REG - Cobra Resources PLC - ISR Bench Scale Study Completion
04/11/2024 07:00
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RNS Number : 6891K Cobra Resources PLC 04 November 2024
THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF
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4 November 2024
Cobra Resources plc
("Cobra" or the "Company")
ISR Bench Scale Study Completion
Achieved high recoveries from high grade ore through a mining process to
deliver bottom quartile operating costs
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 Elements ("REEs") discovery at its Boland Project
in South Australia, is pleased to announce that final recoveries have been
achieved from its bench scale in situ recovery ("ISR") testing. The study has
confirmed that ISR is a suitable mining technique to deploy at Boland,
supporting the Company's ambition to commercialise the ionic rare earths
project.
Highlights
· Further recovery increases have been achieved:
o Total Rare Earth Oxide ("TREO") recoveries increased from 50% to 56% TREO
o Valuable Magnet Rare Earth Oxides ("MREO") recoveries increased from 48%
to 57% MREO
o Strategic Heavy Rare Earth Oxides ("HREO") recoveries increased from 43%
to 50% HREO
o Strong recoveries achieved by lowering the sample pH from 7.1 to 3.0
· Low levels of impurities (deleterious elements) alongside low levels
of acid consumption were reported
· Flow sheet development has been advanced: the pregnant liquor
produced from the test is being used to advance metallurgical flowsheet
development. Impurity removal tests are currently underway which are expected
to generate a sufficient quantity of Mixed Rare Earth Carbonate ("MREC") to
evaluate product specifications and impurities
· The low-cost, low-disturbance ISR recovery process has been
successfully demonstrated
Rupert Verco, CEO of Cobra, commented:
"We're delighted to have completed bench scale in situ recovery trials which
have significantly increased our confidence in ISR being the ideal mining
method to cost effectively extract rare earths from Boland - just as it has
been leveraged to recover uranium from South Australian operations for many
years. These further improvements in recoveries validate the potential low
cost of production that Boland could deliver and, in the context of rare earth
projects, achieving 57% MREO recoveries from a high grade (0.45% TREO) sample
at such a benign acidity is a fantastic result. In addition, achieving these
recoveries through a process that eliminates physical mining and clay
treatment is truly exceptional.
Follow-up impurity removal tests will advance the development of our
flowsheet. We anticipate that the results of this work will be available in
4-5 weeks where we expect to demonstrate the value of Boland in the form of a
saleable product.
We are taking a strategic approach to demonstrating the significance of our
opportunity, carefully de-risking the project at every step along the
commercialisation pathway. We aim to demonstrate a simple, low-cost process
for impurity removal to produce a high-purity product, well weighted with
heavy rare earths of crucial importance to modern technology and the global
energy transition."
Cobra's unique and highly scalable Boland discovery is a strategically
advantageous ionic rare earth discovery where high grades of valuable HREOs
and MREOs 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.
Cobra engaged the Australian Nuclear Science and Technology Organisation
("ANSTO") to execute a detailed work programme to confirm and optimise the
recovery of REEs through the ISR process. Highlights of the final results
include:
· Low capital mining process: the permeability of the orebody was used
to percolate lixiviant. A permeation rate of 0.14 pore volumes per day was
achieved which is comparable to operating ISR uranium mines. This demonstrates
that geological conditions can be used to mitigate the cost of capital
infrastructure for ore handling and processing
· High desorption recoveries to date: rare earths commenced reporting
to solution when the Pregnant Liquor Solution ("PLS") in the column dropped
below pH 5.2 and rapidly continued until the PLS reached pH 3.0. Final
recoveries are:
o 56% TREOs
o 57% MREOs
o 50% HREOs
· Further recovery upside: increased recoveries of 78% Pr, 86% Nd, 86%
Dy and 87% Tb using a pH 2.0 lixiviant supported by diagnostic tests across
three composite samples(1)
· Low acid consumption: no further acid consumption beyond the
previously reported total sulphuric acid consumption of 15.0 kg per tonne of
ore treated in column ISR study
· Low impurity levels: low levels of impurities (deleterious elements)
compared to recovered rare earths support a low cost, simple process for
purification
Follow this link to watch a short video of CEO Rupert Verco explaining the
results released in this announcement:
https://investors.cobraplc.com/link/0rJk9P
(https://investors.cobraplc.com/link/0rJk9P)
Further information relating to metallurgical results are presented in the
appendices.
(1) Please refer to the announcement dated 1 October 2024 for details of
optimisation recoveries.
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 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
· 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 Conrad Wilkins
who is the Group Process Engineering Lead at Wallbridge Gilbert Aztec, a
Fellow of the Australian Institute of Mining and Metallurgy (FAusIMM),
Chartered Professional Engineer and Member of Engineers Australia (CPEng
MIEAust). Mr Wilkins 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 Wilkins 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
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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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 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 1: Comparison between the Chinese and the proposed Boland process for
ISR mining of REEs
Appendix 2: ISR study process and results
The bench scale ISR study conducted by ANSTO is based on a process routinely
implemented to demonstrate the amenability of uranium ores to be mined via
ISR. ISR is enabled by orebody permeability. These characteristics enable
multiple steps to be removed from the traditional mining and processing. The
objective of the study was to demonstrate and identify optimal parameters in
which ISR could be utilised to minimise the economics of recovering REEs. The
test parameters are scaled to emulate the actual field process. A photograph
of the test sample is detailed in Figure 2.
The ISR process occurs in two phases:
1. Preconditioning: The period where injection and extraction occurs to
impregnate the orebody and modify the acidity of the aquifer. It took
approximately 10 pore volumes (~80 days) to lower the pH from 7.1 to 5.7.
Through this period acid consumption occurred due to the presence of minor
acid consuming minerals. When the PLS pH dropped below pH 5.7, REEs began
reporting to the PLS
2. Extraction: When the acidity reaches a point in which the ion
exchange can occur, REE recovery commences. In this circumstance, this
occurred from pH 5.7. REEs reported to the PLS during 10 pore volumes (~68
days)
Figure 2: ANSTO bench scale ISR test
Results of the study demonstrate:
· Orebody characteristics are amenable to ISR mining - a maximum
permeability rate of 0.16 pore volumes per day which is comparable to
permeability rates of operating uranium mines
· High ionic REE recoveries of 56% TREO, 57% MREO and 50% HREO achieved
by lowering the sample acidity to pH3
· Low acid consumption of 15.0 kg/t sulphuric acid (H(2)SO(4))
· High purity REE extraction: low impurity levels that support a simple
purification process. This enables further optimisation to increase
recoveries. PLS impurity concentrations shown in the table below
Table 1: Achieved recoveries in PLS (mg/L) of REE and impurities during the
extraction phase of the ISR process
TREY Th U Al Fe Si
379 0.008 0.08 55 46 31
Figure 3: Cumulative recoveries of REE to PLS plotted against PLS acidity
Table 2: Head grade and subsequent recoveries of bench scale ISR testing
Hole ID Sample ID Sample Head Grade ppm
TREO Nd2O3 Pr6O11 Dy2O3 Tb2O3
CBSC0004 COBR-3 4,506 708 183 112 19
Bench Scale ISR Recoveries 56% 61% 59% 35% 39%
Appendix 3: JORC Code, 2012 Edition - Table 1
Criteria JORC Code explanation Commentary
Sampling techniques · Nature and quality of sampling (eg cut channels, random chips, or 2024
specific specialised industry standard measurement tools appropriate to the
minerals under investigation, such as down hole gamma sondes, or handheld XRF SONIC
instruments, etc). These examples should not be taken as limiting the broad
meaning of sampling. · Core was scanned by a SciAps X555 pXRF to determine sample intervals.
Intervals through mineralized zones were taken at 10cm. Through waste, sample
· Include reference to measures taken to ensure sample representivity intervals were lengthened to 50cm. Core was halved by knife cutting. XRF scan
and the appropriate calibration of any measurement tools or systems used. locations were taken on an inner surface of the core to ensure readings were
taken on fresh sample faces.
· Aspects of the determination of mineralisation that are Material to
the Public Report. Full core samples were submitted to Australian Nuclear Science and Technology
Organisation (ANSTO), Sydney for XRF analysis and to ALS Geochemistry
· In cases where 'industry standard' work has been done this would be Laboratory (Brisbane) on behalf of ANSTO for lithium tetraborate digest
relatively simple (eg 'reverse circulation drilling was used to obtain 1 m ICP-MS. The core was split in half along the vertical axis, and one half
samples from which 3 kg was pulverised to produce a 30 g charge for fire further split into 10 even fractions along the length of the half-core.
assay'). In other cases more explanation may be required, such as where there Additional sub-sampling, homogenisation and drying steps were performed to
is coarse gold that has inherent sampling problems. Unusual commodities or generate ~260 g (dry equivalent) samples for head assay according to the
mineralisation types (eg submarine nodules) may warrant disclosure of detailed laboratory internal protocols.
information.
Drilling techniques · Drill type (eg core, reverse circulation, open-hole hammer, rotary 2024
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, · Sonic Core drilling completed Star Drilling using 4" core with a
whether core is oriented and if so, by what method, etc). 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
geotechnically logged to a level of detail to support appropriate Mineral
Resource estimation, mining studies and metallurgical studies. Sonic Core
· Whether logging is qualitative or quantitative in nature. Core (or · Logging was carried out in detail, determining lithology and clay/ sand
costean, channel, etc) photography. content. Logging intervals were lithology based with variable interval
lengths.
· The total length and percentage of the relevant intersections logged.
· 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
taken.
Sonic Drilling
· If non-core, whether riffled, tube sampled, rotary split, etc and
whether sampled wet or dry.
· For all sample types, the nature, quality and appropriateness of the · Field duplicate samples were taken nominally every 1 in 25 samples where
sample preparation technique. the sampled interval was quartered.
· Quality control procedures adopted for all sub-sampling stages to · Blanks and Standards were submitted every 25 samples
maximise representivity of samples.
· Half core samples were taken where lab geochemistry sample were taken.
· Measures taken to ensure that the sampling is representative of the
in situ material collected, including for instance results for field · In holes where column leach test samples have been submitted,
duplicate/second-half sampling. full core samples have been submitted over the test areas.
· Whether sample sizes are appropriate to the grain size of the
material being sampled.
Quality of assay data and laboratory tests · The nature, quality and appropriateness of the assaying and Sample Characterisation Test Work performed by the Australian Nuclear Science
laboratory procedures used and whether the technique is considered partial or and Technology Organisation (ANSTO)
total.
· For geophysical tools, spectrometers, handheld XRF instruments, etc,
the parameters used in determining the analysis including instrument make and · Full core samples were submitted to Australian Nuclear Science and
model, reading times, calibrations factors applied and their derivation, etc. 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
· Nature of quality control procedures adopted (eg standards, blanks, even fractions along the length of the half-core. Additional sub-sampling,
duplicates, external laboratory checks) and whether acceptable levels of homogenisation and drying steps were performed to generate ~260 g (dry
accuracy (ie lack of bias) and precision have been established. 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.
· 1 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 are
being taken to confirm PLS assays
Verification of sampling and assaying · The verification of significant intersections by either independent · Sampling data was recorded in field books, checked upon digitising
or alternative company personnel. 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 Resources
· Discuss any adjustment to assay data. 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 · 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 4: 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 Barngarla People.
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 yield permeability and promote insitu recovery
potentail
Drillhole Information · A summary of all information material to the understanding of the · Exploration results being reported represent a small portion of the
exploration results including a tabulation of the following information for Boland target area. Coordinates for Wellfield drill holes are presented in
all Material drill holes: Table 3.
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)
· MREO = Nd(2)O(3) + Pr(6)O(11) + Tb(4)O(7) + Dy(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 the
extensions or depth extensions or large-scale step-out drilling). 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, · Future metallurgical testing will focus on producing PLS under leach
provided this information is not commercially sensitive. 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.
· 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)
· MREO = Nd(2)O(3) + Pr(6)O(11) + Tb(4)O(7) + Dy(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.
· 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.
Table 3: 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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