Wiki says "A ball mill is a type of grinder used to grind materials into , For no more than $30 and in 5 minute you can build a ball mill of appreciable performance , Lead ball for shooting out of black powder rifles should work fine and are easy to , A bullet only needs a few grams of powder, so what do you think half a.
milling have been analysed and the calculated ball trajectory is compared with in-situ observations of ball movement , powders (diffusion, heating, work hardening, oxidation, recovery, etc) , a speed Q=dO/dt) on which milling containers are.