Tests conducted by rare earths metallurgical specialists ANSTO Minerals have validated Red Metal’s breakthrough leach results using chip samples from its new Sybella discovery near Mt Isa in North Queensland.
Red Metal says ANSTO’s supplementary findings back up its phase-one testwork – which was completed by Core Resources and revealed last month – that showed high recoveries and low impurities using low levels of acid consumption for both valuable magnet and heavy rare earth oxides.
ANSTO Minerals is an arm of the Australian Nuclear Science and Technology Organisation – a statutory agency that reports to the Federal Parliament. It ran similar bottle roll leach tests to the ones carried out by Core that used coarse non-pulverised chip samples from reverse-circulation (RC) drilling at Sybella.
Red Metal believes the matching results from both sets of testwork may point to an opportunity for low-cost processing, potentially using heap leach methods. It says only minor differences in acid consumption and rare earths extraction levels were identified and its planned phase-two testwork will use crushed drill core that will aid in the understanding of any slight variances in the results.
The phase-two work will evaluate how a range of size fractions respond to the leach testing using varying conditions and timeframes, to assist with providing improved data for an early-stage mining study.
Red Metal managing director Rob Rutherford said: “It is expected the current Phase-2 metallurgical work on the crushed drill core will provide the optimised data necessary to firm-up the metallurgical characteristics and processing options needed to define what potentially economic ore may look like. With this assessment we can fine-tune our step-out drilling, which is set to begin in May, focusing first on the most economic portions of the large 12k- by-3km rare earths-enriched granite.”
The company believes that its granite-hosted Sybella is a “world-first” new type of rare earths discovery that, like clay-hosted ionic and non-ionic deposits, can potentially provide a low-capex and low-cost heap leach processing option. It says the softer weathered granite in the top 20m adds advantages with the mining and comminution process and adds that granite is also a low-acid consuming rock.
Sybella is 20km south-west of Mount Isa, with excellent infrastructure such as a power plant, smelter and acid plant close to the historic mining town.
Red Metal notes the rare earth-enriched granite-intrusion at the project is exposed at surface for about 12km in length and 3km in width, with the bulk of the rare earths in soluble fluoro-carbonate minerals. RC drilling revealed two higher-grade zones, each about 1km in width.
Management believes there is vast tonnage potential, with zones open north, south and at depth. It says future plans for proposed mining would involve open pit mining and an expected magnet rare earth oxides (MREO) figure of about 70 to 80 per cent payable, based on anticipated recovery levels.
Red Metal also has several other projects and interestingly, owns about 53 per cent of Maronan Metals, the company it spun-out and floated in April 2022. Maronan has a highly-prospective lead-silver-copper-gold project that is also based in the Mt Isa region.
Now that it has validated the potential for economic extraction and processing of its Sybella rare earth deposit, the future pathway to generating real value from the project could be a game-changer for Red Metal.
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By Craig Nolan
