2nd question:
With ball milling of cpus, do you need a really big mill?
Would a small thing that sits on a desk work?
Example link
No - at least not effectively for milling ceramic
Ceramic is VERY HARD & with that small mill you can't put balls big enough & heavy enough in it to be "effective" at "crushing" ceramic (to fine powder)
To have any real effect on the ceramic in that mill the ceramic would have to first be broken down to at least 1/4 inch size pieces (so you are back to the break them with a hammer) & even then it would likely take 2 - 3 days running in the mill to mill the ceramic to powder (100 mesh or finer)
That mill will have NO effect on "whole" (or even large pieces) of ceramic
To effectively mill ceramic to powder you need a mill that is big enough to hold a "load" of balls made up of balls ranging in size of 1 inch balls 1 1/4 inch balls 1 1/2 inch balls & 2 inch balls
The 1 1/2 inch balls & 2 inch balls have the heavy weight to "break" the ceramic while the 1 inch balls 1 1/4 inch balls work at crushing/grinding the ceramic (as the ceramic mills smaller & smaller in size)
The mill needs to carry out 2 functions
1) the balls first need to lift to the top of the mill so they "drop" down on the material being milled so that the balls work at "breaking" the material
2) at the same time some of the balls need to stay in the bottom of mill with a spinning action so that they effect a grinding/crushing action
That mill (your link) is just what it says - a "lab" mill
It is used for milling VERY small samples of ore for doing fire assays
Ore mills MUCH easier then ceramic
Even then the ore is first broken down to around 1/4 inch minus before putting it in that mill to then mill it to at least 100 minus mesh (or finer) for doing their fire assays
Not say that mill won't work - just that it will not be very effective at doing it --- don't waste your money
Kurt