VANCOUVER, BC, Jan. 17,
2023 /CNW/ - Western Copper and Gold Corporation
("Western" or the "Company") (TSX: WRN) (NYSE American: WRN)
announces results from a metallurgical program (the "Metallurgical
Program") and a drill program (the "Drill Program") executed in
2022 for its wholly owned Casino Copper-Gold Project
("Casino").
The Metallurgical and Drill Programs were developed in
collaboration with Rio Tinto as outlined in the Investor Rights
Agreement and Subscription Agreement entered as part of an
investment by Rio Tinto Canada in Western (see news release dated
May 17, 2021). Results from the
Programs were reviewed by a joint team consisting of Rio Tinto and
Western personnel and consultants.
"Metallurgical results from the recent testing support and in
some cases improve upon the metallurgical recoveries used in the
Feasibility Study", said Paul
West-Sells, President and CEO, "and the drill results
continue to build out our geological understanding of the
deposit."
Metallurgical Program
Test work consisted of detailed mineralogy, heap leach testing,
comminution testing, flotation testing and detailed analysis of
flotation concentrates. Sample selection and composite sample
generation followed the expected mining plan, as outlined in the
2022 feasibility study (the "Feasibility Study", see news release
dated August 9, 2022). Heap
leach test work within the Metallurgical Program was completed at
SGS Mineral Services of Burnaby,
B.C., while all other test work was completed at ALS
Metallurgy of Kamloops, B.C.
The Metallurgical Program primarily used drill core composites
of material representing both potential mill and heap leach feed
taken from the 2021 diamond drilling program (see news release
dated March 24, 2022). Seven
drill holes were used to create 21 metallurgical composites for
testing. These holes intersected all significant lithologic
zones of the Casino deposit, ranging from a copper depleted leached
cap ("CAP") zone near surface, through a supergene zone ("SUP") of
low to moderate copper mineral oxidation and secondary sulphide
mineralization, to unweathered hypogene ("HYP") material at
depth.
The heap leach test work included samples that were taken in
2020 from near surface (0.5 m or
greater below the overburden-bedrock interface) using an excavator
and separated into lithologic composites representing Dawson Range
Batholith ("WR"), Patton Porphyry ("PP") and Intrusive Breccia
("IX") mineralization and assay rejects.
Grinding and Flotation Test
Work
Test Samples
Table 1 shows drill holes DDH21-6 and DDH21-7, indicating
composite intervals generated, as well as sample grades and
lithologies. The HYP and SUP zones represent approximately 70
and 30 percent of the planned mill feed respectively.
Table 1: Flotation composite sample characterization of
selected test samples.
Composite
|
Hole
|
From
(m)
|
To
(m)
|
Lithology
|
Cu
(%)
|
CuOx*
(%)
|
Mo
(%)
|
Au
(g/t)
|
7
|
DDH21-6
|
161.1
|
241.1
|
SUP
|
0.30
|
14.6
|
0.023
|
0.42
|
8
|
DDH21-6
|
241.1
|
324.6
|
SUP
|
0.18
|
6.7
|
0.025
|
0.30
|
9
|
DDH21-7
|
51.7
|
143.7
|
HYP
|
0.53
|
1.1
|
0.026
|
0.66
|
10
|
DDH21-7
|
143.7
|
257.7
|
HYP
|
0.48
|
0.9
|
0.032
|
0.60
|
11
|
DDH21-7
|
257.7
|
326.1
|
HYP
|
0.22
|
1.4
|
0.030
|
0.26
|
*Oxide copper is shown
as percentage of total copper contained in the feed
sample.
|
Comminution Test Results
Comminution test work expanded the database of results available
to support the project. There were no significant new
comminution results that altered the expected grinding
characteristics of the Casino materials from previous test work.
Sag Media Competency testing and JKTech Drop Weight tests
were completed and used in grinding simulations, indicating a SAG
mill power requirement of 7.6 to 10.6 kWh/t. Bond Ball mill
work index results ranged from 11.0 to 16.1 kWh/t, which is
considered as "soft to average" hardness in terms of ball milling
energy requirements.
Flotation Test Results
The Casino Project proposes using flotation to produce saleable
copper-gold and molybdenum concentrates using an industry standard
process flowsheet. Gold values are expected to be recovered within
a copper concentrate and be payable under typical copper
concentrate smelting terms. Table 2 shows metallurgical
recoveries obtained for SUP and HYP composites using locked cycle
testing and reflecting the selected samples shown in Table 1.
Table 2: Summary of locked cycle flotation results for
selected samples.
Composite
No.
|
Copper Concentrate
Grade
|
Metal
Recoveries
|
|
Cu
(%)
|
Au
(g/t)
|
Cu
(%)
|
Au
(%)
|
Mo
(%)
|
7
|
26.5
|
35.7
|
75.7
|
66.9
|
81.9
|
8
|
26.3
|
39.6
|
80.0
|
59.6
|
55.8
|
9
|
28.0
|
29.5
|
91.7
|
82.8
|
76.5
|
10
|
30.1
|
25.9
|
91.9
|
67.6
|
77.4
|
11
|
29.5
|
29.5
|
90.9
|
67.6
|
84.1
|
The results in Table 2 show the impact of weathering and
oxidation of copper minerals on the copper recovery for composites
7 and 8 and is typical of Casino material. HYP materials
demonstrate consistently high copper recoveries and very good
quality copper concentrates. Copper concentrate quality does
not appear to be significantly impacted when processing SUP
weathered materials, and minor reductions in copper content appear
to be offset by increases in gold grades produced from these
weathered zones. For the SUP samples that contain a component
of copper as copper oxide minerals, the expected reduction in
overall copper recovery in flotation is approximately equal to the
copper oxide content. Gold recovery to copper concentrates is
not expected to be significantly impacted when processing SUP
materials in the Casino flotation plant.
Copper Concentrate Quality
The flotation concentrates produced from the Casino project
continue to demonstrate very good grades in terms of copper and
gold, as well as low levels of potential penalty elements.
Shown below is a summary table of the concentrates produced from
the recent test work from selected samples, including key penalty
elements relevant to smelter terms.
Table 3: Casino concentrate analysis – key elements for
smelter terms.
Composite
No.
|
Copper
Concentrate
Grades
|
Smelter Sensitive
Elements
|
|
Cu
(%)
|
Au
(g/t)
|
S (%)
|
As
(%)
|
Sb
(%)
|
Hg
(g/t)
|
F (%)
|
7
|
26.5
|
35.7
|
30.5
|
0.148
|
0.108
|
1.19
|
na
|
8
|
26.3
|
39.6
|
31.8
|
0.086
|
na
|
0.49
|
na
|
9
|
28.0
|
29.5
|
33.4
|
0.011
|
0.005
|
0.03
|
0.013
|
10
|
30.1
|
25.9
|
32.8
|
0.158
|
0.076
|
0.36
|
0.016
|
11
|
29.5
|
29.5
|
31.2
|
0.406
|
0.168
|
0.81
|
0.025
|
Heap Leach Test Work
Test Samples
Gold recovery by heap leaching is planned from the oxidized,
upper zones of the Casino Deposit. This near surface material
is typically depleted in copper and has retained the gold values
originally contained in the deposit. Column leaching of
crushed samples was used to determine an expected gold recovery and
to obtain key metallurgical parameters related to heap leaching.
For the column leach tests, three composite samples from the 2021
drill program and three excavated samples were used as outlined
below in Table 4.
Table 4: Composite and excavated samples used in column
tests
Sample
|
Hole
|
From
(m)
|
To
(m)
|
Cu
(%)
|
Au
(g/t)
|
Ag
(g/t)
|
Comp 1
|
DDH21-04
|
29.8
|
108.9
|
0.05
|
0.52
|
3.4
|
Comp 12
|
DDH21-02
|
5.2
|
99.2
|
<0.01
|
0.40
|
4.0
|
Comp 14
|
DDH21-03
|
4.1
|
88.7
|
<0.01
|
0.16
|
1.4
|
IX Comp
|
excavated
|
-
|
-
|
0.05
|
0.46
|
4.2
|
PP Comp
|
excavated
|
-
|
-
|
0.06
|
0.35
|
2.1
|
WR Comp
|
excavated
|
-
|
-
|
0.02
|
0.44
|
1.8
|
Crusher Work Index and Bond Abrasion Test Results
Crusher Work Index testing was completed to better understand
the crushing energy requirements of preparing heap leach
feed. The crusher work indices covered a wide range, from 3.7
to 12.0 kWh/t with an average value of 8.5 kWh/t and fell in
the very soft to moderately hard range of hardness. The bond
abrasion indices also varied widely from 0.027 to 0.417 g with an
average value of 0.247 g and fell in the very mild to moderately
abrasive range of abrasiveness.
Column Test Results
Column testing was carried out in 20-foot high by 4-inch
diameter PVC columns irrigated at 10 L/h/m2 with a
solution containing 1.0 g/L NaCN and 300 mg/L Cu to approximate the
buildup of copper in the expected operating circuit, at a pH
between 11 and 11.5 for 96 days. The samples were crushed to
100 percent passing ¾ inch which is consistent with the design
criteria from the Feasibility Study.
Table 5: Gold and silver recovery and cyanide and lime
consumption for column tests after rinsing.
Sample
|
Gold Recovery
(%)
|
Silver Recovery
(%)
|
NaCN
Consumption
(kg/t)
|
Lime
Consumption
(kg/t)
|
Comp 1
|
82.7
|
19.1
|
1.47
|
3.36
|
Comp 12
|
83.8
|
7.4
|
1.48
|
4.57
|
Comp 14
|
78.0
|
15.1
|
1.55
|
3.58
|
IX Comp
|
85.8
|
21.8
|
1.37
|
3.36
|
PP Comp
|
88.3
|
25.2
|
1.87
|
3.50
|
WR Comp
|
85.1
|
24.9
|
1.23
|
3.70
|
Gold recoveries for the 6 samples tested ranged from 78.0 to
88.3 percent, which compares favorably to the 80 percent gold
recovery used in the Feasibility Study and suggests that some of
the material designated for the heap leach pad may produce gold
recoveries in excess of what is carried in the Feasibility Study.
Lime and cyanide consumption are also consistent with previous
testing.
Drill Program
The Drill Program included a diamond drill hole (DDH22-01)
targeting a deep-seated magnetotelluric ("MT") geophysical anomaly
indicating potential for a conical mineralized zone directly
southeast of the Casino Deposit core zone. Additionally, 23
short diamond drill holes totaling 853.71
m, and 9 combined sonic/diamond drill holes totaling
364.43 m, were completed on various
targets for geotechnical and water-monitoring purposes. The
program also included 34,387 m of
drill core scanning utilizing the GeologicAI scanning device built
by Enersoft Inc.
DDH22-01 was collared along the Casino deposit's southeastern
limit (UTM NAD 83, Zone 7V coordinates: 611160E, 6958125N, elev.
1,236 m) and drilled at an azimuth of
170° and dip of -80° to a depth of 1,008 m. Downhole
measurements were made at regular intervals to verify that the hole
was on target and successfully intersected the projected MT
feature. The top of the anomaly was encountered at
approximately 800 m total depth.
The lithology of the entire drill hole was dominated by
Dawson Range granodioritic intrusive
rocks, crosscut by only a few dykes, interpreted as members of the
younger Patton Porphyry intrusion. Intrusive Breccias, the
principal host rock of the Casino deposit, were not
intersected. Phyllic and argillic alteration was logged at
shallow depths along the deposit margin, and propylitic alteration
dominated within and directly overlying the anomaly. Elevated
copper, gold, and silver values were exclusively hosted by thin
pyritiferous structural zones throughout the drill hole. The
top of the sulphide zone was encountered at approximately
100 m depth; the percentage of
sulphides decreased with depth, apart from those hosted by the thin
structures. Select intervals are shown in Table 6.
Table 6: Select Intervals of DDH22-01.
Interval
From
(m)
|
Interval
To
(m)
|
Width1
(m)
|
Au
(g/t)
|
Ag
(g/t)
|
Cu
(%)
|
Mo
(g/t)
|
950.20
|
953.20
|
3.00
|
4.85
|
10.1
|
0.85
|
1.1
|
989.20
|
992.20
|
3.00
|
1.76
|
2.9
|
0.43
|
0.5
|
992.20
|
995.20
|
3.00
|
2.92
|
7.0
|
0.91
|
1.1
|
1Widths are core length, not
true width of mineralized intersection
|
Qualified Persons
The metallurgical information in this news release has been
prepared in accordance with Canadian regulatory requirements set
out in National Instrument 43-101 Standards of Disclosures for
Minerals Projects of the Canadian Securities Administrators ("NI
43-101") and supervised, reviewed, and verified by Jeffrey B. Austin, P.Eng., President of
International Metallurgical and Environmental Inc., a "Qualified
Person" as defined by NI 43-101.
The geological information in this news release has been
prepared in accordance with Canadian regulatory requirements set
out in National Instrument 43-101 Standards of Disclosures for
Minerals Projects of the Canadian Securities Administrators ("NI
43-101") and supervised, reviewed, and verified by Carl Schulze, P.Geo., a "Qualified Person" as
defined by NI 43-101.
QA/QC protocol for DDH22-01, including assurance of chain of
custody, has been implemented. Core samples are evenly cut by rock
saw, then prepared and analyzed by ALS Geochemistry. Prepared
samples are initially run using a four-acid digestion process and
conventional multi-element ICP-AES analysis. Additional assaying
for total copper and molybdenum is run using a four-acid digestion
– AES or AAS method to a 0.001% detection limit. Gold assays are
run using 30-gram samples by fire assay with an AA finish to a
0.005 ppm detection limit, with samples greater than 10 ppm
finished gravimetrically. The QA/QC procedure involves regular
submission of Certified Analytical Standards and property-specific
duplicates. Check samples are also included and are sent to a
secondary lab to test the primary labs' methods/procedures.
ABOUT WESTERN COPPER AND GOLD
CORPORATION
Western Copper and Gold Corporation is developing the Casino
Project, Canada's premier
copper-gold mine in the Yukon
Territory and one of the most economic greenfield
copper-gold mining projects in the world. For more
information, visit www.westerncopperandgold.com.
The Company is committed to working collaboratively with our
First Nations and local communities to progress the Casino project,
using internationally recognized responsible mining technologies
and practices.
On behalf of the board,
"Paul West-Sells"
Dr. Paul West-Sells
President and CEO
Western Copper and Gold Corporation
Cautionary Disclaimer Regarding Forward-Looking Statements
and Information
This news release contains certain forward-looking statements
concerning anticipated developments in Western's operations in
future periods. Statements that are not historical fact are
"forward-looking statements" as that term is defined in
the United States Private
Securities Litigation Reform Act of 1995 and "forward-looking
information" as that term is defined in National Instrument 51-102
("NI 51-102") of the Canadian Securities Administrators
(collectively, "forward-looking statements"). Forward-looking
statements are frequently, but not always, identified by words such
as "expects", "anticipates", "believes", "intends", "estimates",
"potential", "possible" and similar expressions, or statements that
events, conditions or results "will", "may", "could" or "should"
occur or be achieved. In making the forward-looking statements
herein, the Company has applied certain material assumptions
including, but not limited to, the assumption that general business
conditions will not change in a materially adverse manner.
Forward-looking statements are statements about the future
and are inherently uncertain, and actual results, performance or
achievements of Western and its subsidiaries may differ materially
from any future results, performance or achievements expressed or
implied by the forward-looking statements due to a variety of
risks, uncertainties and other factors. Such risks and other
factors include, among others, risks involved in fluctuations in
gold, copper and other commodity prices and currency exchange
rates; uncertainties relating to interpretation of drill results
and the geology, continuity and grade of mineral deposits;
uncertainty of estimates of capital and operating costs, recovery
rates, production estimates and estimated economic return; risks
related to joint venture operations; risks related to cooperation
of government agencies and First Nations in the development of the
property and the issuance of required permits; risks related to the
need to obtain additional financing to develop the property and
uncertainty as to the availability and terms of future financing;
the possibility of delay in construction projects and uncertainty
of meeting anticipated program milestones; uncertainty as to timely
availability of permits and other governmental approvals; and other
risks and uncertainties disclosed in Western's AIF and Form 40-F,
and other information released by Western and filed with the
applicable regulatory agencies.
Western's forward-looking statements are based on the
beliefs, expectations and opinions of management on the date the
statements are made, and Western does not assume, and expressly
disclaims, any intention or obligation to update or revise any
forward-looking statements whether as a result of new information,
future events or otherwise, except as otherwise required by
applicable securities legislation. For the reasons set forth above,
investors should not place undue reliance on forward-looking
statements.
SOURCE Western Copper and Gold Corporation