Copper producer Austral Resources Australia Ltd (ASX:AR1) (“Austral” or the “Company”) has announced a JORC-compliant Mineral Resource Estimate (MRE) for its Mt Kelly Heap Leach stockpile, marking a significant step forward in potential low-cost copper production.
Highlights:
- JORC Inferred Resource: 22.6 million tonnes grading 0.20% copper, totaling 44.6kt of contained copper metal within Austral’s Heap Leach stockpile.
- Economic Potential: The MRE includes material above a 0.14% copper cut-off grade, with reasonable prospects for economic extraction.
- Proximity to Infrastructure: The stockpile is located adjacent to Austral’s existing Mt Kelly Solvent Exchange - Electrowinning (SX-EW) Plant, enabling efficient reprocessing.
- Feasibility Studies Planned: The MRE will support further testwork, including drilling and metallurgical sampling, to inform a Scoping and Pre-feasibility Study.
- Low-Cost Production Opportunity: Re-mining the stockpile is anticipated to be low-cost, requiring minimal rehandling with no need for new mining or crushing.
The Heap Leach stockpile is considered an important additional resource to the Company. Further testwork and studies will assist Austral in increasing confidence in the MRE and determining appropriate next steps to determine the feasibility of re-mining the Heap Leach stockpiles (Heap Leach Re-mine). Progression of the Heap Leach Re-mine is expected to provide Austral with a pathway to low-cost production.
The Mt Kelly processing plant was commissioned in October 2007 under the ownership of Copper Co. Ltd (Copper Co) which was then sold to CST Minerals in 2009. The total ore mined, crushed, and treated via Heap Leach to date is 22.6Mt at an average grade of 0.85% Cu. It is estimated that there is circa 45kt of residual copper metal in situ and unrecovered for various reasons; some of which include the premature over stacking of ore prior to the terminal recovery being reached due to historically aggressive mining/processing campaigns. Previous operators employed a mining fleet that was two to three times the size of what was required resulting in over mining and exceeding the run of mine (RoM) capacity, which put pressure on the processing circuit, and ultimately resulted in over stacking these pads prematurely.
Legacy recoveries averaged 77% prior to Austral taking over the operation. With the current price of copper, Austral sees an opportunity to remine the legacy pads to recover acid-soluble copper remaining in the ore. This process only requires a small rehandling excavator, without the need/cost of mining, hauling and crushing. The heap leach circuit is expected to be remined and re-irrigated within the next 12 months and become an added source of production for the Company.
Austral’s Chairman, Mr David Newling, provided the following comment in relation to the MRE: “Establishment of the MRE for the Mt Kelly Heap Leach stockpile represents an outstanding outcome for the Company. The MRE is another step for Austral towards its strategy of repositioning as a leading Australian midtier copper production company. The results are extremely exciting with the outcomes and cut-off grades commensurate to the proximity of the stockpile to the Mt 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.
“I want to thank all our stakeholders and shareholders for their continued support, and I look forward to sharing more positive updates as we continue to progress the recapitalisation of the Company.”
About us:
Austral Resources is located in Queensland Gulf country, and produces LME Grade A copper cathode from its open cut mine. The company is listed on the Australian Securities Exchange (ASX code AR1).
Contact details:
Jane Morgan
jm@janemorganmanagement.com.au