BHP Billiton is taking a significant step towards a viable plan to expand the Olympic Dam mine in South Australia’s Far North.
Buoyed by successful laboratory trials in Adelaide of a cost-effective way of processing the mine’s complex ore body, BHP has applied to the Federal and State Governments to build a pilot processing plant at the Olympic Dam site.
This would be the next step in its assessment of the heap-leach processing of the lucrative ore which contains copper, uranium, gold and silver.
Olympic Dam will need to get internal financial approval for the pilot plant. It would cost many million dollars but BHP cannot estimate a cost until it knows what government conditions it must meet.
A successful trial on site would be an encouraging signal for the mine expansion although any final investment decision is still a long way off.
“The heap leach trial is intended as a demonstration and proof of concept,” BHP said, but added a successful trial “will not necessarily lead to a full scale project”.
Since postponing the expansion nearly two years ago, BHP Billiton has gone back to the drawing board to work out cheaper processing and mining methods.
Infrastructure at Olympic Dam. AFP PHOTO / BHP BILLITON.
SA Chamber of Mines and Energy chief executive Jason Kuchel cautiously welcomed the move.
“It’s good to see BHP Billiton moving ahead one step at a time, hopefully towards an expansion,” he said.
Mineral Resources and Energy Minister Tom Koutsantonis said the BHP move was “encouraging”.
“It seems the trials have been going well,” he said.
“It’s a step in the right direction although it’s by no means a panacea.
“I’ll be looking forward to the results.
“Olympic Dam is a world class ore body. One day it will be expanded — the question is when, not if.”
In an application to the Federal Government, BHP seeks approval for the pilot plant under environmental laws.
It says the environmental impact would be “very low to negligible” and wants federal clearance to proceed with conditions but without a major new assessment process.
It also has applied to the State Government for a variation on its mining licence.
Mr Koutsantonis said he didn’t foresee any major impediments although the usual assessments would be applied.
The pilot plant would sit on about 18ha on the Olympic Dam site.
Ore from the mine would be crushed and piled in heaps on a specially prepared impregnable pad.
An acidic solution would then be dribbled through the ore pile to leach out uranium and some of the copper, with the pregnant liquor taken off for recovery of the target minerals.
Once the pile has been leached for 300 days, the ore pile would be sent through conventional processing to extract the rest of the copper as well as gold and silver.
Construction of the plant would begin in the second half of next year if the approvals process goes smoothly.
The proposal to the Federal Government is open for public comment until August 11, with a decision on whether federal assessment is needed due by August 22.
“If it does need approval, it will be subjected to a thorough environmental assessment that will include another opportunity for public comment,” a spokesman for Environment Minister Greg Hunt said.
BHP has a target of October 2016 to begin operations of the pilot plant.
October 2016 is the date that federal and state approvals for the expansion are due to expire unless BHP has approved the project.
The pilot plant is likely to operate for at least three years.