How Coda’s New Leach Process Could Boost Copper Recovery to 96%

Metallurgical Breakthrough at Elizabeth Creek

Coda Minerals Limited (ASX, COD) has announced a significant advancement in its processing technology at the Elizabeth Creek Copper-Cobalt Project in South Australia. Recent metallurgical testwork on ore from the Emmie Bluff deposit demonstrated that whole-ore leach techniques can achieve copper recoveries as high as 95.9%, substantially outperforming the 82.8% average recovery from the previous flotation-based flowsheet.

The company trialled two distinct leaching methods, a catalysed ammonia oxidative leach and an ammonium chloride oxidative leach. Both methods achieved excellent copper recoveries within just eight hours of leaching, with the ammonium chloride leach delivering the highest recovery. Silver recoveries also improved markedly, reaching 97.3% with the ammonium chloride method.

Simplifying the Processing Flowsheet and Cost Implications

One of the most compelling aspects of this breakthrough is the potential to simplify the processing plant dramatically. By adopting whole-ore leaching, Coda can eliminate the need for complex and capital-intensive flotation plants, Albion circuits, and oxygen plants. Instead, the process would rely on simpler polycarbonate tanks, which could lead to significant capital expenditure (CAPEX) reductions.

This simplification also promises operational cost savings (OPEX) by reducing process complexity. The company is currently advancing detailed CAPEX and OPEX estimation work alongside trade-off studies to compare the new flowsheet against the existing base case. These efforts aim to quantify the economic benefits and inform an updated project feasibility assessment.

Project Economics and Strategic Outlook

Elizabeth Creek’s previous scoping study, published in December 2024, outlined a robust project with a pre-tax net present value (NPV7) of approximately A$1.2 billion and an all-in sustaining cost of US$1.80 per pound of copper, based on an average copper recovery of 82%. The new metallurgical results suggest that copper recovery could increase by over 10 percentage points, directly translating into higher revenue potential over the mine’s life.

CEO Chris Stevens highlighted the significance of the recovery uplift, stating that improving recoveries is the most powerful lever for value creation. He emphasized that the company is focused on progressing Elizabeth Creek to a construction-ready state, leveraging this breakthrough to enhance project economics and appeal to global investors seeking quality copper assets in Tier 1 jurisdictions.

Ongoing Work and Exploration Potential

Coda is continuing metallurgical optimisation, including efforts to improve silver recovery from the catalysed ammonia leach and to develop effective cobalt extraction methods. While cobalt is not recovered in the initial oxidative leach phases, secondary leaching or flotation remain viable options.

In parallel, exploration drilling has confirmed additional mineralisation outside the known Emmie Bluff basin, indicating potential resource growth. The company plans to integrate these findings into future resource updates and mine planning.

Despite the promising results, Coda cautions that the metallurgical testwork is preliminary and requires further validation through variability testing, engineering studies, and economic modelling before definitive production or financial outcomes can be confirmed.