What is the best method for grinding powders? I need to go anywhere from a rice grain size to a table salt size to a good powder (the finer the better). I have heard of just using a mortar and pestle, but then also using marbles in a can. I was wondering if these same methods woud work for grinding Al foil into powder form. Also some one mentioned some sort of "tumbler" that they put marbles in. Do they mean like a rock polishing tumbler?

 

Thanks for all the help!

I have some white american ginseng in my backyard that I would like to grind into a powder...so im wondering the same thing...I might just go with a mortal and pestol

I find a mortal and pestle works great for some things. Of course, it works much better if the substance you are tying to pulverize is very dry. You might think about laying it out in the sun or putting it in the oven if its not very flammable. Also, it only works well on things that are relatively soft without malleability or elasticity.