Although iron ore accounts for the largest share of the ASX-listed miner’s earnings, copper production proved the standout feature of the trading update, up 33 per cent from 2017, to 634,000 tonnes, and beating expectations. The company said the result reflected the strong performance at Escondida and increased production from Rio Tinto Kennecott.

“We delivered a strong operational performance in the final quarter of 2018, in particular across our copper assets,” Rio Tinto chief executive Jean-Sebastien Jacques.

“During the year, we further strengthened our portfolio, continuing to invest in high-quality growth.”

Delivering its 2019 production forecasts, Rio Tinto said a recent fire that engulfed part of one of its major ports in the Pilbara would result in “limited disruption” on its shipments of Robe Valley lump and fine iron ore products.

The fire, on January 10, broke out at Rio Tinto’s Cape Lambert Port near Karratha, causing damage to a part of the plant that separates the two products. As a result, the company declared “force majeure” on its contracts with affected customers. The blaze did not affect shipments of Rio Tinto’s premium product, the “Pilbara Blend”.

Friday’s forecast boost in iron ore production for 2019 comes after the miner also announced it had successfully deployed its network of AutoHaul autonomous trains across its Pilbara mining operations, establishing the world’s first automated heavy-haul, long-distance rail network.

“Rio Tinto has steadily increased the number of autonomous journeys in a controlled and safe manner, with over 1.6 million kilometres now travelled autonomously,” the company said in a statement.

“The program will now focus on optimising autonomous operations.”

Following the fourth-quarter trading update, Rio shares were trading 0.3 per cent higher, at $80.66, by 2pm on Friday.