The longwall changeover significantly hampered productivity at Kestrel, with thermal coal produced from the mine tipping in at 52,000t, compared with 76,000t for the quarter prior.

Coking coal production yielded from Kestrel was 375,000t, significantly down from 1.096Mt produced in the December quarter.

Overall Australian hard coking coal production during the quarter was 1.7Mt tonnes, up 5% from the first quarter of 2011, but 35% below the December 2011 quarter.

Rio Tinto’s share of thermal coal production for the quarter was 3% higher than the same corresponding period on the back of increased ownership in Coal & Allied operations.

The company conceded that severe wet weather had impacted production across Queensland and New South Wales.

It anticipated interruptions from wet weather to continue throughout the March quarter.

Back in March the company told ILN that its Hail Creek mine in Queensland had been affected by the deluge which had struck the central coast of Queensland.

This event reflected on production results, with the mine producing 1.7Mt of coal in the recent quarter, dipping from a recorded 2.1Mt in the December 2011 quarter.

Production at the company’s New South Wales mines managed to increase, despite the wet weather experienced in the state.

Its Bengalla mine for the quarter came in at 1.4Mt, up from 1.2Mt in the previous quarter.

Overall production at its Mount Thorley operations was 769,000t, up from 601,000t in the December quarter.

Rio did say however that its New South Wales collieries were impacted by the “knock-on” effect of reduced explosive supplied in the fourth quarter of 2011.

During the quarter, first coal was produced from Rio’s Benga mine in Mozambique, with coal processed via the wash plant.

Coal is expected to be railed to port at the end of April, with first shipment of hard coking coal from the Beira port anticipated for the middle of the second quarter.

Despite mixed production results for the quarter, Rio chief executive officer Tom Albanese said the company had experienced a robust start to the year.

“We had a solid first quarter with increased production of iron ore, coal, bauxite, alumina and titanium dioxide compared with the first quarter of 2011,” Albanese said.

“This was driven by a combination of our consistently high operating performance and reduced impact from severe weather than in 2011.

“We were therefore well positioned for the relatively strong markets in the first quarter, albeit with continued volatility as we anticipated.”

Rio’s share of coking coal production for 2012 is expected to total 9Mt while its share of thermal coal is expected to tip in at 20Mt.