By Rhiannon Hoyle

Rio Tinto on Wednesday reported the highest second-quarter output from its Australian iron-ore mines since 2018, while flagging around $300 million of gross costs from U.S. tariffs on its Canadian aluminum exports.

The world's second-biggest miner by market value said its Pilbara iron-ore operations, which account for the bulk of its profits, had recovered well from setbacks in the first quarter when cyclones lashed Australia's northwest coast.

Rio Tinto said it produced 83.7 million metric tons of iron ore in the Pilbara in the three months through June, up 5% on the year-earlier period. Shipments were down by 1% year over year, at 79.9 million tons.

The company said it continues to expect annual shipments from that business to be at the lower end of its guidance--of between 323 million and 338 million tons--in line with remarks it made in April.

Rio Tinto, which on Tuesday named iron ore boss Simon Trott as its next CEO, said it has notified customers of changes to the Pilbara Blend, its flagship iron ore product, following a previously announced review. From July, Rio Tinto will combine its Pilbara Blend and SP10 products into a single blend, reducing the iron content to an average 60.8% from 61.6% previously.

The miner also said it is accelerating the first shipment from the Simandou high-grade iron ore project in Guinea, where it now expects its first shipment around November. Simandou is one of the world's largest and richest undeveloped deposits of iron ore, and has the potential to reshape the global market as it ramps up.

Rio Tinto, which produces a number of other commodities including aluminum and copper, highlighted geopolitical tensions and trade barriers as continued near-term risks.

In its aluminum unit, "all produced metal has been shipped with sales pricing, product mix and shipping destinations flexed to optimize our position in the wake of the changing tariff environment," the company said.

Aluminum came into the crosshairs early on in Trump's push to reshape global trade, with a 25% tariff imposed on imported metal in March. The U.S. increased that tariff to 50% in June.

Rio Tinto said the $300 million in first-half costs from U.S. tariffs on aluminum imports were substantially offset by an increase in U.S. metal prices. American premiums "rapidly adapted to the 25% tariffs level in 1Q, but, at the end of 2Q, was not fully compensating for the 50% tariff," Rio Tinto said.

In its copper business, Rio Tinto said it now expects 2025 output to be at the high end of its annual forecast range, and for unit production costs to be around the low end.

The miner said that reflects success in ramping up the Oyu Tolgoi underground mine in Mongolia, where it reported a record quarter of production, and a good performance at Escondida in Chile, the world's biggest copper mine.

Write to Rhiannon Hoyle at rhiannon.hoyle@wsj.com

(END) Dow Jones Newswires

July 15, 2025 19:43 ET (23:43 GMT)

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