Dear maynman1751,
I melt down MASSIVE amounts of scrap in AR, then process that into gold dust. Like tons. Depending on the origin of said scrap, some is more valuable than others, i.e., I make money in scads by buying what some guy has no idea the plate value and melting it down. I also teach classes on how to do this, and it's nice to have that stuff laying around for which I can calculate a precise value of gold mass that should precipitate under ideal conditions.
Mind you, I also prospect my own ore and gold locally and process and sell that as well. That dust derives from maybe 20 lbs of extremely high grade ore. Of which I have 20+ tons. In order to process that much ore, you need a lot of chemicals, which cost money. So, I sell some dust, sell some ore, buy my chemicals, make a few pounds of gold, smelt it, cash it, and onto the next batch.