OD6 Metals (ASX:OD6) reports preliminary ore sorting results from Quinn Fluorspar Project
OD6 Metals has reported head assay, mineralogical and preliminary sensor based ore sorting results from its ongoing metallurgical development program for the Quinn Fluorspar Project in Nevada, USA.
The current program combines modern mineralogical characterisation and conventional beneficiation studies being undertaken by Core Resources in Brisbane with sensor based ore sorting investigations undertaken by TOMRA at its Test Centre in Wedel, Germany.
Highlights
TOMRA ore sorting results demonstrated clear discrimination between high grade fluorspar, lower grade and mixed material, and barren waste.
QXRD identified fluorite as the only fluorine bearing mineral, supporting the interpretation of the fluorine assays.
OD6 intends to progress larger scale TOMRA sorting trials using approximately 500 to 1,000 kg bulk samples to establish quantitative mass rejection, grade uplift and recovery performance.
A total of approximately 166 kg across 11 large format samples from Mammoth, Blue Bell, Horseshoe and Big Jim was delivered for the metallurgical program, with individual samples ranging from approximately 8 to 25 kg.
The samples were collected and composited from different localities within the 4 projects to build a representivity of typical ore types, as well as waste rock and mixed waste and ore exposed at surface at Quinn.
The program included high grade mineralisation, medium and lower grade mineralisation, mixed ore and host rock, breccia mineralisation, footwall material, hanging wall material and internal waste and host rock.
Head grades confirmed across the principal mineralised domains included 98.3% CaF₂ from the Big Jim main vein, 90.0% CaF₂ from Horseshoe high grade mineralisation, 86.7% CaF₂ from the Blue Bell main vein, 76.2% CaF₂ from Horseshoe breccia mineralisation and 40.4% CaF₂ from Mammoth breccia mineralisation.
Independent QXRD mineralogy returned 98.6% fluorite at Big Jim, 90.4% at Horseshoe, 91.6% at Blue Bell and 48.5% at Mammoth.
TOMRA was presented with coarse 5 to 12 mm representative samples, with laser sorting used to evaluate differences in surface properties, colour, brightness and crystalline characteristics, while X Ray Transmission differentiated particles according to differences in atomic density.
The preliminary investigation demonstrated the ability to distinguish fluorite rich material from lower grade and waste material.
At Horseshoe, Laser sorting demonstrated clear differentiation between 2 styles of high grade fluorspar and the limestone host and internal dilution material.
At Big Jim, both Laser and XRT clearly differentiated the massive high grade fluorspar vein from footwall and hanging wall material, while at Blue Bell the volcanic host rock provided strong contrast to the fluorspar veins, with both methods demonstrating clear differentiation between the ore and waste domains.
At Mammoth, preliminary sorting was less definitive due to similarities between crystalline quartz and fluorite bearing material.
OD6 Managing Director Brett Hazelden said,
“We deliberately did not just send TOMRA and Core our best-looking fluorspar.”
Multi element characterisation of the metallurgical samples returned very low concentrations of a range of potentially deleterious elements within the high grade fluorspar material.
The announcement states that arsenic, cadmium, base metals, sulphur and uranium achieve Metspar and Acidspar requirements even before upgrade, with detailed product quality assessment forming part of the ongoing metallurgical program.
Big Jim is a high grade shallow dipping vein approximately 2 m thick, with historic mine plans indicating a strike length of approximately 230 m.
Blue Bell consists of a 1 to 2 m high grade vein which dips steeply to the north and outcrops in a historic open pit over 60 m strike, while Mammoth is a breccia body currently interpreted to be steeply dipping, with an inferred footprint extending over 9,000 square metres, a strike of approximately 250 m and a thickness of 50 to 60 m.
The Core Resources program incorporates head characterisation, mineralogy and liberation, Heavy Media Separation, grind establishment and flotation, with cleaner flotation and final reporting through H2 2026.
OD6's next steps also include Metspar product assessment, Acidspar flotation optimisation, development of an integrated process flowsheet and incorporation of the resulting metallurgical parameters into future project engineering and economic studies.
Fluorspar is classified as a critical mineral in the United States, which currently imports 100% of all fluorspar consumed domestically, with >60% of global supply sourced from China.