Ball Milling 101

Written by Harry Gilliam

Topics: How to Make Fireworks

I have some lump charcoal that just came out of my retort after I cooked it, and I want to turn it into airfloat charcoal.

Or, the directions say to ball mill my rocket fuel for an hour.

An article tells me to ball mill my star composition prior to pressing my stars.

Maybe I just got some crystalline potassium nitrate that looks like sugar, and I want to turn it into a fine, talc-like powder.

And, perhaps most of all, I want to be able to make commercial-quality, high-performance black powder.

In Volume 1 of Bill Ofca’s Technique in Fire, he states that “small particle size is important to good chemical reaction. The smaller the particle size, the greater the specific area, hence the most complete and fastest reaction.”

Except for very small batches, ball milling is the best way for the amateur fireworker to reduce particle size in their chemicals. With small batches of individual chemicals, some folks use electric coffee mills to grind the chemicals into fine powder. NEVER grind mixed compositions in a coffee grinder, though. To do so would be to court disaster.

Lloyd Sponenburgh, in his Ball Milling Theory and Practice for the Amateur Pyrotechnician, tells us his explorations into ball milling began when he was faced with having to do all that grinding with a mortar and pestle to achieve small particle size and intimately mix his chemicals. Lloyds’s book is the most complete and practical resource I know for information on ball milling theory and for plans to actually build your own ball mill. Here’s a shot of a nice, double-barrel mill I built based on his principles.

Homemade Double-Barrel Ball Mill

Homemade Double-Barrel Ball Mill

Ball milling replaces potentially unsafe hand grinding of chemicals and compositions. The crushing of the material is accomplished by the repeated falling of heavy balls onto it, over and over, inside the mill jar.

So, it sounds like I need a ball mill. I want my chemicals to have small particle size and be intimately mixed. What are my choices?

I can either get Lloyd’s book and build my own ball mill, or I can purchase one. (I’d still recommend getting the book for all of the other valuable milling information contained in it, though.)

Skylighter sells a nice ball mill which comes with a mill jar. All you have to do is add milling media. More on that in just a minute.

Iā€™m also including how-to info for a few other milling accessories that will increase your milling productivity. You can make this yourself: a bucket screen to separate your milled powders from the media; a simple little soundproof cabinet to put your mill in: and weatherproof sandbags for safely barricading the mill.

Here’s a ball mill you could get here at Skylighter. This size jar is typically referred to as a ‘one gallon jar’ because its volume is, indeed, one gallon.

Skylighter Ball Mill

Skylighter’s Ball Mill

Continue Reading: Ball Milling 101…

2 Comments For This Post I'd Love to Hear Yours!

  1. Jay says:

    I bought some ‘hardened lead’ milling balls from skylighter.
    I milled some fine charcoal and threw it away (as mentioned earlier to clear any wax or oils off the balls). Then I milled a measured amount of KNO3 . When the balls went IN they were shiney (almost like chrome)….when they came OUT they were dull (just like lead sinkers).

    Normal or not ?
    Thanks in advance, Jay.

  2. Bob PAtrick says:

    Hi. Good web page. When I was about 18 I lived in Northeast Ohio. Hudson Fireworks blew up one night. It was one of the largest fireworks plants in the USA
    (This would have been somewhere around 1966, a couple of years one way or the other, a long time ago) It broke windows over 10 miles away. But because the facility was properly built no one got hurt or killed. No one was at the plant, and I think it was about 2AM when it blew up. I woke up, not hearing the explosion, standing on my feet. I was 18 miles away. Safety makes a lot of sense. A lb of black powder burning in open air with no confinement makes quite an explosion. In a ball mill it would be significantly stronger due to the confinement and the ball media,

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