BHP sinks $555M into Olympic Dam amid expansion bid

BHP (ASX: BHP) is investing more than A$840 million ($555 million) in its Olympic Dam copper, gold and uranium complex in South Australia, advancing a series of growth projects ahead of a multibillion-dollar expansion decision expected in 2028.

The spending will fund an underground access tunnel into the Southern Mine Area, opening up new sections of the deposit considered vital for technology supply chains and the global energy transition. Other projects include a backfill system to deliver paste fill to deeper mine areas, expanded ore pass capacity and a new oxygen plant to boost smelter performance and copper processing capabilities.

“BHP is the largest producer of copper in the world, and we expect to grow our copper base from 1.7 million tonnes to around 2.5 million tonnes per annum,” chief operations officer Edgar Basto said in the statement. He called the projects “building blocks” toward unlocking future production.

Olympic deposits

Olympic Dam hosts one of the world’s largest copper, uranium and gold deposits, making it central to BHP’s long-term strategy and Australia’s role as a top copper supplier for the low-carbon transition. The mine has consistently produced more than 300,000 tonnes of copper annually for the past three years.

BHP shares were down 2.5% to $41.47 apiece in Sydney on Wednesday, for a market capitalization of $210.6 billion. The stock has traded in a 12-month range of $33.25 to $45.74.

The mining giant had previously targeted a 2027 final investment decision on a major smelter and refinery expansion but in August shifted that date to 2028. BHP, the world’s largest miner, is considering doubling copper output in South Australia to 650,000 tonnes by the mid-2030s.

The project’s future will hinge on energy costs and broader economic conditions, CEO Mike Henry said last month. BHP has floated and shelved Olympic Dam expansion plans repeatedly over the past 15 years.

Copper champion

Copper SA, BHP’s South Australian division, operates Olympic Dam along with the Prominent Hill and Carrapateena mines. Exploration at Oak Dam could pave the way for a fourth operation. Combined with its Escondida mine in Chile, BHP controls the world’s largest known copper resources.

The company produced more than two million tonnes of copper in the 2025 financial year ending June 30, marking a 28% increase over three years, according to its latest annual report.