blink and you might miss it, page-44

Researching PLA at the moment as a prospective long term investment.
It appears this company is doing a really good job at renovating from the inside out - in particular smokey hill. What I was wondering though looking at the most recent half yearly, why are there such high production cost for pulling the platinum? I assume most of the costs are associated with the flotation and subsequent refinement of the ore. Any further enlightenment on this from current holders would be much appreciated.