Perhaps someone could help me out here. TNC reports to the ASX...

Perhaps someone could help me out here. TNC reports to the ASX that it has produced 70.38 MetricT of copper metal and also 288 Metric T of copper sulphate. Using todays prices of AUD 12.40 for copper metal and AUD 18.50 for copper sulphate (which obviously were not attained throughout) this equates to a product value of AUD 6,200,712. 00. As 24.39% copper in copper sulphate = ~70.38 metric tonnes of copper metal , why would they turn copper sulphate valued at $18.50/kg into copper metal valued at $12.40/kg for a loss of $4,455,288.00 plus the cost of conversion from sulphate to metal??
Obviously something's amiss with the info I've received?????