the website  
www.hobbyfireworks.com

and I made excellent BP with it (using the traditional mix of 75% KNO3

- 15% C(willow) -10% S).  I ran it without any water added to the
powder and lead media for 5 hours. When I ignited it in a test, it
almost burned as fast as perc/Al flash powder (no flash of light as in
Al) and it left no residue.
 
 In retrospect, I think dry milling BP is dangerous.  Has anyone
ball-milled using boiling water -- not to merely dampened it -- but to
make it a thick liquid (like oil)?  It seems to me that this takes
away most of the risk of accidental ignition, provided there are no
leaks.  Of course drying it out would be slow (but I am not in a rush)

-- perhaps in shallow cookie tins in the sun. Would the component
chemicals be less intimately combined sitting for hours in solution
while drying in the sun?  When it dries to about 4% moisture I would
then press it in my hydraulic press (from Harbour Freight) under 12
tons pressure and corn/screen.  What % proportion  powder  vs  water
should I use (for example,  30% water and 70% powder by weight in the
mill ????).  Would the finished product be just as good as one that
had been dry milled?  Thanks,  Clark.   :-)
 


Don Thompson 	
1/3/02

If you put water in the ballmill, (other than perhaps a light misting to
help with the dust, unnecessary, I don't do that but I have heard that some
do), and then attempt to air dry the powder you have defeated the purpose of
the mill. The KNO3 will grow into large crystals while the water is
evaporating and separate out from the mix.
--
Don Thompson
Another Thompson Scion



"clark kromer"  wrote in message
news:fee751d.0201032025.11aac2a0@posting.google.com...

- show quoted text -
 
Bill Nelson 	
1/4/02

clark kromer  wrote:
>  
>  In retrospect, I think dry milling BP is dangerous.  Has anyone
It can be risky - which is why you put the mill in a remote place where
it will not cause any damage if it explodes.

> ball-milled using boiling water -- not to merely dampened it -- but to
> make it a thick liquid (like oil)?  It seems to me that this takes
> away most of the risk of accidental ignition, provided there are no
> leaks.  Of course drying it out would be slow (but I am not in a rush)
> -- perhaps in shallow cookie tins in the sun. Would the component
> chemicals be less intimately combined sitting for hours in solution
> while drying in the sun?  When it dries to about 4% moisture I would

Yes, it will be less intimate. Much of the nitrate will be free crystals.
It would be better than the "CIA" powder, but not nearly as good as the
dry milled product.

-- 
Bill Nelson   (bi...@peak.org)

 


Doc Ferguson 	
1/4/02

A light misting of alcohol and water holds down the dust, there is a bit 
of caking at first, but
if you feel better about a slightly moist mixture it does work. 
 Personally dry milling with a
remote cord is still the best.  If your drum is tight, no leakage sparks 
the danger goes down.
Doc Ferguson

- show quoted text -

Lloyd E. Sponenburgh 	
1/4/02

clark kromer wrote:

> A few months ago I bought a ball mill from the website
> www.hobbyfireworks.com

harumph!

>  In retrospect, I think dry milling BP is dangerous.  Has anyone
> ball-milled using boiling water -- not to merely dampened it -- but to
> make it a thick liquid (like oil)?

Not effective.  During drying, you'll 'undo' the milling as the KNO3
crystalizes.

You should note that at moisture content from 0% to about 3%, black
powder becomes MORE sensitive and powerful as the moisture content
increases.

Mill remotely, dry, and avoid static-causing situations.  This is NOT a
good time of year to be milling any explosives.

LLoyd

 


clark kromer 	
1/4/02

Dear NG,

Thanks for all who answered my post. I quess dry milling is the best
way to go. Unfortunately, I live in the city and a mill explosion
would alarm neighbors (and police!).  Too many people around me.  I
have been thinking about getting a portable AC generator (about $350
from Coleman, I think?), 300 ft extension chord and going way, way,
way back into the woods to mill. Really isolated.  Bringing a fire
estinquisher might not be a bad idea if a mishap takes place.
Speaking of milling BP, I know the type of charcoal makes all the
difference. Even when ball milling for 10 HOURS!!! using grocery store
grilling charcoal "bricks", the resulting powder burns painfully slow
and leaves a lot of residue.  Steve B. (I think that is his name), who
has recently posted to this group, sells excellent airfloat willow
charcoal and the service is fast.

 


Bill Nelson 	
1/4/02

Lloyd E. Sponenburgh  wrote:

> harumph!

Well, Lloyd. You can't expect everyone to know that you sell the best
mill kit around. After all, you do not do much self promotion.

-- 
Bill Nelson   (bi...@peak.org)

 


Richard Ogden 	
1/4/02

"Lloyd E. Sponenburgh"  wrote in message
news:3C35A61B.93C72E6@mindspring.com...

> Mill remotely, dry, and avoid static-causing situations.  This is NOT a
> good time of year to be milling any explosives.

Lloyd, they're not all in the Northern Hemisphere. But I certainly wouldn't mill
BP or mix flash in Florida right now...I got a nice jolt just grabbing the car
door handle this morning. I momentarily forgot my trick of holding tight to a
key and touching the key to the metal first.

-Rich

 


Lloyd E. Sponenburgh 	
1/7/02

The "harumph" was not aimed toward the quality of the the kit,
which I assume to be the best.  Rather, it was to the unattibuted,
copyrighted design -- which _is_ the best.
LLoyd

- show quoted text -

Jeff 	
1/7/02

Bill Nelson  wrote 
> Well, Lloyd. You can't expect everyone to know that you sell the best
> mill kit around. After all, you do not do much self promotion.

"Not much" is a bit of an understatement. I have been on this group
for two years and had no idea. Sorry, Lloyd. I'll never mention the
"H" word again if someone asks about a mill. Can you tell me about
your kit?

Jeff

 


Lloyd E. Sponenburgh 	
1/8/02

I have a 'real job', now.  I dissolved Bridge City Enterprises about two
years ago, and offered to certain avid amateurs to license my designs.
One frequent poster to this group has negotiated with me to begin
marketing kits of my design.  When he's ready to announce (soon, I
believe), you'll see it here.  He is a capable craftsman, and should do as
good a job as I did making a quality kit.

LLoyd

- show quoted text -

deefault 	
1/10/02

"Lloyd E. Sponenburgh"  wrote:
> Not effective.  During drying, you'll 'undo' the milling as the KNO3
> crystalizes.

[SNIP!]

Nice thought. I've been wondering for a long time why BP incorporation
mills throoughout history haven't changed a lot: The heavy wheel mills
in modern facilities (Goex, DuPont, and pictures in Davis' text,
etc...) haven't really changed from their water-wheel-driven
predecessors where the moistened powder is basically crushed by a
multi-ton wheel. Eh? (why fool with a good thing?)

This is combined with reports of ball-millers reporting
exceptionally-fast batches of BP made in high-temperature (summer time
or in a "Sponen-Mill" with a closed lid allowing temperatures to rise)
conditions. IIRC, several authors under these conditions have emptied
their mills to find their product agglomerated into a single hardened
mass accumulated into one side of the mill jar. I would think that
this is from the small amount of (atmospheric-derived from humidity?)
water in the mixture going into the mill. But, the quantity of water
would be small.

Shimizu, then, in his chapter in the third edition of Lancaster,
(paraphrased) says that the wet-method of mixing the three components
of BP, subsequently ground in a ball mill, makes the fastest product.

All of this makes me wonder: Prior to graining BP, is the best method
of BP preparation to merely finely sub-divide the composition (i.e.,
dry-milling)? Or, is moisture a way to get (dissolved) nitrate more
intimately associated with the other componets (particularly charcoal,
and maybe sulfur too)? Von Maltitz describes the Goex Pennsylvania
plant's process similar to Davis' account: wet/moist milling of the
components in a multi-ton wheel mill. Both authors note that
particular attention is paid to the quantity of moisture used.

Although I haven't done the math (It's been a long time since
thermochemistry), I suspect that multiple tons of pressure produced by
a wheel mill could adibatically (frictionally?) heat the moistened
mixture immediately beneath the wheel. This could dissolve the
nitrate, at least transiently. Then, with rapid (adiabatic) cooling as
the wheel rolls-off the mixture, nitrate crystals would rapidly
come-out of solution, presumably in a very fine or inimately
associated state with the other components. This cycle would then
repeat each time the powder was rolled-over by the milling wheel,
along with the mixing and crushing of the components.

Are the observed agglomerated fast-lots of ball-milled powder formed
by at least partial dissolution of the nitrate? Could one reliably
reproduce this effect? Is this a testable hypothesis? I for one would
doubt that the Goex people (as nice as they are) would let me place a
termistor with a lot of green powder beneath one of their ball mill
wheels. For safety sake, I don't know that I'd like to hang around to
find out, eh? Could one construct a ball mill with a big enough
diameter, say with a jar based on a 5 gallon bucket or a trash-can,
where the weight of the milling media (I guess using a non-sparking
ceramic) would cause adiabatic solution of nitrate? Am I really
worrying about something so over-the-edge that I should simply go to
bed and dream about something more productive? I, for one, would have
to wait for the spring thaw before I could run a ball mill in warm
conditions. Anyone here able to test this in a warmer climate?

 


PiRho Tech 	
1/21/02

If your remote site is in a forest, likely nothing will help a fire(by the
time you get there anyway).  If it's a grassy area, a rake will work far
better, and less expensively, than any designed fire extinguisher- as anyone
w/ display fireworks can attest.
Mark D.