TORONTO, Feb. 21, 2023 /PRNewswire/ -- Mandalay Resources
Corporation ("Mandalay" or the "Company") (TSX: MND) (OTCQB: MNDJF)
is pleased to announce an updated Mineral Resources and Reserves
(MRMR) estimates for its Björkdal gold mine in Skellefteå,
Sweden as at December 31, 2022. All dollar amounts in this
press release are in U.S. dollars unless otherwise noted.
Highlights:
- Mineral Reserves increased by 32,000 oz net of yearly
depletion;
- Mineral Reserves gold grade increased by 11% to 1.54 g/t,
predominantly through the exploration of the high grade Eastern
plunge extension; and
- Mineral Measured and Indicated Resources increased by 72,000 oz
net of yearly depletion with an increase in gold grade of 10% to
2.27 g/t.
Dominic Duffy, President and CEO
of Mandalay, commented:
"Mandalay's near-mine exploration efforts at Björkdal have been
designed around the goal of bringing higher grades into the near
and medium term mine plan. This goal was realized in 2021 through
drilling of the Eastern Plunge Extension of the Main Zone and
Central Zone veining within the underground mine at Björkdal.
Impressive grades have been seen through this drilling including
47.7 g/t gold over 11.7 m (see news
release dated January 24, 2022),
amongst others, within what is thought to be a geologically
favourable environment for further gold endowment along the eastern
flank of the mine.
"During 2022, this area was further drilled with continued
success – improving our confidence in our vein model grade
estimations supporting an increase in Indicated Mineral Resource
and Mineral Reserves. As such, gold grades of our combined Mineral
Resource and Mineral Reserves increased by 10% and 11%,
respectively. While there are many influencing factors in the
evolving Reserves, the Eastern Plunge Extension is the main reason
for this increase. The higher grades resulted in higher overall
Mineral Reserves of 32,000 gold oz and 72,000 gold oz in Mineral
Resources, representing a 48,400 oz gain net of mining depletion
over 2022. Furthermore, these additional Mineral Reserves were
added at a cost-effective exploration cost of US$31.47 per ounce of gold.
"Since the data cut-off in September
2022, drilling has continued on the eastern flank with
further success (see news release on June
21, 2022), as well as on other major growth potential areas
such as the Aurora system extension and North Zone delineation. We
expect these areas will contribute to further reserve increases in
the future.
"At Costerfield, Mineral Resources and Reserves have not been
updated for year-end 2022. The exploration programs in 2022 were
more directed towards drill testing of regional targets and large
step-outs from the central corridor system. This change in
direction came off the back of a large Mineral Reserve increase at
year-end 2021, which saw Mineral Reserves grow by 24% with an
extended mine life of two years (see news release dated
February 16, 2022)."
Table 1: Comparison of Björkdal Mineral
Reserves and Resources from December 31,
2021, to December 31
2022
|
Proven and
Probable
Reserve
|
Measured and
Indicated
Resources
|
Inferred
Resources
|
Year
End
|
Contained
Au (koz)
|
Au Grade
(g/t)
|
Contained
Au (koz)
|
Au Grade
(g/t)
|
Contained
Au (koz)
|
Au Grade
(g/t)
|
2021
|
542
|
1.39
|
1,146
|
2.07
|
359
|
1.64
|
2022
|
574
|
1.54
|
1,218
|
2.27
|
265
|
1.70
|
|
Notes:
|
1.
|
Mineral Reserves and
Resources are contained at Björkdal property only.
|
2.
|
See footnotes in tables
2 and 3 for details of Proven and Probable Reserve tonnages and
grades, including cut-off grades and Qualified Persons.
|
|
|
Details of the Mineral Resources and Reserves estimates at
Björkdal are related below. Estimates were prepared or verified by
SLR Consulting Ltd. ("SLR").
The year-end 2022 estimates of Mineral Resources and Reserves
for Björkdal will be fully documented in an independent Technical
Report prepared in accordance with National Instrument 43-101 ("NI
43-101") to be filed on www.sedar.com and the Mandalay website
www.mandalayresources.com within 45 days of this press
release.
Björkdal Mineral Resource and
Mineral Reserve Summary
Since the data cut-off date of September
30, 2022 for the year end 2022 MRMR statement, Björkdal
completed 54 drill holes totalling approximately 25,239 m in length to September 30, 2022. The data cut-off date at
Norrberget remains the same, September 30,
2017. In addition, underground operations included
5,495 m of on-vein development, which
was mapped and sampled in detail according to the grade control
protocols.
Other than the normal course updating of the mineralization
wireframes to account for new drilling and sampling information,
the workflow and estimation parameters used to prepare the year end
2022 Björkdal long term block model were largely unchanged.
One of the changes included the addition of a clipping surface
to act as a spatial boundary for gold grades. This surface is
currently viewed as a fault surface and was created to account for
the improved understanding of its impact on the gold distribution
in the veins.
A second change included the use of reporting panels as
constraints for preparing the Mineral Resource statement for the
Aurora Zone vein (wireframe LZA1). The goal of this new approach is
to arrive at a more accurate statement of the tonnage and grade for
Aurora that considers the spatial continuity of the above-cut-off
grade material as well as the below cut-off grade material that is
present as internal dilution.
A third change implemented for the year end 2022 Mineral
Resource reporting was the consideration of Mineral Resources that
may be residing as remnant materials that can no longer meet the
Reasonable Prospects for Eventual Economic Extraction ("RPEEE")
requirement of the Canadian Institute of Mining, Metallurgy and
Petroleum ("CIM") Definition Standards for Mineral Resources and
Mineral Reserves (CIM (2014) definitions). Mineral Resources are
not reported for any blocks with volumes less than the minimum size
for a stope, nor for any blocks residing within an area identified
as having limited or no access for mining operations.
Classification criteria for Measured Resource was changed to
include only material of the Aurora veining in near proximity to
sampled, on-vein, development drives.
The year end 2022 Mineral Resource statement for the Norrberget
deposit is prepared using a revised pit surface that was created
using an updated metal price.
Other than the normal course updating of the underground
long-term wireframes and the re-optimization of the Björkdal and
Norrberget open pits to account for the updated long term resource
model, the workflow and modifying factors used to prepare the year
end 2022 Björkdal Mineral Reserves were largely unchanged from
those used during the previous year.
The reporting cut-off grades for the Mineral Resource and
Mineral Reserve statement were modified slightly to reflect the
higher gold prices used to prepare the estimate. Updated
operational costs and input parameters based upon Q4, 2021 to Q3,
2022 actual figures, and the 2023 budget, were used in the Mineral
Reserve estimation process.
The Mineral Resource estimates are presented in Table 2. The
Mineral Reserve estimates are presented in Table 3.
Table 2: Mineral Resources at Björkdal, Inclusive of Mineral
Reserves, as of December 31,
2022
Category
|
Area
|
Tonnage
(kt)
|
Au Grade
(g/t)
|
Contained Au
(koz)
|
Measured
|
|
|
|
|
|
Björkdal
Underground
|
526
|
2.39
|
40
|
Indicated
|
|
|
|
|
|
Björkdal
Underground
|
11,084
|
2.60
|
926
|
|
Björkdal Open
Pit
|
2,533
|
2.31
|
188
|
|
Norrberget Open
Pit
|
191
|
2.93
|
18
|
|
Stockpiles
|
2,357
|
0.60
|
45
|
Total Measured &
Indicated
|
16,691
|
2.27
|
1,218
|
Inferred
|
|
|
|
|
|
Björkdal
Underground
|
1,815
|
2.10
|
123
|
|
Björkdal Open
Pit
|
3,032
|
1.46
|
142
|
|
Norrberget Open
Pit
|
8
|
3.21
|
1
|
Total
Inferred
|
4,847
|
1.70
|
265
|
|
Notes:
|
1.
|
Björkdal Mineral
Resources are estimated using drill hole and sample data as of
September 30, 2022 and depleted for production through December 31,
2022. Norrberget Mineral Resources are based on a data cut-off date
of September 30, 2017.
|
2.
|
CIM (2014) definitions
and the 2019 CIM Estimation of Mineral Resources and Mineral
Reserves Best Practice Guidelines were followed for Mineral
Resources.
|
3.
|
Mineral Resources are
inclusive of Mineral Reserves.
|
4.
|
Mineral Resources are
estimated using an average gold price of $1,750/oz and an exchange
rate of 9.3 SEK/US$.
|
5.
|
Bulk density is 2.74
t/m3 for veins and host rock. Bulk density is 2.92
t/m3 for skarn ore bodies.
|
6.
|
High gold assays were
capped to 30 g/t Au for the Björkdal open pit mine.
|
7.
|
High gold assays for
the underground mine were capped at 60 g/t Au for the first search
pass and 40 g/t Au for subsequent passes.
|
8.
|
High gold assays at
Norrberget were capped at 24 g/t Au.
|
9.
|
Interpolation was by
inverse distance cubed utilizing diamond drill, reverse
circulation, and chip channel samples.
|
10.
|
Björkdal open pit
Mineral Resources are estimated at a cut-off grade of 0.36 g/t Au
and constrained by a resource pit shell.
|
11.
|
Norrberget open pit
Mineral Resources are estimated at a cut-off grade of 0.42 g/t Au
and constrained by a resource pit shell.
|
12.
|
Underground Mineral
Resources are estimated at a block cut-off grade of 0.82 g/t Au for
all veins except the Aurora vein. The Mineral Resources for the
Aurora vein were constrained by reporting panels.
|
13.
|
A nominal 2.5 m minimum
mining width was used to interpret veins.
|
14.
|
Reported Mineral
Resources are depleted for previously mined underground development
and stopes and exclude remnant material.
|
15.
|
Stockpile Mineral
Resources are based upon surveyed volumes supplemented by
production data.
|
16.
|
Mineral Resources that
are not Mineral Reserves do not have demonstrated economic
viability.
|
17.
|
Numbers may not sum due
to rounding.
|
18.
|
The Independent
Qualified Person for the Björkdal and Norrberget Mineral Resource
estimates is Reno Pressacco, M.Sc.(A)., P.Geo., Associate Principal
Geologist with SLR, who is a Qualified Person as defined by NI
43-101.
|
Table 3: Mineral Reserves at Björkdal, as of December 31, 2022
Category
|
Area
|
Tonnage
(kt)
|
Au Grade
(g/t)
|
Contained Au
(koz)
|
Proven
|
|
|
|
|
|
Björkdal
Underground
|
661
|
1.61
|
34
|
Total
Proven
|
661
|
1.61
|
34
|
Probable
|
|
|
|
|
|
Björkdal
Underground
|
5,617
|
2.10
|
379
|
|
Björkdal Open
Pit
|
2,816
|
1.12
|
101
|
|
Norrberget Open
Pit
|
170
|
2.74
|
15
|
|
Stockpiles
|
2,357
|
0.60
|
45
|
Total
Probable
|
|
10,960
|
1.53
|
540
|
Total Proven &
Probable
|
11,622
|
1.54
|
574
|
|
Notes:
|
1.
|
Björkdal Mineral
Reserves are estimated using drill hole and sample data as of
September 30, 2022 and depleted for production through December 31,
2022.
|
2.
|
Norrberget Mineral
Reserves are based on a data cut-off date of September 30,
2017.
|
3.
|
CIM (2014) definitions
were followed for Mineral Reserves.
|
4.
|
Open pit Mineral
Reserves for Björkdal are based on mine designs carried out on an
updated resource model, applying a block dilution of 100% at 0.0
g/t Au for blocks above 1.0 g/t and 100% at in-situ grade for
blocks below 1.0 g/t, but above a cut-off grade of 0.39 g/t Au. The
application of these block dilution factors is based on historical
reconciliation data from 2018 and 2019. A marginal cut-off grade of
0.39 g/t Au was applied to estimate open pit Mineral
Reserves.
|
5.
|
Open pit Mineral
Reserves for Norrberget are based on 15% dilution at 0.0 g/t Au and
a cut-off grade of 0.46 g/t Au.
|
6.
|
Underground Mineral
Reserves are based on mine designs carried out on an updated
resource model. Minimum mining widths of 4.07 m for stopes (after
dilution) and 4.75 m for development (after dilution) were used.
Stope dilution was applied by adding 0.6 m on each side of stopes
as well as an additional 10% sidewall over break dilution. An
overall dilution factor of 25% was added to development design
widths. Mining extraction was assessed at 95% for contained ounces
within stopes and 100% for development. A cut-off grade of 1.00 g/t
Au was applied to material mined within stopes. An incremental
cut-off grade of 0.46 g/t Au was used for development
material.
|
7.
|
Stockpile Mineral
Reserves are based upon surveyed volumes supplemented by production
data as of December 31, 2022.
|
8.
|
Mineral Reserves are
estimated using an average long term gold price of US$1,600/oz for
Björkdal and Norrberget, and an exchange rate of 9.3
SEK/US$.
|
9.
|
Tonnes and contained
gold are rounded to the nearest thousand.
|
10.
|
Numbers may not sum due
to rounding.
|
11.
|
The Independent
Qualified Person for the Björkdal Mineral Reserve estimate is Rick
Taylor, MAusIMM (CP), Principal Mining Engineer with SLR, who is a
Qualified Person as defined by NI 43-101.
|
|
|
A total of 80,400 ounces of gold have been added to Mineral
Reserves at an exploration cost in 2022 of US$2.53 million, not including regional
exploration expenditure. The net increase of 32,000 ounces of gold
in Proven and Probable Mineral Reserves at 2022 year end, relative
to 2021 year end, included mining depletion of 48,400 ounces of
gold during 2022. The exploration cost of adding these additional
Mineral Reserves was US$31.47 per
ounce of gold.
Qualified Persons:
All Qualified Persons listed below have read and approved the
contents of this news release as it pertains to the Mineral
Resource and Mineral Reserve estimates disclosed in this news
release.
- The Mineral Resource estimates for Björkdal and Norrberget were
carried out under the supervision of Reno Pressacco, M.Sc.(A).,
P.Geo., Associate Principal Geologist, an employee of SLR and
independent of Mandalay. He is a Qualified Person for the purpose
of NI 43-101.
- The QP is not aware of any environmental, permitting, legal,
title, taxation, socio-economic, marketing, political, or other
relevant factors that could materially affect the Mineral Resource
estimate.
- The Mineral Reserve estimate was carried out under the
supervision of Rick Taylor, CP,
MAusIMM, Principal Mining Engineer, an employee of SLR and
independent of Mandalay. He is a Qualified Person for the purposes
of NI 43-101.
- The QP is not aware of any mining, metallurgical,
infrastructure, permitting, or other relevant factors that could
materially affect the Mineral Reserve estimate.
About Mandalay Resources
Corporation:
Mandalay Resources is a Canadian-based natural resource company
with producing assets in Australia
(Costerfield gold-antimony mine), Sweden (Björkdal gold mine). The Company is
focused on growing its production and reducing costs to generate
significant positive cashflow. Mandalay is committed to operating
safely and in an environmentally responsible manner, while
developing a high level of community and employee engagement.
Mandalay's mission is to create shareholder value through the
profitable operation and continuing the regional exploration
program, at both its Costerfield and Björkdal mines.
Currently, the Company's main objective is to continue mining the
high-grade Youle vein at Costerfield, bring online the deeper
Shepherd veins, both of which will continue to supply
high-grade ore to the processing plant, and to extend Youle's
Mineral Reserves. At Björkdal, the Company will aim to increase
production from the Aurora zone and other higher-grade areas in the
coming years, in order to maximize profit margins from the
mine.
Forward-Looking
Statements:
This news release contains "forward-looking statements"
within the meaning of applicable securities laws. Readers are
cautioned not to place undue reliance on forward-looking
statements. Actual results and developments may differ materially
from those contemplated by these statements depending on, among
other things, changes in commodity prices and general market and
economic conditions. The factors identified above are not intended
to represent a complete list of the factors that could affect
Mandalay. A description of additional risks that could result in
actual results and developments differing from those contemplated
by forward-looking statements in this news release can be found
under the heading "Risk Factors" in Mandalay's annual information
form dated March 31, 2022, a copy of
which is available under Mandalay's profile at www.sedar.com. In
addition, there can be no assurance that any inferred resources
that are discovered as a result of additional drilling will ever be
upgraded to proven or probable reserves. Although Mandalay has
attempted to identify important factors that could cause actual
actions, events or results to differ materially from those
described in forward-looking statements, there may be other factors
that cause actions, events or results not to be as anticipated,
estimated or intended. There can be no assurance that
forward-looking statements will prove to be accurate, as actual
results and future events could differ materially from those
anticipated in such statements. Accordingly, readers should not
place undue reliance on forward-looking statements.
Dominic Duffy, President and
Chief Executive Officer; Edison Nguyen, Director, Business
Valuation and IR, Contact: 647.260.1566
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