PERTH (miningweekly.com) – Mining giant BHP Billiton has applied for permission to increase the tailings storage capacity at its Olympic Dam copper, uranium and gold mine, in South Australia.

In documents submitted to the federal government, BHP requested to increase the current design height of one of its radioactive storage ponds from 30 m above ground level, to 40 m above ground level.

At current production rates, the storage facility was expected to reach its design capacity in December 2017. However, by increasing the capacity of the storage facility, the miner was hoping to extend the life of the facility by five years, and to avoid the construction of an entirely new facility.

BHP said that raising the embankment height of the existing facility would not result in increased seepage rates, nor would it increase worker or public radiation exposure from the Olympic Dam tailings.

“Due to the requirement for ongoing tailings storage capacity, as a result of the continued operation of the mine and processing plant, taking no action is not a feasible alternative,” the company said in its documentation.

“A feasible alternative, and one that remains the option in the event that the design height of the tailings storage facility is not increased, is to construct and commission a new tailings cell. This option is not preferred, primarily because of the associated increased environmental impacts of additional land clearing and the heightened risk to avifauna from increased tailings storage facility surface area,” the miner added.

BHP pointed out that the construction of a new tailings storage facility would also come at a high capital cost.

In November, BHP revealed that it would spend about $200-million on debottlenecking operations at Olympic Dam, in the hopes of increasing ore production to 11-million tonnes a year and deliver an additional 50 000 t/y of copper from the operation by 2018.

The miner was currently expanding the underground footprint of the Olympic Dam project into the southern mining area, to access higher grade ore. The move to the southern mining area would allow for grade recovery to increase and would enable the full use of the smelter and refinery.

Meanwhile, BHP was also advancing its plans to expand Olympic Dam ore production to about 21-million tonnes a year, allowing for the potential to deliver about 450 000 t/y of copper from the 2024 financial year.