REG - Cobra Resources PLC - ISR Bench Scale Study Update
11/07/2024 07:00
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RNS Number : 9278V Cobra Resources PLC 11 July 2024
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11 July 2024
Cobra Resources plc
("Cobra" or the "Company")
ISR Bench Scale Study Update
Further metallurgical success at world leading ISR rare earth project
Cobra (https://cobraplc.com/) (LSE: COBR)
(https://www.londonstockexchange.com/stock/COBR/cobra-resources-plc/company-page)
, an exploration company advancing a strategy to lower the cost of critical
rare earth production at the Boland Project in South Australia, is pleased to
announce that diagnostic tests being carried out as part of ongoing in situ
recovery ("ISR") bench scale testing of a high-grade core sample, have
produced positive preliminary metallurgical results.
ISR is a low capital, and low disturbance mining process that utilises unique
geological conditions to bypass traditional mining and processing methods with
low environmental risk. ISR has been used for many years to produce uranium
in South Australia from similar geological environments.
The Australian National Scientific and Technical Organisation ("ANSTO") is
undertaking mineral-recovery trials on rare earth mineralisation recovered
from Cobra's recently installed ISR wellfield to demonstrate the value of
applying ISR to Cobra's unique ionic rare earth mineralisation. Testing has
yielded low impurity levels and low acid consumption which support a pathway
for cost-effective recovery.
For further context to the technical information discussed in this
announcement with comparative analysis, please view the Q&A on Cobra's
Investor Hub here:
https://investors.cobraplc.com/link/6rkjLe
(https://investors.cobraplc.com/link/6rkjLe)
Highlights:
· Strong ionic recoveries from a high-grade sample: 41% recoveries of
Rare Earths ("REEs") from a sub-sample grading 2,688 ppm Total Rare Earth
Oxide ("TREO") magnet rare earths Nd2O3 + Pr6O11 total 532 ppm and Dy2O3 +
Tb2O3 total 83 ppm at pH 3, ambient temperature
· Low-cost metallurgical characteristics: Low impurities and low acid
consumption support a simple low-capital flowsheet for purification and
precipitation - favourable for project economics
· Low levels of deleterious radioactive elements: in Pregnant Liquor
Solution ("PLS") of 0.24 mg/L U and <0.01 mg/L Th, important for product
transport and oxide separation
· Ability to increase recoveries through ISR: low acid consumption and
low levels of impurities enable optimisation to further maximise REE recovery.
This is being tested by increasing leach time of the bench scale ISR test and
making lixiviant adjustments
Rupert Verco, CEO of Cobra, commented:
"These initial recoveries are very pleasing. Managing impurities and acid
consumption are significant factors of rare earth processing costs and these
results provide a pathway for cost-effective recovery - particularly when
coupled with ISR mining.
Achieving recoveries of 41% from such a high head grade of 2,688 ppm TREO in
this diagnostic test is highly encouraging for optimising recoveries from the
bench scale ISR tests being performed on a core sample exceeding 4,506 ppm
TREO. There is plenty of room to optimise these recoveries considering the low
level of impurities, low acid consumption and the minimal costs involved in
ISR mining.
Our overarching objective is to produce metals which are critical to energy
efficiency through a mining process with the lowest environmental risk and the
lowest possible cost. We aim to demonstrate the value of this by confirming
recovery via ISR and maximising metallurgical confidence. We look forward to
bringing further metallurgy results to the market in the coming weeks."
Next Steps
Considering these favourable results, the following adjustments to Cobra's
work programme have been made:
1. Extended duration of ISR bench scale study: to determine maximum
recovery / impurity limits with results anticipated over the coming weeks
2. Commencement of a second ISR bench scale ISR study: on core from
CBSC0002 to achieve repeatability and increase the volume of pregnant liquor
for flowsheet development
3. Further diagnostic leach tests: across installed wellfield holes to
enable economic assessment of the complete wellfield and all zones of
mineralisation
4. Resource drilling: planning and design have been completed. The
commencement of resource drilling has been delayed enabling metallurgical
results to be interpreted and evaluated against existing drilling ensuring the
most desirable areas of the palaeochannel are targets
5. Flowsheet advancement: pregnant liquor produced from both bench scale
ISR tests to be used to advance both membrane desorption and traditional REE
purification and precipitation processes
Further information relating to diagnostic leach test 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: "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
· Wudinna Project Update: "Drilling results from Boland Prospect",
dated 25 March 2024
· Wudinna Project Update: "Historical Drillhole Re-Assay Results",
dated 27 February 2024
· Wudinna Project Update: "Ionic Rare Earth Mineralisation at Boland
Prospect", dated 11 September 2023
· Wudinna Project Update: "Exceptional REE Results Defined at Boland",
dated 20 June 2023
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 the Director of Process Engineering at Wallbridge Gilbert Aztec 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 16 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 12 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. Cobra is focused on de-risking the
investment value of the discovery by proving ISR as the preferred mining
method which would eliminate challenges associated with processing clays and
provide Cobra with the opportunity to define a low-cost pathway to production.
Cobra's Wudinna tenements also contain extensive orogenic gold mineralisation,
including a 279,000 Oz gold JORC Mineral Resource Estimate, characterised by
potentially open-pitable, high-grade gold intersections.
Regional map showing Cobra's tenements in the heart of the Gawler Craton
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Appendix 1: Diagnostic leach results
Preliminary metallurgical testing being performed by the Australian Nuclear
Science and Technology Organisation ("ANSTO") aimed at demonstrating the
suitability for ISR mining - a low cost, low-disturbance method - has yielded
low impurity levels and low acid consumption with robust recoveries providing
scope for further optimisation. The objectives of metallurgical testing are
outlined below:
Diagnostic tests are aimed to:
i. Confirm the quantity of recoverable ionic REE
mineralisation
ii. Determine the quantity of acid consumed
iii. Measure the anticipated level of impurities
iv. Enable optimising adjustments to parallel bench scale
ISR tests
The parameters of the diagnostic leach test were:
· Reagent: 0.5M Ammonium Sulphate
· Sulphuric Acid addition to maintain pH3
· Ambient Temperature
· Duration: 24 Hours
The results reported in this announcement are derived from the diagnostic test
The composite sample subject to the diagnostic leach test was from CBSC003
(26.7m to 27.2m) the sub-sample calculated head grade and subsequent
recoveries are presented in table 1 below:
Table 1: Diagnostic leach sample head grade and subsequent recoveries
Pr(6)O(11) ppm Nd(2)O(3) ppm Tb(2)O(3) ppm Dy(2)O(3) ppm MREO % HREO % TREO ppm
Sub-sample (80g) Grade 114 417 11.3 71.6 23% 29% 2,688
Recovery 41% 39% 31% 30% 38% 37% 41%
A favourable characteristic of ionic mineralisation is the low level of
impurities and radioactive deleterious elements that are recovered.
Desorption at benign acidities between pH 3-4 reduces the leaching of key
impurities such as aluminium, iron and silica. A key metric to measure the
level of impurities is the apparent ratio of rare earths to impurities within
a pregnant solution. When the ratio of REEs to impurities in solution is low,
the metallurgical process for purification become complex, and the rate of REE
recovery through purification decreases.
Diagnostic leach results demonstrate that the level of REEs in solution far
exceed the level of impurities, supporting a low-cost, low-temperature
single-step for impurity removal.
Table 2: Diagnostic leach impurity ratios and levels of radioactive
deleterious elements in solution
TREY:Al TREY:Fe TREY:Si U mg/L Th mg/L
13 9.7 >7.9 0.24 <0.01
TREY = La+Ce+Pr+Nd+Sm+Eu+Gd+Tb+Dy+Ho+Er+Tm+Yb+Lu+Y
Al - Aluminium
Fe - Iron
Si - Silica
U - Uranium
Th - Thorium
Appendix 2: ISR bench scale test CBSC003 26.7m - 27.2m
The diagnostic leach sample is a sub-sample of CBSC003 26.7m - 27.2m, a length
of core that is currently subject to bench scale ISR tests. The head grade of
the sample is 4,506 ppm TREO calculated from the sample composites presented
in Table 3
Table 3: Sample composites of the sample subject to the bench scale ISR test
Depth from (m) Depth to (m) Pr(6)O(11) Nd(2)O(3) Tb(2)O(3) Dy(2)O(3) MREO % HREO HREO % TREO
26.7 26.8 317 1,277 35 207 24% 2,286 29% 7,764
26.8 26.9 290 1,144 30 177 23% 1,990 28% 7,187
26.9 27 206 710 18 105 21% 1,129 23% 4,869
27 27.1 84 328 9 56 22% 610 28% 2,144
27.1 27.2 53 211 6 36 22% 401 29% 1,371
26.7 27.2 183 708 19 112 23% 1,239 28% 4,506
MREO = Pr(6)O(11)+ Nd(2)O(3)+ Tb(2)O(3)+ Dy(2)O(3)
HREO = Sm(2)O(3)+ Eu(2)O(3)+ Gd(2)O(3)+ Tb(2)O(3)+
Dy(2)O(3)+Ho(2)O(3)+Er(2)O(3)+Tm(2)O(3) +Yb(2)O(3)+Lu(2)O(3)+Y(2)O(3)
Bench scale ISR test is designed to emulate the ISR process to determine:
i. The rate in which the lixiviant can percolate
through the pore space of the mineralised sample
ii. The subsequent time required to adjust sample pH
iii. The rate and quantity in which rare earths are
liberated to solution
The results of the initial bench scale ISR study are expected over the coming
weeks
Appendix 3: Interpretation of results
· Strong un-optimised recoveries from a high-grade sample: 38%
recoveries of Magnet Rare Earths ("MREO") from a sample grading 2,688 ppm
Total Rare Earth Oxide ("TREO") magnet rare earths Nd2O3 + Pr6O11 total 528
ppm and Dy2O3 + Tb2O3 total 83 ppm
· Low-cost metallurgical characteristics: acid consumption: over 24
hours total sulphuric acid (H(2)SO(4)) consumption of 8.8 kg/t - equivalent to
~A$2/t (£1.06/t)(1)
· Low levels of impurity: TREY:Al ratio of 13:1, TREY:Fe ratio of 9.7:1
TREY:Si ratio of 7.9:1 - these results are considered very favourable for
low-cost purification via a low temperature single step impurity removal
· Low levels of deleterious radioactive elements: in Pregnant Liquor
Solution ("PLS") of 0.24 mg/L U and <0.01 mg/L Th, an important aspect for
product transport and oxide separation
· Un-optimised recoveries with upside: owing to the low level of
impurities and the low acid consumption, the ability to increase REE
recoveries is being evaluated by increasing the length of the bench scale ISR
study and making adjustments to the lixiviant. These results are expected in
the coming weeks.
Figure 1: Aerial photograph of the Boland Project wellfield with significant
intersections
*Partially assayed
(#)Stored for metallurgical testing, pending assay
Appendix 4: Cobra's Boland rare earth discovery
· Ionic clay-hosted rare earths present as a low-capital, low operating
cost source of heavy and magnet rare earth metals
· Processing of clay ores induces several operating challenges,
including productivity loss, material handling, dewatering, reagent use and
reclamation
· Ionic rare earth mineralisation at Boland exists in permeable geology
in an environment that permits ISR, thus bypassing the challenges associated
with processing of clay ores
· ISR is the preferred method of recovery used in the uranium industry,
where(1):
o Global ISR production accounted for ~60% of mined uranium in 2022
o Capital expenditure for ISR is 1-15% of conventional mines
o Operating costs of ISR is generally 30-40% lower than traditional mines
o Environmental impact and rehabilitation cost is significantly lower than
traditional mines
· South Australia is home to Australia's only three operating ISR
uranium mines and has a regulatory framework that supports ISR mining
· Bench-scale leach studies under ISR conditions are currently underway
at ANSTO, a first for ionic REE projects outside of China
· Cobra has installed a wellfield to rapidly advance the project
towards an infield pilot study
· Cobra aims to demonstrate that the cost of production at Boland can
be materially reduced via ISR, providing operating resilience to volatile rare
earth markets which has stalled the commencement of many rare earth projects
· Re-assaying of historic uranium focused drilling is being used to
confirm the scale of rare earth mineralisation. These results confirm the
presence of rare earth mineralisation over a strike of 12 km, where
mineralisation is open in most directions. Follow-up drilling will aim to
infill these results to support a maiden Mineral Resource Estimate ("MRE") at
Boland
Appendix 5: Further information relating to the Boland Project and reported
results
· In February 2024, Cobra drilled five sonic core holes and installed
screened and cased wells to advance ISR mining of ionic rare earths
· On 25 March 2024, the Company announced the assay results of three of
the five holes drilled, revealing three consistent zones of mineralisation
· Core from two holes were preserved and transported to ANSTO for
metallurgical testing. Samples have been kept air-tight and refrigerated to
prevent changes in oxidation and therefore sampling and assaying can only
occur directly before the commencement of metallurgical testing
· Zone three represents the deepest and highest-grade zone of
mineralisation. The wellfield has been designed and installed to pilot test
ISR from zone three
· Further core from CBSC0003 and CBSC0002 is being prepared for further
metallurgical testwork to support flow sheet optimisation
· Drilling results have been reported via a four-acid digest method,
which is a partial digest that represents the ionic / leachable portion of REE
mineralisation. Samples prepared for and subject to metallurgical testing have
been assayed via lithium borate fusion; a complete digest of REE-bearing
minerals. Results from Boland are 10-15% higher when reported via lithium
borate fusion
· Recoveries reported in this announcement have been reported against
head grades calculated via lithium borate fusion assays and are therefore a
reflection of the recoverable quantity of the total rare earth oxide grade
Appendix 6: JORC Code, 2012 Edition - Table 1
Section 1 Sampling Techniques and Data
Criteria JORC Code explanation Commentary
Sampling techniques · Nature and quality of sampling (eg cut channels, random chips, or 2023
specific specialised industry standard measurement tools appropriate to the
minerals under investigation, such as down hole gamma sondes, or handheld XRF RC
instruments, etc). These examples should not be taken as limiting the broad
meaning of sampling. · Samples were collected via a Metzke cone splitter mounted to the
cyclone. 1m samples were managed through chute and butterfly valve to produce
· Include reference to measures taken to ensure sample representivity a 2-4 kg sample. Samples were taken from the point of collar, but only samples
and the appropriate calibration of any measurement tools or systems used. from the commencement of saprolite were selected for analysis.
· Aspects of the determination of mineralisation that are Material to · Samples submitted to Bureau Veritas Laboratories, Adelaide, and
the Public Report. pulverised to produce the 50 g fire assay charge and 4 acid digest sample.
· 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 AC
assay'). In other cases more explanation may be required, such as where there
is coarse gold that has inherent sampling problems. Unusual commodities or · A combination of 2m and 3 m samples were collected in green bags
mineralisation types (eg submarine nodules) may warrant disclosure of detailed via a rig mounted cyclone. An PVC spear was used to collect a 2-4 kg sub
information. sample from each green bag. Samples were taken from the point of collar.
· Samples submitted to Bureau Veritas Laboratories, Adelaide, and
pulverised to produce the 50 g fire assay charge and 4 acid digest sample.
2024
SONIC
· 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 for 4 acid digest ICP
analysis.
Drilling techniques · Drill type (eg core, reverse circulation, open-hole hammer, rotary 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, · Drilling completed by Bullion Drilling Pty Ltd using 5 ¾"
whether core is oriented and if so, by what method, etc). reverse circulation drilling techniques from a Schramm T685WS rig with an
auxiliary compressor.
· Drilling completed by McLeod Drilling Pty Ltd using 75.7 mm NQ
air core drilling techniques from an ALMET Aircore rig mounted on a Toyota
Landcruiser 6x6 and a 200psi, 400cfm Sullair compressor.
2024
· 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
Drill sample recovery · Method of recording and assessing core and chip sample recoveries and Aircore & RC
results assessed.
· Sample recovery was generally good. All samples were recorded for
· Measures taken to maximise sample recovery and ensure representative sample type, quality and contamination potential and entered within a sample
nature of the samples. log.
· Whether a relationship exists between sample recovery and grade and · In general, sample recoveries were good with 10 kg for each 1 m
whether sample bias may have occurred due to preferential loss/gain of interval being recovered from AC drilling.
fine/coarse material.
· No relationships between sample recovery and grade have been
identified.
· RC drilling completed by Bullion Drilling Pty Ltd using 5 ¾"
reverse circulation drilling techniques from a Schramm T685WS rig with an
auxiliary compressor
· Sample recovery for RC was generally good. All samples were
recorded for sample type, quality and contamination potential and entered
within a sample log.
· In general, RC sample recoveries were good with 35-50 kg for each
1 m interval being recovered.
· No relationships between sample recovery and grade have been
identified.
Sonic Core
· Sample recovery is considered excellent.
Logging · Whether core and chip samples have been geologically and Aircore & RC
geotechnically logged to a level of detail to support appropriate Mineral
Resource estimation, mining studies and metallurgical studies.
· Whether logging is qualitative or quantitative in nature. Core (or · All drill samples were logged by an experienced geologist at the
costean, channel, etc) photography. time of drilling. Lithology, colour, weathering and moisture were documented.
· The total length and percentage of the relevant intersections logged. · Logging is generally qualitative in nature.
· All drill metres have been geologically logged on sample
intervals (1-3 m).
Sonic Core
· Logging was carried out in detail, determining lithology and
clay/ sand content. Logging intervals were lithology based with variable
interval lengths.
· All core drilled has been lithologically logged.
Sub-sampling techniques and sample preparation · If core, whether cut or sawn and whether quarter, half or all core 2021-onward
taken.
· The use of an aluminum scoop or PVC spear to collect the required
· If non-core, whether riffled, tube sampled, rotary split, etc and 2-4 kg of sub-sample from each AC sample length controlled the sample volume
whether sampled wet or dry. submitted to the laboratory.
· For all sample types, the nature, quality and appropriateness of the · Additional sub-sampling was performed through the preparation and
sample preparation technique. processing of samples according to the lab internal protocols.
· Quality control procedures adopted for all sub-sampling stages to · Duplicate AC samples were collected from the green bags using an
maximise representivity of samples. aluminium scoop or PVC spear at a 1 in 25 sample frequency.
· Measures taken to ensure that the sampling is representative of the · Sample sizes were appropriate for the material being sampled.
in situ material collected, including for instance results for field
duplicate/second-half sampling. · Assessment of duplicate results indicated this sub-sample method
provided good repeatability for rare earth elements.
· Whether sample sizes are appropriate to the grain size of the
material being sampled. · RC drill samples were sub-sampled using a cyclone rig mounted
splitter with recoveries monitored using a field spring scale.
· Manual re-splitting of RC samples through a riffle splitter was
undertaken where sample sizes exceeded 4 kg.
· RC field duplicate samples were taken nominally every 1 in 25
samples. These samples showed good repeatability for REE.
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 holes where column leach test samples have been submitted,
full core samples have been submitted over the test areas.
Quality of assay data and laboratory tests · The nature, quality and appropriateness of the assaying and · Samples were submitted to Bureau Veritas Laboratories, Adelaide
laboratory procedures used and whether the technique is considered partial or for preparation and analysis.
total.
· Multi element geochemistry were digested by four acid ICP-MS and
· For geophysical tools, spectrometers, handheld XRF instruments, etc, analysed for Ag, Ce, Cu, Dy, Er, Eu, Gd, Ho, La, Lu, Mg, Na, Nd, P, Pr, Sc,
the parameters used in determining the analysis including instrument make and Sm, Tb, Th, Tm, U, Y and Yb.
model, reading times, calibrations factors applied and their derivation, etc.
· For the sonic samples Ag was removed from the analytical suite
· Nature of quality control procedures adopted (eg standards, blanks, and V was included
duplicates, external laboratory checks) and whether acceptable levels of
accuracy (ie lack of bias) and precision have been established. · Field gold blanks and rare earth standards were submitted at a
frequency of 1 in 25 samples.
· Field duplicate samples were submitted at a frequency of 1 in 25
samples
· 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 and refrigerated.
· These samples were refrigerated throughout transport.
Metallurgical Test Work performed by the Australian Nuclear Science and
Technology Organisation (ANSTO).
ANSTO laboratories prepared a 80g sample from the homogenized core section
CBSC003 26.7-27.2m. The sample was
· Standard desorption conditions:
· 0.5M (NH4)2SO4 as lixiviant
· pH 3
· 30 minutes, 2 hrs, 6 hrs, 12 hrs & 24 hours
· Ambient temperature of 22°C; and
· 4 wt% solids density
· Prior to commencing the test work, a bulk 0.5 M (NH4)2SO4 solution
was prepared as the synthetic lixiviant and the pH adjusted to 3 using H2SO4.
· Each of the leach tests was conducted on 80 g of dry, un-pulverised
sample and 1920 g of the lixiviant in a 2 L titanium/ stainless steel baffled
leach vessel equipped with an overhead stirrer.
· Addition of solid to the lixiviant at the test pH will start the
test. 1 M H2SO4 was utilised to maintain the test pH for the duration of the
test, if necessary. The acid addition was measured.
· At the completion of each test, the final pH was measured, the slurry
was vacuum filtered to separate the primary filtrate.
· The primary filtrate was analysed as follows: • ICP-MS for Ce, Dy,
Er, Eu, Gd, Ho, La, Lu, Mn, Nd, Pb, Pr, Sc, Sm, Tb, Th, Tm, U, Y, Yb (ALS,
Brisbane); • ICP-OES for Al, Ca, Fe, K, Mg, Mn, Na, Si (in-house, ANSTO);
· The water wash was stored but not analysed.
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 programmes
showed acceptable spatial and grade repeatability.
· Physical copies of field sampling books are retained by Cobra
Resources for future reference.
· Elevated pXRF grades were checked and re-tested where anomalous.
pXRF grades are semi quantitative.
Location of data points · Accuracy and quality of surveys used to locate drill holes (collar Pre 2021
and down-hole surveys), trenches, mine workings and other locations used in
Mineral Resource estimation. · Collar locations were pegged using DGPS to an accuracy of +/-0.5
m.
· Specification of the grid system used.
· Downhole surveys have been completed for deeper RC and diamond
· Quality and adequacy of topographic control. drillholes
· Collars have been picked up in a variety of coordinate systems
but have all been converted to MGA 94 Zone 53. Collars have been spatially
verified in the field.
· Collar elevations were historically projected to a geophysical
survey DTM. This survey has been adjusted to AHD using a Leica CS20 GNSS base
and rover survey with a 0.05 cm accuracy. Collar points have been re-projected
to the AHD adjusted topographical surface.
2021-onward
· Collar locations were initially surveyed using a mobile phone
utilising the Avenza Map app. Collar points recorded with a GPS horizontal
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
Data spacing and distribution · Data spacing for reporting of Exploration Results. · Drillhole spacing was designed on transects 50-80 m apart.
Drillholes generally 50-60 m apart on these transects but up to 70 m apart.
· Whether the data spacing and distribution is sufficient to establish
the degree of geological and grade continuity appropriate for the Mineral · Additional scouting holes were drilled opportunistically on
Resource and Ore Reserve estimation procedure(s) and classifications applied. existing tracks at spacings 25-150 m from previous drillholes.
· Whether sample compositing has been applied. · Regional scouting holes are drilled at variable spacings designed
to test structural concepts
· Data spacing is considered adequate for a saprolite hosted rare
earth Mineral Resource estimation.
· No 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.
Orientation of data in relation to geological structure · Whether the orientation of sampling achieves unbiased sampling of · RC drillholes have been drilled between -60 and -75 degrees at
possible structures and the extent to which this is known, considering the orientations interpreted to appropriately intersect gold mineralisation
deposit type.
· Aircore and Sonic drill holes are vertical.
· 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. Pre 2021
· Company staff collected or supervised the collection of all
laboratory samples. Samples were transported by a local freight contractor
· No suspicion of historic samples being tampered with at any stage.
· Pulp samples were collected from Challenger Geological Services and
submitted to Intertek Genalysis by Cobra Resources' employees.
2021-onward
· 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.
· 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 · RC drilling occurred on EL 6131, 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. · Alcrest Royalties Australia Pty Ltd retains a 1.5% NSR royalty over
future mineral production from licenses EL6001, EL5953, EL6131, EL6317 and
· The security of the tenure held at the time of reporting along with EL6489.
any known impediments to obtaining a licence to operate in the area.
· Baggy Green, Clarke, Laker and the IOCG targets are located within
Pinkawillinnie Conservation Park. Native Title Agreement has been negotiated
with the NT Claimant and has been registered with the SA Government.
· Aboriginal heritage surveys have been completed over the Baggy Green
Prospect area, with no sites located in the immediate vicinity.
· A Native Title Agreement is in place with the relevant Native Title
party.
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. · The gold and REE deposits are considered to be related to the
structurally controlled basement weathering of epidote- pyrite alteration
related to the 1590 Ma Hiltaba/GRV tectonothermal event.
· Mineralisation has a spatial association with mafic
intrusions/granodiorite alteration and is associated with metasomatic
alteration of host rocks. Epidote alteration associated with gold
mineralisation is REE enriched and believed to be the primary source.
· Rare earth minerals occur within the saprolite horizon. XRD analysis
by the CSIRO identifies kaolin and montmorillonite as the primary clay phases.
· SEM analysis identified REE bearing mineral phases in hard rock:
· Zircon, titanite, apatite, andradite and epidote.
· SEM analyses identifies the following secondary mineral phases in
saprock:
· Monazite, bastanite, allanite and rutile.
· Elevated phosphates at the base of saprock do not correlate to rare
earth grade peaks.
· Upper saprolite zones do not contain identifiable REE mineral phases,
supporting that the REEs are adsorbed to clay particles.
· Acidity testing by Cobra Resources supports that pH chemistry may act
as a catalyst for Ionic and Colloidal adsorption.
· REE mineral phase change with varying saprolite acidity and REE
abundances support that a component of REE bursary is adsorbed to clays.
· Palaeo drainage has been interpreted from historic drilling and
re-interpretation of EM data that has generated a top of basement model.
· Ionic REE mineralisation is confirmed through metallurgical
desorption testing where high recoveries are achieved at benign acidities
(pH4-3) at ambient temperature.
· Ionic REE mineralisation occurs in reduced clay intervals that
contact both saprolite and permeable sand units. Mineralisation contains
variable sand quantities that is expected
Drillhole Information · A summary of all information material to the understanding of the · Exploration results are not being reported as part of the Mineral
exploration results including a tabulation of the following information for Resource area.
all Material drill holes:
o easting and northing of the drill hole collar
o elevation or RL (Reduced Level - elevation above sea level in metres) of
the drill hole collar
o dip and azimuth of the hole
o down hole length and interception depth
o hole length.
· If the exclusion of this information is justified on the basis that
the information is not Material and this exclusion does not detract from the
understanding of the report, the Competent Person should clearly explain why
this is the case.
Data aggregation methods · In reporting Exploration Results, weighting averaging techniques, · Reported summary intercepts are weighted averages based on length.
maximum and/or minimum grade truncations (eg cutting of high grades) and
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 · No metal equivalent values have been calculated.
results and longer lengths of low grade results, the procedure used for such
aggregation should be stated and some typical examples of such aggregations · Gold results are reported to a 0.3 g/t cut-off with a maximum of 2m
should be shown in detail. internal dilution with a minimum grade of 0.1 g/t Au.
· The assumptions used for any reporting of metal equivalent values · Rare earth element analyses were originally reported in elemental
should be clearly stated. form and have been converted to relevant oxide concentrations in line with
industry standards. Conversion factors tabulated below:
Element Oxide Factor
Cerium CeO(2) 1.2284
Dysprosium Dy(2)O(3) 1.1477
Erbium Er(2)O(3) 1.1435
Europium Eu(2)O(3) 1.1579
Gadolinium Gd(2)O(3) 1.1526
Holmium Ho(2)O(3) 1.1455
Lanthanum La(2)O(3) 1.1728
Lutetium Lu(2)O(3) 1.1371
Neodymium Nd(2)O(3) 1.1664
Praseodymium Pr(6)O(11) 1.2082
Scandium Sc(2)O(3) 1.5338
Samarium Sm(2)O(3) 1.1596
Terbium Tb(4)O(7) 1.1762
Thulium Tm(2)O(3) 1.1421
Yttrium Y(2)O(3) 1.2699
Ytterbium Yb(2)O(3) 1.1387
· The reporting of REE oxides is done so in accordance with industry
standards with the following calculations applied:
· TREO = La(2)O(3) + CeO(2) + Pr(6)O(11) + Nd(2)O(3) + Sm(2)O(3) +
Eu(2)O(3) + Gd(2)O(3) + Tb(4)O(7) + Dy(2)O(3) + Ho(2)O(3) + Er(2)O(3) +
Tm(2)O(3) + Yb(2)O(3) + Lu(2)O(3) + Y(2)O(3)
· CREO = Nd(2)O(3) + Eu(2)O(3) + Tb(4)O(7) + Dy(2)O(3) + Y(2)O(3)
· LREO = La(2)O(3) + CeO(2) + Pr(6)O(11) + Nd(2)O(3)
· HREO = Sm(2)O(3) + Eu(2)O(3) + Gd(2)O(3) + Tb(4)O(7) + Dy(2)O(3)
+ Ho(2)O(3) + Er(2)O(3) + Tm(2)O(3) + Yb(2)O(3) + Lu(2)O(3) + Y(2)O(3)
· NdPr = Nd(2)O(3) + Pr(6)O(11)
· TREO-Ce = TREO - CeO(2)
· % Nd = Nd(2)O(3)/ TREO
· % Pr = Pr(6)O(11)/TREO
· % Dy = Dy(2)O(3)/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 · All reported intercepts at Boland are vertical and reflect true width
Exploration Results. intercepts.
· If the geometry of the mineralisation with respect to the drill hole · Exploration results are not being reported for the Mineral Resource
angle is known, its nature should be reported. area.
· 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').
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 the Mineral Resources
locations and appropriate sectional views. area.
Balanced reporting · Where comprehensive reporting of all Exploration Results is not · Not applicable - Mineral Resource and Exploration Target are defined.
practicable, representative reporting of both low and high grades and/or
widths should be practiced to avoid misleading reporting of Exploration · Exploration results are not being reported for the Mineral Resource
Results. area.
Other substantive exploration data · Other exploration data, if meaningful and material, should be · Refer to previous announcements listed in RNS for reporting of REE
reported including (but not limited to): geological observations; geophysical 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 lateral · The metallurgical testing reported in this announcement represents
extensions or depth extensions or large-scale step-out drilling). the first phase of bench scale studies to test the extraction of ionic REEs
via ISR processes.
· Diagrams clearly highlighting the areas of possible extensions,
including the main geological interpretations and future drilling areas, · Hydrology, permeability and mineralogy studies are being performed on
provided this information is not commercially sensitive. 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 = La(2)O(3) + CeO(2) + Pr(6)O(11) + Nd(2)O(3) + Sm(2)O(3) +
Eu(2)O(3) + Gd(2)O(3) + Tb(4)O(7) + Dy(2)O(3) + Ho(2)O(3) + Er(2)O(3) +
Tm(2)O(3) + Yb(2)O(3) + Lu(2)O(3) + Y(2)O(3)
· CREO = Nd(2)O(3) + Eu(2)O(3) + Tb(4)O(7) + Dy(2)O(3) + Y(2)O(3)
· LREO = La(2)O(3) + CeO(2) + Pr(6)O(11) + Nd(2)O(3)
· HREO = Sm(2)O(3) + Eu(2)O(3) + Gd(2)O(3) + Tb(4)O(7) + Dy(2)O(3)
+ Ho(2)O(3) + Er(2)O(3) + Tm(2)O(3) + Yb(2)O(3) + Lu(2)O(3) + Y(2)O(3)
· NdPr = Nd(2)O(3) + Pr(6)O(11)
· TREO-Ce = TREO - CeO(2)
· % Nd = Nd(2)O(3)/ TREO
· % Pr = Pr(6)O(11)/TREO
· % Dy = Dy(2)O(3)/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').
· All reported intercepts at Boland are vertical and reflect true width
intercepts.
· Exploration results are not being reported for the Mineral Resource
area.
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 the Mineral Resources
area.
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 applicable - Mineral Resource and Exploration Target are defined.
· Exploration results are not being reported for the Mineral Resource
area.
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.
· The metallurgical testing reported in this announcement represents
the first phase of bench scale studies to test the extraction of ionic REEs
via ISR processes.
· 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: Drillhole coordinates
Prospect Hole number Grid Northing Easting Elevation
Boland CBSC0001 GDA94 / MGA zone 53 6365543 534567 102.9
Boland CBSC0002 GDA94 / MGA zone 53 6365510 534580 104.1
Boland CBSC0003 GDA94 / MGA zone 53 6365521 534554 102.7
Boland CBSC0004 GDA94 / MGA zone 53 6365537 534590 105
Boland CBSC0005 GDA94 / MGA zone 53 6365528 534573 103.2
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