A Pilbara deposit that has created headlines around the world is now poised to become one of Australia’s top-five producing gold mines. 

De Grey Mining’s Hemi discovery has captured global attention since it was first announced in 2019. In May it revealed an upgrade to its resource to 8.5 million ounces– up from an already impressive maiden 6.8 million ounces – and noted that it was now Australia’s biggest undeveloped gold mine. 

But more good news arrived today with the publication of a prefeasibility study that indicated mine life of 13.6 years (an increase from 10), average gold production of 550,000 ounces per annum for the mine’s first 10 years (an increase from 473,000) and recovered gold of 6.4 million ounces over the project’s life (an increase from 4.3 million). 

If all that comes to reality, Hemi would rank in the top-five producing Australian gold mines and among the top three undeveloped gold projects in the world. 

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The study also projected Hemi and other deposits within the company’s Mallina Gold Project would be in the lowest quartile of Australian producing gold mines and one of the world’s lowest capital intensive gold projects. 

And renewable energy is likely to play a key role in the eventual mine, the location of which will help it take advantage of existing infrastructure in the Pilbara. 

“We’re located 85km by road south of Port Hedland. That’s about a one-hour drive,” De Grey’s Managing Director Glenn Jardine told a conference call after the announcement of the pre-feasibilty study. 

“But we’re surrounded by world class existing infrastructure, including sealed highways – the Great Northern Highway to the east of us and the Coastal Highway to the north – and also two gas pipelines and a 220 kV transmission line. 

“The other important thing about this location is that there’s a lot of projects underway or planned in the Pilbara in terms of renewable energy, and one of the options that we’ve got is to hook into the existing or proposed expanded grid in the Pilbara, so that we can take advantage of those renewable energy projects in our baseline power supply. 

“We’ve also got sufficient good quality water for both dust suppression in the mine and mining requirements, as well as for the process plant.” 

De Grey remains hopeful that the Hemi resource may be increased further through further drilling and has also noted promising results at the neighbouring Diucon and Eagle targets. 

  • DeGrey Pilbara

While the Pilbara is best known for iron ore and LNG production, the North West of WA’s link to the gold industry is actually more well-entrenched than widely realised. The State’s first gold rush was recorded at Halls Creek in the Kimberley in 1885 and a teenager named Jimmy Withnell discovered a collection of gold nuggets in 1888 at Mallina Station, 90 kilometres south-west of Port Hedland. 

Telfer – once recognised as WA’s most isolated town – has been home to a gold mine since 1977, and earlier this year Calidus Resources achieved first production with its Warrawoona project near Marble Bar. Meanwhile, Capricorn Metals’ Karlawinda project poured its first gold in June 2021. 

De Grey’s Senior Geologist Nicole Young told resourc.ly last year there was a significant buzz on-site because of the scope and potential of the Hemi discovery. 

“The way the project has developed so quickly and expanded, it’s made it a very dynamic, fast-paced and fun environment,” Young said.  

“Every geologist wants to be on a project like that, where it’s not just one little discovery but continually expanding.  

“It’s busy, it’s very challenging, there’s a lot of juggling and things change pretty rapidly. But more than anything it’s exciting – everybody is amped to be there and about the results coming out.”