Thermal coal production of 4.7Mt was flat.
Rio CEO Sam Walsh described the quarter’s performance as “solid”
“By making best use of our high-quality assets, low cost base and operating and commercial capability, our aim is to protect our margins in the face of declining prices and maximise returns for shareholders throughout the cycle,” he said.
Pre-tax and pre-divestment exploration and evaluation expenditure for the first quarter was $US126 million ($A163.2 million), compared to $155 million for the same period of 2014.
The bulk, or 39%, was incurred by the copper and coal group, with copper exploration in the US, Chile, Peru, Zambia and Kazakhstan.
A further 21% was incurred by the diamonds and minerals group, and 6% in iron ore, with the balance by the exploration team.
The company conducted nickel and uranium exploration in the US, bauxite field mapping and drilling in Brazil and Laos, coal work in Australia, and diamond exploration in India and Canada.