TIDMAURA
RNS Number : 0581V
Aura Energy Limited
29 November 2019
AURA ENERGY LIMITED
("Aura" or the "Company")
Metallurgical Results for Haggan Vanadium Project
aura completes additional Häggån
Vanadium leaching testwork
V(2) O(5) recovery averaged 96.5% in vanadium targeted oxidative
acid pressure leaching tests
leaching results are Strongly supportive for
Häggån vanadium project
Aura Energy Limited (AEE:ASX, AURA:AIM) is pleased to announce
that it has completed a successful program of metallurgical leach
test work examining vanadium recovery by acid pressure leaching for
the Häggån Vanadium Project, Sweden.
The program was carried out on a total of three drill hole
composite samples defined as representative of the mineralisation
within the Häggån Vanadium High Grade Resource following
consultation with the ASX on the Häggån Scoping Study.
The test work resulted in vanadium recoveries of up to 96.9% to
leach solution, with average recovery of 96.5% V(2) O(5) . This
strong result for scoping level leaching test work provides the
company with confidence that the proposed process flow sheet for
the Häggån Vanadium Project is robust. A summary of results is
presented in Table 1.
Table 1 - Summary of acid pressure leach test vanadium recovery
results
Test Sample Leach Recovery
Vanadium
AC1035 DDH006 96.1%
-------- ---------------
AC1036 DDH022 96.9%
-------- ---------------
AC1037 DDH031 96.7%
-------- ---------------
Average 96.5%
---------------
Following Aura's initial submission of the Häggån Vanadium
Project Scoping Study in early September 2019, several technical
queries were raised during the ASX review process. These queries
related predominantly to assumptions regarding vanadium leach
recovery. To ensure a comprehensive response to the issue and
provide additional confidence in the results of the Häggån Vanadium
scoping study Aura commissioned a vanadium targeted metallurgical
test work program at ALS Minerals, by acid pressure leaching.
The results of these metallurgical tests exceeded the
expectations for recovery of vanadium from the Häggån Resource and
provide the company with great confidence that it has developed a
robust flow sheet.
Aura is currently incorporating these results into the Häggån
Vanadium Scoping Study and expect to deliver the scoping study
shortly allowing progress of the project to its next stages.
Häggån test work results
Acid pressure leaching is generally considered the most
efficient method for extraction of vanadium from Black Shale
resources. In 2018, METS Engineering (METS) undertook a review of
historic test work on the Häggån Resource, determining that acid
pressure leaching was the best technically viable process
option.
The current program was commissioned to validate this technical
assessment by undertaking acid pressure leach tests at conditions
targeted at vanadium extraction, as recommended by METS.
The metallurgical test work program was undertaken on splits of
three samples used in the 2018 beneficiation and flotation program
undertaken at ALS Minerals (Refer to ASX release: Häggån Vanadium
Project Study Progressing Well, 25(th) October 2018). These samples
were considered representative of mineralisation in the Häggån
resource, with a range of vanadium grades. A summary of the samples
used has been presented in Table 2.
Table 2 - Summary of diamond drill hole composite samples used
in acid pressure leaching test work program. Full details of drill
hole composites may be found in the October 2018 ASX Release
Sample Test Head Grade
V(2) O(5) K(2) O
---------- -------
DDH006 AC1035 0.30% 3.66%
-------- ---------- -------
DDH022 AC1036 0.29% 3.64%
-------- ---------- -------
DDH031 AC1037 0.22% 3.36%
-------- ---------- -------
The acid pressure leach conditions were determined based on
recommendations from METS Engineering. These conditions were
targeted at extraction of vanadium and have been summarised in
Table 3.
Table 3 - Acid pressure leach conditions, ALS Minerals 2019
Parameter Test Condition
Grind P80 of 75um
---------------
Oxygen partial pressure 1,200 kPa
O(2)
---------------
Total acid concentration 200 g/L H(2)
- H(2) SO(4) SO(4)
---------------
Residence time 2 hours
---------------
Temperature 180degC
---------------
The results of acid pressure leaching tests targeted at vanadium
recovery have been summarised in Table 4.
Table 4 - Summary of vanadium extraction by acid pressure
leaching by sample
Test Sample Leach Recovery
Vanadium Potassium
--------- ----------
AC1035 DDH006 96.1% 78.8%
-------- --------- ----------
AC1036 DDH022 96.9% 84.4%
-------- --------- ----------
AC1037 DDH031 96.7% 86.8%
-------- --------- ----------
Average 96.5% 83.3%
--------- ----------
These results demonstrated that consistently high vanadium
extraction could be achieved across a range of samples. The tests
returned an average vanadium extraction of 96.5%, with only 0.4%
deviation from this average between the tests.
PREVIOUS Metallurgical Test Work
In October 2018 Aura announced successful completion of
beneficiation and flotation test work for material from the Häggån
Vanadium Project (Refer to ASX release: Häggån Vanadium Project
Study Progressing Well, 25(th) October 2018). These results
demonstrated recovery of an average of 85% vanadium to a
concentrate with an average of 64% of the feed mass. The
concentrate mass reduced to a total of 50% of feed mass with
removal of the carbon component.
The preferred Häggån Vanadium flow sheet includes beneficiation,
acid pressure leaching and solvent extraction of vanadium. The
overall expected recovery for the Häggån vanadium process,
including each of these components will be included in the Häggån
Vanadium Scoping Study.
For more information please visit www.auraenergy.com.au or
contact the following:
Aura Energy Limited Telephone: +61 (3) 9516 6500
Peter Reeve (Executive Chairman) info@auraenergy.com.au
SP Angel Corporate Finance LLP Telephone: +44 (0) 203 470
(Nominated Advisor and Joint Broker) 0470
Ewan Leggat
Jamie Spotswood
WH Ireland Limited
(Joint Broker) Telephone: +44 (0) 207 220
Adrian Hadden 1666
James Sinclair-Ford
Telephone: +44 (0) 7769 325
Yellow Jersey PR Limited 254
Felicity Winkles
Joe Burgess
The information contained within this announcement is deemed by
the Company to constitute inside information under the Market Abuse
Regulation (EU) No. 596/2014.
Competent Person Statement
The Competent Person for the Häggån Metallurgical Test Work is
Dr Will Goodall. Dr Goodall is Principal Metallurgist and a full
time consultant to Aura Energy Ltd. The information in the report
to which this statement is attached that relates to the test work
is based on information compiled by Dr Will Goodall. Dr Goodall has
sufficient experience that is relevant to the test work program and
to the activity which he is undertaking. This qualifies Dr Goodall
as a Competent Personas defined in the 2012 edition of the
'Australasian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves'. Dr Goodall is a Member of The
Australasian Institute of Mining and Metallurgy (AusIMM). Dr
Goodall consents to the inclusion in the report of the matters
based on his information in the form and context in which it
appears.
JORC Code
2012 Edition
Table 1 report
Section 1 Sampling Techniques and Data
(Criteria in this section apply to all succeeding sections.)
Criteria JORC Code explanation Commentary
Sampling techniques Nature and quality of The 2019 Häggån resource estimate was based on
sampling (e.g. cut several drilling campaigns:
channels, random chips, or -- 2008: 3453m in 17 diamond drillholes
specific specialised -- 2010: 5091m in 25 "
industry -- 2011: 2279m in 10 "
standard measurement tools -- 2012: 2226m in 14 "
appropriate to the -- 2015: 149m in 1 "
minerals under -- 2017: 374m in 2 "
investigation, such as -- 2018/19: 2930m in 22 "
down hole
gamma sondes, or handheld
XRF instruments, etc). All drill samples were obtained by diamond drilling.
These examples should not Drillcore samples were provided to ALS
be taken as limiting Global at Piteå in Sweden (ALS) for preparation.
the broad meaning of Samples were analysed by ICP by ALS.
sampling. The Alum Shale, host to the mineralisation, has a
Include reference to relatively consistent content of the target
measures taken to ensure metals.
sample representativity Half-core was cut by diamond saw using a sample interval of
and the appropriate 2m unless the interval included
calibration of any a lithological contact in which case each lithology was
measurement tools or sampled separately. Samples were dried
systems used. at 105degC, then prepared by ALS method Prep 22 (Crush to
Aspects of the 70% less than 6mm, pulverize entire
determination of sample to better than 85% passing 75 microns). A 100g
mineralisation that are sample of pulp was taken by mini-riffle
Material to the Public splitter for analysis.
Report.
In cases where 'industry
standard' work has been
done this would be
relatively simple (e.g.
'reverse circulation
drilling was used to
obtain 1 m samples from
which 3 kg was pulverised
to produce a 30 g charge
for fire assay'). In other
cases, more explanation
may be required,
such as where there is
coarse gold that has
inherent sampling
problems. Unusual
commodities
or mineralisation types
(e.g. submarine nodules)
may warrant disclosure of
detailed information.
Drilling techniques Drill type (e.g. core, Diamond drill core; standard tube; all BQTQ (core diameter
reverse circulation, 47mm) or an equivalent size depending
open-hole hammer, rotary on the contractor used.
air blast, auger, Bangka, All 2018/19 holes & approximately 20% of previous holes
sonic, etc) and details were surveyed downhole, generally
(e.g. core diameter, at 3m intervals. The majority of holes surveyed have
triple or standard tube, limited deviation, with a maximum deviation
depth of diamond tails, at the bottom of a hole of c. 11 m.
face-sampling bit or other All holes but 1 drilled in 2010 were collared vertically.
type, whether core is The 1 inclined hole was drilled
oriented and if so, by at an angle of -65deg to 090deg and drillcore was oriented.
what method, etc).
Drill sample recovery Method of recording and Any core loss was marked by the drillers and measured and
assessing core and chip recorded by the geologist during
sample recoveries and core logging.
results assessed. The Alum Shale, host to the mineralisation, consistently
Measures taken to maximise has recoveries of +95%.
sample recovery and ensure Assays in the few intervals which include higher core loss
representative nature of appear typical of assays in areas
the samples. of high recovery nearby. There is no evidence of any grade
Whether a relationship bias that might arise from the
exists between sample small number of intervals with poor or no core recovery.
recovery and grade and
whether sample bias may
have occurred due to
preferential loss/gain of
fine/coarse material.
Logging Whether core and chip Core was aligned and checked for continuity and marked out
samples have been in one-meter intervals. It was
geologically and checked for drill bit marking as bit matrices are known to
geotechnically logged to a contain molybdenum. Comments were
level recorded in the database regarding the presence of bit
of detail to support marks.
appropriate Mineral Core was geologically logged, recording lithology,
Resource estimation, oxidation, mineralogy (where possible),
mining studies and texture, fracture density & structure and radiation levels
metallurgical recorded by handheld scintillometer.
studies. Down hole depth intervals were recorded with an accuracy of
Whether logging is 20 cm.
qualitative or All core was photographed.
quantitative in nature. All core was geologically logged.
Core (or costean, channel,
etc)
photography.
The total length and
percentage of the relevant
intersections logged.
Sub-sampling techniques If core, whether cut or Core was sawn in half using a core saw.
and sample preparation sawn and whether quarter, All drill holes were diamond drill holes.
half or all core taken. * Half core was taken using a sample interval of 2 m.
If non-core, whether Sample was dried at 105degC, then crushed to 70% -2
riffled, tube sampled, mm using ALS method Prep 22 (crush to 70% less than
rotary split, etc and 6mm, pulverize entire sample to better than 85%
whether sampled wet or passing 75 microns). 100g sample of pulp to split off
dry. using mini-riffle splitter for analysis.
For all sample types, the
nature, quality and
appropriateness of the * Precision of sampling and analysing pulps is based on
sample preparation QC sample results, considered to be within +/- 5% and
technique. acceptable for use in resource estimation at any
Quality control procedures confidence level.
adopted for all
sub-sampling stages to
maximise representivity * The grain size of the Alum Shale is extremely fine,
of samples. less than 10 microns, and commonly around 1 micron.
Measures taken to ensure The uranium mineralisation is finely disseminated
that the sampling is throughout the shale, again at a micron scale or
representative of the less. Consequently, the mineralisation and its host
in-situ material rock are very well represented in the 2m samples of
collected, core collected (average sample 3.3 kg). Sample size
including for instance is therefore appropriate.
results for field
duplicate/second-half
sampling.
Whether sample sizes are
appropriate to the grain
size of the material being
sampled.
Quality of assay data and The nature, quality and Multi-element assaying was done by ALS Method ME-ICP61 on a
laboratory tests appropriateness of the 0.25g sample (4 acid digestion
assaying and laboratory with ICP-AES finish). The ICP method after 4 acid digestion
procedures used and is reported to give near total
whether the technique is assay for all resource elements.
considered partial or For quality control every 25 samples submitted for assay
total. included 1 duplicate, 1 blank, and
For geophysical tools, 1 CRM (certified reference material). The 3 CRMs used in
spectrometers, handheld the latest round of drilling were
XRF instruments, etc, the produced from Häggån Alum Shale to ensure matrix
parameters used in matching and certified by OREAS.
determining the analysis QAQC data were inspected by Aura before data were accepted
including instrument make and entered into the Aura database.
and model, reading times, Review of these QAQC results indicates acceptable levels of
calibrations accuracy and precision have been
factors applied and their established.
derivation, etc.
Nature of quality control
procedures adopted (e.g.
standards, blanks,
duplicates, external
laboratory checks) and
whether acceptable levels
of accuracy (i.e. lack of
bias) and precision
have been established.
Verification of sampling The verification of No twin holes were drilled.
and assaying significant intersections The following information primary data is recorded: Collar,
by either independent or alteration, assays, drilling type,
alternative company Geology, Geotech, Magnetic susceptibility, mineralisation,
personnel. radiometrics, samples, scintillometer,
The use of twinned holes. spectrometer, structure, veining, surface samples, batch
Documentation of primary details.
data, data entry All logging was done by the geologist digitally in an Excel
procedures, data spreadsheet. Photos of the core
verification, data storage are taken after the hole was logged. Data is kept on site
(physical on an external hard drive as well
and electronic) protocols. as being sent by email to Aura Energy in Australia where it
Discuss any adjustment to was uploaded into the independently
assay data. managed EarthSQL data base.
No data enters the database without verification by the
Database Manager.
Database is managed by external contractor EarthSQL.
No adjustment has been made to assay data as received from
the laboratory.
Location of data points Accuracy and quality of Initial location was taken during drilling with handheld
surveys used to locate GPS at an accuracy of +/- 3metres.
drill holes (collar and All holes on which the Indicated Resource are based were
down-hole surveys), subsequently surveyed by DGPS with
trenches, mine workings an accuracy of better than 20cm.
and other locations used All drill collars prior to 2015 were recorded in Swedish
in Mineral Resource grid system RT 90 2.5. Subsequent
estimation. holes were recorded in grid system SWEREF 99 TM following a
Specification of the grid change by the Swedish Government.
system used. All collars were converted to SWEREF 99 TM for the 2018 and
Quality and adequacy of 2019 resource estimation.
topographic control. Holes were vertical in all cases except Hole 39. Aura
conducted down hole surveys for deviation
using a Reflex Ex Trac survey device. All drillholes since
2015 have been downhole surveyed.
Approximately 20% of drillholes prior to 2015 were downhole
surveyed. The maximum deviation
occurred in Hole 22 which had a dip of 75 at 250 m. This
represents an average deviation of
0.3 degrees per meter and a maximum location error at the
bottom of the hole of 11 m for holes
assumed to be vertical. Other surveyed holes had visibly
less deviation.
Drillholes on which the Inferred Resource is based were
drilled on an approximately 100m x
100m pattern, and holes on which the Inferred Resource is
based are located on an approximate
400 m by 400 m grid; precise locations depended partially
on access.
Topography: Collar RLs were determined by GPS to an
accuracy of approx..3m. Hole collars used
in the Indicated Resource were re-surveyed by DGPS to an
accuracy of better than 20cm.
Data spacing and Data spacing for reporting Exploration Results are not reported here as Mineral
distribution of Exploration Results. Resource Estimates exist.
Whether the data spacing H&S Consultants (H&SC) consider the drillhole spacing to be
and distribution is sufficient for their Resource
sufficient to establish Classification as Indicated and Inferred.
the degree of geological The vast majority of sample intervals are 2 m in length.
and grade continuity For the purposes of Resource Estimation,
appropriate for the samples were composited to 2 m intervals. The boundaries of
Mineral Resource and Ore the mineralisation wireframes
Reserve estimation were honoured.
procedure(s)
and classifications
applied.
Whether sample compositing
has been applied.
Orientation of data in Whether the orientation of As the mineralisation occurs in sub-horizontal sheets,
relation to geological sampling achieves unbiased vertical drilling is an appropriate
structure sampling of possible drilling orientation.
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 Drillcore was collected by Aura personnel from the drill
ensure sample security. sites and immediately taken and housed
in Aura's local locked core shed. After logging the core
was transported to ALS Laboratories
facility by either Aura or ALS personnel for core sawing,
sample preparation and assaying.
Audits or reviews The results of any audits Procedures were reviewed during visits by independent
or reviews of sampling consultants Rupert Osborn of H&S Consulting
techniques and data. in Dec 2018 and by W H Ireland in 2016 and no issues were
identified.
=========================== =========================== ============================================================
Section 2 Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this
section.)
Criteria JORC Code explanation Commentary
Mineral tenement and Type, reference name/number, location and ownership including All Resources of the
land tenure status agreements or material issues Häggån Project
with third parties such as joint ventures, partnerships, are located on
overriding royalties, native title Exploration Permit
interests, historical sites, wilderness or national park and Häggån
environmental settings. No. 1. This permit is
The security of the tenure held at the time of reporting along held in the name of the
with any known impediments Aura Energy Ltd
to obtaining a licence to operate in the area. 100%-owned Swedish
subsidiary
company, Vanadis Battery
Metals AB, which holds a
100% interest in this
permit and adjoining
permits.
Only standard Swedish
Government royalties
apply to these permits.
No native title interests
are known to exist in the
permits.
A small, 2-hectare Natura
2000 area occurs against
the eastern boundary of
Häggån
No.1 permit; this area is
not in the vicinity of
the currently-planned
mining area should
a project be initiated at
Häggån.
The Häggån Nr 1
Exploration Permit on
which the entire resource
is situated is valid
until 28/8/2022.
Exploration done by Acknowledgment and appraisal of exploration by other parties. Aura is not aware of any
other parties prior exploration by
others.
Geology Deposit type, geological setting and style of mineralisation. Mineralisation at
Häggån is
hosted by bedded black
shales of the Cambrian to
Ordovician
Alum Shale in
tectonically or otherwise
stratigraphically
thickened metal-enriched
north-north-west-striking
elongated geological
domains. The mineralised
sequence outcrops in an
area in the east of
the tenement but
elsewhere underlies a
variably thin cover of
limestone. Minor
inter-beds
of carbonate-enriched
shale or siltstone
occasionally occur within
the mineralised sequence.
The mineralised unit
overlies a mixed sequence
of siltstone and massive
mineralized back shale
above a granitoid
gneissic basement.
It is interpreted that
there are a series of
overthrusts which have
displaced and caused
thickening
of Alum Shale within the
resource area, and the
sub-horizontal thrust
sheets have influenced
the grade distribution
within the
Häggån deposit.
Drill hole Information A summary of all information material to the understanding Drillhole collar
of the exploration results including locations are shown in
a tabulation of the following information for all Material figures in the 10 October
drill holes: 2019 ASX announcement
* easting and northing of the drill hole collar made
by Aura "Häggån
Battery Metal Project
* elevation or RL (Reduced Level - elevation above sea Resource Upgrade Estimate
level in metres) of the drill hole collar Successfully Completed"
which this table
accompanied. Further
* dip and azimuth of the hole specific drillhole data
is not relevant to the
reporting
* down hole length and interception depth of this resource
estimation.
* 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 In reporting Exploration Results, weighting averaging No Exploration Results
methods techniques, maximum and/or minimum grade are reported here as they
truncations (e.g. cutting of high grades) and cut-off grades are superseded by Mineral
are usually Material and should Resource Estimates.
be stated.
Where aggregate intercepts incorporate short lengths of high
grade results and longer lengths
of low grade results, the procedure used for such aggregation
should be stated and some typical
examples of such aggregations should be shown in detail.
The assumptions used for any reporting of metal equivalent
values should be clearly stated.
Relationship between These relationships are particularly important in the reporting As the mineralisation
mineralisation widths of Exploration Results. occurs in sub-horizontal
and intercept lengths If the geometry of the mineralisation with respect to the drill sheets, downhole lengths
hole angle is known, its nature are believed to be
should be reported. a close approximation to
If it is not known and only the down hole lengths are reported, true widths.
there should be a clear statement
to this effect (e.g. 'down hole length, true width not known').
Diagrams Appropriate maps and sections (with scales) and tabulations of Appropriate maps and
intercepts should be included sections and tabulations
for any significant discovery being reported These should of intersects can be
include, but not be limited to a found on the Aura Energy
plan view of drill hole collar locations and appropriate website
sectional views. (www.auraenergy.com.au)
or in releases to the
Australian Stock Exchange
(ASX), available
on the ASX website.
Balanced reporting Where comprehensive reporting of all Exploration Results is not No Exploration Results
practicable, representative are reported here as they
reporting of both low and high grades and/or widths should be are superseded by Mineral
practiced to avoid misleading Resource Estimates.
reporting of Exploration Results.
Other substantive Other exploration data, if meaningful and material, should be This information has been
exploration data reported including (but not reported to the ASX over
limited to): geological observations; geophysical survey the 11 years since the
results; geochemical survey results; discovery drillhole
bulk samples - size and method of treatment; metallurgical test in 2008.
results; bulk density, groundwater,
geotechnical and rock characteristics; potential deleterious or
contaminating substances.
Further work The nature and scale of planned further work (e.g. tests for Further work plans are
lateral extensions or depth extensions outlined in the report
or large-scale step-out drilling). which this table
Diagrams clearly highlighting the areas of possible extensions, accompanies.
including the main geological Areas for likely
interpretations and future drilling areas, provided this extension of the
information is not commercially sensitive. mineralisation are
indicated on block model
sections in
the report that this
table accompanies.
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