Exceptional Results - In-Field Permeability Study

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.

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17 November 2025

Cobra Resources plc

("Cobra" or the "Company")

Exceptional Results from In-Field Permeability Study

Results support high production potential for ISR of heavy rare earths from Boland mineralisation

Positioned to deliver some of the lowest costs for the recovery of heavy rare earths globally

Cobra (LSE: COBR), a South Australian mineral exploration and development company, is pleased to announce that field trials at the Company's Boland Ionic Heavy Rare Earth Project in South Australia have delivered exceptional hydrological properties that support the cost-efficient and low impact recovery of heavy rare earth elements ("REEs") through In Situ recovery ("ISR").

Field trials have confirmed the hydrological properties of the Boland aquifer and that geological conditions are conducive to ISR and support commerciality of future mining operations.

Highlights

·    In-field Pump tests have proven that the ionic heavy rare earth mineralisation at Boland is contained in a laterally uniform permeable sand aquifer that is bounded above and below by impermeable aquicludes. This circumstance is not known to occur elsewhere in the world and it makes certain that the Boland mineralisation is amenable to recovery in solution form by ISR techniques

·    This testwork has shown that ISR lixiviants are efficiently contained within the mineralised aquifer and that the lixiviant will not move vertically into the overlying and underlying formations

·    Pump testing yielded a sustainable discharge rate of 0.21 litres per second (approximately 18,000 litres per day) which is consistent with expectations raised by the results of recent bench scale recoveries of 66% Heavy Rare Earths ("HREO")

·    Uniform borehole drawdown during pump testing established that the there is good lateral connectivity within the Boland mineralised horizon. These circumstances are expected to result in efficient wellfield design and good mineralisation recovery characteristics

·    A connectivity tracer test that involved the injection of water treated with a bromide dye showed excellent connectivity. At a 7 m inter-well spacing, bromide was observed in the extraction well after under 24 hours

·    60% of the bromide dye was recovered after four days. These results are consistent with Cobra's expectation that injected lixiviants will be efficiently circulated through the mineralised horizon to recover rare earth metals

·    All the in-field test results are consistent with Cobra's expectation that the Boland rare earth mineralisation is amenable to recovery by ISR techniques

Follow this link to watch a short video of Managing Director Rupert Verco explaining the results of the trials: https://investors.cobraplc.com/link/Pm51XP

Rupert Verco, Managing Director of Cobra, commented:

"These field results have provided us the trifecta of technical requirements to enable sustainable and productive ISR: permeability, productive flow rates, and uniform connectivity. This, when coupled with our highly desirable metallurgy, sets the Boland Project apart from all other known ionic rare earth projects.

Results of this field study provide robust metrics to support the case for commercial development. Alongside our current flow sheet optimisation programme, we are well positioned to deliver some of the lowest costs for the recovery of heavy rare earths globally.

The test work just completed has significantly derisked the Boland Project's REE extraction parameters. The Company will now continue resource definition drilling, targeting a significant maiden resource estimate to support a scoping study by mid next year."

Context - Why is this so important?

Ionic Rare Earth deposits in Southern China are recovered by a form of ISR that relies on gravity to permeate the mineralised horizon. Acid injection is unconstrained, limiting mining control and introducing environmental risk through acid mine drainage.

Ionic clay projects outside of China are challenged by managing a trade-off between the cost-efficient treatment of clay mineralisation with environmental risk and operating efficiency.

The Boland Project has now been shown to face neither of the above challenges.

The Boland Project's geology is (thus far) unique in the world insofar as its mineralisation has now been shown to be amenable to ISR, the lowest cost and most sustainable form of mining. 

The results from this study highlight the ability for Boland to deliver a risk-resilient source of dysprosium and terbium from a project that requires less capital and can be self-supporting by producing the materials required for operation.

Figure 1. Rare earths under the rainbow - Tracer study underway at the Boland Project

Boland Project

At Boland, Cobra has discovered what it believes to be a unique, scalable instance where ionic rare earth elements - containing economically attractive grades of valuable heavy and magnet rare earths - occur in a permeable horizon confined between horizons of impermeable clay.

Bench scale ISR testing has confirmed that this mineralisation is amenable to ISR recovery techniques. ISR techniques are currently in use (and have been used successfully for decades) in geologically similar environments, to recover uranium in South Australia which maintains a well-established ISR regulatory system.

Results of Cobra's ongoing mineral recovery test work indicate that, with minor optimisation, ISR techniques will enable non-invasive and low-cost production of critical REEs from its discovery at Boland.

Further information relating to Boland and these results are presented in the appendices.

Enquiries:

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

About Cobra

Cobra Resources is a South Australian critical minerals developer, advancing assets at all stages of the pre-production pathway.

In 2023, Cobra identified the Boland ionic rare earth discovery at its Wudinna Project in the Gawler Craton - Australia's only rare earth project suitable for in situ recovery (ISR) mining. ISR is a low-cost, low-disturbance extraction method that eliminates the need for excavation, positioning Boland to achieve bottom-quartile recovery costs.

In 2025, Cobra further expanded its portfolio by optioning the Manna Hill Copper Project in the Nackara Arc, South Australia. The project contains multiple underexplored prospects with strong potential to deliver large-scale copper discoveries.

In 2025, Cobra sold its Wudinna Gold Assets to Barton Gold (ASX: BDG) for up to A$15 million in cash and shares.

Regional map showing Cobra's tenements in South Australia

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Appendix 1: Background information - the Boland Project and ISR

·    The Boland Project was discovered by Cobra in 2023. Mineralisation is ionically bound to clays and organics within palaeochannel sands within the Narlaby Palaeochannel

·    Mineralisation occurs within a permeable sand within an aquifer that is saltier than sea water and is confined by impermeable clays

·    ISR is executed through engineered drillhole arrays that allow the injection of mildly acidic ammonium or magnesium sulphate lixiviants, using the confining nature of the geology to direct and lower the acidity of the orebody. This low-cost process enables mines to operate profitably at lower grades and lower rates of recovery

·    Once REEs are mobile in solution in groundwater, it is also possible, from an engineering standpoint, to recover the solution to surface via extraction drillholes, without any need for excavation or ground disturbance

·    The capital costs of ISR mining are low as they involve no material movements and do not require traditional infrastructure to process ore - i.e. metals are recovered in solution

·    Ionic mineralisation is highly desirable owing to its high weighting of valuable HREOs and the cost-effective method in which REEs can be desorbed

·    Ionic REE mineralisation in China is mined in an in-situ manner that relies on gravity to permeate mineralisation. The style of ISR process is unconfined and cannot be controlled, increasing the risk for environmental degradation. This low-cost process has enabled China to dominate mine supply of HREOs, supplying over 90% globally

·    Confined aquifer ISR is successfully executed globally within the uranium industry, accounting for more than 60% of the world's uranium production. This style of ISR has temporary ground disturbance, and the ground waters are regenerated over time

·    Cobra is aiming to demonstrate the economic and environmental benefits of recovering ionic HREOs through the more environmentally aquifer controlled ISR - a world first for rare earths

Figure A1: Comparison between the Chinese and the proposed Boland process for ISR mining of REEs

Appendix 2: Results of field hydrology study

Rendement Principal Hydrogeologist, Ben Jeuken was engaged to perform hydrogeological tests at Boland that included an aquifer pumping test and a connectivity tracer test. The study has generated key hydrogeological characteristics of the deposit, such as hydraulic conductivity (permeability), storage coefficient, and the degree of confinement provided by the surrounding geological units above and below the mineralised zone. Methodology and testing results are presented below:

Pumping Test

Methodology

·    A downhole pump was set in well CBSC0010. The pump was positioned at a depth of 25m. The static water level was at 4.5 m, giving available water level drawdown of approximately 20.5 m

·    A pumping test was conducted comprising a constant rate step pumping at 13 m³/day for 0.33 days (8 hours) to determine aquifer properties.

·    The pumping rate was incrementally increased up to 18 m³/day to determine the maximum capacity of the well. Water level drawdown was measured in five observation wells screened within the mineralised body, one well screened within each of the overlying confining bed, and the underlying saprolite

Results

·    The pumping test demonstrated that the extraction well had the capacity to yield at a rate of up to 18 m³/day

·    During the constant rate test, consistent drawdown was observed in all observation wells within mineralisation demonstrating relatively homogeneous aquifer properties

·    Aquifer properties derived from analysis of the drawdown data are summarised in Table 1. The hydraulic conductivity of the mineralisation is 0.1 m/day, consistent with a fine sand.

·    The drawdown response in the mineralized zone indicated a confined aquifer with very low leakage from the confining layers. The vertical conductivity of the overlying confining layer is estimated at 0.001 m/day. The monitoring well completed in the overlying Garford confining layer exhibited no drawdown at all, further demonstrating that the Garford formation is an effective confining layer

·    The well completed in the underlying saprolite exhibited a very muted drawdown response. The hydraulic conductivity estimated from the drawdown data is approximately 0.002 m/day. This is some two orders of magnitude less than the hydraulic conductivity of the mineralisation. This indicates that the saprolite will be an effective confining layer beneath the ore

Table 1: Aquifer Properties

Figure A2: Cross section of the Boland Wellfield

Figure A3: Water level drawdown in CBSC0010

Figure A4: Water level drawdown in observation wells

Connectivity Tracer Test

Methodology

·    The connectivity tracer test comprised the extraction of water from well CBSC0005. The water was dosed with the tracer and then re-injected into CBSC0010 located 7 m from the extraction well. The test was undertaken over four days from 31/10/2025 to 4/11/2025

Results

·    The total volume circulated during the trial was 32 m³ 

·    The tracer was injected with an average bromide concentration of 280 mg/L against a natural background bromide concentration of 15 mg/L

·    The recovery of the injected water was calculated from the concentration of bromide analysed in samples taken from the extraction well 

·    The data is shown in Figure 3 where data indicates good connection between the two wells completed in the mineralised horizon. Tracer arrival occurred after circulation of approximately 10 m³, within 24 hours, and the concentration of tracer at the extraction well continued to rise as the test progressed reaching a maximum concentration of 60% at the end of the test

Figure A5: Connectivity trial - tracer recovery

Conclusions

The results are extremely encouraging for ISR recovery of REE mineralisation at the Boland Prospect:

.

·    Well yields of up to 18 m³/day and hydraulic properties give confidence that satisfactory leaching flow rates can be achieved, and this data will be used to design a field recovery trial

·    The formations above and below the mineralised body provide effective confining seals. This is an optimal condition and gives confidence that the lixiviant can be efficiently contained within the mineralised horizon host aquifer and will not move vertically into overlying and underlying formations

·    The efficient recovery of the tracer during the circulation trial gives confidence that injected lixiviant can be efficiently circulated through the mineralised Pidinga formation to leach the rare earths mineralisation and be recovered at the extraction well

Appendix 3: JORC Code, 2012 Edition - Table 3

Appendix 3: Section 2 reporting of exploration results