Kilgore Project Achieves >92% Gold Recoveries
January 08 2020 - 7:30AM
Otis Gold Corp. (“
Otis” or the
“
Company”) (
TSX-V:
OOO) (
OTC: OGLDF) is pleased to
announce up to 92.6% gold recovery from column leach metallurgical
testing of near-surface mineralized volcanic rock at its Kilgore
Project. The test samples came from drill hole 17OKC-379, a larger
diameter PQ drill hole that contained a true width interval of 120
feet (35.6 metres) with a calculated head grade of 1.49 g/t Au; the
PQ core hole was a twin of 17OKC-356.
Highlights:
- Gold extraction of 92.6% on half-inch (0.5”) crush columns over
200 days (see Figure 1).
- Gold extraction of 85.9% on one and a half-inch (1.5”) crush
columns over 200 days.
- Gold extraction of 56.1% on three-inch (3.0”) crush columns.
The three-inch column was terminated after 120 days once no further
gold extraction was recorded.
- Finer crush sizes improved the gold extraction rate, reaching
60% gold extraction in approximately 24 days (0.5”) versus 56 days
at the next coarser crush size (1.5”).
- Notable was that at 0.5” and 1.5” crush sizes gold recoveries
had not plateaued after 200 days.
- Gold recoveries for 0.5” crush and simulated 3.0” Run-of-Mine
(ROM) mineralized material processing are significantly higher than
the respective 82% and 50% recoveries used in the Kilgore
Preliminary Economic Assessment (see Otis News Release dated August
27, 2019).
- Silver was also recovered during all phases of testing. Column
leach extractions were 41.9%, 37.2% and 17.4% respectively (see
Table 1), indicating that additional work is required to assess
silver’s potential impact on Kilgore’s economics.
Table 1: Summary of Column Leach
Results |
Crush Size
|
Extraction % |
Residue Assay |
Calc. Head |
NaCNConsumption
(kg/t) |
Lime Consumption (kg/t) |
Au |
Ag |
Au (g/t) |
Ag (g/t) |
Au (g/t) |
Ag(g/t) |
0.5" |
92.6 |
41.9 |
0.111 |
1.3 |
1.493 |
2.2 |
4.664 |
4.561 |
1.5" |
85.9 |
37.2 |
0.143 |
1.8 |
1.012 |
1.8 |
3.260 |
1.276 |
3.0" |
56.1 |
17.4 |
0.313 |
2.1 |
0.713 |
2.5 |
2.362 |
1.121 |
Otis submitted approximately 450kg of PQ core
from drill hole 17OKC-379 to Resource Development Inc. of Denver,
CO for metallurgical testing. The drill samples to be tested came
from the interval: 13ft (4.0m) to 133ft (40.5m), an interval of
120ft (35.6m), and returned head assays of 1.49 g/t Au and 2.2 g/t
Ag, including 5ft (1.52m) from 119ft to 124ft (36.3-37.8m) of 42.68
g/t Au and 15 g/t Ag. These assays are significantly higher than
those from the original, smaller diameter, HQ core hole 17OKC-356
which returned a mineralized interval of 124ft (37.8m) averaging
0.31 g/t Au; the difference in returned gold values highlighting
the variable nature of gold mineralization at Kilgore. The samples,
as analyzed in both holes, came from near surface, hydrothermally
altered and oxidized rhyolite-composition lithic tuffs.
Metallurgical testing of the samples consisted
of:
- Initial head grade assay of each of the drill intervals
submitted
- Bench-top bottle roll leach tests
- Column leach tests at 0.5-inch, 1.5-inch and 3.0-inch crush
sizes
The test work was conducted to confirm the
suitability of this material to treatment by cyanide heap leaching
and to validate the crush size required for efficient gold
extraction. Each of the tests was conducted in a typical heap leach
configuration. Mineralogical examination of the higher-grade gold
occurrences within the samples submitted revealed gold grains
associated with Jarosite, a mineral product of oxidation of iron
sulfides, varying in size from <2 microns to 70 microns (Figure
2).
Alan Roberts, Vice President of Explorations,
stated: “The improvement in recovery revealed by this round of
metallurgical testing shows the amenability of the Kilgore Deposit
to heap leach gold and silver recovery; both the gold recoveries
for 0.5” crush and simulated 3.0” Run-of-Mine mineralized material
processing are significantly higher than the respective 82% and 50%
recoveries used in our recently-released Preliminary Economic
Assessment. Furthermore, the identification of the direct
association between Gold and jarosite is an important step in
understanding the nature and character of mineralization at
Kilgore.”
Alan Roberts, MSc, CPG (AIPG: CPG#11260), Vice
President of Exploration, is the Qualified Person for this news
release and has reviewed and approved the technical content
contained herein.
About the Kilgore ProjectThe
Kilgore Project has a current NI 43-101 Indicated Resource of
825,000 ounces Au in 44.6 million tonnes at a grade of 0.58 g/t Au
and an Inferred Resource of 136,000 ounces Au in 9.4 million tonnes
at a grade of 0.45 g/t Au. The maiden Preliminary Economic
Assessment (or “PEA”) showed an after-tax NPV (5% discount rate) of
US$110.4 million and IRR of 34.0%, with a 3-year payback period and
LOM net cash flow of US$151.8 million at a $1,300 gold price.
Please note the PEA is preliminary in nature and includes Inferred
resources that are too speculative geologically to have the
economic considerations applied to them. There is no certainty that
the PEA will be realized. Mineral resources that are not mineral
reserves do not have demonstrated economic viability.
About the Company Otis is
a resource company focused on the acquisition, exploration, and
development of precious metal deposits in Idaho, USA. Otis is
currently developing its flagship property, the Kilgore Project,
located in Clark County, Idaho and the Oakley Project, located in
Cassia County, Idaho.
ON BEHALF OF THE BOARD
“Craig T. Lindsay”
President & CEO
For additional information, please contact:
Mr. Tony Perri – Corporate Development
Tel: (604) 424-8100 Email: tony@otisgold.com
Neither TSX Venture Exchange nor its Regulation
Services Provider (as defined in the policies of the TSX Venture
Exchange) accepts responsibility for the adequacy or accuracy
of this release.
This News Release does not constitute an offer
to sell or a solicitation of an offer to sell any securities in the
United States. The securities have not been and will not be
registered under the United States Securities Act of 1933, as
amended (the “US Securities Act”) or any State securities laws, and
may not be offered or sold within the United States or to US
Persons unless registered under the US Securities Act and
applicable State securities laws, or an exemption from such
registration is available.
Photos accompanying this announcement are available at:
https://www.globenewswire.com/NewsRoom/AttachmentNg/771bd995-d361-48eb-adf0-3ed14f886eef
https://www.globenewswire.com/NewsRoom/AttachmentNg/592945d6-830f-4603-a150-d899488fe808
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