I heard a mining exec say in one of the videos I've watched...

I heard a mining exec say in one of the videos I've watched lately that there are 3 key things that affect a mining project 1. FX, 2 metallurgy, 3. I can't remember but it may have been grade which is obviously important. Metallurgy is a big winner for MOD. What's the currency risk? According to Wikipedia the Botswana Pula remains one of the strongest currencies in Africa. But MOD is likely to raise equity in London and borrow where? China? Apparently smelters will fight for the concentrate but they are all in China. And Cu is sold for USDs. FX,  hmmm, too complicated for this simple punter!