MINING
For the gold recovery , OceanaGold will be utilizing a fine grinding method that consists of grinding down the ore to very small particles . Once ground to a sand-like material , the sulphide minerals containing the gold are concentrated using flotation . Gold is then leached from the concentrate using a solution of sodium cyanide – allowing the company to recover nearly 84 percent of the gold . According to Wilkes , the method of grinding the ore very finely to allow
the gold to be recovered wasn ’ t cost-effective until very recently .
“ Before the technology we have now , extracting gold required an expensive process that was not economic at the grades we are looking at here at Haile ,” said Wilkes . “ The technology we are using allows us to unlock unoxidised gold ore at new depths , making it economic to recover gold in the sedimentary rock .”
OceanaGold is on track to start the ore processing facilities at the
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