Originally Posted by A-Files

Black Powder (Milling Method)

Though it requires more specialized equipment than the precipitation method, the milling method
generally produces much higher quality and faster burning black powder. You can find more information on
ball mills and presses elsewhere in the A Files.

Materials:
• Potassium nitrate. (KNO3) Also called saltpeter. You can buy it from http://www.pyrotek.org .
• Sulfur. You can also get this from Pyrotek.
• Charcoal dust. The type of charcoal you use plays an important role in the quality of the end product.
You’ll want charcoal that is carbonized evenly and all the way through. Willow and grapevine charcoals
are generally regarded as the best to use, being very reactive. See the article titled “Charcoal” for more
information.

Equipment:
• A ball mill with a load of heavy balls and a load of fairly light balls. See “Ball Mills” for more
information and a plan to make your own.
• A hydraulic press. See “Hydraulic Presses” for more information.
• A vessel of smashing. There are two methods to go with: The first involves using a pot or a bowl and
crushing the powder in it. The second involves putting the powder in a plastic bag and hitting it with
something to crush it. Whichever method you use is up to you.
• Something to crush black powder cakes with. A wooden baseball bat, a weight bar, or even a hammer
will do. Make sure you can use it with your vessel of smashing. (For example, a hammer and a pot
doesn’t work well, but a hammer and a bag does.)

Procedure:
1. The first step is to gather up all your ingredients and mill them. Load your ball mill with 75% potassium
nitrate, 15% charcoal, and 10% sulfur (by weight, not volume). Also load in the heavy balls and fire it up.
Milling time will vary depending on the size of your mill, the weight of the balls, the amount of ingredients,
&c. A good time to check on it is after three hours of milling. If you have a uniformly colored mass of very
fine powder then you are ready for the next step. You should have a hard time seeing the particles in the mix
without magnification. If it looks coarser than this, put it back in for another spin in the mill. You can’t
overmill it, so don’t worry about that.

2. The powder you now have is called “green powder”, and though it is not finished black powder yet it is
useful for some things like fuses and lift charges. You will now have to moisten your powder just enough to
make it clump together. Load this into your press and press it down until it forms a solid hard cake. This
cake should hold it’s shape well and be of uniform consistency. If it isn’t, press it some more. This process
is called “corning”.

3. Allow your cake of pressed powder to dry out completely before attempting the next step.

4. It is now time for the step that I call “smashing”. It is fairly simple. Place your powder cake in something
durable and crush it into grains. The goal here is to break it into smaller pieces with a high enough surface
area to promote fast burning, but not to the point where the ingredients fall apart (become “unpressed”, so to
speak) into useless powder. A good grain size for most applications is about half a millimeter. Larger grains
are useful as well, mostly for lift charges and powering large cannons. You may wish to separate your
different grain sizes with a set of screens.

Your black powder is now ready for use.