Converting a solid into a powder

[cyb3r0]

After the reaction of sulfuric acid with liquid methamphetamine, I have a semi-solid substance that I want to turn into a powder. What is the method? Thank you

 

[MadHatter]

You filter it and let it dry. Put it in a coffeefilter, drain off as much liquid as you can, then lay it out on a paper and let it dry.

 

[William D.]

read here and here