RENO,
Nev., June 27, 2024 /PRNewswire/ - i-80 GOLD
CORP. (TSX:IAU) (NYSE:IAUX) ("i-80", or the
"Company") is pleased to announce the results of
Metallurgical work completed by Blue Coast Research Ltd. ("BCR") on
samples from the company's Ruby Hill and Golden Hill (FAD) Projects
located in Eureka County and along
the southeastern end of the Battle
Mountain/Eureka gold trend
in Nevada. The Properties are host
to multiple polymetallic base metal deposits and/or zones of
mineralization that are being advanced by the Company concurrent
with the gold deposits.
The BCR Study was commissioned to enhance the understanding of
the various deposits for planning purposes related to the recovery
of the multiple metals contained within each zone. Locked cycle
testing was completed on sulphide dominant composites from the
Hilltop (Upper, Lower and East), and the FAD (East, West and Gold
Hill Oxide) Zones. Highlights from the Company's 2023/2024
metallurgical programs include:
- High grade zinc and/or lead concentrates were produced with
positive recoveries for each of the four sulphide dominant
composites – with zinc recoveries of up to 96.0%, lead recoveries
of up to 97.9% and silver recoveries of up to 85.0%
- Positive gold recoveries from cyanidation were achieved for
the upper oxidized mineralized zones, realizing 86.8% for Upper
Hilltop and 85.1% for Golden Hill
- Notably, the composites contain low silica and low
deleterious metals, enhancing the expected potential of future
concentrates
- Work in 2024 will include additional metallurgical work on
the Mineral Point deposit at Ruby Hill that is host to a measured
and indicated resource of 3.2 M
ounces of gold and 97.5 M ounces of
silver (203.2 M tonnes, 0.49 g/t Au,
14.9 g/t Ag) and an inferred resource of 1.9
M ounces of gold and 72.3 M
ounces of silver (157.3 M tonnes,
0.37 g/t Au, 14.3 g/t Ag). This makes it one of the largest
gold/silver deposits in the United
States.1
__________
|
1
|
See Ruby Hill Technical
report title "NI 43-101 Report on 2021 Ruby Hill Mineral Resource
Estimate Eureka Country, Nevada, USA" with Effective Date July 31,
2021 at
https://www.i80gold.com/wp-content/uploads/2021/10/RubyHill-Tech-Report-2021.pdf
and on Sedar or at www.i80gold.com
|
The Ruby Hill and Golden Hill Properties collectively represent
one of the Company's primary assets - host to multiple gold, base
metal and precious metal-rich polymetallic deposits and
mineralization. Drilling completed between 2022 and 2024 at the
Blackjack, Hilltop and FAD zones intersected significant high‑grade
mineralization with all zones remaining open for expansion. Initial
polymetallic (base metal) resource estimates are being planned as
part of the Company's mine development strategy for these
properties with mine workings accessing both the gold and
polymetallic deposits.
"We are encouraged by the positive recovery of the multiple
metals contained within the Hilltop and FAD deposits", stated
Todd Esplin, Technical Director of
i-80 Gold. "We believe that this work will be included in future
resource estimates, mine planning and economic studies."
The scope of the program completed by BCR included chemical and
mineralogical characterization, comminution test work, cyanidation
test work and bench top flotation testing. A total of eight
samples were submitted for both chemical and mineralogical
characterization. Chemical characterization for the samples
is shown in Table 1 below.
Table 1 - Summary of head chemical characterization of all
composites
Sample
ID
|
Au
(g/t)
|
Ag
(g/t)
|
Pb(%)
|
Zn(%)
|
Fe(%)
|
S2-
(%)
|
Upper Hill Top Oxide
(Upper HT Ox)
|
10.89
|
395
|
14.7
|
2.1
|
15.2
|
2.2
|
Lower Hill Top
(Lower HT)
|
1.74
|
336
|
9.7
|
12.9
|
11.6
|
14.7
|
East Hill Top
(HTE)
|
0.04
|
4.3
|
0.0
|
11.3
|
10.4
|
11.6
|
Upper Hill Top
Sulphide (Upper HT Sul)
|
0.74
|
475
|
27.2
|
11.9
|
11.5
|
15.9
|
Upper Hill Top
Sulphide-B (Upper HT Sul-B)
|
2.88
|
708
|
37.2
|
8.9
|
13.9
|
19.1
|
FAD West
(FAD_W)
|
6.02
|
396
|
6.4
|
21.2
|
22.4
|
24.3
|
FAD East
(FAD_E)
|
4.68
|
249
|
3.9
|
14.4
|
18.8
|
21.1
|
Gold Hill Oxide
(GH_Ox)
|
2.27
|
21.1
|
0.4
|
4.5
|
12.6
|
0.1
|
Differences in the chemical and mineralogical properties between
each of the zones resulted in metallurgical testing tailored to the
specific characteristics of each sample. Base metal rich (Zinc and
Lead) sulphide dominant mineralization occurs in the Hilltop, FAD
and Blackjack samples with higher pyrite (and gold) in the FAD
samples. Non-sulphide lead (cerussite) is present in the oxidized
portion of the Upper Hilltop Zone. Only trace sulphides were found
in the Golden Hill oxide gold mineralization.
A cyanidation program was initiated for near-surface, oxidized
mineralization, from the Upper Hilltop and Golden Hill oxide gold
zone that demonstrate that both are amenable to cyanidation. Whole
rock bottle roll tests on these composites achieved positive
cyanidation gold recoveries of 86.8% for Upper Hilltop and 85.1%
for Golden Hill.
Flotation Test Work
Sulphide dominant samples (Lower HT, HTE, FAD_E, FAD_W)
underwent extensive floatation test work and utilized a
conventional sequential lead-zinc flow sheet depending on the
mineralogy. This testing ultimately culminated in successful locked
cycle tests being conducted on each composite with high grade zinc
and/or lead concentrates being produced at acceptable recoveries.
All lead concentrates produced grades at 58% or greater and all
zinc concentrates graded at 53% or greater. The results are
summarized in Table 2.
Table 2 - Summary of program final flotation results for
selected composites
Composite
|
Test
ID
|
Product
|
Assays
|
Distribution as %
of
contained metal
|
Au
(g/t)
|
Ag
(g/t)
|
Pb
(%)
|
Zn
(%)
|
Au
|
Ag
|
Pb
|
Zn
|
Lower HT
|
LCT-2
|
Pb Clnr 2
Conc
|
6.8
|
2330
|
75.4
|
4.3
|
37.9
|
85.0
|
97.9
|
3.9
|
Zn Clnr 2
Conc
|
1.4
|
191
|
0.4
|
56.9
|
13.9
|
11.9
|
1.0
|
89.8
|
HTE
|
LCT-3
|
Zn Clnr 3
Conc
|
-
|
9.4
|
-
|
53.9
|
-
|
53.0
|
-
|
96.0
|
FAD_E
|
LCT-6
|
Pb Clnr 3
Conc
|
3.0
|
2598
|
60.6
|
8.9
|
3.4
|
63.4
|
88.8
|
3.8
|
Zn Clnr 3
Conc
|
1.0
|
222
|
0.9
|
54.9
|
4.9
|
21.7
|
5.2
|
92.6
|
FAD_W
|
LCT-5
|
Pb Clnr 3
Conc
|
2.8
|
2834
|
58.4
|
11.3
|
4.9
|
76.1
|
89.2
|
6.2
|
Zn Clnr 3
Conc
|
1.5
|
198
|
1.5
|
54.2
|
7.2
|
14.8
|
6.3
|
82.3
|
Upper HT Ox
|
F-29
|
Pb Clnr 3
Conc
|
91.7
|
3840
|
77.1
|
-
|
17.3
|
22.4
|
13.2
|
-
|
Oxide Clnr 3
Conc
|
17.2
|
1086
|
61.9
|
-
|
17.6
|
34.5
|
57.5
|
-
|
Combined Pb
Conc.
|
28.7
|
1514
|
64.3
|
-
|
34.9
|
56.9
|
70.7
|
-
|
The oxide/transition samples in the Upper Hilltop Zone (Upper
HTOx and Upper HTSul) required a different approach due to the more
complex mineralogy owing to the presence of cerussite (lead
carbonate). For these samples, a sulphidization stage was
added after a lead-pyrite flotation flowsheet, that resulted in a
significant improvement in lead recovery compared to a conventional
lead sulphide (only) flowsheet. A successful batch test using this
approach was conducted on Upper HTOx (F-29 shown above) which
produced a combined lead concentrate grading 64% lead and recovery
of 70.7%.Due to the complexity of Upper HTSul mineralization, a
limited flotation program was conducted. However, detailed
mineralogical analysis of the flotation products provided a path
forward and suggest that (1) sphalerite misplaced to the galena
concentrate can be reduced by reducing the rougher flotation time
and (2) opportunity may exist to improve lead recovery by utilizing
a similar flotation flowsheet as Upper HTOx (pyrite flotation
followed by sulphidization of cerussite with NaSH).
Based on the work completed by BCR on the FAD mineralization,
the majority of the gold mineralization reports to the rougher and
cleaner tails. The scope of work focused solely on the base metal
mineralization and future test work will include a focus on gold
recoveries from polymetallic mineralization at FAD.
Blackjack Flotation Test Work:
In 2008 Barrick Gold commissioned G & T Metallurgical
Services Ltd to conduct flotation test work on Blackjack Lead-Zinc
mineral composites.
Composition of Low and High Zinc Composites
Composite
|
Assay in % or
g/t
|
Cu
|
Pb
|
Zn
|
Fe
|
Ag
|
Au
|
S
|
C
|
As
|
Pb(ox)
|
Zn(ox)
|
Low
Zinc
|
0.022
|
0.72
|
3.7
|
16.5
|
24
|
0.45
|
17.4
|
0.05
|
0.26
|
0.13
|
0.17
|
High
Zinc
|
0.029
|
2.45
|
24.5
|
4.1
|
196
|
0.47
|
16.0
|
1.07
|
0.03
|
0.19
|
0.13
|
Note: Aq and Au assays
are reported in g/tonne, all others are in percent.
|
The lock cycle testing on the high zinc composite produced good
metallurgical results with approximately 91% of the lead recovered
into a lead concentrate grading approximately 70% lead.
Approximately 85% of the silver in the feed reported to the lead
concentrate, which contained almost 5600 g/t silver. Zinc
recovery into the zinc concentrate was 97% at a zinc concentrate
grade of nearly 61%.
Future work will look to build upon the previously completed
work and optimize recoveries from the Blackjack deposit.
Note - Blue Coast Research
Ltd was not involved or did not conduct any Blackjack
metallurgical flotation test work
Overall, this program showed that the samples tested responded
positively to flotation and future metallurgical work recommended
by BCR includes the evaluation of a larger number of samples to
better understand the project, completing a larger and more
rigorous comminution study to understand milling requirements,
conduct additional metallurgical work on Blackjack samples, conduct
D-IMS analysis of Lower HT, FAD_E and FAD_W to quantify the amount
of gold mineralization locked with pyrite, and determine if primary
grinding inert media can improve selectivity in HTE and Lower HT
samples.
Hole ID and Location of Composites used in Testing
Composite
|
Hole
ID
|
Easting Nad83
UTM
|
Northing Nad83
UTM
|
Elevation
(m)
|
Lower HT
|
iRH22-38
|
587348
|
4375336
|
1979
|
iRH22-39
|
587346
|
4375338
|
1978
|
iRH22-40
|
587346
|
4375348
|
1978
|
iRH22-41
|
587345
|
4375342
|
1978
|
HTE
|
iRH22-61
|
587520
|
4375184
|
1994
|
FAD_E
|
PC22-07
|
587179
|
4373123
|
2102
|
FAD_W
|
GH21-03
|
587090
|
4373069
|
2115
|
GH21-04
|
587114
|
4373182
|
2114
|
GH21-05
|
587114
|
4373177
|
2114
|
PC22-01
|
587033
|
4373235
|
2107
|
Upper HT Ox
|
iRH22-54
|
587456
|
4375134
|
1999
|
iRH22-55
|
587618
|
4375134
|
2006
|
iRH22-70
|
587388
|
4375282
|
1986
|
High and Low Zn G &
T Sample
|
BRH-75C
|
587677
|
4375547
|
1738
|
Sample material was selected through reviewing drill core
visually and geochemically to determine differences in
mineralization styles. Intervals were then selected on the basis of
being representative of the particular composite within each
mineralized zone.
Joint Venture Update
The negotiation of definitive documentation related to the
previously announced proposed joint venture of the Ruby Hill
Property continues to advance. Metallurgical work completed to-date
as part of the due diligence program related to this partnership
has indicated recoveries similar to those achieved in the BCR
work.
Qualified Person
Tim George, PE, is the Qualified Person for the technical
information contained in this press release and is a Qualified
Person within the meaning of National Instrument 43-101. Mr. George
has reviewed and approved this press release.
About i-80 Gold Corp.
i-80 Gold Corp. is a Nevada-focused, mining company with a goal of
achieving mid-tier gold producer status through the development of
multiple deposits within the Company's advanced-stage property
portfolio with processing at i-80's centralized milling facilities.
i-80 Gold's common shares are listed on the TSX and the NYSE
American under the trading symbol IAU:TSX and
IAUX:NYSE. Further information about i-80 Gold's portfolio
of assets and long-term growth strategy is available at
www.i80gold.com or by email at info@i80gold.com.
Certain statements in this release constitute "forward-looking
statements" or "forward-looking information" within the meaning of
applicable securities laws, including but not limited to, the
results of the Company's 2023/2024 metallurgical programs, the
interpretation of such results and management's expectations based
on such results; potential relating to metallurgical recovery
rates, the expansion or mineral resources at Ruby Hill and Golden
Hill and the potential of the Ruby Hill and Golden Hill
projects, the timing and results of technical and economic
studies and the completion of the Ruby Hill joint venture
transaction. Such statements and information involve known and
unknown risks, uncertainties and other factors that may cause the
actual results, performance or achievements of the company, its
projects, or industry results, to be materially different from any
future results, performance or achievements expressed or implied by
such forward-looking statements or information. Such statements can
be identified by the use of words such as "may", "would", "could",
"will", "intend", "expect", "believe", "plan", "anticipate",
"estimate", "scheduled", "forecast", "predict" and other similar
terminology, or state that certain actions, events or results
"may", "could", "would", "might" or "will" be taken, occur or be
achieved. These statements reflect the Company's current
expectations regarding future events, performance and results and
speak only as of the date of this release.
Forward-looking statements and information involve significant
risks and uncertainties, should not be read as guarantees of future
performance or results and will not necessarily be accurate
indicators of whether or not such results will be achieved. A
number of factors could cause actual results to differ materially
from the results discussed in the forward-looking statements or
information, including, but not limited to: material adverse
changes, unexpected changes in laws, rules or regulations, or their
enforcement by applicable authorities; the failure of parties to
contracts with the company to perform as agreed; social or labour
unrest; changes in commodity prices; and the failure of exploration
programs or studies to deliver anticipated results or results that
would justify and support continued exploration, studies,
development or operations.
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