Total processed volumes increased 9% from a year earlier to 12.4 mt.
While its Chichester Hub operations reached its target run rate of 55 mtpa at the end of the quarter, major scheduled maintenance shutdowns at Cloudbreak and the Herb Elliott Port, Port Hedland, together with works to complete the tie-in of the second inload and outload circuit infrastructure at the Port, will restrain September quarter 2011 shipments to a range of 12-12.5 mt, Fortescue said in its June production report.
The company also said that cash costs per tonne rose during the June quarter despite the increased throughput.
"Cost increases were driven primarily by additional waste movement with strip ratios increasing by 33 per cent quarter-on-quarter."
"Additionally, the continued strengthening of the Australian dollar, which averaged US$1.06 over the period compared to US$1.01 in the March quarter 2011, negatively impacted cash costs, which are predominantly denominated in Australian dollars," it said in its report.