Chinova Resources aims to reopen Starra Line mines in 2021 to continue to feed the 2Mtpa copper-gold flotation plant at Osborne, 150km south of Cloncurry.
The option is being weighed up under the company’s Osborne Extended Mine Life (EML) feasibility study as mining at Osborne winds down due to ore depletion.
Chinova chief executive officer Shu Zhang said the plan would lift workforce numbers from 90 to more than 200 in the coming two to three years and generate increased supply and service opportunities for local contractors.
“Chinova would like to get this going as soon as possible – but it is subject to finance,” he said.
The Osborne mine has been operational since 1995.
The major underground gold-copper mine closed in 2015 after the payable ore was exhausted. But the owners subsequently launched a cutback of the original open pit and built up a stockpile of ore for processing in 2017 and 2018.
In May last year, Chinova commenced four small underground drives into the walls of the pit to recover remnant ore.
Mr Zhang said this remnant mining was due to finish in January 2021, with the Osborne concentrator expected to finish processing the last of the ore in March 2021.
“Fortunately the company holds the old mining leases in the Selwyn precinct,” he said.
“This area is 50km north of Osborne and has been mined for copper and gold for literally more than 100 years.”
Mr Zhang said the company was fast-tracking technical studies to confirm the viability of mining ore in the Selwyn area under the Osborne EML plan. This was expected to add about five years to Osborne operations.
The timing of this move is key – as strong current gold prices are a critical factor in the viability trucking the ore over the 50km to the Osborne plant.
The regional tenements under investigation include the Starra Line and Mount Elliott mineral systems.
The Starra Line – expected to be targeted first – has hosted four open pit operations (Starra 222, 244, 251 and 257) and five underground developments (Starra 222, 244, 251, 257 and 276) since 1988.
Together they produced 11.4Mt of ore grading at 2.1 per cent copper and and 3.2g/t gold.
Mr Zhang said Chinova was also also hoping to progress a heap leaching project at Mount Dore to extract copper metal contained in the oxide ore.