13 June 2024
Panthera Resources Plc
("Panthera" or "the
Company")
Kalaka Metallurgical Test
Results
Panthera Resources Plc (AIM: PAT), the
diversified gold exploration and development company with assets in
West Africa and India, is pleased to announce the results for
bottle roll metallurgical tests on samples of crushed diamond drill
core.
Highlights
· These
test results showed recoveries between 67% and 88%, a positive
result for the coarse size tested (minus 10mm).
· All
samples tested show relatively fast cyanide leaching with most gold
extracted within 12 hours of leaching.
· The
initial tests show an ore amenable to simple cyanide leaching
and build on previous encouraging Leachwell
analysis1 which
also returned positive cyanide extractable gold recovery
results.
Commenting on the results, Mark Bolton, Managing Director of
Panthera said:
"The positive
results from this metallurgical testing together with the
previously reported favourable Leachwell test results further
underpin our growing confidence in the potential at Kalaka which is
a significant mineralised gold system.
This testing
represents another important step in our multi-step approach
towards assessing the potential for Kalaka mineralisation to be
developed by heap leach processing. If this and future work
confirm this approach to be viable, the body of work will
demonstrably lift confidence in the Kalaka mineralisation to be
able to be economically developed."
Bottle Roll
Cyanide Leach Metallurgical Test Work
The Company engaged metallurgist Ray Burring of
4 Dragons Gold Pty Ltd to advise on the test design and
interpretation of the test results.
The objective of this testing was to provide
further metallurgical data on the sulphide leach performance of the
Kalaka mineralisation, as one of the steps in our overall plan to
assess the potential for this mineralisation to be developed by
heap leach processing.
A cyanide bottle roll test is the industry
standard first step in assessing the gold recovery possible by
cyanide leaching. During a bottle roll test, prepared ore is gently
agitated in a cyanide lixiviant or leaching solution and usually
analysed at various leach time intervals.
It is cautioned that although these initial
tests show an ore amenable to simple cyanide leaching, further
bench scale testing will be required of various sizes in columns to
simulate leaching in a heap scenario and bench testing using
material ground to -75 microns be completed to determine the
recovery potential in a carbon in leach (CIL) plant to evaluate the
metallurgical properties of the ore.
The samples were taken over one metre intervals of
available quarter core from two of the historical diamond
drill holes at the K1A Prospect. The core samples were submitted to
the SGS Laboratory located in Bamako, Mali and crushed
to a minus 10mm size, under supervision of Panthera staff.
The metallurgical testing was completed by SGS Ouagadougou
in Burkina Faso.
The following summarizes key aspects of the process
method used:
· tests
were completed on 14 one metre interval quarter core samples where
each sample weighed 2kg or less;
· the
samples of drill core were crushed to a nominal 10mm;
·
Each entire sample was treated by bottle rolling
in cyanide liquor, wherein aliquots are drawn off after time
intervals of 2, 12, 24 and 48 hours, and assayed by AAS for gold
contents; and
·
The residue is then Fire
Assayed2 for gold content after the 48 period, a head grade is
calculated from these results and all time-determined recoveries
calculated and reported.
Results and
Observations of Bottle Roll Metallurgical
Testing.
Presented in Table 1 below is a summary of the
SGS Burkina SA analytical report with sample descriptions contained
in the Appendix.
The tests were carried at 50% solids by weight,
as per normal practice, and the head grade calculated from the
addition of the assay at the end of the test (48 hours) and the
tailings residue. The results from samples KA-Met-24 numbers
007 to 020 were split into low calculated head grades < 1ppm and
calculated head grades >1ppm.
TABLE 1.
Samples
Crushed to <10mm
|
|
|
Low Grade
<1 ppm
|
|
|
|
Calc Head
Grade
|
Tails
Grade
|
Au Rec'y
at 2 hrs
|
Au Rec'y
at 12 hrs
|
Au Rec'y
at 24 hrs
|
Au Rec'y
at 48 hrs
|
|
|
|
|
KA-MET-24-007
|
0.794
|
0.16
|
75.1%
|
76.2%
|
76.4%
|
79.8%
|
|
|
KA-MET-24-011
|
0.995
|
0.13
|
69.0%
|
76.5%
|
82.6%
|
86.9%
|
|
|
KA-MET-24-012
|
0.445
|
0.10
|
74.8%
|
74.2%
|
75.3%
|
77.5%
|
|
|
KA-MET-24-015
|
0.647
|
0.14
|
74.0%
|
76.5%
|
77.3%
|
78.4%
|
|
|
KA-MET-24-018
|
0.554
|
0.15
|
71.3%
|
70.4%
|
74.2%
|
72.9%
|
|
|
KA-MET-24-019
|
0.554
|
0.16
|
66.2%
|
67.1%
|
69.7%
|
71.1%
|
|
|
KA-MET-24-020
|
0.457
|
0.07
|
77.9%
|
77.5%
|
84.0%
|
84.7%
|
|
|
Grade
>1 ppm
|
|
|
|
Calc Head
Grade
|
Tails
Grade
|
Au Rec'y
at 2 hrs
|
Au Rec'y
at 12 hrs
|
Au Rec'y
at 24 hrs
|
Au Rec'y
at 48 hrs
|
|
|
|
|
KA-MET-24-008
|
1.075
|
0.17
|
80.5%
|
82.0%
|
82.6%
|
84.2%
|
|
|
KA-MET-24-009
|
1.379
|
0.30
|
75.7%
|
77.7%
|
77.7%
|
78.2%
|
|
|
KA-MET-24-010
|
1.167
|
0.23
|
70.2%
|
76.4%
|
79.4%
|
80.3%
|
|
|
KA-MET-24-013
|
1.276
|
0.15
|
79.0%
|
83.4%
|
84.9%
|
88.2%
|
|
|
KA-MET-24-014
|
3.750
|
0.55
|
70.4%
|
79.3%
|
82.9%
|
85.3%
|
|
|
KA-MET-24-016
|
1.995
|
0.65
|
62.5%
|
59.6%
|
66.6%
|
67.4%
|
|
|
KA-MET-24-017
|
4.016
|
0.90
|
71.9%
|
71.8%
|
76.2%
|
77.6%
|
|
|
|
|
|
Discussion
· Samples
were from core crushed to <10mm.
· The
recoveries from the low grade <1ppm samples were all acceptable
showing low tailings grades and could be extracted using heap leach
techniques.
· The
recoveries from the higher grades >1ppm were all relatively good
for coarse material crushed to <10mm. The higher grades showed
high tailings grades, as would be expected. To possibly improve on
these test results in following steps towards assessing
applicability of heap leach processing, such higher grade samples
would be crushed and ground to much finer sizes and higher
recoveries can be expected.
· The
recoveries ranged from 67% to 88%. These are interpreted as good
recoveries for material crushed <10 mm.
· All samples
tested show relatively fast leaching with most of the gold
extracted after 12 hours of leaching.
Conclusions
· The samples
of low grade from the crushed samples achieved reasonable
recoveries with low tailings grades.
· The samples
of the higher grades from the crushed samples gave good recoveries
for coarse material.
Kalaka Project
Background
At the Kalaka Project, Panthera has
an 85% joint venture interest with the remaining 15% interest held
by our local partner, Golden Spear Mali SARL. Panthera is the
operator of the project.
The project is located in southeast
Mali, between Morila and Syama gold mines and is approximately 260
km southeast of Bamako. It lies approximately 80 km south of the
Morila gold mine (8m oz) and 85 km northwest of Resolute's Syama
gold mine (6m oz) and is situated adjacent and to the east of the
regional Banifin Shear Zone.
At the K1A target area, the
Company's Competent Person Report (prepared by Golder Associates
Pty Ltd), which was disclosed in the Company's AIM Admission
Document, reported that drilling by past explorers defined a
potential endowment of 250,000 to 500,000 ounces. Furthermore,
Golder Associates Pty Ltd ("Golder") reported that this represents
an exploration target where further infill drilling may lead to the
estimation of a Mineral Resource.
More recently, follow-up work by
Panthera including re-examination of all available drill data at
K1A, identified a mineralised envelope that broadly conforms to the
potential endowment mentioned by Golder. This work identifies an
exploration target of between 0.5 Moz to 1 Moz gold.
Importantly, the Company is yet to drill the northern extension of
the mineralisation at K1A together with several similar targets on
the project area. Taken together this would potentially expand the
exploration target to approximately 3 Moz of gold.
Notes:
1. The
Leachwell analytical technique is formulated for treating large
samples, typically plus 2kg weight, by fast cyanide ("CN") leach
gold analysis. The technique provides a preliminary indication of
the CN leachability of pre-metallurgical sample testing. As
Leachwell analysis is carried out on larger samples (typically 2 kg
or more in weight it can be considered representative of gold
content especially when particle gold may occur. After the CN gold
leaching cycle has been completed the CN solution is analysed. The
'tails' after the gold extraction by the CN method are then
processed using fire assay technique to identify the residual
content of gold in the sample.
2.
Fire assay method has been practiced since ancient times and
remains the industry-standard technique for determining gold
content in all sample types. This well-understood technique
provides accurate results across geological sample types. However,
practiced skill is essential to achieving a successful fire assay.
A range of fire assay methods are available with 30g or 50g sample
aliquots taken after a larger representative sample has been
crushed and pulverised for homogenisation. Multiple options for
detection ranges to suit the needs of the project.
APPENDIX - Sample Description and Analytical
Data
Contacts
Panthera Resources PLC
Mark Bolton (Managing
Director)
|
+61 411
220 942
contact@pantheraresources.com
|
|
|
Allenby Capital Limited (Nominated Adviser & Joint
Broker)
John Depasquale / Vivek Bhardwaj
(Corporate Finance)
Guy McDougall / Kelly Gardiner (Sales
& Corporate Broking
|
+44 (0) 20
3328 5656
|
|
|
Novum Securities Limited (Joint Broker)
|
+44 (0) 20
7399 9400
|
Colin Rowbury
|
|
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Qualified
Persons
The technical information contained in this
disclosure has been read and approved by Ian S Cooper (BSc, ARSM,
FAusIMM, FGS), who is a qualified geologist and acts as the
Qualified Person under the AIM Rules - Note for Mining and Oil
& Gas Companies. Mr Cooper is a geological consultant to
Panthera Resources PLC.
The technical information contained in this
disclosure relating to the metallurgical test work has been read
and approved by Ray Burring. Ray is the owner and
principal engineer of the Consulting Company, 4 Dragons Gold Pty
Ltd, that has operated since 1989. Ray has a degree in Mineral
Processing from Leeds University and is a Member of the Australian
Institute of Mining and Metallurgy, Member of the Institute of
Materials, Minerals and Mining and a Chartered Engineer. Ray is a
Metallurgist with extensive experience of Gold and Base Metal
operations, both operating and design. This work has been carried
out in Australia, Vietnam, Laos, New Zealand, France, Iran,
Mauritania, Russia and Eritrea. Ray Burring acts as
the Qualified Person under the AIM Rules - Note for Mining and Oil
& Gas Companies. Mr Burring is a Metallurgical consultant
to Panthera Resources PLC.
UK
Market Abuse Regulation (UK MAR) Disclosure
The information contained within
this announcement is deemed by the Company to constitute inside
information for the purposes of Regulation 11 of the Market Abuse
(Amendment) (EU Exit) Regulations 2019/310. Upon the publication of
this announcement via a Regulatory Information Service ("RIS"),
this inside information is now considered to be in the public
domain.
Forward-looking Statements
This news release contains
forward-looking statements that are based on the Company's current
expectations and estimates. Forward-looking statements are
frequently characterised by words such as "plan", "expect",
"project", "intend", "believe", "anticipate", "estimate",
"suggest", "indicate" and other similar words or statements that
certain events or conditions "may" or "will" occur. Such
forward-looking statements involve known and unknown risks,
uncertainties and other factors that could cause actual events or
results to differ materially from estimated or anticipated events
or results implied or expressed in such forward-looking statements.
Such factors include, among others: the actual results of current
exploration activities; conclusions of economic evaluations;
changes in project parameters as plans continue to be refined;
possible variations in ore grade or recovery rates; accidents,
labour disputes and other risks of the mining industry; delays in
obtaining governmental approvals or financing; and fluctuations in
metal prices. There may be other factors that cause actions, events
or results not to be as anticipated, estimated or intended. Any
forward-looking statement speaks only as of the date on which it is
made and, except as may be required by applicable securities laws,
the Company disclaims any intent or obligation to update any
forward-looking statement, whether as a result of new information,
future events or results or otherwise. Forward-looking statements
are not guarantees of future performance and accordingly, undue
reliance should not be put on such statements due to the inherent
uncertainty therein.
**ENDS**