Ask The Experts - How do I recover gold in pyrite? - ICMJ
The best answer as to how to recover that gold depends on the amount of pyrite you intend to process. If you have only a few pounds, it can be roasted by heat in the open air and then mixed with a flux like sodium borate and melted with a collector metal like copper. The melt can be poured into a mold and the gold will now be alloyed in the copper.