Have you looked at purchasing micro sieves? You can get them in various sizes which includes 10 microns.

Here is a quick google for one at various sizes:

http://www.biodesignofny.com/microsie.htm

But you may find another company you like.

Great idea Jet-Sing, thanks. So you would disperse the carbons in an aqueous solution then filter, then dry (rather than filter dry, correct?)

You can do either, though the last link is probably more suitable for solutions as the mesh is loose.

I would purchase a mesh built into a frame like the following linked for ease of only having to shake the powder in the frame. They supply aperture sizes of 5 microns upwards.

http://www.haver-partikelanalyse.com/en/sieve-analysis/haver-test-sieves/test-sieves-with-stainless-steel-frames/

Good luck!

This one will work best since we already have the 8" shaker sieve setup. Thanks again!

http://www.globalgilson.com/8-inch-precision-electroform-sieve-half-height-10um