Andrada Mining Limited Mineral Resource Update at Uis

RNS Number : 1616W

Andrada Mining Limited

06 February 2025

 

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 (MAR) AS IN FORCE IN THE UNITED KINGDOM PURSUANT TO THE EUROPEAN UNION (WITHDRAWAL) ACT 2018. UPON THE PUBLICATION OF THIS ANNOUNCEMENT VIA REGULATORY INFORMATION SERVICE (RIS), THIS INSIDE INFORMATION WILL BE IN THE PUBLIC DOMAIN.

Andrada Mining Limited

("Andrada" or "the Company")

Updated Mineral Resource Estimate for the Uis tin mine V1V2 pegmatite

Andrada Mining Limited (AIM: ATM, OTCQB: ATMTF), a critical raw materials producer with mining and exploration assets in Namibia, announces an updated Mineral Resource Estimate ("MRE") for the V1V2 pegmatite at the Uis tin mine. This is an update on the MRE announced on 6 February 2023¹, and incorporates analytical results from the final 16 drill holes of the 2022 drilling programme, as well as a volume depletion surface as at 30 August 2024.

HIGHLIGHTS

§ Increases in average lithium grade and volumes of the measured and indicated resource classifications

§ Average lithium grade increases to 0.79% Li₂O from 0.73% Li₂O declared in 2023¹

−   Contained lithium oxide ("Li₂O") increases from 587 000 tonnes to 610 000 tonnes

§ Measured resource tonnage increases by 30% to c27.3 million tonnes ("mt")

§ Indicated resource tonnage increases by 2% to c17.5mt

§ MRE total tonnage decreases from 81mt in 2023 to 77.5mt due to depletion from on-going mining

Anthony Viljoen, Chief Executive Officer, commented:

"This updated resource estimate is another positive step toward our goal of being a premiere African producer of tin, lithium and tantalum. Our exploration team has once again demonstrated that the V1V2 pegmatite has significant lithium potential, shown by increases in both the average lithium grade and contained metal tonnage. Critically, this updated resource also allows us to better quantify the potential lithium concentrate credits we can generate alongside our tin production, optimising the overall project economics.  Furthermore, the updated MRE further enhances the project economics of the Uis mine operations and will enable the determination of a lithium mineral reserve.

RESULTS Overview

The MRE has been informed by 145 historical ISCOR drillholes comprising eight (8) Diamond Drillholes ("DD") and one hundred and thirty-seven (137) Reverse Circulation ("RC") drillholes, together with seventy-seven (77) validation drill holes, comprising forty-eight (48) DD and twenty-nine (29) RC drillholes drilled by Andrada between 2018 and 2023. The Andrada drillholes were completed on a nominal grid spacing of 60m by 60m, with wider spacing of up to 80m by 200m for the deeper portions. Most holes were drilled at a vertical orientation, but selected shallower holes were inclined at angles up to -70° southeast, to obtain intersections more perpendicular to the dipping pegmatite. The locations of all V1V2 drillhole collars are shown in Figure 1.

The 2023 MRE¹ update was determined from geological information of all holes above, except for 16 holes (V1V2034, 35, 37, 38, 40, 43, 44, 48, 50, 51, 52, 53, 54, 58, 63 and 80) whose data were not available at the date of publication. The current MRE update includes analytical data from the final 16 drillholes obtained subsequent to the previously published MREs (see announcements dated 2 February 2023² and 30 March 2023³).

  

¹ https://polaris.brighterir.com/public/andrada_mining/news/rns/story/x4g8q3x

² https://polaris.brighterir.com/public/andrada_mining/news/rns/story/x8en45x

³ https://polaris.brighterir.com/public/andrada_mining/news/rns/story/xoo1nmx

 

 

Figure 1: Image indicating the location and name of the drill holes from the 2022 programme.

The updated V1V2 MRE is reported in accordance with the JORC Code (2012) and identifies 77.51 Mt of mineralised pegmatite with an average grade of 0.79 % Li₂O, 0.15 % Sn and 82 ppm Ta. This MRE includes 27.33 mt at an average grade of 0.82 % Li₂O, 0.15 % Sn and 90 ppm Ta for the near surface Measured category, 17.50 mt at an average grade of 0.79 % Li₂O, 0.15 % Sn and 86 ppm Ta for the Indicated category, and 32.68 mt with an average grade of 0.76 % Li₂O, 0.16 % Sn and 73 ppm Ta for the Inferred category. The contained lithium is also stated in terms of Lithium Carbonate Equivalent, being the metal converted to lithium carbonate by a factor of 5.323.

The MRE is reported within a conceptual pit shell to demonstrate reasonable prospects for eventual economic extraction ("RPEEE") and incorporates the sale of petalite and cassiterite. Rubidium (Rb - in mica), tantalite and niobium associated with Ta in the columbite group minerals (CGM)) concentrations and tonnages were also estimated but have not been included in the RPEEE considerations.

The MRE is reported on a gross basis in Table 1. An attributed-basis tabulation of resources, as presented in previous estimates, is no longer applicable because the V1V2 pegmatite is within the Uis mining license (ML 134) now wholly owned by Andrada Mining and its subsidiaries (see announcement dated 27 June 2024). Proportional changes in the tonnages and grade between the 2023 MRE and the current MRE are presented in Table 2.

Table 1: V1 and V2 deposit MRE in accordance with JORC (2012)

Classification	Tonnes (mt)		Grades
			Sn (%)		Li (ppm)		Li2O (%)	Rb (ppm)		Ta (ppm)	Nb (ppm)
Measured	27.33		0.15		3 814		0.82	1 435		90	117
Indicated	17.50		0.15		3 656		0.79	1 370		86	115
Measured and indicated	44.83		0.15		3 753		0.81	1 410		89	116
Inferred	32.68		0.16		3 520		0.76	1 279		73	110
Total	77.51		0.15		3 655		0.79	1 355		82	114
Classification	Contained metal (kt)
	Sn	Li		Li2O		LCE*		Rb	Ta		Nb
Measured	40.0	104.2		224.4		554.5		39.2	2.5		3.2
Indicated	26.5	64.0		137.8		340.4		24.0	1.5		2.0
Measured and indicated	66.5	168.2		362.2		895.1		63.2	4.0		5.2
Inferred	51.6	115.0		247.7		611.9		41.8	2.4		3.6
Total	118.0	283.3		610.0		1 507.0		105.0	6.4		8.8

 

Source: ERM, 2025

Note: The constraining pit shell is based on a tin price of USD 25 500/t and a price of USD 1 500/t for a 4% Li₂O petalite concentrate. Losses and mining dilution were set at 5%. Pit slope angles were assumed to be 55°. An assumed metallurgical recovery of 80% was used for Sn producing a concentrate with Sn metal content of 60%, and Li₂O (as petalite) recovery of 45%. The mining, treatment, G&A and selling costs have been supplied by Andrada and reviewed for reasonableness by ERM. Tabulated data has been rounded off which may result in minor computational errors.

*  The contained lithium is also stated in terms of Lithium Carbonate Equivalent being the metal converted to lithium carbonate by a factor of 5.323 (i.e. LCE = Li x 5.323).

The operator is Andrada being the 100% owner of the Uis mining licence (ML134).

Table 2: Percentage change of tonnes contained, grades and deposit size.

MRE Year	Tonnes (Mt)	Sn %	Contained Sn metal (t)	Li2O %	Contained Li2O (t)	Ta ppm	Contained Ta metal (t)
2023	81	0.15	120 000	0.73	587 000	86	6 960
2025	77.51	0.15	118 000	0.79	610 000	82	6 400
% Change	-4%	0%	-2%	8%	4%	-5%	-8%

This MRE update provides an increase of the lithium grade and tonnage in the Measured and Indicated classification. These results further outline the polymetallic potential of the V1V2 pegmatite. The surface information used for the basis of this MRE was acquired at the end of August 2024, and the volumes mined since the previous MRE¹ have been accounted for, resulting in a reduced overall tonnage.

Geology and geological interpretation

The V1V2 deposit is hosted within rocks formed during the Damara Orogen, a typical Pan-African orogenic belt, which formed between 750 Ma and 440 Ma during the assembly of Gondwana. The orogenesis resulted in the production of voluminous quantities of granitic magma during the syntectonic phases of collision. This was followed by a pegmatitic phase of magmatism in the post-tectonic environment, populating the Damara Orogen with numerous pegmatitic intrusions.

The V1V2 pegmatite has a sigmoidal shape in plan and is hosted in biotite schists and a distinctive cordierite (with biotite and quartz replacement of cordierite)-bearing knotted schist (the so-called "knottenschiefer"). The pegmatite strikes to the northeast and dips to the northwest at angles of between 30° and 50°. The tin and lithium mineralisation is primarily magmatic with some tin mineralisation associated with a late-stage mica-rich greisen phase. The primary lithium mineral identified within the pegmatite is petalite.

Modelling and estimation

An in-situ Mineral Resource Estimate (MRE) was undertaken for the pegmatite bodies. Mineralisation wireframes were guided entirely by geology and resulted in the generation of three-dimensional (3D) geological models of the V1 and V2 pegmatites that merge at depth to form the V1V2 pegmatite body. The pegmatite wireframes were also used to define the mineralisation envelopes. Internal waste was represented by the xenolith wireframes. The August 2024 monthly photogrammetric survey at Uis was used to generate a high-resolution topographic surface that was subsequently used to constrain the resource.

A block model, constrained by the interpreted mineralised envelopes and topographic surfaces, was constructed. A parent cell size of 20 m(E) x 20 m(N) x 10 m(RL) was adopted with standard sub-celling to 2 m(E) x 2 m(N) x 1 m(RL) to maintain the resolution of the mineralised lenses. The samples were composited to 2m lengths.  A small number of tin samples were considered grade outliers, and a top-cut of 1.0% for Sn applied to the dataset (only Sn grades were top-cut). These composites were the basis for the estimation of all Sn, Li, Nb, Rb and Ta grades into the block model using Ordinary Kriging (OK) interpolation, with the V1 and V2 pegmatites treated as separate domains. The block grades were validated both visually and statistically against composite grades. A mean dry bulk density value of 2.65 was assigned to all pegmatite material. Cross sections through the resulting block model, provide an indication of the typical grade profiles for Sn, Li and Ta respectively, as presented in Figure 2,Figure 3, and Figure 4. No significant statistical correlation between the various metals was identified from the data, resulting in each metal being estimated independently.

Figure 2: Typical cross section of the Block model and Input Composite data coloured by Sn Grade, looking northeast. Source: ERM, 2025

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3: Typical cross section of the Block model and Input Composite data coloured by Li Grade, looking northeast. Source: ERM, 2025

 

 

 

 

 

 

 

 

 

 

 

Figure 4: Typical cross section of the Block model and Input Composite data coloured by Ta Grade, looking northeast. Source: ERM, 2025

 

Mineral resource classification criteria

The Mineral Resource has been classified into Measured, Indicated and Inferred categories in accordance with guidelines specified within the JORC Code 2012 Edition. The classification level is based upon an assessment of the geological understanding of the deposit, geological and grade continuity, drillhole spacing, quality control results, search and interpolation parameters, and an analysis of available density information.

Geostatistically, confidence classifications were assigned based on the slope of regression (SoR) metrics per block for Sn, being the lowest confidence analyte overall to be estimated. A SoR value of > 0.8 was used to classify blocks as Measured and a SoR > 0.55 was to classify blocks as Indicated. All other Mineral Resources not already classified and constrained to blocks with a SOR of > 0.25 and not more than 50 m from at least four samples, were classified as Inferred. It was found that Measured and Indicated Mineral Resources were interspersed, so that wireframe boundaries between the two categories were imposed, as guided by the SoR and distances from informing samples. These wireframes defined coherent zones for each classification assignment.

 

 

 

 

 

 

 

 

 

 

 

Figure 5: Plan View of the MRE Block Model, Coloured by CLASS (Red = Measured, Green = Indicated, Blue = Inferred), with drillhole collars displayed coloured by drill phase. Source: ERM, 2025

Competent Person statement

The technical data relating to the Mineral Resources in this announcement have been reviewed by Anthony Wesson who was an employee of ERM Ltd when the work was undertaken and is a Fellow of the Australasian Institute of Mining and Metallurgy. Anthony Wesson has sufficient experience relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as Competent Persons as defined in the 2012 Edition of the Australasian Code for the Reporting of Exploration Results, Mineral Resources, and Ore Reserves (JORC Code). Anthony Wesson consents to the disclosure of information in this report in the form and context in which it appears.

The technical data relating to the exploration results in this announcement have been reviewed by Michael Cronwright an employee of ERM UK Ltd, a Fellow of the Geological Society of South Africa and a Professional Registered Natural Scientist (Geology) with the South African Council of Natural Scientific Professions. He has sufficient experience 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 the Reporting of Exploration Results, Mineral Resources, and Ore Reserves (JORC Code). Mr Cronwright consents to the inclusion of the information in the form and context in which it appears.

Glossary of abbreviations

CGM	Columbite Group Minerals. This includes tantalite (Ta2O5) and columbite (Nb2O5) that host Ta and Nb mineralisation in pegmatite deposits.
DD	Diamond core drilling
LCE	Lithium Carbonate Equivalent.
Li	Symbol for Lithium
Li → Li2O	Metal to metal-oxide conversion factor of 2.153
Li → LCE	Metal to lithium carbonate equivalent conversion factor of 5.323
Li2O	Lithium oxide
JORC	The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves
KE	Kriging Efficiency
MRE	Mineral Resource Estimate
Nb	Symbol for Niobium
PPM	Parts Per Million
QA/QC	Quality Assurance / Quality Control
Rb	Symbol for Rubidium
RC	Reverse Circulation drilling
RPEEE	Reasonable Prospects for Eventual Economic Extraction
SG	Specific Gravity
Sn	Symbol for Tin
SoR	Slope of Regression
Ta	Symbol for Tantalum
V1V2	Name of the targeted pegmatite unit, V1V2 denotes where the V1 and V2 pegmatites have merged at depth.

Glossary of technical terminology

Apparent thickness	The relationship between apparent width and true thickness is based on the formula by Addie (1968 Economic Geology, vol 63, pp 188-189).
Dip angle	The angle of inclination measured downward from horizontal.
Geological model	The interpretation of mineralisation and geology that controls mineralisation.  This is usually generated in a three-dimensional computer environment.
Indicated Mineral Resource	The part of a Mineral Resource for which quantity, grade, quality, etc., can be estimated with a level of confidence sufficient to allow the appropriate application of technical and economic parameters, to support mine planning and evaluation of economic viability
Inferred Mineral Resource	The part of a Mineral Resource for which quantity and grade or quality can be estimated on the basis of geological evidence and limited sampling and reasonably assumed, but not verified, geological and grade continuity
Measured Mineral Resource	The part of a Mineral Resource for which quantity, grade or quality, etc., are well enough established that they can be estimated with confidence sufficient to allow the appropriate application of technical parameters to support production planning and evaluation of economic viability
Mineral resources	Mineral Resources are sub-divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories. An Indicated Mineral Resource has a higher level of confidence than an Inferred Mineral Resource but has a lower level of confidence than a Measured Mineral Resource.
Pegmatite	An igneous rock typically of granitic composition, which is distinguished from other igneous rocks by the extremely coarse and systematically variable size of its crystals, or by an abundance of crystals with skeletal, graphic, or other strongly directional growth habits, or by a prominent spatial zonation of mineral assemblages, including monomineralic zones.
Petalite	Lithium bearing aluminosilicate (LiAlSi4O10) with a maximum theoretical Li content of 4.5%. Current applications largely in the glass and ceramic industry but can potentially be used in the battery chemical market employing similar processes and technologies used to process spodumene.
Xenolith	A foreign rock fragment (e.g., schist) within an intrusive body (e.g. pegmatite) that is unrelated to the igneous body.

 

 

CONTACTS Andrada Mining Anthony Viljoen, CEO Sakhile Ndlovu, Investor Relations	[phone]
NOMINATED ADVISOR & BROKER
Zeus Capital Limited Katy Mitchell Harry Ansell Andrew de Andrade	[phone]
CORPORATE BROKER & ADVISOR
H&P Advisory Limited Andrew Chubb Jay Ashfield Matt Hasson	[phone]
Berenberg Jennifer Lee Natasha Ninkov	[phone]
FINANCIAL PUBLIC RELATIONS
Tavistock (United Kingdom) Emily Moss Josephine Clerkin	[phone] [e-mail]

About Andrada Mining Limited

Andrada Mining Limited is listed on the London Stock Exchange (AIM), New York (OTCQB) and Namibia Stock Exchange with mining assets in Namibia, a top-tier investment jurisdiction in Africa. Andrada strives to produce critical raw materials from a large resource portfolio to contribute to a more sustainable future, improved living conditions and the upliftment of communities adjacent to its operations. Leveraging its strong foundation in Namibia, Andrada is on a strategic path to becoming a leading African producer of critical metals including lithium, tin, tungsten, tantalum and copper. These metals are important enablers of the green energy transition, being essential for components of electric vehicles, solar panels and wind turbines.

 

 

APPENDIX A            JORC TABLE (2012 EDITION), TABLE 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 downhole 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 (e.g. '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 (e.g. submarine nodules) may warrant disclosure of detailed information	ISCOR Historical drilling completed by ISCOR (Iron and Steel Corporation (Pty) Ltd) was used and in the exploration database and comprised 13 diamond (DD) drillholes and 138 percussion holes with 1 m sampling intervals, within the V1 and V2 pegmatite area. Although there are no reports discussing details of the sampling protocols, there is evidence that investigations into sample reproducibility and repeatability were carried out and the nuggety nature of the tin mineralisation was recognised. Despite this local variability, the average grade of tin appeared to be consistent around 0.14% Sn, similar to what has been estimated in this MRE. Andrada  2018 to 2019 26 diamond (DD) drillholes totalling 4,434.7 m were drilled by Andrada Mining Limited (Andrada). Assay results for the deep holes (21 to 26) were not available at the time of reporting but geological logging from these holes were used to constrain the geological modelling. Assay results from holes 1 to 20 have been reported.  Sample intervals were determined by the geologist, where possible samples were taken in 1 m intervals at the start of each metre mark. In areas where lithological contacts were present (xenoliths included), the sample was taken from the nearest metre mark to the contact.  Drill core was either sampled as full core (all core taken for sample) or cut in half using a core cutter, then sampled as half core with the other half remaining in the core tray. Approximately 33% of the core was sampled as full core.  All samples were crushed to a <1 mm grain size before being split by rotary splitter, where required, duplicate samples were also split during this stage. A 150 g sample was split from each core sample and for further processing and analysis. The remainder of the sample was re-bagged with an original sample ticket and marked as coarse reject. These samples have been placed in secure storage. 2022 22 DD drillholes totalling 3,286.02 m and 29 reverse circulation (RC) holes totalling 4,332 m were drilled by Andrada. Assay results for the deep holes (V1V2021 to 026) were not available at the time of reporting but geological logging from these holes were used to constrain the geological modelling. Assay results from these holes have since been reported and included in subsequent updates.

 

Criteria	JORC Code explanation	Commentary
		For the DD holes, the sample intervals were determined by the geologist, where possible samples were taken in 1 m intervals at the start of each metre mark. In areas where lithological contacts were present (xenoliths included), the sample was taken from the nearest metre mark to the contact.  Drill core was cut in half using a core cutter, then sampled as half core with the other half remaining in the core tray.  The RC drilling produced bags of pulverised rock material at 1 m intervals weighing approximately 30 kg on average. These 1 m bulk percussion samples were split 50%:50% using an RSE Projects rotary splitter down to produce ~15 kg subsamples. Field duplicates were prepared from the remaining discarded material. All samples were crushed to a <1 mm grain size before being split by rotary splitter to produce a 500 g aliquot, where required, duplicate samples were also split during this stage. The 500 g aliquots were split and combined (homogenised) using a rotary splitter to separate the 150 g sample which was further processed for analysis. Each 150 g sample was then further milled until 97% of the sample passed through a 0.075 mm sieve. A 2 g aliquot was taken from the pulverised material for digestion and assay. The remainder of the sample was re-bagged with an original sample ticket and marked as coarse reject. These samples have been placed in secure storage.
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.).	ISCOR Available archive material sets out that an Atlas Copco ROC61 percussion rig, with a 115 mm hammer, was the predominant rig type used for the percussion drilling. Samples were collected on a 1 m basis. No information is available for the diamond drilling undertaken by ISCOR. Andrada 2018 to 2019 For the 2018-2019 DD drilling campaign, all samples were obtained through DD drilling, primarily at PQ size, utilising standard 1.5 m or 3.0 m core barrels. Majority of the drilling was vertically orientated with some of the shallower drillholes were inclined, up to 70°, to intersect closer to a true thickness. 2022 For the 2022 drilling, a combination of HQ diameter diamond drilling, utilising standard 1.5 m or 3.0 m core barrels and 137 mm diameter RC drilling. Majority of the drilling was vertically orientated with some of the shallower drillholes were inclined, up to 70°, to intersect closer to a true thickness.

 

Criteria	JORC Code explanation	Commentary
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.	ISCOR No recovery information was available. Andrada 2018 to 2019 Core recovery is calculated as the length of recovered core over the driller length or each recovered drill run. Recoveries were good overall with small losses occurring in areas where the schist has been fractured. Recoveries for pegmatite material were excellent (>97%). No special methods were used to aid core recovery in fractured areas. Sample loss in these areas is not thought to be material as the pegmatite is the primary mineralised lithology. 2022 Core recoveries for the DD holes was calculated as per previous drilling and averaged 98%. Recoveries for the RC drilling averaged ~77% through pegmatite intersections - based on theoretical maximum recovery of specific gravity (SG) 2.65 material and hole diameter of 137 mm. Sample masses averaged ~30 kg and ranged from 3.4 kg to 57.6 kg.
Logging	Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies.	ISCOR Simplified metre-based geological logs and accompanying tin assay data are available for the ISCOR drilling and have been digitised by Andrada. Andrada 2018 to 2019 Each core box was photographed five times. Once dry and four times on different brightness and contrast settings while wet. All photographs were taken under two oppositely spaced 5000 lumen spotlights. The entire length of core was logged for all intersections. Geological logs are all qualitative. For each drillhole, both simple and detailed geological logs were created. The following observations were defined in each log entry: alteration type and intensity, mineral occurrences, mineralogical modal abundances, iron-manganese and iron-oxide presence, a qualitative modal abundance of observed tintantalum-niobium oxides, lithium-phases or sulphides, mineralogical textures, weathering intensity, colour, grain size and grain size distributions, contacts type (gradational or sharp) and any other geological comment the geologist may have had. This was done for both host rocks and pegmatites. Geotechnical logging was also carried out. Downhole surveys were completed on all drillholes after completion and all hole positions were surveyed using a differential global positioning system (GPS). Fractures, faults and veins within the core were also logged.

 

Criteria	JORC Code explanation	Commentary
		2022 Each core box was photographed twice. Once dry and once while wet. All photographs were taken under four 7700 lumen light which emit >95% of the visible colour spectrum. The entire length of core was logged for all intersections. Geological logs are all qualitative. For each drillhole, both simple and detailed geological logs were created. The following observations were defined in each log entry: alteration type and intensity, mineral occurrences, mineralogical modal abundances, iron-manganese and iron-oxide presence, a qualitative modal abundance of observed tintantalum-niobium oxides, identified lithium-phases or sulphides, mineralogical textures, weathering intensity, colour, grain size and grain size distributions, contacts type (gradational or sharp) and any other geological comment the geologist may have had. This was done for both host rocks and pegmatites. Geotechnical logging was also carried out. Downhole surveys were completed on all drillholes after completion and all hole positions were surveyed using a differential GPS. Fractures, faults and veins within the core were also logged.
Subsampling 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 subsampling 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.	ISCOR No information about subsampling for the historical drilling was available. Andrada 2018 to 2018 Approximately 33% of drillholes were sampled as full core, with the remainder sampled as half core. The full-core analysis was utilised to test the nugget effect and determine potential bias associated with sample size. No bias was detected, and half-core samples are considered reliable for their use in the MRE. The sample size used is appropriate for the coarse-grained nature of the pegmatite deposit as the largest diamond core drill size commercially available was utilised for this program.  Where core was sampled as whole core, no cutting/splitting was involved. The entire drilled sample was then sent for assay. Half-core samples were cut in half using a diamond studded blade in a core saw, a consistent side of the split core was sampled. Samples were then transported to a controlled facility where they were further processed. Irrespective of the sample type; full or half core, each sample was crushed in its entirety to <1 mm prior to sample splitting.  Samples were split and combined using a rotary splitter to separate the 150 g sample which was further processed for analysis. Each 150 g sample was then further milled until 97% of the sample passed through a 0.075 mm sieve. 5% of all samples were split in duplicate to verify representativity.

 

Criteria	JORC Code explanation	Commentary
		2022 All drill core (HQ diameter) was sampled as half core and is considered appropriate for the coarsegrained nature of the pegmatite and associated mineralisation. The entire sample of RC drilling chips were collected from each 1m interval weighing approximately 30 kg. These 1 m bulk percussion samples were split 50%:50% using an RSE Projects rotary splitter down to produce ~15 kg subsamples. All samples were crushed to a <1 mm grain size before being split by rotary splitter to produce a 500 g aliquot, where required, duplicate samples were also split during this stage. The 500 g aliquots were split and combined (homogenised) using a rotary splitter to separate the 150 g sample which was further processed for analysis. Each 150 g sample was then further milled until 97% of the sample passed through a 0.075 mm sieve. A 2 g aliquot was taken from the pulverised material for digestion and assay. 5.8% of all samples were split in duplicate to verify representivity. Crush duplicates (<1 mm material) were taken for the DD holes and a combination of field duplicates (66%) and crush duplicates (33%) collected from the RC holes duplicate samples.
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.	ISCOR Historical assay work (tin only) was performed using an x-ray fluorescence (XRF). No information regarding historical quality assurance/quality control (QAQC) or laboratory testwork was available for historical samples. Andrada 2018 to 2019 The primary assay laboratory (UIS Labs, Pretoria, South Africa) reported tin, tantalum and niobium assays by lithium borate fusion with nitric acid dissolution and ICP-MS (inductively coupled plasma-mass spectrometry) finish, and lithium by multi-acid high pressure microwave digestion with ICP-MS finish. These methods are considered total dissolution methods for the elements listed and appropriate for the elements of interest The umpire laboratory (ALS Chemex, Vancouver) used method ME-MS89L (sodium peroxide fusion with an ICP-MS finish) to report all elements of interest - this is considered an appropriate total dissolution technique for all reported elements. Two different certified reference material (CRM) standards were created from bulk samples acquired from the deposit to ensure the CRMs were matrix matched.  One CRM remained as it was processed to represent the average expected grade of the deposit (AMIS 0629) the other CRM (AMIS 0631) was seeded with additional cassiterite, sourced from artisanal processing within the Uis mine area; this resulted in the certification of a higher grade standard to ensure accuracy remains for samples above average.

 

Criteria	JORC Code explanation	Commentary
		Standards comprised 5% of the assay data and were inserted at set intervals. Blank samples were also inserted in a ratio of 20:1 so ensure clean lab practices. In addition, the analytical laboratory inserted their own duplicates and blanks.  A further 20% of the samples were transported to a second independent laboratory for analysis as an additional verification process of the initial results. Acceptable levels of accuracy and precision have been achieved and the results are considered acceptable for the estimation of Mineral Resources. Some remedial work was undertaken to re-certify some of the custom-made CRMs produced by Andrada and commercially certified by AMIS due to consistent high bias issues noted at the primary laboratory (both as blind and known CRMs) and the umpire laboratory which have been acknowledged by the CRM manufacturer. This has since been resolved and all CRM certificates re-issued. 2022 The primary assay laboratory (UIS Labs, Pretoria, South Africa) reported tin, tantalum and niobium assays by lithium borate fusion with nitric acid dissolution and ICP-MS finish, and lithium by multi-acid high pressure microwave digestion with ICP-MS finish. These methods are considered total dissolution methods for the elements listed and appropriate for the elements of interest. The umpire laboratory (SGS, Johannesburg) used methods GE_ICP90A50 and GE_IMS90A50 (sodium peroxide fusion with an ICP-MS finish) to report a 46-element suite including tin, tantalum and lithium - this is considered an appropriate total dissolution technique for all reported elements. Two different CRM standards were created from bulk samples acquired from the deposit to ensure the CRMs were matrix matched representing the average expected grade of the deposit (AMIS 0629) the other CRM (AMIS 0631) was seeded with additional cassiterite as a higher grade tin standard to ensure accuracy remains for samples above average. Standards comprised 5% of the assay data and were inserted at set intervals. Blank samples, comprising a silica pulp sourced from AMIS (AMIS 0577), were also inserted in a ratio of 20:1 so ensure clean lab practices. In addition, the analytical laboratory inserted their own duplicates and blanks.  A further 415 samples (11%) of the samples were transported to the second independent laboratory (i.e. Intertek) for analysis as an additional verification process of the initial results.
Verification of sampling and assaying	The verification of significant intersections by either independent or alternative company personnel.	Two site visits were conducted during the drill programmes completed to date by the independent Competent Persons to verify the existence and intersections of the drilled core. The first visit was conducted by Mr Wesson in October 2018 and the second by Mr Cronwright in June 2022. Several holes drilled in 2018-2019 were closely spaced to historical data to test intersections of the deposit spatially; however, due to the heterogeneity of the tin mineralisation in the pegmatite intrusion, the twinned holes were not expected to be identical in terms of mineralisation or petrology. Mineralised widths in twinned holes were found to be consistent with the original drillhole.

 

Criteria	JORC Code explanation	Commentary
		No adjustments were made to the primary assay data. Andrada's in-house database was used for data validation and storage and data was also validated on import into Leapfrog which was used for the geological modelling. No verification sampling was conducted during the 2022 drilling program.
Location of data points	Accuracy and quality of surveys used to locate drillholes (collar and downhole surveys), trenches, mine workings and other locations used in Mineral Resource estimation.	ISCOR Many of the historical collars have been identified in the field by Andrada and surveyed using a differential GPS. These positions are consistent with positions recorded in the ISCOR dataset providing confidence in the historical data. Andrada All collar positions of drillholes were surveyed onto the ground by an independent surveyor using a differential GPS (3 cm accuracy for X and Y and 8 cm accuracy for Z). The coordinate system used throughout was Universal Transverse Mercator (UTM) 33S, WGS84. Upon finalisation of the program, the drill collars were surveyed by the surveyor employed by Andrada. In some areas, the collar location was slightly altered due to access and safety concerns. Downhole surveys were conducted using an EZTrak™ and accelerometer survey tool. Multiple downhole surveys were taken for each hole and the tools calibration standards were checked and up to date. Downhole readings were taken every 9 m. The typical other data such as magnetic and gravitation readings were also recorded for each station within the hole for the downhole survey to do quality checks. For example, stations where magnetic readings varied from the average across the hole by more than 200 nT were highlighted and double checked. Readings were removed if data were found to be inaccurate based on typical validation techniques utilised on downhole surveys. WGS 1984 UTM 33S was used for the project coordinate system for collar positions and grids. Drone stereopairs, with a 6.6 cm image resolution and are georeferenced using 18 ground control points, to create digital elevation models of the exploration area for a highly accurate control on the topography
Data spacing and distribution	Data spacing for reporting of Exploration Results.	The 2019 drilling program proposed by CSA Global and completed by Andrada comprised 26 DD holes drilled in six fences, spaced approximately 200 m apart and spanning the main part of the V1/V2 pegmatite. Hole spacing on the fences ranges between 30 m and 70 m for the most part, with a final line of deep holes spaced 200 m from the previous DD hole drilled by Andrada. These DD drillholes supplement the ISCOR drilling which has an average drill density of one hole every 50 m (spaced 25 m along strike) on an irregular grid constrained by access and highwall positions. The current 2021-2022 drilling program executed by Andrada comprised 22 DD holes and 29 RC holes drilled spanning the main part of the V1/V2 pegmatite as infill to the 2019 drilling program resulting in a nominal 60 m drillhole spacing.  The MRE and classification were based on the sufficiency and spacing of the drillholes. For tin, variographic analyses is robust and the resulting estimates have been classified according to estimation precision using ordinary kriging parameters. The downhole semi-variogram has a relatively high nugget variance (about 50%), and a short range of about 5 m, but is well structured.

 

Criteria	JORC Code explanation	Commentary
		Variography for lithium, niobium and tantalum is not robust with the exception of the downhole direction; the primary reason for this is likely to be the data paucity for these three elements. All estimates for these three analytes were classified as Inferred Mineral Resources. Whilst the grade variability is highly nuggety the overall geology, which defines the mineralised pegmatite is continuous over the extent of the model. Drilling spacing is adequate for a high degree of confidence in the mineralised model. Xenoliths of waste within the pegmatite are less continuous and can be defined with a moderate level of confidence. The xenoliths are expected to be limited in extent, supported by observations in the current excavation on site. Sample compositing has not been undertaken at the exploration or sampling stage.
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.	In most cases, the drillholes were drilled vertically. In the instances where the drillhole was angled the orientation of drillholes is perpendicular to the strike of the intrusion/sigmoidal shape of the pegmatite intrusive deposit.  Due to the undulatory nature of the intrusion, the primarily vertical orientation of the drillholes was chosen to reduce bias in any specific orientation.  Orientated drillholes were sited in areas where the attitude of the pegmatite below surface was known with a relatively high level of confidence.
Sample security	The measures taken to ensure sample security.	ISCOR No information was available regarding the sample security of historical samples. Andrada All sampling and sample processing (cutting, tagging, packaging and loading) was conducted within the core shed by qualified geologists or technicians under the supervision of the geologists. Work was carried out according to sample lists prepared by the geologist using the acQuire database software in 2019 and using an in-house database for the 2022 drilling.  Samples were processed individually wherever possible to reduce the chance of sample swapping occurring.  Sample processing in the laboratory was undertaken by trained technical staff and the chain of custody was followed.
Audits or reviews	The results of any audits or reviews of sampling techniques and data.	A representative of ERM, Michael Cronwright, undertook a site visit during the 2022 infill drill program to review the drilling, sampling and QAQC procedures and reported these practices to be acceptable.  Mr Anthony Wesson conducted a site visit in August 2018 during the first phase of drilling by Andrada.  No further audits have been undertaken.

Section 2: Reporting of Exploration Results

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 oaining a licence to operate in the area.	Exploration activities occurred on mining licence (ML) 134, issued to Guinea Fowl Investments Twenty Seven (Pty) Ltd (Guinea Fowl). ML 134 expires in 2028 and is renewable under Namibian Mining Law. The Guinea Fowl company name was changed to Uis Tin Mining Company (UTMC) at the end of 2019.  Andrada, through a Namibian subsidiary, initially controlled 85% of UTMC with the remaining 15% controlled by the Small Miners of Uis (SMU), a not-for-profit company owned by the Namibian government. In August 2024 an agreement was reached between Andrada and the SMU which resulted in Andrada acquiring 100% of the mining license ML 134. The area investigated in this report is classified as state land, as a result no compensation agreement is required prior to commencement of operations. The deposit lies within the historical Uis Tin Mine licence area. This area was previously extensively mined and no rehabilitation was carried out prior to closure. Due to this existing impact the area is not considered environmentally sensitive. Andrada has also been issued with a valid Environmental Clearance Certificate which allows mining and exploration activities to be conducted.
Exploration done by other parties	Acknowledgment and appraisal of exploration by other parties.	Exploration was carried out by ISCOR between the early 1960s and 1989. The resulted in a reserve and mine plan being compiled by SRK in 1989, a few months before mining operations ceased.  A significant portion of the exploration data was obtained and digitised by Andrada. Relevant information has been validated by current exploration activities and utilised in this report. As the ISCOR drilling was used to inform the tin estimate, it was necessary to evaluate if they were appropriate to use for the MRE. Some basic statistical checks, which included simple histograms and cumulative frequency plots, were augmented by a comparison of the downhole experimental semivariograms. All parameters, such as means and variances of the composited data, were considered of similar tenor and the similarity of the semi-variogram parameters further supported using the two datasets jointly for the MRE. As further validation, a number of twinned drillholes were drilled adjacent to ISCOR drillholes as part of Andrada's 2019 program. Unsurprisingly, because of the nuggety nature of the cassiterite (tin) distribution, the correlation between samples from the twinned holes varied between good and not correlated although, in general, the widths of the mineralised intercepts showed reasonable agreement. This was not considered to be a risk, as when comparing the grades of consecutive downhole 2 m composites, high variability was apparent as indicated by the semi-variogram.
Geology	Deposit type, geological setting and style of mineralisation.	The deposit is hosted within the Damara Orogen, a typical pan African-aged (750-440 Ma) orogenic belt which represents the assembly of Gondwana during which the Congo, Rio De la Plata and Kalahari cratons collided within a triple point located in Swakopmund, Namibia. Orogenesis produced voluminous quantities of granitic magmatism during the syn-tectonic phases of collision. This was followed by a pegmatitic phase of magmatism in the post-tectonic environment, populating the Damara Orogen with numerous pegmatitic intrusions

 

Criteria	JORC Code explanation	Commentary
		The V1 and V2 pegmatites are magmatic intrusive bodies with sigmoidal shapes in plan. They formed when a low viscosity and undercooled magma crystallised to form a pegmatite. Various alteration types are present and related to the emplacement, crystallisation and cooling of the pegmatite The pegmatites strike to the northeast and dip to the northwest at between 30° and 50°. The mineralisation style is primarily magmatic although some may be alteration related. Primary cassiterite crystallised during the late stages of the magmatic phases of the pegmatites crystallisation history when sufficient magmatic fractionation has increased the abundance of Li and Sn to insoluble levels. The lithium mineralisation crystalised as petalite during this time as well along with the bulk of the other silicate minerals like feldspar, quartz and muscovite.  The pegmatite then exsolved an aqueous fluid when water and flux saturation was reached. Elements such as tin, tantalum, lithium, boron, rubidium and niobium segregated into this fluid. This fluid then resulted in significant amounts of resorption and replacement of magmatic assemblages in places to form a quartz-muscovite assemblage known as a greisen. Simultaneous and abundant cassiterite crystallisation occurred during this alteration phase.
Drillhole information	A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drillholes: x Easting and northing of the drillhole collar x Elevation or RL (Reduced Level - elevation above sea level in metres) of the drillhole collar x Dip and azimuth of the hole x Downhole length and interception depth x 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.	See table in this report and announcements for collar and survey data for newly acquired drillholes used in this Mineral Resource update. The subject of this JORC report is an MRE and exploration results are not being reported. The relevance of the individual characteristics of each drillhole is superseded by the interpretation that is created using all the drillholes. The quality of the data used, and the assumptions around their use, are documented here. All relevant information has been reported in press releases by Andrada, and available on their website (https://andradamining.com/media/rns/) on the following dates: 20 May 2019, 10 June 2019 and 26 June 2019, 16 September 2019 (MRE), 11 October 2021, 8 June 2022, 20 July 2022, 11 October 2022, 22 November 2022, 5 December 2022, 31 January 2023, 2 February 2023, 6 February 2023 (MRE update) and 30 March 2023.
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.	Not relevant; Exploration Results are not being reported here. Mineral Resources are being disclosed (see Section 3).

 

Criteria	JORC Code explanation	Commentary
	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 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 drillhole angle is known, its nature should be reported. If it is not known and only the downhole lengths are reported, there should be a clear statement to this effect (e.g. 'downhole length, true width not known').	Not relevant; Exploration Results are not being reported here. Mineral Resources are being disclosed (see Section 3).
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 drillhole collar locations and appropriate sectional views.	Relevant maps and diagrams are included in the body of the report, to which this report applies.
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.	Not relevant; Exploration Results are not being reported here. Mineral Resources are being disclosed (see Section 3).
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.	Andrada carried out extensive mapping of the V1/V2 pegmatite which has been used to constrain the geological model. The extensive historical dataset from ISCOR was statistically validated and used to support the MRE.
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).	Processing testwork related to the petalite-hosted lithium mineralisation is ongoing. Other recommendations have been made in Section 11 of this report.
Criteria	JORC Code explanation	Commentary
	Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.

Section 3: Estimation and Reporting of Mineral Resources

Criteria	JORC Code explanation	Commentary
Database integrity	Measures taken to ensure that data has not been corrupted by (e.g. transcription or keying errors) between its initial collection and its use for Mineral Resource estimation purposes. Data validation procedures used.	The information was captured into an auditable sequel database which was developed with the assistance of Andrada. The entries were checked and verified by a database administrator to ensure accuracy.  Data used in the MRE (Section 3) was sourced from an export from the database system into csv format for use in Isatis. Validation checks were carried out on the data imported which included checks for overlapping intervals, missing survey data, missing lithological data and missing collars.
Site visits	Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken, indicate why this is the case.	A site visit was undertaken by the Competent Person, Anthony Wesson, in October 2018, at which time Andrada was undertaking infill and extensional drilling. The core logging procedure was explained, and logging was observed against these procedures. As part of the site visit a sampling and assaying QAQC program was discussed with and agreed upon with Andrada representatives. A visit to the UIS laboratory in Midrand was undertaken to discuss the requirements of the QAQC program with laboratory staff. The most recent site visit was undertaken by Michael Cronwright in June 2022 during Andrada's infill RC and DD drilling program on the V1/V2 pegmatites. The core logging and sampling procedure was explained, and logging was observed. Some checks on the logging and sampling intervals were conducted as well as confirmation of collar locations in the field.
Geological interpretation	Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology.	There is high confidence in the interpretation at surface, due to close spaced drilling supported by surface mapping. Confidence reduces at depth due to drill spacing. A 3D geological model has been constructed using drillhole logging and surface mapping. Alternate interpretations are limited close to surface, apparent steepening of dip at depth is supported by limited drilling, further drilling may result in a change of interpretation at depth. Apparent reduction in xenoliths with depth may be a function of drill spacing.  The pegmatite vein has been used as a constraint to mineralisation. Geological grade and continuity are controlled by the presence of pegmatite, there is no zonation  evident in the geology, supported by a single grade population for tin. The presence of diluting xenoliths, which occur as discreet units within the pegmatite, is difficult to estimate and model. They occur at random and are not continuous hole to hole. The effect of these xenoliths is expected to be minor from in pit and surface observations.

 

Criteria	JORC Code explanation	Commentary
		Geological wireframes were composed from drillhole logging, the wireframes were utilised to code the drillholes and to generate a proportional block model
Dimensions	The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource.	The V1 and V2 pegmatites are exposed in the V1/V2 pit and are two of the largest pegmatites on ML 134. The V1 pegmatite is exposed in the northeast of the pit, and the V2 in the northwest and the pegmatites merge within the pit. The V1 pegmatite extends strikes northeast-southwest for approximately 600 m, dipping at 50° to the northwest, with an average thickness of about 25 m. In the western portion of the pit, the V1 Pegmatite merges with the V2 Pegmatite and the pegmatite dips at 30-40° to the northwest and west-northwest, discordant to the country-rock schist which dips to the southeast.  The V2 Pegmatite is around 10 m thick in the east, but thickens to >40 m towards the southwest, along the northwestern highwall of the pit where it merges with the V1 pegmatite, and dips into the northwest highwall. It is exposed along the entire northwest pit face and is traceable within the pit and for at least 650 m on surface to the southwest or south-southwest. Together, the V1 and V2 pegmatites extend along a northeast-southwest strike distance of over approximately 1.2 km, and consistently reach thicknesses of over 20 m.
Estimation and modelling techniques	The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen, include a description of computer software and parameters used. The availability of check estimates, previous estimates and/or mine production records and whether the MRE takes appropriate account of such data. The assumptions made regarding recovery of byproducts. Estimation of deleterious elements or other non-grade variables of economic significance (e.g. sulphur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation was used to control the resource estimates.	An in-situ MRE was undertaken for the two pegmatite bodies referred to as the V1 and V2 pegmatites. Raw data were loaded and used to build the geological model; part of the process included coding the drillholes by geology/lithology then exporting those coded data from Datamine software to Isatis software for geostatistical analyses. Once the data were loaded into Isatis and prior to composting, the raw data statistics were generated by geological domain and compared to the input data file statistics on the same basis. After compositing to 2 m, the data statistics were compared to the raw data to confirm that the compositing procedure generated reliable results and that residuals were treated as follows: x If the analysed length of the last core at the end of the line was smaller than 50% of the composite length, it was ignored  x If the analysed length of the last core was greater than 50% of the composite length, it was kept as it is. Correlation between all variables was low with no pair having a correlation greater than 0.4. The MRE was carried out for tin, lithium, niobium, rubidium and tantalum by ordinary kriging into a block model of 20 m x 20 m x 10 m (X x Y x Z). The block size was selected after sensitivity analyses were undertaken on a range of block sizes with an emphasis on the grade/tonnage sensitivity around the expected cut-off grade. This is an operating mine, and the block dimensions are appropriate given the size of the mining fleet and the scale of operations.  The shape of the distributions of all five elements as described by their coefficient of variations (CVs) is low (0.3 to 0.6), nevertheless, top cutting was applied to tin (1.0% Sn) for both the V1 and V2 pegmatites but made minimal difference to the average-declustered grade.

 

Criteria	JORC Code explanation	Commentary
	Discussion of basis for using or not using grade cutting or capping. The process of validation, the checking process used, the comparison of model data to drillhole data, and use of reconciliation data if available.	The quality of the experimental variography is element dependent and ranges from poor to moderate. Although tin has significantly more 2 m composites for modelling than the other elements, a short scale, 50 m, first structure accounting for between 70% and 80% of the total variance, generates, by design, smoothed estimates appropriate for a global estimate and an operation which is non-selective and mines the entire Mineral Resource model. Estimation of the five elements was carried out in three passes, each time extending the search ellipse and decreasing the minimum number of samples to be used for estimation. The first pass search ellipse had the same dimensions as the semi-variogram ranges. Subsequent estimation passes were extended, and the minimum number of samples used was reduced until in the third pass the minimum was set to four samples. No attempt was made to fill all blocks with estimates for any or all elements as this would have resulted in unwanted extrapolation and poor-quality estimates based on the assessment of the slope of regression (SOR) metric and distance from the nearest samples. Estimation was constrained to 50 m from the nearest samples. Estimates were validated by comparing graphical sections showing block grades vs composite grades, domain averages with de-clustered means and by trend (swath) plots. The previous MRE was carried out by ERM (as CSA Global) in September 2019 when only tin material was classified as Measured, Indicated and Inferred, and all tantalum and Li2O Mineral Resources were classified as Inferred. Estimated grades for tin, tantalum and Li2O are similar between the two models, but tonnages have increased due to infill and extensional drilling. No previous production records are available for reconciliation with the model. The estimate has been reported below the current mined surface, with depleted material being removed from the model.
Moisture	Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content.	Tonnages have been estimated on a dry, in-situ basis with no allowance for porosity although given the crystalline and unweathered nature of the pegmatite, porosity is considered negligible.
Cut-off parameters	The basis of the adopted cut-off grade(s) or quality parameters applied.	The entire Mineral Resource will be consumed using the current parameters tabulated below.
Mining factors or assumptions	Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made.	It has been assumed that the deposit is amenable to open cut mining methods and are potentially economic to exploit to the depths indicated by the pit shell optimisation exercise. An in-situ Mineral Resource model was generated using a block size of 20 m x 20 m x 10 m without dilution factors applied. Mining will be undertaken by truck (80-tonne) and shovel. A bulk mining scenario has been assumed, and lithium and tantalum have been considered as byproducts and have not been used to inform revenue.  A pit shell at a revenue factor (RF) of 1.0 was created in Datamine Studio NPVSTM  software to support the reporting of Mineral Resources. The parameters used to undertake the pit shell optimisation are provided below and parameters supplied by Andrada were reviewed for reasonableness by ERM:
			Parameter	Unit	Value	Comments and source

 

Criteria	JORC Code explanation	Commentary
		Base currency	US$
		Resource categories to be optimised		Measured + Indicated + Inferred
		Commodity	Li and Sn
		Mining Waste mining cost (fixed cost) US$/t 1.3 RPEEE_parameters.xls Ore mining cost (fixed cost) US$/t 4.3 RPEEE_parameters.xlsx Mining recovery % 95 RPEEE_parameters.xlsx Mining dilution % 5 RPEEE_parameters.xlsx Rehabilitation US$/t 0.07 Overall slope angle ° 55 RPEEE_parameters.xlsx Petalite LI unit in block model ppm - Li % % Li/10000 Li2O % % (Li ppm/10000)*2.153 Petalite concentrate price US$/conc t 1500 Petalite payablity % 100 Royalty % 3 Petalite processing recovery % 45 Petalite concentrate grade % 4 Petalite processing cost  US$/t ore 3.5 Petalite logistic cost US$/t conc 155 Petalite sales commission US$/t conc - Petalite treatment charge and penalties US$/t conc - Overheads US$/t conc - Sn
		Sn price	US$/t	25,500
		Sn concentrate price	US$/conc t	15,300
		Royalty	%	3
		Sn processing recovery	%	80
		Sn concentrate grade	%	60	76% SnO2 conc grade
		Sn processing cost	US$/t ore	3.75
		Sn logistic cost	US$/t conc	155
		Sn sales commission	US$/t conc	-
		Sn treatment charge and penalties	US$/t conc	985
		Overheads	US$/t conc	1250

 

Criteria	JORC Code explanation	Commentary
Metallurgical factors or assumptions	The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made.	Historical recoveries reported by ISCOR and internal Andrada testwork support the recovery of 80% Sn and the production of a 60% Sn concentrate which have been used to generate the pit shell from which Mineral Resources have been reported. The resulting concentrates include up to 1.5% Ta content which can be separated magnetically, although the economic viability of doing this remains to be ascertained. Lithium mineralogy, based on available xray diffraction (XRD) data and some test work that has been completed and reported, appears to be petalite dominated which will aid the potential production of a lithium concentrate.
Environmental factors or assumptions	Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered, this should be reported with an explanation of the environmental assumptions made.	ERM has not undertaken a review of the environmental factors that may be associated with the project and these will be covered in detail in subsequent phases of study work. Andrada hold a valid Mining Permit with contingent environmental responsibilities that will need to be adhered to in order to advance the project.
Bulk density	Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc.), moisture and differences between rock and alteration zones within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials.	Dry bulk density has been based on specific gravity of samples, determined by commercial pycnometric methods. This is considered appropriate given the competent, crystalline nature of the pegmatite. For every sample collected by Andrada, a SG was measured using the pycnometer method which is considered equivalent to the dry bulk density. The range of dry bulk densities for the pegmatites is low (2.55 t/m3 to 2.83 t/m3) with an average value of 2.65 t/m3. The average density value of 2.65 was used in the block model.

 

Criteria	JORC Code explanation	Commentary
Classification	The basis for the classification of the Mineral Resources into varying confidence categories. Whether appropriate account has been taken of all relevant factors (i.e. relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). Whether the result appropriately reflects the Competent Person's view of the deposit.	In the first instance, classification was assigned based on geological interpretation of the V1/V2 orebodies and the ordinary kriging output metrics, the SOR and kriging efficiency (KE). The SOR generates values between zero and unity and as with most regression analyses, unity means perfect correlation and the lower the value, the poorer the estimate is. Another useful measure of estimation confidence is the KE; it is a measure of the ratio of the estimation variance to that of the block variance and ranges from negative values to unity; it is a measure of estimation smoothing, a value of zero or negative values means that the estimation variance is equal to or greater than the block variance and a KE of zero is equivalent to an SOR of 0.5. When the estimation variance is equal to the block variance, it is more efficient to apply the mean of the domain, if it can be precisely measured, to those blocks with negative KE values.  No attempt was made to fill all blocks within the geological/estimation domains with grade estimates. It is the norm, that when working with multiple elements, the element which generates the lowest confidence estimates is used to guide classification. For V1 it is clearly tin, and in V2 it is lithium followed by tin, and for consistency, the tin SOR was used to define the classification system. Any SOR >0.5 means that the estimate of a block is better than assigning the global average to the block. The initial classification assignment was as follows: x Measured Mineral Resources, a SOR >0.8 was required x Indicated Mineral Resources, a SOR >0.6 was required. All other Mineral Resources not already classified and constrained to blocks not more than 50 m from at least four samples, were classified as Inferred Mineral Resources. However, it was found that Measured and Indicated Mineral Resources were interspersed, therefore boundaries between the two categories were imposed guided by the SOR and distances from informing samples. Only blocks which have all elements estimated (tin, lithium, niobium, rubidium, tantalum), have been classified and reported in the Mineral Resources table.
Audits or reviews	The results of any audits or reviews of MREs.	Internal audits and peer review were completed by ERM which verified and considered the technical inputs, methodology, parameters and results of the estimate.  No external audits have been undertaken.
Discussion of relative accuracy/ confidence	Where appropriate, a statement of the relative accuracy and confidence level in the MRE using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate.	As this is an operating mine, reconciliation between the mined and modelled Sn grade is reported to be within an acceptable range (±15%). No reconciliation information for Li is available yet. This is a global estimate reported without the application of a cut-off grade as the entire Mineral Resource is within the optimised pit shell. Estimates are intentionally smoothed as no cut-off has been applied and the tin semi-variograms have a short-range high variance component. Tin and lithium are the main economic drivers of the Uis Mine operation. The following neighbourhood parameters were considered for each of the elements: x The initial search ellipse was set to the semi-variogram ranges.
Criteria	JORC Code explanation	Commentary
	The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available.	x The minimum and maximum numbers of samples were chosen so that a consistently good SOR and KE could be achieved. The quality of these two parameters is largely a function of the number of samples used and the semi-semi-variogram models. The sum of positive weights was reviewed and by default the sum of the negative weights. A small percentage of negative weights (< 2%) is acceptable because that gives an indication that the search distances have been extended sufficiently far enough.  The importance of the weight of the mean (WOM) should not be underestimated. A high WOM implies that the local mean grade is well known and increases when a restricted estimation neighbourhood is applied. Ideally, the WOM should be around 10% to 15%. The ranges chosen for the first pass were set to the semi-variogram ranges so that the constraint is the number of samples, not the ranges. The second pass usually entails dropping the minimum number of samples while extending the search ellipse. The third pass can extend beyond the ranges and the search ellipse from the previous two passes and may include a further reduction to the minima. Some constraints were placed on the number of samples used from a drillhole to ensure that more than one drillhole was accessed. Restrictions to the maximum distance without a sample were imposed to constrain estimates, so that extrapolation was kept to reasonable distances less than 50 m. Tin in V2 was estimated with a restricted neighbourhood to compare the estimates with that of the MRE to assess the similarities/differences. As was expected, the local biases were evident, but the global estimate was identical considering that no cut-off was applied to the Mineral Resource model.

 

 

 

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