REG - Cobra Resources PLC - Favourable Boland Metallurgical Results
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RNS Number : 7296R Cobra Resources PLC 21 July 2025
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21 July 2025
Cobra Resources plc
("Cobra" or the "Company")
Favourable Boland Metallurgical Results
Demonstrate a pathway to optimal in situ recovery rare earth production
Cobra (https://cobraplc.com/) (LSE: COBR)
(https://www.londonstockexchange.com/stock/COBR/cobra-resources-plc/company-page)
, the mineral exploration and development company advancing a potentially
world-class ionic Rare Earth Element ("REEs") discovery at its Boland Project
("Boland") in South Australia, is pleased to announce initial results from
flowsheet optimisation testing being carried out by the Australian Nuclear
Scientific Technology Organisation ("ANSTO").
Cobra has commenced a scaled metallurgical study aimed at optimising its
existing flowsheet to maximise recoveries and product value. Completed
diagnostic testing from six bulk samples sourced from recently completed sonic
drillholes from across the Boland mineralisation footprint have delivered
valuable results supporting high recoveries with low-cost inputs and provided
a geometallurgical pathway to characterise ore, enhance exploration targeting,
improve resource characterisation and support future mine optimisation.
Highlights
Diagnostic leaches performed on six bulk sample composites delivered results
including:
· Exceptional recoveries up to 89% Dy+Tb and 93% Nd+Pr using ammonium
sulphate ("AMSUL") at pH2.5 with low acid consumption of 6.9 kg/t
· Very high recoveries up to 84% Dy+Tb and 86% Nd+Pr using ammonium
sulphate ("AMSUL") at pH3 with very low acid consumption of 2.6 kg/t
· High recoveries up to 83% Dy+Tb and 84% Nd+Pr using magnesium
sulphate ("MAGSUL") at pH3 with very low acid consumption of 2.7 kg/t
· High recoveries from the two different lixiviants trialled, reducing
exposure to price volatility in securing critical reagents
· All tests consumed less than 8 kg/t of acid, providing some of the
lowest cost recoveries of any Australian clay hosted rare earth projects(1)
· Testing at stronger acidities of pH 2.5 showed slight increases in
recoveries without increasing acid consumption or impacting the ratio of
impurities
· Results show a strong positive correlation between the dysprosium and
terbium proportion and rate of recovery providing a geometallurgical marker to
model recoveries and to ultimately inform future economics
· Further tests are being completed aimed at removing low-value and
relatively abundant cerium and lanthanum through an in situ recovery ("ISR")
'preconditioning' phase, designed to increase the overall value of a Mixed
Rare Earth Carbonate ("MREC")
· Bulk ~50kg composite ISR column being prepared to produce bulk liquor
for further flowsheet optimisation and MREC production for offtake testing
Rupert Verco, Managing Director of Cobra, commented:
"Our metallurgical strategy is relatively simple: maximise the value of
dysprosium and terbium within our product. We aim to achieve this by
leveraging the considerable advantages that ISR allows for minimal cost
flowsheet modifications. These initial results demonstrate favourable
mineralisation characteristics that will further optimise our flowsheet and
ultimately enable the commercialisation of a valuable product.
It is great to be able to identify such a significant geometallurgical
indicator at such an early stage. In ionic rare earth systems, recoveries can
be highly variable, and it is therefore difficult to apply realistic recovery
factors to mining scenarios.
Results generated from this testing will not only assist in forward
exploration targeting, but they will also support economic grade valuation
within a near term resource estimate and support future economic analysis
enabling higher margin ore to be prioritised in production.
We expect results for our regional re-analysis programme soon, and learnings
from these metallurgical results will greatly assist in follow-up drill
targeting."
New ANSTO Metallurgical Leach Results
In 2024, Cobra successfully produced a quality Mixed Rare Earth Carbonate
("MREC") with a grade of 62.4% TREO and relatively low in impurities from a
bench scale ISR study that achieved a magnet rare earth ("MREO") recovery of
68% from a high-grade sample of 0.44% TREO
The metallurgical programme currently underway at ANSTO laboratories is
designed to maximise the Dy+Tb within the produced MREC whilst minimising
recovery costs, by evaluating:
· Alternative, cost efficient lixiviants
· Acid strength (pH)
· Leaching residence times
· Testing optimum lixiviant conditions to maximise economics of a
scaled bench scale ISR study:
a. Define the optimum pH, to manage impurities and acid consumption
b. Determine optionality subject to market availability of acid
· Reduction of low value REEs Cerium and Lanthanum by:
a. Implementing a preconditioning removal phase of ISR at pH 4.5-5.0
b. Flowsheet step removal through membrane oxidation
· Optimise impurity removal by:
a. Optimising pH levels used for impurity precipitation
b. Trialling selective membranes
c. Management of radionuclides
· Produce MREC through an optimised flowsheet to:
a. Determine the level of radionuclides
b. Supply samples to offtakers for testing
· Finalise a flowsheet for financial analysis
Results presented within this announcement reflect step one of the current
metallurgical programme, highlighting several important factors that
contribute favourably to project economics:
· REE recoveries correlate with Dy+Tb proportion of total TREO. Overall
TREO grade, whilst important, does not impact the rate of recovery; however,
as the ratio of valuable Dy+Tb increases as a percentage of the TREO,
metallurgical recovery rates increase. This benefits:
o Exploration targeting - where higher proportions of Dy+Tb can be flagged
from historic drillhole re-analysis for followup drilling
o Resource classification - provides a geometallurgical factor from which
economic cut-over grades can be evaluated against market pricing
o Mine planning - Define future wellfield sequencing to target ore with the
higher Dy+Tb ratios and the most economic recoveries*
Figure 1: Relationship between Dy+Tb proportion and increasing recoveries
* Further assessment of this relationship shall be tested by increasing the
dataset
· Samples with the lowest Dy+Tb proportion yielded the lowest
recoveries. This supports heavy rare earth enrichment being a consequence of
the relative abundance of, and the absorption capacity of fine organic "clay"
within the sandy matrix of the Pidinga Formation
o The Commonwealth Scientific and Industry Research Organisation ("CSIRO")
is currently evaluating the physical properties of the material hosting
absorbed REEs
· Robust recoveries were achieved with low acid consumption and low
impurities. An increase in acidity from pH3 to pH2.5 increased the recovery of
Dysprosium by almost 6% with a negligible increase in acid consumption and
without impacting impurity ratios
Table 1. Average key metallurgical metrics from the six bulk composite samples
pH 3 pH 3 pH 2.5
0.5 M (NH4)2SO4 0.5 M MgSO4 0.5 M (NH4)2SO4
Est Acid consumption kg/t 4.9 5.3 5.1
Average Recovery Tb % 48.1% 47.1% 51.7%
Average Recovery Dy % 46.5% 46.1% 52.4%
Average Recovery Nd % 39.0% 37.6% 43.1%
Average Recovery Pr % 36.4% 34.9% 39.3%
Averate TREO:Al ratio 6.60 6.60 7.20
Figure 2: Statistical ranges of recoveries using MAGSUL and AMSUL as
lixiviant, yielding similar recoveries across six bulk samples
Figure 3: Statistical ranges of key economic factors of rare earth metallurgy
being estimated acid consumption and TREO/Al impurity ratio
Boland Project
Cobra's unique and highly scalable Boland discovery is a strategically
advantageous ionic rare earth discovery where high grades of valuable heavy
and magnet rare earths occur concentrated in a permeable horizon confined by
impermeable clays. Bench scale ISR testing has confirmed that mineralisation
is amenable to ISR mining. ISR has been used successfully for decades within
geologically similar systems to recover uranium within South Australia.
Results of this metallurgical test work support that, with minor optimisation,
ISR techniques should enable non-invasive and low-cost production of critical
REEs from Cobra's Boland discovery.
Follow this link to watch a short video of CEO Rupert Verco explaining the
results released in this announcement:
https://investors.cobraplc.com/link/Pbn2oP
(https://investors.cobraplc.com/link/Pbn2oP)
Further information relating to Boland and these drilling results are
presented in the appendices.
Enquiries:
Cobra Resources plc via Vigo Consulting
Rupert Verco (Australia) +44 (0)20 7390 0234
Dan Maling (UK)
SI Capital Limited (Joint Broker) +44 (0)1483 413 500
Nick Emerson
Sam Lomanto
Global Investment Strategy (Joint Broker) +44 (0)20 7048 9437
James Sheehan james.sheehan@gisukltd.com
Vigo Consulting (Financial Public Relations) +44 (0)20 7390 0234
Ben Simons cobra@vigoconsulting.com
Kendall Hill
The person who arranged for the release of this announcement was Rupert Verco,
Managing Director of the Company.
Information in this announcement relates to exploration results that have been
reported in the following announcements:
· Wudinna Project Update: "Boland Aircore Drill Results", dated 25(th)
February 2025
· Wudinna Project Update: "Further Positive Metallurgy Results from
Boland Project", dated 16 December 2024
· Wudinna Project Update: "2(nd) Bench Scale ISR Study & £1.7M
Placing", dated 26 November 2024
· Wudinna Project Update: "ISR Bench Scale Study Completion", dated 4
November 2024
· Wudinna Project Update: "ISR bench scale study delivers exceptional
results", dated 1 October 2024
· Wudinna Project Update: "ISR bench scale update - Exceptionally high
recoveries with low impurities and low acid consumption; on path to disrupt
global supply
of heavy rare earths", dated 28 August 2024
· Wudinna Project Update: "ISR bench scale update -Further
metallurgical success at world leading ISR rare earth project", dated 11 July
2024
· Wudinna Project Update: "ISR bench scale update - Exceptional head
grades revealed", dated 18 June 2024
· Wudinna Project Update: "Re-Assay Results Confirm High Grades Over
Exceptional Scale at Boland", dated 26 April 2024
Competent Persons Statement
The information in this report that relates to metallurgical results is based
on information compiled by Cobra Resources and reviewed by Mr James Davidson
who is Principal at Rendement Consulting and a Fellow of the Australian
Institute of Mining and Metallurgy (F AusIMM). Mr Davidson has sufficient
experience that is relevant to the metallurgical testing which was undertaken
to qualify as a Competent Person as defined in the 2012 edition of the
"Australasian Code for Reporting of Exploration Results, Mineral Resources and
Ore Reserves". Mr Davidson consents to the inclusion in this report of the
matters based on this information in the form and context in which it appears.
Information in this announcement has been assessed by Mr Rupert Verco, a
Fellow of the Australasian Institute of Mining and Metallurgy. Mr Verco is an
employee of Cobra and has more than 17 years' industry experience which is
relevant to the style of mineralisation, deposit type, and activity which he
is undertaking to qualify as a Competent Person as defined in the 2012 Edition
of the Australasian Code for Reporting Exploration Results, Mineral Resources
and Ore Reserves of JORC. This includes 13 years of Mining, Resource
Estimation and Exploration.
About Cobra
In 2023, Cobra discovered a rare earth deposit with the potential to re-define
the cost of rare earth production. The highly scalable Boland ionic rare earth
discovery at Cobra's Wudinna Project in South Australia's Gawler Craton is
Australia's only rare earth project amenable for in situ recovery (ISR) mining
- a low cost, low disturbance method enabling bottom quartile recovery costs
without any need for excavation or ground disturbance. Cobra is focused on
de-risking the investment value of the discovery by proving ISR as the
preferred mining method and testing the scale of the mineralisation footprint
through drilling.
Cobra's Wudinna tenements also contain extensive orogenic gold mineralisation,
including a 279,000 Oz gold JORC Mineral Resource Estimate, characterised by
low levels of over-burden, amenable to open pit mining.
Regional map showing Cobra's tenements in the heart of the Gawler Craton
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Engage with us by asking questions, watching video summaries and seeing what
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Appendix 1: Background information - the Boland Project and ISR
· The Boland Project was discovered by Cobra in 2023. Mineralisation is
ionically bound to clays and organics within palaeochannel sands within the
Narlaby Palaeochannel
· Mineralisation occurs within a permeable sand within an aquifer that
is saltier than sea water and is confined by impermeable clays
· ISR is executed through engineered drillhole arrays that allow the
injection of mildly acidic ammonium or magnesium sulphate lixiviants, using
the confining nature of the geology to direct and lower the acidity of the
orebody. This low-cost process enables mines to operate profitably at lower
grades and lower rates of recovery
· Once REEs are mobile in solution in groundwater, it is also possible,
from an engineering standpoint, to recover the solution to surface via
extraction drillholes, without any need for excavation or ground disturbance
· The capital costs of ISR mining are low as they involve no material
movements and do not require traditional infrastructure to process ore - i.e.
metals are recovered in solution
· Ionic mineralisation is highly desirable owing to its high weighting
of valuable HREOs and the cost-effective method in which REEs can be desorbed
· Ionic REE mineralisation in China is mined in an in-situ manner that
relies on gravity to permeate mineralisation. The style of ISR process is
unconfined and cannot be controlled, increasing the risk for environmental
degradation. This low-cost process has enabled China to dominate mine supply
of HREOs, supplying over 90% globally
· Confined aquifer ISR is successfully executed globally within the
uranium industry, accounting for more than 60% of the world's uranium
production. This style of ISR has temporary ground disturbance, and the ground
waters are regenerated over time
· Cobra is aiming to demonstrate the economic and environmental
benefits of recovering ionic HREOs through the more environmentally aquifer
controlled ISR - a world first for rare earths
Figure 4: Comparison between the Chinese and the proposed Boland process for
ISR mining of REEs
Appendix 2: Metallurgical sample information
Drillhole From (m) To (m) ID Pr6O11 Nd2O3 Tb2O3 Dy2O3 TREO
ppm ppm ppm ppm ppm
CBSC0006 31.15 33.05 CBSC006-comp 12 48 1.3 8 264
CBSC0007 49.28 50.5 CBSC007-comp 10 34 0.7 4 322
CBSC0008 50.48 53.69 CBSC008-comp 41 163 2.3 11 1,207
CBSC0009 25.55 26.89 CBSC009-comp 53 215 6.8 38 1,261
CBSC0010 26.00 27 CBSC0010-comp 151 470 9.2 52 2,999
CBSC0014* 39.06 56.55 CBSC0014-comp 66 250 2.5 12 916
*Multiple sections throughout the Pidinga Formation
Appendix 3: Diagnostic test results
Sample Reagent Est Acid ConsumedKg/t Pr_% Nd_% Tb_% Dy_% TREY_% TREE:Al Ratio
CBSC009-comp 0.5 M (NH4)2SO4 pH3 5.7 87 87 85 82 84.6 8.2
CBSC009-comp 0.5 M MgSO4 pH3 6.1 75 76 71 70 74.4 7.8
CBSC009-comp 0.5 M (NH4)2SO4 pH2.5 6.9 92 93 90 89 89.3 38.4
CBSC008-comp 0.5 M (NH4)2SO4 pH3 5.5 36 35 35 38 31.4 14.1
CBSC008-comp 0.5 M MgSO4 pH3 5.8 34 35 37 37 29.4 3.6
CBSC008-comp 0.5 M (NH4)2SO4 pH2.5 6.5 27 27 32 31 21.5 3.3
CBSC007-comp 0.5 M (NH4)2SO4 pH3 7.8 30 27 23 26 17.4 1.8
CBSC007-comp 0.5 M MgSO4 pH3 8.0 20 16 34 28 11.7 0.4
CBSC006-comp 0.5 M (NH4)2SO4 pH3 2.6 85 86 84 84 83.4 8.0
CBSC006-comp 0.5 M MgSO4 pH3 2.7 84 84 83 83 82.8 2.1
CBSC006-comp 0.5 M (NH4)2SO4 pH2.5 2.9 89 90 86 85 86.4 2.4
CBSC0014-comp 0.5 M (NH4)2SO4 pH3 2.4 23 24 29 35 26.2 2.9
CBSC0014-comp 0.5 M MgSO4 pH3 3.1 20 21 29 38 24.6 2.9
CBSC0014-comp 0.5 M (NH4)2SO4 pH2.5 2.7 21 22 33 38 25.7 7.0
CBSC0010-comp 0.5 M (NH4)2SO4 pH3 5.4 50 62 79 77 56.1 13.4
CBSC0010-comp 0.5 M MgSO4 pH3 5.8 44 56 67 65 50.0 15.6
CBSC0010-comp 0.5 M (NH4)2SO4 pH2.5 6.3 51 65 85 83 57.4 49.6
Appendix 4: JORC Code, 2012 Edition - Table 3
Criteria JORC Code explanation Commentary
Sampling techniques · Nature and quality of sampling (eg cut channels, random chips, or Pre 2023
specific specialised industry standard measurement tools appropriate to the
minerals under investigation, such as down hole gamma sondes, or handheld XRF · Historic Rotary Mud drilling targeting paleochannel hosted
instruments, etc). These examples should not be taken as limiting the broad uranium was completed. Some residue samples were retained in the Tonsley Core
meaning of sampling. Library, downhole geophysical logging was the primary data collected for these
holes.
· 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 · Select historic sample residues over Boland were analysed as
the Public Report. reported in RNS 1834M (26 April 2024)
· 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 2023
assay'). In other cases more explanation may be required, such as where there
is coarse gold that has inherent sampling problems. Unusual commodities or Aircore
mineralisation types (eg submarine nodules) may warrant disclosure of detailed
information. · A combination of 2m and 3m samples were collected in green bags
via a rig mounted cyclone. A PVC spear was used to collect a 2-4kg sub sample
from each green bag. Sampling commenced from the collar point with samples
submitted for analysis from the top of saprolite.
· Samples were submitted to Bureau Veritas Laboratories, Adelaide
and pulverized to produce a 4-acid digest sample.
2024-2025
SONIC
· Drill results are outlined in RNS 0297I (25 March 2024)
· Core was scanned by a SciAps X555 pXRF to determine sample
intervals. Intervals through mineralized zones were taken at 10cm. Through
waste, sample intervals were lengthened to 50cm. Core was halved by knife
cutting. XRF scan locations were taken on an inner surface of the core to
ensure readings were taken on fresh sample faces.
· Samples were submitted to Bureau Veritas Laboratories, Adelaide
and pulverized to produce a 4 acid digest sample.
Aircore
· 1m sample intervals of 2-4 kg were taken via PVC spear from green
bags at the rig. Select samples were submitted to the lab for analysis. From
0-6 m in each hole samples were composited to 3m.
· Samples were submitted to Bureau Veritas Laboratories, Adelaide
and pulverized to produce a 4 acid digest sample.
Drilling techniques · Drill type (eg core, reverse circulation, open-hole hammer, rotary Pre 2023
air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or
standard tube, depth of diamond tails, face-sampling bit or other type, · Drill methods include Rotary Mud and AC
whether core is oriented and if so, by what method, etc).
2023
· Drilling completed by McLeod Drilling Pty Ltd using 75.7mm NQ air
core drilling techniques from an ALMET aircore rig mounted on a Toyota
Landcruiser 6x6 and a 200psi, 400cfm Sullair compressor.
2024-2025
· Sonic Core drilling completed Star Drilling using 4" core with a
SDR12 drill rig. Holes were reamed to 6" or 8" to enable casing and screens to
be installed
· Aircore Drilling completed by McLeod Drilling Pty Ltd using
75.7mm NQ air core drilling techniques from an ALMET aircore rig mounted on a
Toyota Landcruiser 6x6 and a 200psi, 400cfm Sullair compressor.
Drill sample recovery · Method of recording and assessing core and chip sample recoveries and · Aircore Sample recovery is good for the style of drilling. All
results assessed. samples were recorded for sample type, quality and contamination potential and
entered within a sample log.
· Measures taken to maximise sample recovery and ensure representative
nature of the samples. · In general, sample recoveries range between 5-10kg for each 1 m
interval being recovered from AC drilling.
· Whether a relationship exists between sample recovery and grade and
whether sample bias may have occurred due to preferential loss/gain of · Mineralisation occurs within a confined aquifer where ground
fine/coarse material. water does influence sample recovery
· Mineralisation within the targeted Pidinga Formation is bound to
fine, organic rich material, the potential loss of mineralized material from
coarser host sands is possible
· Any grade bias is expected to be grade loss
· The potential loss of fine material is being evaluated by sizing
fraction analysis and follow-up sonic core drilling where aircore holes will
be twinned.
Sonic Core
· Sample recovery is considered excellent.
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. · All drill samples were logged by a qualified geologist at the
time of drilling. Lithology, colour, weathering and moisture were documented.
· Whether logging is qualitative or quantitative in nature. Core (or All core drilled has been lithologically logged.
costean, channel, etc) photography.
· All Aircore drill metres have been geologically logged on sample
· The total length and percentage of the relevant intersections logged. intervals (1-3 m).
· All Sonic Core drill metres have been logged to lithological
boundaries.
Sub-sampling techniques and sample preparation · If core, whether cut or sawn and whether quarter, half or all core Pre 2023
taken.
· Historic Residue samples were generally 2m composites and were
· If non-core, whether riffled, tube sampled, rotary split, etc and stored at the South Australian Drill Core Reference Library at Tonsley, a
whether sampled wet or dry. subsample of approximately 20g was removed for lab submission.
· For all sample types, the nature, quality and appropriateness of the · Select samples of geological interest were selected for lab
sample preparation technique. submission
· Quality control procedures adopted for all sub-sampling stages to · No QAQC samples were included in the submission of these samples.
maximise representivity of samples. Sample results were intended to indicate mineralisation potential but would
not be suitable for resource estimation
· 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.
Post 2023
· Whether sample sizes are appropriate to the grain size of the
material being sampled. · A PVC spear was used to collect 2-4kg of sub-sample from each AC
sample length controlled the sample volume submitted to the lab.
· Additional sub-sampling was performed through the preparation and
processing of samples according to the Bureau Veritas internal protocols.
· Field duplicate AC samples were collected from the green bags
using a PVC spear scoop at a 1 in 25 sample frequency.
· Sample sizes are considered appropriate for the material being
sampled.
· Assessment of duplicate results indicated this sub - sample
method provided appropriate repeatability for rare earths.
Sonic Drilling
· Field duplicate samples were taken nominally every 1 in 25
samples where the sampled interval was quartered.
· Blanks and Standards were submitted every 25 samples
· Half core samples were taken where lab geochemistry sample were
taken in 2024.
· For 2025 drilling, quarter core was submitted to the lab for
geochemical testing.
· In holes where only column leach test samples have been
submitted, full core samples have been submitted. In holes where geochemical
samples were submitted three quarter core sanmples were submitted for column
leach testing..
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. · Samples were submitted to Bureau Veritas, Adelaide for
preparation and analysis. Multi-element geochemistry were digested by four
· For geophysical tools, spectrometers, handheld XRF instruments, etc, acid ICP-MS/ ICP-OES and analysed for Ag, Ce, Cu, Dy, Er, Eu, Gd, Ho, La, Lu,
the parameters used in determining the analysis including instrument make and Mg, Na, Nd, P, Pr, Sc, Sm, Tb, Th, Tm, U, Y and Yb.
model, reading times, calibrations factors applied and their derivation, etc.
· Nature of quality control procedures adopted (eg standards, blanks,
duplicates, external laboratory checks) and whether acceptable levels of · Field rare earth standards were submitted at a frequency of 1 in
accuracy (ie lack of bias) and precision have been established. 25 samples.
· Field duplicate samples were submitted at a frequency of 1 in 25
samples.
· Reported assays pass the companies implemented QAQC database
reports
· Internal lab blanks, standards and repeats for rare earths
indicated acceptable assay accuracy.
Sample Characterisation Test Work performed by the Australian Nuclear Science
and Technology Organisation (ANSTO)
· Full core samples were submitted to Australian Nuclear Science
and Technology Organisation (ANSTO), Sydney for preparation and analysis. The
core was split in half along the vertical axis, and one half further split
into 10 even fractions along the length of the half-core. Additional
sub-sampling, homogenisation and drying steps were performed to generate ~260
g (dry equivalent) samples for head assay according to the laboratory internal
protocols.
· Multi element geochemistry of solid samples were analysed at
ANSTO (Sydney) by XRF for the major gangue elements Al, Ca, Fe, K, Mg, Mn, Na,
Ni, P, Si, S, and Zn.
· Multi element geochemistry of solid samples were additionally
analysed at ALS Geochemistry Laboratory (Brisbane) on behalf of ANSTO by
lithium tetraborate digest ICP-MS and analysed for Ce, Dy, Er, Eu, Gd, Ho,
La, Lu, Nd, Pr, Sm, Tb, Th, Tm, U, Y and Yb.
· Reported assays are to acceptable levels of accuracy and
precision.
· Internal laboratory blanks, standards and repeats for rare earths
indicated acceptable assay accuracy.
· Samples retained for metallurgical analysis were immediately
vacuum packed, nitrogen purged and refrigerated.
· These samples were refrigerated throughout transport.
Metallurgical Leach Test Work performed by the Australian Nuclear Science and
Technology Organisation (ANSTO)
· ANSTO laboratories prepared ~80g samples for diagnostic leaches, a
443g sample for a slurry leach and a 660g sample for a column leach.
Sub-samples were prepared from full cores according to the laboratory internal
protocols. Diagnostic and slurry leaching were carried out in baffled leach
vessels equipped with an overhead stirrer and applying a 0.5 M (NH4)2SO4
lixiviant solution, adjusted to the select pH using H2SO4.
· 0.5 M H2SO4 was utilised to maintain the test pH for the duration of
the test, if necessary. The acid addition was measured.
· Thief liquor samples were taken periodically.
· At the completion of each test, the final pH was measured, the slurry
was vacuum filtered to separate the primary filtrate.
· The thief samples and primary filtrate were analysed as follows:
o ICP-MS for Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Mn, Nd, Pb, Pr, Sc, Sm, Tb, Th,
Tm, U, Y, Yb.
o ICP-OES for Al, Ca, Fe, K, Mg, Mn, Na, Si.
· The water wash was stored but not analysed.
· Column leaching was carried out in horizontal leaching column. The
column was pressurised with nitrogen to 6 bar and submerged in a temperature
controlled bath.
· A 0.5 M (NH4)2SO4 lixiviant solution, adjusted to the select pH using
H2SO4 was fed to the column at a controlled flowrate.
· PLS collected from the end of the column was weighed, the SH and pH
measured and the free acid concentration determined by titration. Liquor
samples were taken from the collected PLS and analysed as follows:
o ICP-MS for Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Mn, Nd, Pb, Pr, Sc, Sm, Tb, Th,
Tm, U, Y, Yb.
o ICP-OES for Al, Ca, Fe, K, Mg, Mn, Na, Si.
· The column leach test has been completed. Assays of the column have
adjusted head grades of the initial bench scale study. Recoveries have been
adjusted accordingly.
Verification of sampling and assaying · The verification of significant intersections by either independent · Sampling data was recorded in field books, checked upon
or alternative company personnel. digitising and transferred to database.
· The use of twinned holes. · Geological logging was undertaken digitally via the MX Deposit
logging interface and synchronised to the database at least daily during the
· Documentation of primary data, data entry procedures, data drill programme.
verification, data storage (physical and electronic) protocols.
· Compositing of assays was undertaken and reviewed by Cobra
· Discuss any adjustment to assay data. Resources staff.
· Original copies of laboratory assay data are retained digitally
on the Cobra Resources server for future reference.
· Samples have been spatially verified through the use of Datamine
and Leapfrog geological software for pre 2021 and post 2021 samples and
assays.
· Twinned drillholes from pre 2021 and post 2021 drill programs
showed acceptable spatial and grade repeatability.
· Physical copies of field sampling books are retained by Cobra
Resources for future reference.
· Significant intersections have been prepared by Mr Robert
Blythman and reviewed by Mr Rupert Verco
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. 2021-2023
· Specification of the grid system used. · Collar locations were initially surveyed using a mobile phone
utilising the Avenza Map app. Collar points recorded with a GPS horizontal
· Quality and adequacy of topographic control. accuracy within 5 m.
· RC Collar locations were picked up using a Leica CS20 base and
Rover with an instrument precision of 0.05 cm accuracy.
· Locations are recorded in geodetic datum GDA 94 zone 53.
· No downhole surveying was undertaken on AC holes. All holes were
set up vertically and are assumed vertical.
· RC holes have been down hole surveyed using a Reflex TN-14 true
north seeking downhole survey tool or Reflex multishot
· Downhole surveys were assessed for quality prior to export of
data. Poor quality surveys were downgraded in the database to be excluded from
export.
· All surveys are corrected to MGA 94 Zone 53 within the MX Deposit
database.
· Cased collars of sonic drilling shall be surveyed before a
mineral resource estimate
2024 Aircore
· Collar locations were initially surveyed using A mobile phone GPS
utilising the Avenza Map app. Collar points recorded with a horizontal
accuracy within 5m.
· Locations are recorded in geodetic datum GDA 94 zone 53.
· No downhole surveying was undertaken on AC or Sonic holes. All
holes were set up vertically and are assumed vertical.
· Higher accuracy GPS will be undertaken on sonic core drilling to
support future resource estimates
Data spacing and distribution · Data spacing for reporting of Exploration Results. · Drillhole spacing was designed on transects 200 to 500m apart.
· 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. · Additional scouting holes were drilled opportunistically on
existing tracks at spacings 25-150 m from previous drillholes.
· Whether sample compositing has been applied.
· Sonic core holes were drilled at ~20m spacings in a wellfield
configuration based on assumed permeability potential of the intersected
geology
· Drillhole spacing is not expected to introduce any sample bias.
· Assessment of the drillhole spacing for resource estimation will be
made once a sufficient data set can provide statistical analysis
· .
Orientation of data in relation to geological structure · Whether the orientation of sampling achieves unbiased sampling of · Aircore and Sonic drill holes are vertical.
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.
Sample security · The measures taken to ensure sample security. · Transport of samples to Adelaide was undertaken by a competent
independent contractor. Samples were packaged in zip tied polyweave bags in
bundles of 5 samples at the drill rig and transported in larger bulka bags by
batch while being transported.
· Refrigerated transport of samples to Sydney was undertaken by a
competent independent contractor. Samples were double bagged, vacuum sealed,
nitrogen purged and placed within PVC piping.
· There is no suspicion of tampering of samples.
Audits or reviews · The results of any audits or reviews of sampling techniques and data. · No laboratory audit or review has been undertaken.
· Genalysis Intertek and BV Laboratories Adelaide are NATA (National
Association of Testing Authorities) accredited laboratory, recognition of
their analytical competence.
Appendix 5: 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 · Boland is located on EL5953, currently owned 100% by Peninsula
agreements or material issues with third parties such as joint ventures, Resources limited, a wholly owned subsidiary of Andromeda Metals Limited.
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 · In 2024, Cobra through its subsidiary Lady Alice Mines purchased
with any known impediments to obtaining a licence to operate in the area. the remaining ownership of the Wudinna Project tenements.
· An application through partial surrender is currently with the
South Australian Government which will see LAM as the 100% owner of areas of
the Wudinna Project.
· Alcrest Royalties Australia Pty Ltd retains a 1.5% NSR royalty
over future mineral production from licenses EL6001, EL5953, EL6131, EL6317
and EL6489.
· A Native Title Agreement is in place with the Barngarla people.
· Aboriginal heritage surveys have been completed over EL5953, with
no sites located in the immediate vicinity of aircore drilling
Exploration done by other parties · Acknowledgment and appraisal of exploration by other parties. · On-ground exploration completed prior to Andromeda Metals' work
was limited to 400 m spaced soil geochemistry completed by Newcrest Mining
Limited over the Barns prospect.
· Other than the flying of regional airborne geophysics and coarse
spaced ground gravity, there has been no recorded exploration in the vicinity
of the Baggy Green deposit prior to Andromeda Metals' work.
· Paleochannel uranium exploration was undertaken by various
parties in the 1980s and the 2010s around the Boland Prospect. Drilling was
primarily rotary mud with downhole geophysical logging the primary
interpretation method.
Geology · Deposit type, geological setting and style of mineralisation. · Target mineralisation is ionic rare earth mineralisation that
occurs primarily within the Pidinga Formation within the Narlaby
Palaeochannel, immediately above REE enriched Hiltaba Suite Granites
· Ionic REE mineralisation also occurs in and adjacent to the
Garford formation clays and silty sands.
· Significant chemical (pH & eH) differences exist between
underlying saprolite and overlying Palaeochannel sediments. REEs are absorbed
to reduced organics found within the Pidinga Formation
· Benchtop metallurgy studies indicate ISR amenability of rare
earths within the Pidinga Formation basal sands summarized in RNS 1285Q (16
December 2024)
· Ionic REE mineralisation is confirmed through metallurgical
desorption testing where high recoveries are achieved at benign acidities
(pH4-3) at ambient temperature.
· QEMSCAN and petrology analysis support REE ionic mineralisation,
with little to no secondary phases identified.
· Ionic REE mineralisation occurs in reduced clay intervals that
contact both saprolite and permeable sand units. Mineralisation contains
variable sand quantities that yield permeability and promote in-situ recovery
potential
· Mineralisation is located within a confined aquifer
Drillhole Information · A summary of all information material to the understanding of the · Exploration results being reported represent a small portion of
exploration results including a tabulation of the following information for the Boland target area. Coordinates for Wellfield drill holes are presented in
all Material drill holes: Table X.
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.
Data aggregation methods · In reporting Exploration Results, weighting averaging techniques, · Reported summary intercepts are weighted averages based on
maximum and/or minimum grade truncations (eg cutting of high grades) and length.
cut-off grades are usually Material and should be stated.
· No maximum/ minimum grade cuts have been applied.
· Where aggregate intercepts incorporate short lengths of high
grade results and longer lengths of low grade results, the procedure used for · No metal equivalent values have been calculated.
such aggregation should be stated and some typical examples of such
aggregations should be shown in detail. · Rare earth element analyses were originally reported in elemental
form and have been converted to relevant oxide concentrations in line with
· The assumptions used for any reporting of metal equivalent values industry standards. Conversion factors tabulated below:
should be clearly stated.
Element Oxide Factor
Cerium CeO2 1.2284
Dysprosium Dy2O3 1.1477
Erbium Er2O3 1.1435
Europium Eu2O3 1.1579
Gadolinium Gd2O3 1.1526
Holmium Ho2O3 1.1455
Lanthanum La2O3 1.1728
Lutetium Lu2O3 1.1371
Neodymium Nd2O3 1.1664
Praseodymium Pr6O11 1.2082
Scandium Sc2O3 1.5338
Samarium Sm2O3 1.1596
Terbium Tb4O7 1.1762
Thulium Tm2O3 1.1421
Yttrium Y2O3 1.2699
Ytterbium Yb2O3 1.1387
· The reporting of REE oxides is done so in accordance with
industry standards with the following calculations applied:
· TREO = La2O3 + CeO2 + Pr6O11 + Nd2O3 + Sm2O3 + Eu2O3 +
Gd2O3 + Tb4O7 + Dy2O3 + Ho2O3 + Er2O3 + Tm2O3 + Yb2O3 + Lu2O3 + Y2O3
· CREO = Nd2O3 + Eu2O3 + Tb4O7 + Dy2O3 + Y2O3
· LREO = La2O3 + CeO2 + Pr6O11 + Nd2O3
· HREO = Sm2O3 + Eu2O3 + Gd2O3 + Tb4O7 + Dy2O3 + Ho2O3 +
Er2O3 + Tm2O3 + Yb2O3 + Lu2O3 + Y2O3
· MREO = Nd2O3 + Pr6O11 + Tb4O7 + Dy2O3
· NdPr = Nd2O3 + Pr6O11
· TREO-Ce = TREO - CeO2
· % Nd = Nd2O3/ TREO
· % Pr = Pr6O11/TREO
· % Dy = Dy2O3/TREO
· % HREO = HREO/TREO
· % LREO = LREO/TREO
· XRF results are used as an indication of potential grade only.
Due to detection limits only a combined content of Ce, La, Nd, Pr & Y has
been used. XRF grades have not been converted to oxide.
Relationship between mineralisation widths and intercept lengths · These relationships are particularly important in the reporting · Preliminary results support unbiased testing of mineralised
of Exploration Results. structures.
· If the geometry of the mineralisation with respect to the drill · Most intercepts are vertical and reflect true width intercepts.
hole angle is known, its nature should be reported.
· Follow-up sonic drilling is planned to delineate portions of the
· If it is not known and only the down hole lengths are reported, reported intersections that are recoverable and unrecoverable via ISR
there should be a clear statement to this effect (eg 'down hole length, true
width not known').
Diagrams · Appropriate maps and sections (with scales) and tabulations of · Relevant diagrams have been included in the announcement.
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 · Exploration results are not being reported for existing mineral
locations and appropriate sectional views. resources.
· Drilling is aimed at defining new mineral resources.
Balanced reporting · Where comprehensive reporting of all Exploration Results is not · REE mineralization occurs in several phases, primary phase
practicable, representative reporting of both low and high grades and/or mineralisation occurs within the Pidinga Formation which is amenable to ISR
widths should be practiced to avoid misleading reporting of Exploration recovery and the Garford Formation, REO values within both of these formations
Results. have been reported. Mineralisation occurring within the saprolite is
considered secondary phase mineralisation.
Other substantive exploration data · Other exploration data, if meaningful and material, should be · Refer to previous announcements listed in RNS for reporting of
reported including (but not limited to): geological observations; geophysical REE results and metallurgical testing
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.
Further work · The nature and scale of planned further work (eg tests for · ISR study 1 was performed to achieve a pH 3 whilst ISR study 2
lateral extensions or depth extensions or large-scale step-out drilling). was performed at a pH of 3.
· Diagrams clearly highlighting the areas of possible extensions, · Future metallurgical testing will focus on producing PLS under
including the main geological interpretations and future drilling areas, leach conditions to conduct downstream bench-scale studies for impurity
provided this information is not commercially sensitive. removal and product precipitation.
· Hydrology, permeability and mineralogy studies are being
performed on core samples.
· Installed wells are being used to capture hydrology base line
data to support a future infield pilot study.
· Trace line tests shall be performed to emulate bench scale pore
volumes.
· The reporting of REE oxides is done so in accordance with
industry standards with the following calculations applied:
· TREO = La2O3 + CeO2 + Pr6O11 + Nd2O3 + Sm2O3 + Eu2O3 +
Gd2O3 + Tb4O7 + Dy2O3 + Ho2O3 + Er2O3 + Tm2O3 + Yb2O3 + Lu2O3 + Y2O3
· CREO = Nd2O3 + Eu2O3 + Tb4O7 + Dy2O3 + Y2O3
· LREO = La2O3 + CeO2 + Pr6O11 + Nd2O3
· HREO = Sm2O3 + Eu2O3 + Gd2O3 + Tb4O7 + Dy2O3 + Ho2O3 +
Er2O3 + Tm2O3 + Yb2O3 + Lu2O3 + Y2O3
· MREO = Nd2O3 + Pr6O11 + Tb4O7 + Dy2O3
· NdPr = Nd2O3 + Pr6O11
· TREO-Ce = TREO - CeO2
· % Nd = Nd2O3/ TREO
· % Pr = Pr6O11/TREO
· % Dy = Dy2O3/TREO
· % HREO = HREO/TREO
· % LREO = LREO/TREO
· XRF results are used as an indication of potential grade only.
Due to detection limits only a combined content of Ce, La, Nd, Pr & Y has
been used. XRF grades have not been converted to oxide.
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 (eg 'down hole length, true
width not known').
· Preliminary results support unbiased testing of mineralised
structures.
· Most intercepts are vertical and reflect true width intercepts.
· Follow-up sonic drilling is planned to delineate portions of the
reported intersections that are recoverable and unrecoverable via ISR
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.
· Relevant diagrams have been included in the announcement.
· Exploration results are not being reported for existing mineral
resources.
· Drilling is aimed at defining new mineral resources.
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.
· REE mineralization occurs in several phases, primary phase
mineralisation occurs within the Pidinga Formation which is amenable to ISR
recovery and the Garford Formation, REO values within both of these formations
have been reported. Mineralisation occurring within the saprolite is
considered secondary phase mineralisation.
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.
· Refer to previous announcements listed in RNS for reporting of
REE results and metallurgical testing
Further work
· The nature and scale of planned further work (eg 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.
· ISR study 1 was performed to achieve a pH 3 whilst ISR study 2
was performed at a pH of 3.
· Future metallurgical testing will focus on producing PLS under
leach conditions to conduct downstream bench-scale studies for impurity
removal and product precipitation.
· Hydrology, permeability and mineralogy studies are being
performed on core samples.
· Installed wells are being used to capture hydrology base line
data to support a future infield pilot study.
· Trace line tests shall be performed to emulate bench scale pore
volumes.
Appendix 6: (1)Peer comparison - acid consumption
Project Name Company Acid/Lixiviant pH Acid Consumption (kg/t) Leach Method Date of Announcement/Report
North Stanmore Victory Metals Sulfuric acid pH1 ~25 kg/t avg Ambient sulphuric acid diagnostic pulp leach 6-Nov-23
Splinter Rock OD6 Metals Hydrochloric acid Recent news on Cobra Resources
See all newsREG - Cobra Resources PLC - Result of General Meeting
AnnouncementREG - Cobra Resources PLC - Favourable Boland Metallurgical Results
AnnouncementREG - Cobra Resources PLC - Boland Sonic Drill Results
AnnouncementREG - Cobra Resources PLC - Notice of General Meeting
AnnouncementREG - Cobra Resources PLC - Result of AGM
Announcement