Production from the company’s coking coal mines was also freed up from geology-related issues that impacted production in H1 2012.
Yield improvements at Tahmoor also contributed to the higher production in the six months to June.
Australian thermal coal (including semi-soft) production for the half was 28.2Mt, an increase of 15%.
The continued ramp-up of the Ravensworth North, Rolleston and UIan open cut operations, together with the return to full-scale production at South Blakefield in H1 2013, were the main drivers of the higher production.
Total own coal production was 67.8Mt, a 4% increase over the comparable period, relating mainly to higher thermal coal production as key expansion projects in Australia and Prodeco in Colombia delivered growth, partly offset by lower production at Cerrejón due to a strike.
In H1, Prodeco’s production increased 22% to 9.6Mt, in line with its planned expansion.
The increased volumes and associated productivity resulted in a 12% reduction in unit FOB cash costs.
There was also a significant improvement by the change from barge to direct loading.
The new direct-loading port (Puerto Nuevo) started loading in April and achieved an average rate of 1.6Mt per month.
The $550 million project was delivered on time and on budget.
Cerrejón produced 4.5Mt of coal, 26% below the prior year. The reduction mainly related to the 32-day strike that impacted production in Q1.
Following the restart of production, it has been broadly in line with the prior year period.