Newmont plans to build a spur line from the Amadeus Gas Pipeline that runs between Darwin and Alice Springs out to the Dead Bullock Soak mine and Granites.

At the moment Newmont’s Tanami operations have two diesel-fired power stations – one at the Granites open pit mine and processing plant and the other at the  Dead Bullock Soak underground operation about 44km away.

Those stations generate a combined 28 megawatts to 34MW.

However, with the DBS mine going deeper, the power draw there is likely to increase as ventilation and refrigeration demands rise.

The average rock temperature at the sort of depths DBS will be heading to is 58C, meaning some sort of cooling will be needed.

“With cooling alone we can cool the air to 28C,” Hardy said.

That temperature issue is based on the existing plan for DBS.

Newmont is working on a further expansion of the underground operation, which will likely take it below 2km depth and add several years to the mine life there.

Another problem the mine faces is the potential for isolation in the event of a heavy rain event.

Newmont Mining Corporation regional project director Francois Hardy said a rain event earlier this year had resulted in the mine having to be evacuated.

The rain caused flooding on the Tanami plain, which cut road and stopped diesel shipments getting through.

Hardy said the company was yet to determine who would be supplying the gas.

“We’re still negotiating the various contracts,” he said.

Permitting is still to be completed, however, a decision on the relevant approvals is expected next month.

Hardy said the pipeline spur would probably be about 110km north of Alice Springs.

With the gas pipeline in place, Newmont will again look to have two power stations, only this time they will be gas fired.

“We wanted to make sure we had the flexibility to run Granites on its own should something happen to DBS,” Hardy said.

He said the larger of the two power stations would be at DBS.

The combined output of those two stations is expected to be 34MW-41MW.

Newmont is in negotiations with potential power station providers to build those two generators.

Hardy said the incumbent power station provider Kalgoorlie Power Systems was on site at the moment and had been there through the entire process.

Besides the increased power and operational security benefits, Newmont is also expecting to get some sizeable cost benefits from going to gas.

On a recent results call Newmont chief operating officer Tom Palmer said the company expected to get some significant benefits.

“The roughly 25c kilowatt hour power cost today, diesel fire power stations at Tanami and with gas coming in gas power stations, you'll expect to see in the order of 20% improvement there,” he said.

Palmer said there would switching to gas would also reduce the mine’s carbon footprint.