Considering you're a citizen of the US (I assume you are), I wonder why it is so important for you to break the law by processing pennies :?:
From my vantage point, assuming your profile is correct, you risk creating a criminal record that can follow you for life, possibly eliminating any chance of gaining employment in your chosen field.
Beyond that, I'm sure I speak for every honest citizen of the US when I suggest to you that all you'd be doing is stealing money from our pockets to put in yours. Try to remember that coins are made at tax payer's expense.
Zinc is more than willing to distill, all you have to do to eliminate the stuff is heat it beyond it's molten state and it slowly goes off without much assistance. The less there is present, the slower will be the loss. It is likely to be quite difficult to bring the copper pure by heat alone, however.
I think, even if it was legal, you'd have to be one hell of a lot more desperate than I've ever been to go to such lengths to pick up a few cents.
Have you given any thought to pursuing something that's legal? There's nothing quite as satisfying as earning honest money.
Harold