OD6 Metals Limited (ASX: OD6) – Quinn Fluorspar Builds the Grade and Processing Case in Nevada
- Noel Ong
- May 28
- 11 min read
Historic data from Union Carbide's drilling and metallurgical testwork have added geological and processing support to OD6 Metals’ Quinn Fluorspar Project, positioning the Nevada asset as a developing US critical minerals opportunity.
Samso News | ASX: OD6 | Fluorspar | Nevada | Acidspar | Critical Minerals | Union Carbide
OD6 Metals Limited (ASX: OD6) has added another layer of technical foundation to the Quinn Fluorspar Project in Nevada, USA (Figure 4), with historic Union Carbide drill data confirming high-grade, near-surface fluorspar mineralisation at Horseshoe.
The company had recently acquired a rare dataset of geological records from Union Carbide Corporation.
On analysing this historic data, OD6 delineated historic grades up to 93.7% CaF₂, - interpreting the system as open up-dip, down-dip and at depth.
Together with historical metallurgical testwork indicating potential acidspar production . Quinn is now developing into a more defined US critical minerals opportunity pending modern validation.
Samso Summary
Table 1: OD6 Metals Summary
Item | Details |
Company | OD6 Metals Limited |
ASX Code | OD6 |
Project | Quinn Fluorspar Project |
Location | Nevada, USA |
Commodity | Fluorspar / fluorite |
Main Prospects Referenced | Horseshoe, Mammoth, Big Jim |
Key Drilling Update | Historic Union Carbide drilling confirmed high-grade, near-surface fluorspar mineralisation at Horseshoe |
Key Metallurgical Update | Historic testwork indicated potential to produce acidspar through conventional grinding and flotation |
Best Historic Drill Grade | Peak result of 93.7% CaF₂ over 1.2m in H1 |
Key Historic Metallurgical Result | Mammoth testwork achieved 97.83% CaF₂ at 70% recovery and 95.0% CaF₂ at 82.7% recovery |
Product Relevance | Potential production of metspar and acidspar, subject to modern confirmation |
Next Work Programs | Modern assays, geological modelling, channel and rock-chip sampling, soil geochemistry, drill target definition, TOMRA optical ore sorting and flotation testwork |
Provenance of the Dataset
The Union Carbide work at Quinn was conducted across two seasons. In 1957, Union Carbide Nuclear Company and The Galigher Company in Salt Lake City completed preliminary metallurgical amenability testing on samples from Mammoth and Horseshoe. In 1958, Union Carbide returned to drill four diamond holes at the Horseshoe deposit, supported by a summary report prepared by H.M. Wharton dated 27 August 1958. A second metallurgical program was scheduled to commence at The Galigher Company in July 1958, with new samples already despatched (Figure 1).
Figure 1: Example Drill map of UCC Horseshoe (AKA Higrade) deposits, Nye County, Nevada (Source: OD6 ASX Announcement May 7, 2026)
The 1958 follow-up program did not proceed. A local prospector disputed Union Carbide's claims and denied the Company access to the site and to a water supply, and the program was discontinued. The dataset has remained unpublished for the intervening six and a half decades.
OD6 acquired the full archive of Union Carbide records relating to Quinn, on terms disclosed in the 7 May 2026 ASX announcement. The acquired material includes high-quality scans of cross-sections, maps, geological logs, original assay sheets, and the underlying Galigher and Union Carbide Nuclear Company metallurgical reports. The Competent Persons engaged by the Company have reviewed the underlying records and have concluded that the reported head grades are consistent with grades observed in recent OD6 field sampling, and that the flotation reagents and processing techniques described remain broadly consistent with conventional fluorspar processing methods used today.
Historic Drilling at Horseshoe
Union Carbide Corporation’s drill program consisted of four shallow drill holes, H1 to H4, with an average depth of approximately 38 metres (Figure 2). OD6 reported that the drilling confirmed high-grade fluorspar mineralisation from surface and intersected significant widths of CaF₂ mineralisation.
Table 2: Reported Historic Drill Intercepts
Hole | Reported Intercept |
H4 | 14.3m @ 70.9% CaF₂ from surface |
H2 | 14.0m @ 59.9% CaF₂ from 19.5m |
H1 | 25.8m @ 46.2% CaF₂ from 0.9m |
H3 | 6.4m @ 46.2% CaF₂ from 22m |
Within H1, OD6 reported:
Interval | Result |
12.8m from 0.9m | 60.9% CaF₂, including a peak result of 93.7% CaF₂ over 1.2m |
3.4m from 16.8m | 58.8% CaF₂, including a peak result of 82.0% CaF₂ over 1.2m |
3.5m from 22.3m | 43.7% CaF₂, including a peak result of 66.1% CaF₂ over 0.3m |
The historic drilling targeted the southern corner of the system and did not test the high-grade core later exposed in open-pit mining. The assaying only tested bulk fluorspar intercept zones and that multiple sections of core were not assayed despite being logged with fractured breccia and/or vein material that may be fluorspar-bearing.
OD6 interprets the mineralisation at Horseshoe as a fault-controlled replacement system with an exposed footprint of approximately 3,000 square metres. The company states that the system remains open up-dip, down-dip and at depth.
Figure 2: Historic Drilling Results (Source: OD6 ASX Announcement: May14, 2026)
Management Commentary
“Historic drilling at Horseshoe indicates a rare combination of exceptional high grade and significant widths, with results well above typical global fluorspar benchmarks.
Importantly, these intercepts were returned from the margin of the system, not the high-grade core later exposed in open pit mining (and reported in channel sampling results by the Company 15 April 2026) and were notably only selectively assayed. This indicates the system has the potential to be both higher grade and larger than intercepted in historic drilling.
– Brett Hazeldon Managing Director and CEO, OD6 Metals Ltd
Historic Metallurgical Testwork
In addition, Union Carbide also completed metallurgical testwork on fluorspar mineralisation from Mammoth and Horseshoe.
The Mammoth sample had a head grade of approximately 28.29% CaF₂, while the Horseshoe sample had a head grade of approximately 58.57% CaF₂.
Historical Union Carbide and Galigher Company testwork indicated concentrate grades of 95.0% CaF₂ at 82.7% recovery and 97.83% CaF₂ at 70% recovery from Mammoth mineralisation.
These historical results suggest that Quinn mineralisation may be capable of producing acidspar using conventional grinding and flotation methods, subject to confirmation through modern metallurgical testwork. OD6 also notes that the historical testwork was preliminary and unoptimised.
The historical Union Carbide metallurgical testwork provides encouraging evidence that fluorspar mineralisation at Quinn may be amenable to conventional processing techniques.
Importantly, the historic results suggest the potential to upgrade both low-grade and high-grade mineralisation to produce commercial fluorspar concentrates, including acid-grade product, subject to confirmation through modern metallurgical testwork.
Acidspar and Metspar Product Context
Fluorspar, also known as fluorite, has the chemical formula CaF₂ and contains 48.9% fluorine by weight. OD6 describes fluorspar as the main mineralogical source of fluorine.
OD6 identifies two main product categories:
Table 3: Difference between Metaspar and Acidspar
Product | Description |
Metspar | A mineral product containing greater than 60% CaF₂, used in the steel industry as a fluxing agent |
Acidspar | An upgraded mineral product containing greater than 97% CaF₂, used for hydrofluoric acid production |
OD6 states that acidspar is used in the chemical industry for hydrofluoric acid production, with downstream applications in nuclear fuels, battery technologies, solar panels, defence technologies and AI chip manufacturing.
Next Phase Metallurgical Program
OD6 is advancing a staged metallurgical testwork program to validate and optimise processing flowsheets.
Recent OD6 field programs have collected extensive metallurgical samples across multiple Quinn prospects for modern testwork. The company plans to send samples for optical ore sorting testwork with TOMRA in Germany.
The stated objectives are to upgrade feed grade prior to processing, reduce processing costs and plant size, and assess reject/waste separation efficiency. OD6 expects TOMRA testwork to commence this quarter, with results expected in quarter three.
OD6 also plans additional flotation testwork covering flotation optimisation, dense media separation, grind size and reagent testing, and product specification validation for acidspar versus metspar. The company expects flotation testwork to commence this quarter, with results anticipated in the second half of the year.
OD6 also intends to apply for bulk sample permits across multiple areas to support advanced metallurgical testwork, representative pilot-scale testing, flowsheet development and potential offtake samples.
With extensive representative samples now collected from across the project, OD6 is preparing to commence modern metallurgical programs, including optical ore sorting with TOMRA and flotation optimisation with specialist laboratories.
These programs are designed to validate the historical results and support the development of Quinn as a potential domestic US source of high-grade fluorspar.
Figure 3: : Quinn Fluorspar Project with, deposit locations, background geology and alteration map (Source: OD6 ASX Announcement May 20, 2026)
Due Diligence and Next Steps
OD6 has outlined the following work programs as part of its due diligence and validation process at Quinn:
Digitise scanned paper logs and cross-sections into a geological model.
Receive and interpret assay results.
Expand systematic channel and rock-chip sampling.
Validate and replicate historic high-grade results.
Undertake detailed geological and structural mapping.
Complete soil geochemistry programs.
Identify and prioritise drill targets.
Initiate permitting for maiden drilling.
Progress metallurgical testwork planning.
The system remains open in all directions and untested at depth, which in conjunction with recent fieldwork confirming extensive mineralisation, provides significant exploration upside and a clear pathway for targeted drilling to define a large scale fluorspar system.
We also look forward to results from our recent mapping and sampling programs, which will further define the scale and potential of Horseshoe
The Fluoride Market - The Basics
Fluorspar (the commercial name for the mineral fluorite, CaF₂) is the world's primary source of fluorine. The market is roughly 8-9 million tonnes per year and valued at around US$2.1-2.8 billion in 2025-2026, with most forecasters expecting low-to-mid single-digit CAGR growth through to 2032-2035. It is split into two main commercial grades: acid-grade (acidspar, ≥97% CaF₂) which feeds the chemical industry, and metallurgical-grade (metspar) which goes into steel and aluminium production.
The headline structural feature of this market is extreme geographic concentration on the supply side (Figure 6).
Figure 6: Global players in the Fluorspar market. China, Mexico and Mongolia together account for ~84% of global supply.
China's position is structurally important because it is also the largest consumer — Asia Pacific accounts for roughly 74% of global volume — meaning Chinese industrial activity and export policy effectively set the global price. The flip side of this concentration is that fluorspar is now formally listed as a critical mineral by the United States, EU, China, Canada, Japan and Australia, and Western governments are actively supporting new supply (the Lost Sheep mine in Utah, the St Lawrence mine restart in Canada, plus projects in Australia, Germany and Kenya).
On the demand side, the market is dominated by chemical applications rather than the traditional metallurgical uses most people associate with the mineral.
Where fluorspar goes — grade split and downstream end-use
The outlook narrative (see Figure 7) — and the reason fluorspar is getting attention now — is the shift in chemical demand toward energy-transition end-uses. The traditional refrigerant market is actually being phased down (the US AIM Act has cut HFC production allowances to 40% below the historic baseline), but this is being more than offset by three rising demand vectors:
Lithium-ion batteries. A Li-ion EV battery uses 5-10x more fluorspar (by mass) than lithium — fluorine compounds appear in the cathode binder (PVDF), the electrolyte salt (LiPF₆), and separator coatings. Benchmark Mineral Intelligence estimates the battery segment alone will pull more than 1.6 Mt of fluorspar annually by 2030, growing at over 20% CAGR.
Semiconductors. Ultra-high-purity hydrogen fluoride is essential for etching silicon wafers, with data centre build-out for AI lifting demand.
Decarbonisation chemistry. Hydrogen fuel cells, green refrigerants, and fluoropolymer membranes all consume acidspar-derived HF.
Figure 7: The distribution of its uses.
The US Department of Energy has projected that under current trajectories, fluorspar demand will exceed current supply by 40-70% by 2035. That gap, combined with the geographic concentration shown in the first chart (Figure 6), China's own declining reserves, and the critical mineral designations is what is bringing new Western producers and developers into the conversation.
It is also worth noting that fluorspar is rarely produced as a by-product; it depends on dedicated mining operations, which makes the supply side less responsive to sudden demand spikes than commodities like cobalt or molybdenum.
Samso Concluding Comments
The OD6 story in the last few months has been transforming and the speed in which data has been released is comforting for shareholders. As you can see in Figure 5 below, the resurrection of the share price is promising but I do feel that there is a certain case of fatigue coming onto the screen. The recent frequency of releases may be counter-intuitive to the journey.
Figure 5: The share price chart for OD6 Metals Limited as of 26th May 2026. (source: Commsec)
One cannot choose the fortunes and misfortunes but the good part of the story is there is urgency and management is definitely trying to make this work. Personally, this is an exciting project as the data slowly unearth the prospectivity of the situation in Nevada. The market for Fluoride or Fluorspar is not something the general public comes across but that is a good thing for OD6 Metals allowing a "educational" educational theme.
What I like about the fluoride industry is that there does not appear to be any new upcoming stories that would create problems for OD6 Metals. Most importantly, the grade that are being talked a bout for OD6 Metals appear to be in the Tier-1 category, so lets see how that plays out over time.
About OD6 Metals Limited
OD6 Metals Ltd (ASX: OD6) is an Australian public company pursuing exploration and development opportunities across the critical minerals sector, with a portfolio spanning fluorspar, rare earth elements, and copper.
Its flagship rare earth asset is the Splinter Rock Project in Western Australia's Esperance-Goldfields region, which hosts one of Australia's largest clay-hosted rare earth deposits with an Indicated Resource of 119Mt at 1,632ppm TREO and an Inferred Resource of 563Mt at 1,275ppm TREO.
In fluorspar, the company holds an option to acquire the Quinn Fluorspar Project located approximately 220km north of Las Vegas, Nevada — a project with documented high-grade mineralisation across multiple systems, including Mammoth, Horseshoe, and now the rediscovered Big Jim lode, each exhibiting grades well above the economic threshold for fluorspar development. The company also holds the Gulf Creek Copper-Zinc VMS Project near Barraba in New South Wales (Figure 4).
Figure 4: Location and neighbourhood of Quinn Flourspar Project in Nevada
Previous Samso News Coverage
Samso has followed OD6 Metals Ltd across multiple ASX releases. The following represents our prior published coverage of the company:
May 19, 2026 -
April 05, 2026 -
April 17, 2026 -
March 18, 2026 -
December 19, 2025-
November 08, 2025-
September 10, 2025-
August 24, 2025 -
August 13, 2025
August 22, 2023
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