BHP Billiton Releases Draft EIS for Proposed Olympic Dam Expansion
The Olympic Dam Draft EIS is an extensive document of 963 pages. The proposed expansion centers on the creation of a new open-pit mine that would lift ore production six-fold at Olympic Dam and would require expanded minerals processing facilities. Major support infrastructure to be built would include a coastal desalination plant, a new power line and possibly a gas-fired power station, a rail line, an airport, port facilities, a village to accommodate workers, and more housing, retail, commercial and community facilities in the mining community of Roxby Downs. The proposed expansion would be a progressive development, requiring construction activity over a period of 11 years.
The Draft EIS is not a commitment to construct. The project schedule ultimately will depend on the timing and nature of government approvals and a final investment decision by BHP Billiton’s board of directors. BHP Billiton is not commenting on issues raised by stakeholders during the public exhibition period but will respond through the Supplementary EIS, which will also be a public document.
Olympic Dam is a multi-mineral orebody located 560 km north of Adelaide. It is the world’s fourth largest known remaining copper and gold deposit and the largest known uranium deposit. It also contains significant quantities of silver. Drilling of the orebody undertaken by BHP Billiton since 2005 has more than doubled the resource estimate from 3.98 billion mt to 8.34 billion mt.
The proposed Olympic Dam open-pit would require five years of pre-stripping to a depth of 350 m to reach the top of the orebody. The current underground mine would continue to operate.
BHP describes the Olympic Dam orebody as being shaped like a frying pan. The proposed open-pit would mine the “pan,” while the underground operation would continue to take ore from the “handle.” Over 40 years, the size of the pit would grow to be 4.1 km long, 3.5 km wide, and 1 km deep. Eventually, the open-pit would produce 60 million mt/y of ore, while the underground mine would continue to produce at its current rate of 12 million mt/y.
A new concentrator would be built, and copper concentrate production would increase from 600,000 mt/y to 2.4 million mt/y. Some concentrate would be shipped to overseas smelters, in contrast to current operations, where all concentrates are smelted and refined on site to produce 235,000 mt/y of refined copper. The expanded operation would produce a total of 750,000 mt/y of refined copper, including refined production from overseas smelters. Uranium oxide production would increase from 4,500 mt/y to 19,000 mt/y, gold bullion production would increase from 100,000 oz/y to 800,000 oz/y, and silver bullion production would increase from 800,000 oz/y to 1.9 million oz/y.