Mining giant Rio Tinto has made a sluggish start to the year, with first quarter shipments and production of iron ore affected by bad weather in Western Australia.
The world's second largest iron ore exporter shipped 76.7 million tonnes of iron ore from its Pilbara operations in the three months to March 31, similar to the volume a year earlier, but leaving it slightly behind the level required to achieve its full year target.
Production declined three per cent to 77.2 million tonnes in the quarter.
"Production and sales were both impacted by significant weather disruptions, which resulted in heavy flooding across several sites including the rail network, along with the suspension of ship loading on a number of occasions," the company said.
Rio Tinto has maintained its full year guidance for iron ore shipments of 330 million to 340 million tonnes.
Rival miner Fortescue Metals Group also stumbled because of bad weather in the quarter, reporting a six per cent decline in its iron ore shipments.
The bad news comes amid a fresh slide in iron ore prices as demand from Chinese steel mills wanes. Iron ore prices, which had sharply rebounded in 2016, are now down by a third since mid-February.
Rio also reported a 37 per cent slump in mined copper production, blaming the 43-day labour strike at its Escondida mine in Chile for the decline.
The strike, along with the curtailment of production at the Grasberg mine in Indonesia, has forced the miner to lower its full year production target to between 500,000 and 550,000 tonnes, down from the previous estimate of 525,000 to 665,000 tonnes.
Coking coal production was also down, by 20 per cent, partly because of planned operational issues.
The company has maintained its full year guidance for coal, aluminium, alumina and bauxite production.
"The softness was not entirely unexpected given the weather impacts on both the east and west coast operations in Australia, as well as the strike at Escondida and uncertainty around Grasberg," RBC Capital Markets analyst Paul Hissey said in a note.
"Rio's updated guidance of copper production is welcome, and the unchanged guidance to the rest of its operations gives us confidence that Rio can make this up over the year," he added.
Rio shares were higher in morning trade, but closed 23 cents weaker at $58.67.
