RED MOUNTAIN MINING LIMITED — Capital/Financing Update 2025

Jun 26, 2025

ASX ANNOUNCEMENT

27 JUNE 2025

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ASX: RMX

Red Mountain Mining Ltd ACN 119 568 106

Australia and Canada based Gold and Battery metals explorer redmountainmining.com.au

HIGH GRADE ANTIMONY CONFIRMS EXCEPTIONAL ARMIDALE POTENTIAL

HIGHLIGHTS

• Multiple High-Grade Antimony rock chip samples at Oaky Creek returned including:

• 28.34% Sb

• 28.33% Sb

• o 16.38% Sb

• High-Grade Antimony assay results have been returned from samples collected up to 500m along strike from historical workings, suggesting potential for a large

orogenic Antimony mineral system

• Shallow costeaning is planned to expose the bedrock beneath strong soil Antimony anomalies with no visible outcrop

• RMX also plans to undertake a soil and rock chip sampling campaign over the East Hills Antimony and Horsley Station Gold prospects in the southern portion of the

Armidale Project

• Gold assays for the Oaky Creek rock samples are pending and expected to be received in July

Red Mountain Mining Limited (“ RMX ” or the “ Company ”) is delighted to report highgrade Antimony rock chip results from Oaky Creek, part of RMX’s 100% owned Armidale Antimony-Gold project (EL9732) in the Southern New England Orogen of New South Wales. Results range up to 28.34% Sb for samples containing quartz-stibnite veining, confirming the high tenor of the mineralisation, and high-grade samples have been collected up to 500m from historical workings, suggesting potential for a large, highgrade, Antimony-bearing orogenic vein system. Similar systems, such as Larvotto’s (ASX: LRV) Hillgrove deposit, also located in the Southern New England Orogen, typically also contain high grade gold mineralisation. RMX has submitted a subset of the Oaky Creek rock chip samples for gold analysis by lead fire assay, with results expected in July.

Extension of Antimony Mineralisation Beyond Historical Workings Confirmed By Antimony Rock Chip Assay Results

During the soil sampling program at Oaky Creek, Red Mountain collected 171 rock chip samples (Refer to ASX Announcement 7 June 2025). Due to sparse outcrop in much of the area covered by the soil survey, the majority of these samples were collected in drainages and close to the Oaky Creek North and Oaky Creek South historical workings (Figure 1).

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Figure 1 compares Antimony rock chip and soil results for Oaky Creek. Two samples of quartz-stibnite veining collected more than 2km apart returned the highest values of 28.34% Sb and 28.33% Sb . One of these samples is float from the Oaky Creek South workings, confirming the tenor of the mineralisation mined historically, while the other is from a creek exposure ~500m NNW of Oaky Creek North (Figure 1, 2 and 3). A total of ten rock chip samples contained over 25,000ppm (2.5%) Sb.

Rock Chip Assays Up to 28.3% Sb Confirm High-Grade Antimony Potential at Oaky Creek

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Figure 1 : Comparison of rock chip and soil antimony results for the Oaky Creek prospect. Note the close spatial relationship between mineralised rock chip samples and the >2ppm Sb soil anomalies at Oaky Creek North (Inset A) and Oaky Creek South (Inset B). Values for rock chip samples that contain over 5000ppm (0.5%) Sb are shown. No rock chips samples were collected within the strong (>50ppm Sb) soil anomalies ~800m SSE of the Oaky Creek North and ~300m NW of the Oaky Creek South historical workings due to a lack of outcropping or float material. Refer to Figure 2 for an overview with location co-ordinates.

The samples were collected from in situ outcropping exposures where possible, but subcrop and float samples were collected where this was not possible. The samples were assayed for antimony and tungsten, using sodium peroxide fusion and ICP-MS finish. Rock chip sample locations, nature (outcrop, subcrop or float) and geochemical results are summarised in Appendix 1.

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Figure 2: A continuation of the Map in Figure 1, showing the broader area and locations of Inset A and Inset B.

Red Mountain interprets that the vein-hosted antimony mineralisation mined at Oaky Creek has a significant inferred strike extent, indicating potential for a large tonnage deposit based on:

• the identification of outcropping high-tenor antimony mineralisation in a creek exposure ~500m NNW of the historical workings at Oaky Creek North;

• the spatial correlation between mineralised and anomalous rock chip samples; and

• elevated Antimony in soils.

Mineralised and anomalous rock chip samples show a strong spatial correlation with anomalous (>2ppm) Sb in soils, although due to paucity of outcropping and float material in parts of the survey area, it was not possible to collect rock chips samples across the full length of the approximately 2km long soil anomaly defined for Oaky Creek North or the approximately 1km long anomaly at Oaky Creek South (Figure 1). Most significantly, no outcrop or float material was found within the two new strong >50ppm Sb soil anomalies that were identified by RMX’s sampling. One of these is located ~800m SSE of Oaky Creek North, while the other lies ~300m NW of Oaky Creek South. Both these anomalies warrant further investigation.

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Figure 3 : TOP: Approximately 5m high mineralised creek exposure ~500m NNW of the Oaky Creek North historical workings. View looking SW. BOTTOM: Stibnite-rich vein material collected from the base of the cliff - sample AAR 126, which returned the second highest assay result of 28.3% Sb.

Further Work Planned By Red Mountain At Oaky Creek

Based on these highly encouraging initial results, RMX will continue to progress the Oaky Creek prospect, with a program of shallow costeaning planned to expose and sample bedrock beneath those parts of the soil antimony anomaly where no outcrop was observed. RMX will also undertake detailed geological mapping of

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the costeans and other exposed geology to better understand the relationship between the Namoi Fault system and orogenic vein-hosted antimony mineralisation, with a goal of generating drill-testable targets at Oaky Creek by late 2025. RMX’s future work plans at Oaky Creek will also be influenced by the rock chip gold results, expected in July.

Two Further Priority Antimony And Gold Targets To Be Tested

In addition to Oaky Creek, RMX’s initial assessment of EL9732 identified two further priority exploration targets[1] , which like Oaky Creek feature evidence of historical mining, likely dating from the early 1900s (Figure 3). Neither the East Hills antimony prospect or the Horsley Station gold prospect have previously been explored systematically, with no soil sampling for gold, antimony or silver previously undertaken at either location.

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Figure 4: Surface geology and known antimony, gold and tungsten mineral occurrences of EL9732 and the surrounding area, showing the location of RMX’s three priority targets of Oaky Creek, East Hills and Horsley Station and the Teatree and Bingarra goldfields.

At the East Hills antimony prospect, several shallow pits and a shaft have been sunk on a stibnite bearing reef striking at 170⁰, approximately parallel to the Cobadah and Peel Faults which lie to the east. Red

1RMX ASX Announcement 2 February 2025. https://investorhub.redmountainmining.com.au/announcements/6794753

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Mountain is planning to collect a total of 88 soil samples over a 500 x 600m grid at 100m line spacing and 50m sample interval (Figure 5) during the second half of 2025.

The Horsley Station gold workings comprise a 10m x 3m x 12m deep open cut mined for gold from a narrow quartz reef striking at 100⁰ and dipping steeply to the north. The prospect lies on the Peel Fault with the host mineralisation including fault slices of serpentinite, which is an analogous setting to the gold deposits of the Bingarra and Teatree goldfields, further north along the Peel Fault (Figure 4). RMX plans to collect a total of 233 soil samples at 50m sample intervals and 100m line spacing to locate gold and antimony (Figure 5).

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Figure 5: RMX planned soils sample locations at the East Hills antimony and Horsley Station gold prospects.

Red Mountain Armidale Antimony-Gold Project Background

Red Mountain’s project lies approximately 100km west of Larvotto’s (ASX: LRV) Hillgrove Project and several of Trigg Minerals’ (ASX: TMG) Antimony Projects and extends for 85km immediately west of the Peel Fault.

The Southern New England Orogen is recognised as Australia’s premier Antimony province (Figure 6). Antimony occurs in hydrothermal quartz veins, breccias and stockworks, often with associated gold and/or tungsten mineralisation.

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----- Start of picture text -----

Red Mountain Mining
Armidale Antimony-Gold
Project
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Figure 6: Known NSW gold and antimony mineral occurrences relative to basement orogenic units. The map clearly demonstrates the prospectivity of the New England Orogen for antimony and gold. The location of the Hillgrove Deposit, Peel Fault and EL9732 are also shown.

The geology of the tenement is dominated by isoclinally folded Carboniferous metasediments of the Tamworth Belt, which is a forearc basinal package related to west-dipping subduction of oceanic crust beneath the Lachlan Orogen. Ultramafic melanges of the Great Serpentinite Belt, which outcrop along the Peel Fault, are considered to be remnants of this oceanic crust. The Peel Fault System has recognised worldclass mineral potential, with over 400 known orogenic gold and base metal mineral occurrences along its over 400km strike extent but is underexplored with less than 200 mostly shallow drillholes over its length, the majority of which are focused on discrete prospects.

Authorised for and on behalf of the Board,

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Mauro Piccini

Company Secretary

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About Red Mountain Mining

Red Mountain Mining Limited (ASX: RMX) is a mineral exploration and development company. Red Mountain has a portfolio of critical minerals including gold, lithium and base metal projects, located in Australia, Canada and USA. Red Mountain is progressing its Armidale Antimony-Gold Project in NSW, Kiabye Gold Project in Western Australia and Fry Lake Gold project, based in Canada. In addition, Red Mountain’s project portfolio includes the Nevada Lithium Projects.

Competent Person Statement

The information in this announcement that relates to Exploration Results and other technical information complies with the 2012 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code). It has been compiled and assessed under the supervision of contract geologist Mark Mitchell. Mr Mitchell is a Member of the Australasian Institute of Geoscientists and has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the JORC Code. Mr Mitchell consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears.

Disclaimer

In relying on the above mentioned ASX announcement and pursuant to ASX Listing Rule 5.23.2, the Company confirms that it is not aware of any new information or data that materially affects the information included in the above-mentioned announcement.

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JOIN THE RED MOUNTAIN MINING INVESTOR HUB

Visit https://investorhub.redmountainmining.com.au for access to the Investor Hub

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Appendix 1: Rock chip assay results

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JORC Code, 2012 Edition - Table 1

1.1 Section 1 Sampling Techniques and Data

Criteria	JORC Code explanation	Commentary
Sampling techniques	• Nature and quality of sampling (e.g. cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. • Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. • Aspects of the determination of mineralisation that are Material to the Public Report. • In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information.	• Rock samples were collected from 1kg grab samples. • Rock chip samples were selective based on visual appearance and are not used for resource determination, only to check if mineralisation is present. • All samples are exploration in nature and not for resource determination. • Rock & Soil samples have been sent to Intertek Townsville laboratory with the soils forwarded on to the Perth Laboratory. Rock samples were assayed by sodium peroxide fusion FP6/OM for Sb and W with an I4CP_MS finish.
Drilling techniques	• Drill type (e.g. core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (e.g. core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by _what method, etc). _	• No drilling reported
Drill sample recovery	• Method of recording and assessing core and chip sample recoveries and results assessed. • Measures taken to maximise sample recovery and ensure representative nature of the samples. • Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material.	• No drilling reported.
Logging	• Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining	• No drilling reported. • Rock sampling is not used for resource estimation.

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Criteria	JORC Code explanation	Commentary
	studies and metallurgical studies. • Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. • The total length and percentage of the relevant intersections logged.
Sub- sampling techniques and sample preparation	• If core, whether cut or sawn and whether quarter, half or all core taken. • If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. • For all sample types, the nature, quality and appropriateness of the sample preparation technique. • Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples. • Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. • Whether sample sizes are appropriate to the grain size of the material being sampled.	• Rock chip sampling was biased towards outcrop that was altered including samples from old shaft workings. • Rock grab samples were taken raw and approximately 1kg each. • Grab rock samples are first pass with size appropriate for initial work and not intended for grade purposes.
Quality of assay data and laboratory tests	• The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. • For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. • Nature of quality control procedures adopted (e.g. standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e. lack of bias) andprecision have been established.	• Rocks were treated at Intertek and with standard procedure of drying, crushed, pulverized (in Nickel crucibles) and sodium peroxide fused and finished with ICP-MS. • Sodium Peroxide fusion is considered an appropriate method for antimony. • No duplicate, blank and standards (CRM) were inserted.
Verification of sampling and assaying	• The verification of significant intersections by either independent or alternative company personnel. • The use of twinned holes. • Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. • Discuss any adjustment to assay data.	• No drill holes reported.
Location of data points	• Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation.	• All sample taken with GPS readings with site locations recorded in GDA94 (z56). • No mineral resource estimation was conducted.

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Criteria	JORC Code explanation	JORC Code explanation	Commentary	Commentary
	• Specification of the grid system used. • Quality and adequacy of topographic control.
Data spacing and distribution	• Data spacing for reporting of Exploration Results. • Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. • Whether sample compositing has been applied.		• Rock sample spacing was biased towards available outcrop which was limited away from incised creek exposures. • Being exploration, any sample results will not be considered sufficient for any ore determinations. • No analytical compositing has been reported.
Orientation of data in relation to geological structure	• Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. • If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material.		• Rock samples were collected along outcrop with strike and dip recorded where available. • No drilling conducted.
Sample security	• The measures taken to ensure sample security.		• Samples were managed by field staff, individually double wrapped and sealed in a 1- ton bulk which was dropped off in a freight forwarding yard. Samples arrived at the laboratorysealed.
Audits or reviews	• The results of any audits or reviews of sampling techniques and data.		• No audit or reviews of sampling techniques and data was reported.
1.2 Section 2 Reporting of Exploration Results (Criteria listed in theprecedingsection also applyto this section.)
Criteria		JORC Code explanation		Commentary
Mineral tenement and land tenure status		• Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. • The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area.		• The Exploration licence EL9732 is granted and 100% wholly owned by Red Mountain Mining and covers 391km2. • The licence is predominantly in Freehold pastoral properties and as such Native Title is extinguished.
Exploration done by other parties		• Acknowledgment and appraisal of exploration by other parties.		• The north-south elongate corridor covered by the project contains no historical mineral exploration drilling and has seen limited previous surface exploration for Antimony and Gold mineralisation. No soil sampling for these elements has been undertaken and

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Criteria	JORC Code explanation	Commentary
		rockchip and stream sediment coverage is limited, leaving the majority of the tenement untested by systematic exploration and therefore is considered having significant potential for discovery
Geology	• Deposit type, geological setting and style of mineralisation.	• The project is located in the Southern New England Orogen. The geology of the tenement is dominated by isoclinally folded Carboniferous metasediments of the Tamworth Belt which is a forearc basin package related to west-dipping subduction of oceanic crust beneath the Lachlan Orogen. Ultramafic melanges of the Great Serpentinite Belt, which outcrop along the Peel Fault, are considered to be remnants of this oceanic crust. • The style of mineralisation target is hydrothermal quartz veins, breccia and stockworks derived from fluids during regional compression and resulting faulting providingthe conduits to the fluids.
Drill hole Information	• A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes: o easting and northing of the drill hole collar o elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar o dip and azimuth of the hole o down hole length and interception depth o hole length. • If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case.	• No drilling conducted
Data aggregation methods	• In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. • Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be	• No aggregated methods are reported

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Criteria	JORC Code explanation	Commentary
	shown in detail. • The assumptions used for any reporting of metal equivalent values should be clearly stated.
Relationship between mineralisation widths and intercept lengths	• These relationships are particularly important in the reporting of Exploration Results. • If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. • If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g. ‘down _hole length, true width not known’). _	• No relationship is made between mineralisation width and intercept lengths
Diagrams	• Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views.	• Appropriate location diagram is presented in the text. The diagram is indicative only as no assumptions of grade, extent or depth are made.
Balanced reporting	• Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results.	• Only pertinent results are given as due to the relevance of the announcement.
Other substantive exploration data	• Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples – size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances.	• There is no other substantive exploration data provided or withheld as this announcement deals with this early phase exploration target.
Further work	• The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large-scale step-out drilling). • Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.	• The forward work programme depends on full sample assay results from the laboratory. If encouraging, then costeaning and drilling programmes will be implements to determine the depth and lateral extent of the stibnite mineralisation. • Diagrams of the sampling positions have been provided in the text.

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