Crushing Lumps of Hard Material

These companies sell the type of equipment that you're looking for. The "Equipment Types" section on this page has a lot of good information, too.

If you are looking for the current tech way of powdering rock, you may wish to look into licensing this design and building a heavy-duty version of the "WindHEXE."

en.wikipedia.org/wiki/Windhexe

I have seen video of one pulverizing chunks of concrete into powder (to be reused), though I am unsure if anyone has yet applied this to a mining situation.
Other videos (from a quick Google for licensees of the design) found here:
www.greenshift.com/taz_open.php

It has some definite advantages over brute-force crushing machines, though you may wish to drive a truck full of your source material up to wherever Greenshift may have a demonstration machine ready, to see the real-world results for yourself.