en.Wedoany.com Reported - Cobra Resources is advancing its rare earth project in South Australia, which it claims is the only project in Australia suitable for In Situ Recovery (ISR) mining. Drilling has delineated mineralization in two separate prospect areas, with approximately 80% of assay and permeability data collected, laying the groundwork for the first mineral resource estimate. Listed on the London Stock Exchange, the company focuses on exploration and development, and its ISR approach offers lower capital intensity, a smaller physical footprint, and potentially faster pathways to production compared to traditional hard rock or open-pit mining.
The company has conducted sonic core drilling in unconsolidated sediments within its South Australian tenement package, now defining two prospect areas. Management emphasizes that these areas represent only a small portion of the company's total landholdings but can trace deltaic or flank mineralization systems extending several kilometers in length. Remaining data is being incorporated into hydrological models to support the first mineral resource estimate. The company is working across three geological horizons: the Pidinga Formation, the Garford Formation, and the Narlaby Formation. The Pidinga Formation, the deepest, is the primary target due to its high permeability and comprehensive hydrological data. The Garford and Narlaby formations, located above, are being evaluated simultaneously to increase tonnage potential without additional drilling costs. The Narlaby Formation exhibits high grade and permeability but requires further work on aquifer containment.
The ISR mining method requires specific geological conditions, where permeability, grade, and acid consumption are the three main levers driving project economics. Cobra Resources has simulated the ISR mining process through tracer studies, achieving nearly 80% recovery of a tracer injected from one well at an equidistant well within two days under a transmissivity of 8 meters per day. This hydraulic connectivity supports well spacing of 15 to 25 meters, and leaching cycle models based on these permeability data indicate well fields can operate for 30 to 60 days. The high tracer recovery also demonstrates leachate containment, a key environmental requirement for ISR permitting.
The composition of Cobra Resources' mixed rare earth carbonate product differs from many similar ionic clay projects. Of the total rare earth content, approximately 43% is heavy rare earths, with dysprosium and terbium together accounting for nearly 5%. Company CEO Rupert Verco attributes this enriched heavy rare earth signature to a reducing geochemical environment, which allows cerium to precipitate during impurity removal without solvent extraction, reducing the material to be transported while recovering more value.
One technical advantage of the project is that the ore body contains natural sulfides, which can oxidize to generate sulfuric acid in situ. Laboratory-scale studies indicate that up to 60 kilograms of sulfuric acid can be generated per tonne of material in certain drill holes. Rupert Verco stated that even under conservative assumptions that not all of this acid can be captured, partially offsetting acid consumption is economically significant. In standard rare earth ISR operations, acid costs account for approximately 30% of total operating costs, and management estimates operating costs at around $18 to $20 per kilogram of MREC. The capital expenditure requirements for the ISR method are only 15% to 20% of those for hard rock operations, and environmental remediation liabilities are significantly reduced, with remediation costs per unit of commodity production approximately 28 times lower than for open-pit operations such as the Ranger uranium mine.
South Australia has conducted multiple ISR pilot studies in uranium and copper projects over the past two years, and there are long-term ISR uranium production operations in geological horizons similar to those of Cobra Resources' project. The company's use of a mild, low-acidity leach solution reduces regulatory risk. The company plans to complete the first mineral resource estimate, which will incorporate permeability and acid generation parameters, and use this as the basis for a scoping study. Additionally, it plans to conduct on-site ISR pilot studies using existing well field infrastructure and processing facilities at the Australian Nuclear Science and Technology Organisation to de-risk the mining method. A diamond drill rig is operating around the clock on the company's porphyry copper project.
This article is compiled by Wedoany. All AI citations must indicate the source as "Wedoany". If there is any infringement or other issues, please notify us promptly, and we will modify or delete it accordingly. Email: news@wedoany.com
