TSX Venture Exchange Symbol: NCX
Highlights
- The recently completed metallurgical tests improved the
copper and gold recovery rates at the Hushamu Deposit by an average
of 17% and 24% respectively, compared to the tests forming the
bases for estimates used in the previously published PEA
- Metallurgical tests also demonstrate potential to recover
silver and rhenium metal content, which was previously excluded
from the PEA economics
- Similar metallurgical tests are underway for the nearby Red
Dog Deposit
- The previously published PEA is being updated to include
upside potential related to higher gold and copper recovery rates,
higher metal prices, and the inclusion of silver and rhenium metal
recovery
VANCOUVER, BC, Sept. 1, 2020
/CNW/ - Northisle Copper and Gold Inc. (TSXV:
NCX) ("Northisle" or the "Company") is pleased to report that
preliminary metallurgical test results demonstrate a significant
improvement in recoveries of copper and gold for the Hushamu
Deposit at its 100%-owned North Island Project located in
British Columbia, Canada.
The test work was designed to investigate alternative flotation
parameters to improve the recovery rates of copper and gold in the
two mineralization types in the Hushamu Deposit. The results
demonstrate that the average copper and gold recovery rates
improved by 17% and 24% respectively, compared to tests used for
the Preliminary Economic Assessment ("PEA") published in
September 2017.
In addition, the metallurgical test work included assaying and
evaluating the recoveries of rhenium and silver which were not
included in earlier test work and in the PEA economics. Results
demonstrate rhenium recoveries of 66.1% and 29.3% into the
low pyrite mineralization concentrate ("CMG") and the high pyrite
mineralization concentrate ("SCP) respectively, and silver content
in the low pyrite mineralization concentrate of 29.3 g/t and 18.0
g/t in the high pyrite mineralization concentrate ("SCP").
Following the successful metallurgical results obtained for the
Hushamu Deposit, a similar program is underway for the nearby Red
Dog Deposit. Once these studies are completed, Northisle expects to
update the PEA to incorporate upside potential related to the
expected higher gold and copper recovery rates, inclusion of silver
and rhenium metal recovery, and higher metal prices.
John McClintock, President and CEO stated:
"These results are very positive as they are expected to
significantly improve the economics of our North Island Project.
Given this success, we are excited about currently underway
metallurgical testing on the nearby Red Dog Deposit. Once these
studies are completed, we are eager to update our PEA to reflect
the upside potential of higher copper and gold recovery rates,
inclusion of silver and rhenium metal recovery, and higher metal
prices."
TEST PROGRAM DETAILS
The metallurgical test program was completed by SGS Canada Inc.
(SGS) at their laboratory facility in Burnaby, BC. The test work was done on two
approximately 100kg composites samples of core; one of the SCP and
the other of CMG mineralization. The CMG composite came from drill
holesH08-08, H12-03, H12-10, H12-12, H14-05 and H17-01 while the
SCP sample came from drill holes H17-01 and H-08-08. The samples
comprising the composites represent a range of high and lower grade
mineralization. The results of the lock cycle tests for the two
mineralization types are presented in the table below. For
comparison, the results of the lock cycle tests used for the PEA
are presented in Table 2. The composites for the earlier
metallurgical work were prepared from core samples from H14-05.
Detailed test work included: sample preparation, QEMSCAN
analysis, sample characterization, batch rougher batch cleaner and
lock cycle test work. Modifications to the original flotation
conditions of the 2016 work included, finer primary grind, a single
stage regrind of the rougher concentrate, new reagent scheme and a
three stage cleaner circuit.
The results of the metallurgical tests demonstrated that the
copper recoveries of low pyrite mineralization improved to 86.6%
from 74.5% and to 87.9% from 75.0% in the high pyrite
mineralization. Gold recoveries in the low pyrite mineralization
improved to 50.6% from 43.7% and to 46.4% from 34.4% in the high
pyrite mineralization.
Table 1: SGS Labs Results Lockcycle Tests
|
Calculated
Feed grade
(% or gpt)
|
PG
(um)
|
Concentrate grade (%
or gpt)
|
Recovery
%
|
|
Cu
|
Au
|
Mo
|
Ag
|
Re
|
|
Cu
|
Au
|
Mo
|
Ag
|
Re
|
Cu
|
Au
|
Mo
|
Ag
|
Re
|
SCP
|
0.33
|
0.38
|
0.01
|
0.56
|
0.38
|
76
|
22.9
|
13.6
|
0.18
|
18.0
|
8.7
|
87.9
|
46.4
|
26.8
|
40.9
|
29.3
|
CMG
|
0.31
|
0.33
|
0.01
|
0.77
|
0.4
|
76
|
23.8
|
14.9
|
0.48
|
29.3
|
23.5
|
86.6
|
50.8
|
69.4
|
43.1
|
66.1
|
Table 2: 2016 Base Met Lockcycle Tests
|
Calculated Feed
grade
(% or gpt)
|
PG
(um)
|
Concentrate grade
(% or gpt)
|
Recovery
%
|
|
Cu
|
Au
|
Mo
|
Ag
|
Re
|
100
|
Cu
|
Au
|
Mo
|
Ag
|
Re
|
Cu
|
Au
|
Mo
|
Ag
|
Re
|
SCP
|
0.31
|
0.36
|
.014
|
na
|
na
|
100
|
19.0
|
10.1
|
0.78
|
na
|
na
|
75.0
|
34.4
|
69.8
|
na
|
na
|
CMG
|
0.25
|
0.28
|
0.009
|
na
|
na
|
100
|
22.0
|
14.4
|
0.41
|
na
|
na
|
74.5
|
43.7
|
37.6
|
na
|
na
|
ABOUT THE NORTH ISLAND PROJECT
The 100%-owned North Island Project consists of the Hushamu and
nearby Red Dog deposits, with Mineral Resources summarized in the
below table.
Table 3: North Island Project Resources as at December 31, 2018
|
Tonnes,
'000
|
Grade
|
Contained
Metal
|
Cu,
%
|
Au,
g/t
|
Mo,
%
|
Re,
ppm
|
Cu Eq,
%
|
Cu, B
lb
|
Au,
Moz
|
Mo, M
lb
|
Re, Kg x
1000
|
Cu eq, B
lb
|
Au eq,
Moz
|
Red
Dog
|
|
|
|
|
|
|
|
|
|
|
|
|
Indicated
|
36,568
|
0.27
|
0.38
|
0.005
|
|
0.52
|
0.22
|
0.45
|
4.0
|
|
0.42
|
0.99
|
Inferred
|
1,774
|
0.20
|
0.30
|
0.003
|
|
0.39
|
0.01
|
0.02
|
0.1
|
|
0.02
|
0.04
|
Hushamu
|
|
|
|
|
|
|
|
|
|
|
|
|
Indicated
|
305,180
|
0.24
|
0.28
|
0.008
|
0.54
|
0.43
|
1.62
|
2.75
|
53.8
|
165
|
2.92
|
6.97
|
Inferred
|
189,640
|
0.19
|
0.24
|
0.007
|
0.35
|
0.36
|
0.79
|
1.46
|
29.3
|
66
|
1.49
|
3.56
|
Total
|
|
|
|
|
|
|
|
|
|
|
|
|
Indicated
|
341,743
|
0.24
|
0.29
|
0.008
|
0.48
|
0.44
|
1.83
|
3.2
|
57.8
|
165
|
3.34
|
7.96
|
Inferred
|
190,788
|
0.19
|
0.24
|
0.007
|
0.35
|
0.36
|
0.80
|
1.48
|
29.4
|
66
|
1.51
|
3.60
|
Mineral Resource estimates follow the Canadian Institute of
Mining, Metallurgy and Petroleum ("CIM") definitions standards for
Mineral Resources and Reserves and have been completed in
accordance with the Standards of Disclosure for Mineral Projects as
defined by National Instrument 43-101. The NI 43-101 reports
co-authored by P Burt PGeo and B Game PGeo documenting the resource
estimate available on the company's website and filed on SEDAR.
Reported tonnage and grade figures have been rounded from raw
estimates to reflect the relative accuracy of the estimate.
Minor variations may occur during the addition of rounded numbers.
Mineral Resources that are not Mineral Reserves do not have
demonstrated economic viability. Copper and gold equivalent
calculated using US$3.10/lb Cu,
US$1300/oz Au and US$9.00/lb Mo and is not adjusted for mining and
metallurgical recoveries as these remain uncertain. The formula
used is as follows: CuEQ = (Cu% x 22.0462 x 3.10) + (Au g/t
x 1300.00/ 31.1035) + (Mo% x 22.0462 x 9.00)/22.046x3.1. AuEQ =(Cu%
x 22.0462 x 3.10) + (Au g/t x 1300.00/ 31.1035) + (Mo% x 22.0462 x
9.00)/(1300/31.1035).
Rhenium values have not been used in
the cut-off grade or Cu or gold
Equivalent calculations.
In September 2017, Northisle
published the results of a PEA which demonstrated the potential
technical and economic viability of the project constructed as an
open-pit mine, with a concentrator processing nominally 75,000
tonnes/day (27Mtpa) with the results summarized in the below table.
This PEA is expected to be updated to reflect the results from the
metallurgical tests described in the sections above.
Table 4: North Island Project PEA Summary
LIFE OF MINE
PHYSICALS
|
|
|
|
|
Mine life,
years
|
22 years
|
|
|
|
Strip ratio,
w:o
|
0.72
|
|
|
|
Throughput
|
27.4Mtpa
|
|
|
|
Resource inventory
tonnes
|
460Mt
|
140Mt
|
|
|
Category
|
Indicated
|
Inferred
|
|
|
Copper
grade
|
0.18%
|
0.14%
|
|
|
Gold
grade
|
0.24g/t
|
0.25%
|
|
|
Molybdenum grade
|
0.01%
|
0.10%
|
|
|
Pyrite
grade
|
9%
|
9%
|
|
|
LOM
production
|
|
|
|
|
Copper
|
1.9B lb
|
|
|
|
Gold
|
1.8Moz
|
|
|
|
Molybdenum
|
55M lb
|
|
|
|
Pyrite
|
17B lb
|
|
|
|
Copper equivalent, M lb pa
|
3.1B
lb
|
|
|
|
Gold equivalent, koz
|
7.4Moz
|
|
|
|
AVERAGE ANNUAL
PRODUCTION
|
|
|
|
|
Copper, M
lb
|
82M lb
|
|
|
|
Gold, koz
|
79koz
|
|
|
|
Molybdenum, M
lb
|
3M lb
|
|
|
|
Pyrite, kt
|
0.64Kt
|
|
|
|
Copper
equivalent, M lb
|
141M
lb
|
|
|
|
Gold
equivalent, koz
|
335koz
|
|
|
|
AVERAGE ANNUAL
PRODUCTION COSTS
|
|
|
|
|
Copper C1 Cash Costs
net of by-products, US$/lb
|
$0.88/lb
|
|
|
|
Copper AISC net of
by-products, US$/lb
|
$1.22/lb
|
|
|
|
Copper
equivalent AISC, US$/lb Cu eq
|
$2.00/lb
|
|
|
|
Gold equivalent
AISC, US$/oz Au eq
|
$840/oz
|
|
|
|
ECONOMICS
|
|
|
|
|
After-tax
NPV5%, US$m
|
$757m
|
|
|
|
After-tax
NPV8%, US$m
|
$413m
|
|
|
|
After-tax IRR,
%
|
14%
|
|
|
|
The commodity prices used are as follows: US$ 3.10/lb Cu, US$
1,300/oz Au, US$ 9.00/lb Mo,
US$ 9/t Py with a CAD/USD of 0.75.
For more information, please consult the 2017 PEA available on
SEDAR under the Company's profile or on Northisle's
website.
For more information on Northisle please visit the
Company's website at www.Northisle.ca.
John McClintock, P. Eng is the
Qualified Person who reviewed and approved the scientific and
technical disclosure in this news release.
On behalf of Northisle Copper and Gold Inc.
"John McClintock"
John McClintock, P. Eng
President, CEO and Director
www.northisle.ca
Neither the TSX Venture Exchange nor its Regulation Services
Provider (as that term is defined in the policies of the TSX
Venture Exchange) accepts responsibility for the adequacy or
accuracy of this news release.
This news release contains forward-looking statements. These
forward-looking statements are based upon the reasonable beliefs of
Northisle and its management as of the date of this news release;
however, forward-looking statements involve risks and uncertainties
and are based upon factors that may change and assumptions that may
prove, with the passage of time, to be incorrect as a result of
exploration and other risk factors associated with mineral
exploration and development that are beyond the control of
Northisle. Accordingly, undue reliance should not be placed upon
such statements. If factors materially change or assumptions are
materially incorrect, the actual results, performance or
achievements of Northisle may be materially different from any
future results, performances or achievements expressed or implied
by such forward-looking statements. Northisle does not undertake
any obligation to update or revise any forward-looking statements
to reflect new information, future events or otherwise, except as
required by applicable law.
SOURCE NorthIsle Copper and Gold Inc.