Positive Met Test Work Results at Conchas

NEWS RELEASE | 28 October 2025

Positive Preliminary Metallurgical Test Work Results at Conchas

Berkeley Energia Limited (Berkeley or the Company) is pleased to announce the positive results of a preliminary metallurgical test work program completed on representative samples from the Conchas Project (Conchas or the Project), as part of the Company's Critical Minerals Exploration Initiative in Spain.

Highlights:

Berkeley Director, Mr Robert Behets, commented:

"These results are extremely encouraging as they have provided a positive initial assessment of the metallurgical characteristics of the multi-commodity mineralisation at Conchas and have confirmed that very good recoveries of Li and Rb can be achieved using flotation and magnetic separation methods.

This milestone follows two successful drilling campaigns which demonstrated the presence of shallow, thick zones of Li and Rb mineralisation at the Project. The presence and fairly consistent grades of rubidium, a high value critical metal used in various high-tech applications in key sectors including defence, military and communications, is of particular interest. 

Given the promising drilling and initial metallurgical results, the Company will continue to systematically advance the Project's development, including 3D modelling of drilling data as a precursor to resource estimation, and a second phase of metallurgical test work to optimise the flotation and magnetic separation processes."

Classification: 2.2 This announcement contains inside information

For further information please contact:

Robert Behets                                      Francisco Bellón         

Acting Managing Director                      Chief Operations Officer

+61 8 9322 6322                                    +34 923 193 903

[email protected]

Critical Minerals Exploration Initiative in Spain

Berkeley continues to advance its exploration initiative targeting Li, Rb, Sn, Ta, Nb, tungsten (W), and other battery and critical metals, within the Company's existing tenements in western Spain.

Conchas Project Overview

The Investigation Permit (IP) Conchas is located in the very western part of the Salamanca province, close to the Portuguese border (Figure 1). The tenement covers an area of ~31km² in the western part of the Ciudad Rodrigo Basin and is largely covered by Cenozoic aged sediments. Only the north-western part of the tenement is uncovered and dominated by the Guarda Batholith intrusion. The tenement hosts a number of sites where small-scale historical tin and tungsten mining was undertaken.

Figure 1: IP Conchas Location Plans and Geology / Drill Hole Location Plan

Berkeley conducted a small drill program comprising five broad spaced reverse circulation (RC) holes for a total of 282m in 2022 to test a Sn-Li soil sampling anomaly. Anomalous results for Li, Sn, Rb, Cs, Nb and Ta obtained from multi-element analysis of drill samples were reported in 2023, demonstrating Conchas' potential for several critical and strategic raw materials included in the European Commission's Critical Raw Materials Act (CRMA). The drill results included 25m @ 0.56% Li₂O & 0.22% Rb₂O from surface (CCR0002).

A follow-up RC and diamond core drilling program was completed in 2024. The drilling program comprised 33 RC holes for 1,857m drilled on a 100m by 100m grid, with depths ranging from 16m to a maximum of 169m. In addition, three diamond core holes for 230m were drilled to collect samples for metallurgical test work purposes.

All drill holes intersected muscovitic leucogranite hosted mineralisation with select intercepts including 61m @ 0.50% Li₂O & 0.21% Rb₂O from surface (CCR0012), 56m @ 0.48% Li₂O & 0.21% Rb₂O from surface (CCR0025), 27m @ 0.44% Li₂O & 0.21% Rb₂O from surface and 14m @ 0.95% Li₂O & 0.39% Rb₂O from 40m (CCR0006) and 18m @ 0.55% Li₂O & 0.23% Rb₂O from surface (CCR0017).

The multi-element mineralisation is largely associated with a sub-horizontal muscovitic leucogranite unit that locally outcrops at surface. The muscovitic leucogranite has a mapped extent of ~2km (in a NE-SW orientation) by ~1.2km (on average in a NW-SE orientation) (Figure 1) and varies in thickness from 7m to over 170m in the drill holes (Figure 2).

Figure 2: IP Conchas 4,492,225 North Cross Section

Preliminary Metallurgical Test Work Program Results

The Company engaged SLR to undertake metallurgical testing on representative samples obtained from three diamond core holes drilled in the 2024 program at the Conchas Project.

The preliminary metallurgical test work program was designed to assess the potential recovery of Li, Rb and the other elements of economic interest, and comprised:

·      Head Sample Characterisation;

·      Scanning Electron Microscope (SEM) Mineralogical Analysis;

·      Gravity Test Work;

·      Flotation Test Work; and

·      Magnetic Test Work.

Head Sample Characterisation

Head Assay

A representative sub-sample was submitted to SLR's in-house analytical laboratory for head assay to determine the levels of target elements present in the composite sample. A sub-sample was also submitted to ALS Global for ICP multi-element analysis. The results of the SLR in-house assay and selected elements of the ALS analysis are given below in Table 1.

Table 1 - Summary of Head Assay Results

Particle Size Distribution

A representative sub-sample of the -2mm feed material was subjected to particle size analysis by screen. The sample was wet screened at 53µm, the fractions dried and the +53µm fraction screened to generate mass data by fractions. The results, which determined a D₈₀ particle size of 1,453µm, are summarised below in Figure 3.

Figure 3 - Graph of -2mm Feed Particle Size Distribution

Class Size Analysis

A 2kg sample was ground to nominally generate a D₈₀ size of 300µm and sized to generate five fractions for size-by-size analysis and sub-samples for mineralogical investigation. Representative sub-samples of the fractions were pulverised and submitted to SLR in-house laboratory for Li, Rb, Ta, Nb, Be, Sn, Iron (Fe) and Ce assay. Cs assays were subcontracted to ALS Global analytical services. The results are summarised below in Table 2.

Table 2 - Results of Class Size Analysis

The results generally show that elemental distributions followed the relative trends observed in the fraction mass distributions, with greater distributions present in the -300 +150µm fractions and the least in the -11µm fines fraction. Li distributions ranged from 33.4% in the -300 +150µm fraction to 5.0% in the -11µm fraction and Rb ranged from 34.2% to 5.2% in the respective fractions.

SEM Mineralogy Analysis

The target mineral phases identified include cassiterite, Nb-Ta oxides, polylithionite and muscovite. Muscovite was the most abundant target phase, maintaining relatively consistent concentrations across all size fractions (Figure 4).

The Li minerals were clustered in the polylithionite group which covers a range of minerals between zinnwaldite and lepidolite depending on the Fe and fluorine (F) contents.

Cassiterite and Nb-Ta oxides were both present in trace quantities. The gangue material was primarily composed of plagioclase and quartz, present in nearly equal proportions. Plagioclase content increases in the finer size fractions, whereas quartz becomes less abundant. K-feldspar appears as a minor phase, while other phases, including phosphates, kaolinite, accessory minerals, tourmaline, sulphides, and topaz occur only in trace amounts.

Figure 4 - Mineral Phase Abundance

Gravity Test Work

The four fractions generated for the class size analysis were subjected to gravity release analysis (GRA) by treating each of the fractions separately on the Mozley super panner, generating six products for assay. The products were dried, weighed and representative sub-samples prepared and submitted for Li, Rb, Ta, Nb, Be, Sn and Fe assay.

Cumulative Li recoveries into the combined concentrates and middling product ranged from 28.0% at a grade of 0.16% Li (-53 +11µm) to 65.8% at a grade of 0.24% Li (0.52% Li₂O) in the -150 +53µm fraction.

Cumulative Rb recoveries into the combined concentrates and middling product ranged from 22.2% at a grade of 2,358ppm Rb (+300µm) to 66.1% at a grade of 2,049ppm Rb (2,242ppm Rb₂O) in the -150 +53µm fraction.

The results showed optimum liberation size for the Conchas composite was in the -150 +53µm fraction.

Flotation Test Work

A short programme of flotation testing was performed on the Conchas composite to evaluate potential grades and recoveries at two grind sizes.

Two rougher tests were conducted at the 300µm (FT1-300) and 150µm (FT2-150) primary grind sizes to identify the better flotation performance, and one cleaner test was then conducted at the better performing grind size to evaluate the effect of kinetic cleaning on grades and recoveries.

The results of the rougher tests confirmed that the finer 150µm grind was the better performing test and was therefore used for cleaner flotation testing (FCT1-150). Cleaner flotation achieved 87.2% Li stage recovery, representing 77.5% overall recovery (after desliming) at a grade of 1.04% Li (2.23% Li₂O), 70.9% Rb stage recovery representing 62.7% overall recovery at a grade of 0.79% Rb (0.87% Rb₂O), and 78.5% Cs recovery at a grade of 661ppm Cs (Appendix A).

Flotation testing of the Conchas material demonstrated that very good recoveries of target minerals could be achieved at acceptable grades.

Figure 5 - Summary of Flotation Test Work Results for Li, Rb and Cs

Magnetic Test Work

Representative sub-samples of the 300µm and 150µm primary grinds were subjected to magnetic separation testing to evaluate potential grades and recoveries at the two grind sizes.

The 300µm sub-sample was screened at 150µm and the two fractions treated separately. The +150µm fraction was treated on an Eriez Log 1.4-disc separator, the -150µm treated on a Bunting Wet High Intensity Magnetic Separator (WHIMS) 500 jaw magnetic separator and the results combined to generate the overall performances. The 150µm sub-sample was treated on the Bunting WHIMS 500 jaw magnetic separator.

The initial magnetic test intensity was 4,000 Gauss with testing conducted in 1000 Gauss increments up to 15,000 Gauss.

Magnetic separation testing on the -300µm +150µm material, which accounted for 36.4% of the mass, showed 76.6% of the Li (32.2% overall) and 57.7% of the Rb (23.4% overall) reporting to the magnetic product grading 2.34% Li₂O and 0.73% Rb (Appendix B). This result may present an opportunity for magnetic separation processing of a coarser +150µm fraction followed by flotation of the finer -150µm material.

Magnetic separation on the -300µm +150µm material also showed 43.5% of the Ta and 50.9% of the Nb reported to the combined 4,000, 6,000 and 9,000 Gauss magnetic concentrates grading 1,161ppm Ta and 1,551ppm Nb.

Summary

Metallurgical testing of the Conchas mineralisation tested demonstrated very good recoveries at acceptable grades using flotation and magnetic separation methods.

The recommended next steps, from a metallurgical test work perspective, include more detailed flotation testing to optimise the rougher and cleaner flotation reagent schemes, optimisation of the magnetic separation on the coarse fractions, and mineral content variability testing to understand how variability affects the beneficiation methods.

Rubidium^1,2,3,4,5

Rb is a critical raw material with growing significance in advanced technology and industrial applications, including in the defence and military, aerospace, communications, biomedical and renewable energy sectors.

Its unique properties make it indispensable for producing special crystals used in night-vision equipment and fibre-optic telecommunications systems. Other applications include precision timekeeping in atomic clocks, which are vital for global positioning systems (GPS), telecommunications, and space exploration.

Rb compounds play a key role in the production of specialty glasses, cutting-edge electronics, radiation detection devices and medical imaging technologies, ensuring their relevance across multiple high-growth sectors.

Specialty glasses, currently the largest market for Rb, are utilised in night vision equipment and fibre-optic telecommunications systems. Rb carbonate is used as an additive to these types of glass, lowering electrical conductivity and improving stability and durability.

Rb's photo-emissive properties lead to its application in motion-sensor devices, night-vision devices, photoelectric cells, and photomultiplier tubes. These applications highlight its importance in advanced electronic devices, particularly in sectors requiring precision and reliability.

Its application in photocells, which convert light into electric currents, is significant. These photocells are primarily used as sensors to regulate lighting in buildings, showcasing Rb's role in energy-efficient technologies.

Rb-based atomic clocks are used in military communication systems, navigation equipment, and precision-guided weapons. The increasing focus on defence modernisation and the need for secure and reliable communication systems are expected to drive the demand for Rb in the military sector. 

Rb is also increasingly used as a key component in advanced batteries, particularly in the development of high-energy-density batteries for electric vehicles and renewable energy applications.

Global production of Rb is limited, with no Rb production recorded globally outside of China in 2023.

Due to its strategic importance and growing demand in high-tech applications used in key industry sectors, the United States of America and Japan have both classified Rb as a Critical Mineral, essential to their economic or national security, and with a supply chain vulnerable to disruption.

Competent Persons Statements

The information in this report that relates to Metallurgical Test Work is based on information compiled by Mr James Turner, a Competent Person who is a Member of the Institute of Materials, Minerals and Mining (IMMM), which is a Recognised Professional Organisation (RPO). Mr Turner is a Technical Director of SLR Consulting Limited who are engaged as independent consultants by Berkeley. Mr Turner has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration 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 of Exploration Results, Mineral Resources and Ore Reserves'. Mr Turner consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.

The information in this announcement that relates to Exploration Results is extracted from an announcement dated 29 January 2025, entitled 'Shallow, thick zones of lithium and rubidium mineralisation intersected in drilling at Conchas Project', which is available to view at www.berkeleyenergia.com. Berkeley confirms that: a) it is not aware of any new information or data that materially affects the information included in the original announcement; b) all material assumptions and technical parameters underpinning the Exploration Results in the original announcement continue to apply and have not materially changed; and c) the form and context in which the relevant Competent Persons' findings are presented in this announcement have not been materially modified from the original announcement.

Forward Looking Statements

Statements regarding plans with respect to Berkeley's mineral properties are forward-looking statements. There can be no assurance that Berkeley's plans for development of its mineral properties will proceed as currently expected. There can also be no assurance that Berkeley will be able to confirm the presence of additional mineral deposits, that any mineralisation will prove to be economic or that a mine will successfully be developed on any of Berkeley mineral properties. These forward-looking statements are based on Berkeley's expectations and beliefs concerning future events. Forward looking statements are necessarily subject to risks, uncertainties and other factors, many of which are outside the control of Berkeley, which could cause actual results to differ materially from such statements. Berkeley makes no undertaking to subsequently update or revise the forward-looking statements made in this announcement, to reflect the circumstances or events after the date of that report.

References

¹ www.mordorintelligence.com/es/industry-reports/rubidium-market

² www.straitsresearch.com/report/rubidium-market

³ www.marketresearchfuture.com/reports/rubidium-market-27298

⁴ U.S Geological Survey, Mineral Commodity Summaries, January 2024 - Rubidium

⁵ www.usgs.gov/news/national-news-release/us-geological-survey-releases-2022-list-critical-minerals

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 ('MAR'). Upon the publication of this announcement via Regulatory Information Service ('RIS'), this inside information is now considered to be in the public domain.

This announcement has been authorised for release by Mr Robert Behets, Director.

Appendix A - Summary of Flotation Test Work Results

Appendix B - Summary of -300µm +150 µm Magnetic Separation Test Work Results

APPENDIX C: JORC CODE, 2012 EDITION - TABLE 1

SECTION 1 - SAMPLING TECHNIQUES AND DATA

SECTION 2 - REPORTING OF EXPLORATION RESULTS