Ionic Rare Earth Mineralisation at Boland Prospect

THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF REGULATION 2014/596/EU WHICH IS PART OF DOMESTIC UK LAW PURSUANT TO THE MARKET ABUSE (AMENDMENT) (EU EXIT) REGULATIONS (SI 2019/310) ("UK MAR"). UPON THE PUBLICATION OF THIS ANNOUNCEMENT, THIS INSIDE INFORMATION (AS DEFINED IN UK MAR) IS NOW CONSIDERED TO BE IN THE PUBLIC DOMAIN.

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY IN OR INTO THE UNITED STATES, AUSTRALIA, CANADA, JAPAN, THE REPUBLIC OF SOUTH AFRICA OR ANY OTHER JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION.

11 September 2023

Cobra Resources plc

("Cobra" or the "Company")

Positive Metallurgy Confirms Ionic Rare Earth Mineralisation at Boland Prospect, Wudinna

&

New Tenement Applications to Increase Project Size

Cobra's Geological Concept Has Capacity to Change Future Supply of Critical REEs to Drive Decarbonisation

Cobra, a gold, rare earth and IOCG exploration company focused on the Wudinna Project in South Australia, is pleased to advise that metallurgical testwork carried out by the Australian Nuclear Science and Technology Organisation ("ANSTO") confirms Rare Earth Elements ("REE") mineralisation at the Boland palaeo-channel prospect to be cost-efficient, easily recoverable ionic adsorption rare earth clays.

Cobra can now attest to having highly desirable ionic rare earth mineralisation at Wudinna, where extraction is low-cost and yields high recoveries of heavy and magnet rare earths which the Company believes to be regionally scalable.

Accordingly, the Company has made two further applications west of the Wudinna Project to establish itself as the dominant landholder on the Narlaby palaeo-channel.

Highlights

·    Ionic metallurgy: testing by ANSTO demonstrates rapid recoveries by desorption leaching within 30 minutes using ammonium sulphate in weak acid conditions (pH4), with low acid consumption and low dissolution of gangue elements, where:

o  Further increases in REE recovery are demonstrated through increased leach time (six hours) and a slight increase in acidity (pH3) where maximum extractions of 58% Magnet Rare Earth Oxides ("MREOs") and 65% Heavy Rare Earth Oxides ("HREOs") were achieved

o  Low acid consumption of 6-30 kg/t supports very positive economic metrics for further processing optimisation

o  Low rates of dissolution of gangue elements (aluminium, calcium, iron, thorium and uranium)

·    Preferred mineralogy: ionic clay REE deposits are a superior source of HREOs and MREOs (neodymium, praseodymium, dysprosium and terbium), owing to their enrichment relative to Light Rare Earth Oxides ("LREOs") and their ability to be desorbed through ion exchange rather than aggressively baked and acid leached which is high cost and increases environmental risk

·    Superior ratios of recovery: high recoveries of high-value HREOs and lower recoveries of low-value LREOs that enable the cost-effective generation of a superior REE carbonate product

·    New concept for ionic mineralisation: the Boland prospect presents as a new alternate source of low disturbance, low-cost MREOs and HREOs owing to its amenability to Insitu Recovery Mining ("ISR") and cost-effective metallurgy

·    Significant scalability: over 430 km² of untested palaeo-channel has been defined over the existing Wudinna Project tenements. These results confirm "proof-of-concept" and are game-changing for future REE expansion drilling

·    Expanded footprint: a further two tenement applications (Figure 1) have been submitted by Lady Alice Mines Pty Ltd (a Cobra subsidiary) to add a further 1,512 km² of prospective palaeo-channel geology making Cobra the dominant holder of palaeo-channel ground in the region

·    Forward plan: to rapidly advance the Boland discovery, the Company plans to:

o  Drill sonic core holes to better understand the nature of mineralisation, define permeability potential, and recover sufficient samples to produce a REE carbonate

o  Install monitoring wells to gather baseline hydrology data to inform pilot ISR extraction tests

o  Resource expansion Aircore ("AC") drilling to define a maiden ionic REE resource

o  Re-analysis of historic drill samples on new tenement applications to define new ionic REE occurrences

o  Regional AC palaeo-channel testing to demonstrate province scale potential

Rupert Verco, CEO of Cobra, commented:

"These metallurgy results place the Company amongst the handful of projects which can attest to having highly desirable ionic rare earth mineralisation.

Low-cost metallurgy, coupled with low-cost insitu recovery mining, are the key ingredients to enable a clean, low-impact sustainable source of rare earth metals.

The REE mineralisation at Boland can be rapidly recovered using a lixiviant comparable to orange juice in acidity, in a mining practice that can be integrated into current agricultural land practices.

It is these attributes that make this discovery significant. The Boland discovery has the right technical components to secure the future supply of critical rare earth metals necessary to decarbonise the western world.

With the further two exploration licence applications, Cobra is now the dominant holder of REE prospective palaeo-channel in the region, a jurisdiction experienced in, and supportive of, insitu recovery mining."

David Clarke, Non-Executive Director of Cobra, commented:

"The proof-of-concept Cobra has delivered at Boland is the result of exceptional geological thinking from Rupert Verco and Robert Blythman whom I congratulate on behalf of the Board. It was a strongly reasoned concept but nothing like this model has previously existed. It may take some time for the full implications of Cobra's model to be apparent - but it is already clear that it is positive for Cobra's shareholders and the western world's ready access to a range of critical rare earth metals required for permanent magnets that are the efficiency enabler for electrification."

Boland Background

AC drilling in April at the Boland prospect was designed for "proof-of-concept" to confirm the mobilisation of REEs from enriched saprolites to the younger clays hosted within the palaeo-channel system.

A total of 17 holes were drilled across a broad area representing ~12 km², and drilling produced multiple intersections, where:

·    Smectite clays hosted within palaeo-channel sands and basal clays in contact with saprolite are enriched in HREOs

·    Intersections extended into underlying saprolite where elevated grades are depleted in heavy rare earths in comparison to overlying smectite clays

·    Intersections in palaeo-channel clays up to 3m at 1,004 ppm Total Rare Earth Oxide ("TREO") and up to 42m at 2,189 ppm TREO in underlying saprolite

A total of 17 representative 3m composite samples from the Boland prospect were submitted to ANSTO for desorption metallurgical testing (see Table 1). Samples are characterised by three geological domains:

1.    Smectite playa clays (five samples)

2.    Contacting palaeo-channel saprolite (five samples)

3.    Underlying saprolite (seven samples)

Metallurgical Results

Results show rapid recoveries by desorption of REEs in the first 30 minutes using 0.5 mol ammonium sulphate as a lixiviant, at ambient temperatures and weak acidic conditions (see Table 1).

The highest recoveries are observed from domain 1 (playa clays hosted within the palaeo-channel) and domain 2 (contacting palaeo-channel saprolite), where mineralisation is interpreted to ionically bind to smectite clays at the contact with channel sands, where ionic adsorption is driven by discrete changes in acidity/alkalinity. 

An important characteristic of ionic clay hosted rare earths is the low acid consumption (results average 6-30 kg/t) and the low dissolution of gangue minerals including cerium, aluminium, calcium and iron. Additionally, the dissolution of uranium and thorium is low.

Increases in REE recovery were achieved by increasing the leach time to six hours (pH4) and lowering the acidity to pH3 over a leach time of up to six hours (see Table 1).

Within the palaeo-channel, maximum recoveries at pH3 (six hours) are 58% for MREOs and 65% for HREOs (see Figure 3). These results are considered highly encouraging with scope for increased recoveries with optimised sample compositing and increased understanding of REE clay adsorption distribution and mineralogy.  

Pleasingly, samples of saprolite in contact with the palaeo-channel exhibit low-moderate extractions under desorption conditions (see Figure 4).  

In contrast, saprolite samples show low <10% recoveries and higher acid consumptions than palaeo-channel sediments under desorption conditions.

Figure 1: Composite LAM9170 exhibits high recoveries of MREOs and HREOs under desorption conditions

Figure 2: Individual REE recoveries from LAM9170 composite under tested desorption conditions

Figure 3: Average recoveries and acid consumption of the five playa clay sample composites

Figure 4: Average recoveries and acid consumption of the five saprolite sample composites in contact with palaeo-channel sediments

Figure 5: Locality plan highlighting the Company's exploration tenement applications on the Narlaby palaeo-channel

About Insitu Recovery Mining

ISR is a highly cost-effective method of mining that involves recovering the ore where it is in the ground, and recovering minerals from it by dissolving them and pumping pregnant solutions to the surface where the minerals can be recovered. This is achieved owing to aquifer permeability and applied in a manner to ensure that mining solutions do not contaminate groundwater away from the orebody. Once ore extraction is complete, aquifers are returned to their natural chemistry by neutralising mining solutions. This style of mining is cost-effective, low in environmental impact on aquifers and surfaces.

Owing to the interbedded nature of mineralised clay beds and permeable sand layers at Boland, and the fast extractions achieved through REE desorption, it is believed that ISR mining could be integrated with current land-uses considerate and adaptable to farming, conservation and indigenous heritage.

South Australia is the leading state in Australia for insitu recovery mining where it is actively endorsed, actively governed and successfully implemented.

Figure 6: Conceptual ISR process for REE extraction at Boland

Next Steps

Cobra will now aim to capitalise on the significance of these results from the Boland prospect and commence a scope of work that includes:

·    Mineralogical and insitu recovery studies - drilling of 3-5 core holes to:

o  Determine the distribution of REEs within clay bands

o  Identify parameters for future insitu recovery testing

o  Define appropriate future composite sample lengths

o  Enable advancement of metallurgical testing to ultimately produce a REE carbonate for commercial marketing

·    Monitoring well installation - to enable baseline monitoring and analysis of aquifers

·    Resource drilling - AC drilling aimed at expanding the footprint of Ionic REE mineralisation at the Boland prospect

·    Maiden Boland Mineral Resource Estimate ("MRE")

·    Regional palaeo-channel testing - AC drilling testing the concept within the Corrobinnie palaeo-channel at the Wudinna Project

·    Sample re-analysis and maiden AC drilling to test palaeo-channel targets on other 100% owned Cobra tenements

·    Further metallurgical testing to optimise recoveries and test further zones of mineralisation

Enquiries:

The person who arranged for the release of this announcement was Rupert Verco, Managing Director of the Company.

About Cobra

Cobra is defining a unique multi-mineral resource at the Wudinna Project in South Australia's Gawler Craton, a tier one mining and exploration jurisdiction which hosts several world-class mines. Cobra's Wudinna tenements totalling 1,832 km², and other nearby tenement rights totalling 1,429 km², contain highly desirable and ionic rare earth mineralisation, amenable to low-cost, low impact insitu recovery mining, and critical to global decarbonisation.

Cobra's Wudinna tenements also contain extensive orogenic gold mineralisation and are characterised by potentially open-pitable, high-grade gold intersections, with ready access to infrastructure. Cobra has 22 orogenic gold targets outside of the current 279,000 Oz gold JORC Mineral Resource Estimate.

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Competent Persons Statement

Information in this announcement has been assessed by Mr Luke Stannard, a Fellow of the Australasian Institute of Mining and Metallurgy ("FAusIMM"). Mr Stannard is a Consultant to Cobra Resources Plc and has sufficient relevant experience in the type of extraction process which he is undertaking to qualify as a Competent person as defined in the 2012 Edition of the Australasian Code for Reporting Exploration Results, Mineral Resources and Ore Reserves (the "JORC" Code). This includes 7 years of leaching extraction.

Information in this announcement has been assessed by Mr Rupert Verco, a Fellow of the Australasian Institute of Mining and Metallurgy ("FAusIMM"). Mr Verco an employee of Cobra Resources Plc has more than 16 years relevant industry experience, which is relevant to the style of mineralisation, deposit type and to the activity which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the Australasian Code for Reporting Exploration Results, Mineral Resources and Ore Reserves (the "JORC" Code). This includes 11 years of Mining, Resource Estimation and Exploration

Information in this announcement relates to exploration results that have been reported in the following announcements:

·    "Maiden Rare Earth Resource Estimate - Unique and Unconstrained" dated 9 January 2023

·    "Drilling Defines REE Resource Extension Potential" dated 12 June 2023

·    "Exception REE Results at Boland" dated 20 June 2023

Definitions

REO - Rare Earth Oxides

TREO - Total Rare Earth Oxides plus yttrium

MREO - Magnet Rare Earth Oxide (Nd₂O₃ + Pr₆O₁₁ + Dy₂O₃ + Tb₂O₃)

HREO - Heavy Rare Earth Oxides

LREO - Light Rare Earth Oxides

MRE - Mineral Resource Estimate

Cobra's REE Strategy

The economic viability of clay hosted REEs is more dependent upon low mining and processing costs, a consequence of mineralogy rather than grade. On this basis, the Company has focused on:

1.    REE resource expansion aimed at growing its complementary dual gold and REE resources, where the spatial proximity of REE mineralisation to gold enables cost efficient, value add potential

2.    Targeting low cost, easily extractable ionic clay hosted mineralisation by defining and targeting conditions that promote ionic mineralisation. The Boland prospect was defined on the basis of chemical and geological conditions that promote the mobility and adsorption of ionic REEs. These metallurgy results at Boland have provided proof of concept and provide an excellent foundation for positive economics

Further Information Regarding the Boland Metallurgy Results

Ionic clay adsorption REE mineralisation is the industry preferred style of rare earth mineralisation owing to its ability to be desorbed from clay particles under relatively benign acidities, with superior ratios of high-value REEs. In general, weaker acids (higher acidities) are more cost effective to produce, less environmentally harmful and operationally safer to manage. As a consequence of the desorption process, extractions occur quickly (minutes to hours) and at ambient temperatures making REE recovery most economically competitive.

Since the prospectivity of REEs at the Wudinna Project was identified in late 2021, the Company has taken a technical approach in understanding the enrichment, mobility, and mineralogy of REE occurrences within clay saprolite and tertiary and quaternary aged clays across the Company's 3,261 km² land tenure.

The identification of REE depletion within the saprolite above and proximal to the 104,000 Oz Barns gold resource, led the Company to theorise that the highly acidic conditions (pH<2) contribute to the re-mobilisation of REEs away from the Barns gold resource and the sulphide rich Hiltaba granites. The Boland prospect is considered to host the right conditions to promote ionic adsorption of mobilised REEs and therefore act as a 'trap' for fluid mobile REEs. These metallurgical results are a proof of concept confirming desorption of REEs from palaeo-channel clays.

ANSTO is a world leader in REE metallurgy and the development in REE metallurgical flowsheets. Diagnostic testing parameters included:

·    0.5 M (NH4)2SO4 as lixiviant

·    pH 4; pH3

·    pH 4: 0.5 h & 6 h, pH3: 0.5 h, 2 h & 6 h

·    Ambient temperature (~22 °C)

·    4 wt% solids density

·    Acidity maintained through the addition of H2SO4

Metallurgical results demonstrate:

·    Desorption is greatest within Eocene age clays

·    Recoveries increase with time and increasing acidity

·    HREOs are recovered in greater ratios than LREOs

·    Moderate desorption times are interpreted to be a consequence of sample composite dilution. Faster desorption rates are likely with refined sample compositing

Table 1: Average recoveries of playa clays (five samples) and contacting saprolite (five samples)

Significant intersections from maiden Boland AC drilling include:

·    CBAC0164: 3m at 942 ppm TREO (22% MREO) from 15m (playa clay), and 3m at 1,333 ppm TREO (13% MREO) from 30m (playa clay) and 42m at 2,189 ppm TREO (25% MREO) from 36m (saprolite clay)

·    CBAC0163: 3m at 559 ppm TREO (24% MREO) from 18m (playa clay), and 3m at 618 ppm TREO (22% MREO) from 21m (playa clay) and 12m at 1,191 ppm TREO (27% MREO) from 36m (saprolite clay)

·    CBAC0168: 12m at 948 ppm TREO (19% MREO) from 42m (saprolite clay)

·    CBAC0176: 3m at 516 ppm TREO (23% MREO) from 27m (playa clay) and 3m at 661 ppm TREO (19% MREO) from 48m (contact saprolite clay) and 1,984 ppm TREO (22% MREO) from 54m (saprolite clay)

·    CBAC0175: 3m at 429 ppm TREO (23% MREO) from 27m (playa clay)

·    CBAC0172: 3m at 685 ppm TREO (20% MREO) from 54m (saprolite clay)

·    CBAC0177: 3m at 545 ppm TREO (26% MREO) from 42m (saprolite clay) to EOH

·    CBAC0162: 6m at 437 ppm TREO (24% MREO) from 42m (playa clay)

Figure 7: Overview of AC drilling results and metallurgical recoveries at the Boland prospect