A $600m expansion at OZ Minerals’ Prominent Hill mine will employ hundreds more people and extend its life

The Prominent Hill mine in Far North South Australia will soon embark on a $600m expansion plan, providing hundreds of new jobs.

A worker at OZ Minerals' Prominent Hill mine in Far North South Australia. Picture: Supplied

THE workforce at OZ Minerals’ Prominent Hill mine in the state’s Far North will swell by up to 250 in coming years as the company embarks on a $600m expansion project to sink a new shaft, with benefits for the production rate, operating costs and emissions.

The copper and gold mine - which was originally envisaged as an open-cut project which was scheduled to close in 2018 - has a current expected mine life out to 2036, with the new investment adding at least six years to previous estimates.

And the company has flagged that there is potential for expansion both below the current ore body and at satellite ore bodies closer to the surface.

Prominent Hill general manager Gabrielle Iwanow said there were currently about 1200 people working at the mine, and the extended longevity of the project was a big boost for all stakeholders, including staff and suppliers.

Ms Iwanow said the project had continued to boost its output over time and was going from strength to strength.

“It started off as an open pit and to become an underground mine-only in 2018, it’s gone from 2.9 million tonnes (of ore) when I started in January 2019, we got up to 4 million tonnes, we then announced plans to expand up to 5 million tonnes by 2022, and with this expansion going up to 6 million tonnes.

“It’s really rewarding and exciting for the team to see that progress.’’

The new “Wira shaft” project, which will extend the mine life to 2036, will also cut trucking costs and emissions at the project substantially.

This was because it would involve using electric hoisting to move the ore to the surface rather than trucks., saving substantial amounts of diesel and time.

“It’s a 1.3km-deep, concrete-lined shaft ... normally we’d use loaded trucks to bring ore to surface,’’ Ms Iwanow said.

“This replaces the need to run to surface for the trucks. It is beneficial for a couple of reasons - one being we are able to lower our operating costs by about 20 per cent.

“The shaft allows us to go deeper into the ore body and the exciting thing at Prominent Hill is that the ore body remains open at depth.

“We know that there’s mineralisation down there but because we haven’t been deep enough in the mine to fully understand what that potential is, that’s also another benefit of the shaft, because we will be able to establish drill platforms ... and continue to drill out the ore body.’’

With the shaft using electrically-driven haulage rather than diesel, there were also savings to be made on carbon emissions.

Work on sinking the shaft is expected to start in the first three months of calendar 2022 and be finished in 2024.

Ms Iwanow said the company is also still following up the results of the Explorer Challenge it ran in 2019, which allowed teams from around the world to develop exploration ideas for the Prominent Hill province.

Prominent Hill started producing copper and gold in 2009, and this year is expected to produce 58,000-70,000 tonnes of copper and 125,000-135,000 ounces of gold.

OZ last week reported it had more than tripled its half year net profit to $269m on revenue of $986.1m, up $410.4m.