A heap leach stockpile neighbouring Austral Resources Australia’s Mount Kelly processing plant holds a resource containing more than 44,000 tonnes of copper metal according to figures released today.

Re-mining the heap leach stockpile is expected to provide Austral with a pathway to low-cost production at the North-West Queensland site.

The company today announced an inferred mineral resource estimate of 22.6 million tonnes grading 0.20 per cent copper for 44.6kt copper metal within the stockpile.

The estimate was restricted to material above a 0.14 per cent copper cut-off grade, with reasonable prospects for eventual economic extraction, Austral said.

Image at top of page: Excavator conducting remine operations in 2019.

“Establishment of the MRE for the Mount Kelly heap leach stockpile represents an outstanding outcome for the company,” Austral chairman David Newling said.

“The MRE is another step for Austral towards its strategy of repositioning as a leading Australian mid-tier copper production company.

“The results are extremely exciting, with the outcomes and cut-off grades commensurate to the proximity of the stockpile to the Mount Kelly facility and the very low-cost nature of the stockpile re-mining.

“Essentially for the cost of an excavator and re-irrigation, the heap leach re-mine provides Austral with a pathway to increased production whilst providing a potential funding pathway to progress Austral’s expansion and exploration assets.”

Related: Study paints positive picture for Austral copper pipeline

Austral Resources, producing from the Anthill mine and Mount Kelly processing plant, went into receivership in May.

But it reached a debt restructuring deal with parties including offtake partner Glencore, Anthill mining contractor Thiess and Secover.

The deal ‘ring-fences’ Austral’s producing Anthill mine, funnelling that operation’s proceeds into repaying $78 million in secured debts.

The company’s Mount Kelly solvent exchange-electrowinning (SX-EW) plant was commissioned in October 2007 under the ownership of Copper Co, which was then sold to CST Minerals in 2009.

Austral said previous operators employed a mining fleet that was two to three times the size required, resulting in overmining and exceeding the run-of-mine (RoM) capacity.

This put pressure on the processing circuit and ultimately resulted in overstacking the leach pads prematurely.

With the current price of copper, Austral sees an opportunity to re-mine the legacy pads to recover acid-soluble copper remaining in the ore.

The company said the heap leach circuit was expected to be re-mined and re-irrigated within the next 12 months and become an added source of production for the site.

Below: Austral Resources Australia mining and exploration tenements in North-West Queensland.