Highlights include:
- Achieved 84% gold recoveries on the Master Composite versus a
recovery of 82% in the 2020 PEA
- Simplified flowsheet with the elimination of saprolite /
sap-rock material and the elimination of the molybdenum concentrate
circuit
- Ausenco-led Pre-Feasibility Study is on schedule for completion
in Q2 2023
VANCOUVER, BC, Jan. 25,
2023 /CNW/ - Lumina Gold Corp. (TSXV: LUM)
(OTCQX: LMGDF) (the "Company" or "Lumina") is pleased to
announce positive results from its ongoing metallurgical test work
that is part of the 2023 Pre-Feasibility Study ("PFS") for the
Company's Cangrejos Copper-Gold project (the "Cangrejos
Project") planned for Q2 2023.
Marshall Koval, President and
CEO commented: "The PFS is on schedule, and several major
components of the study have been completed. The metallurgical
testwork program is near completion and shows improved gold
recoveries over the 2020 PEA; recoveries for copper and silver are
pending. The balance of the metallurgy is expected to be completed
in the next several weeks. Capital and operating cost estimates and
the concentrate marketing study have been initiated and the overall
PFS remains on track for completion in Q2 of this year."
PFS Status
The following PFS work streams have been completed:
- Mineral resource estimation at the Cangrejos and Gran Bestia
deposits
- Revised mine plan incorporating only indicated mineral
resources for the purpose of potential conversion to mineral
reserves
- Process flowsheet design
- Quotes for major mechanical and electrical equipment
- Dry stack tailings design
- Facility siting studies
- Power supply study
- Port materials handling study
Metallurgical Test Work
Description
The current test work program is being performed at C. H. Plenge
& CIA S.A. ("Plenge"), an independent metallurgical laboratory
based in Lima, Peru. The
results presented in this news release were generated based on
testing of a master composite (the "2022 Master Composite")
and 14 individual variability composites that reflect various
anticipated material grades, rock types and time periods. The
composites were prepared using approximately 4,900 kilograms of
drill core collected during the 2021-2022 in-fill and step-out
drilling campaign and are from over 50 different drill holes
spanning the Cangrejos and Gran Bestia deposits.
Test Results
Similar to the preliminary economic assessment for the Cangrejos
Project (the "2020 PEA") included in the Company's technical report
titled "Cangrejos Gold-Copper Project El Oro Province, Ecuador, NI 43-101 Technical Report
Preliminary Economic Assessment", with an effective date of
June 8, 2020, the overall process
flowsheet envisions flotation combined with cyanidation of the
flotation cleaner scavenger tails and concentrate from flotation of
coarse particles ("sand") from rougher flotation tailings. Gravity
concentration will also be used in the flowsheet for recovering
coarse gold.
The 2022 Master Composite was prepared representing "fresh rock"
material from both deposits over the projected mine life and
assayed 0.50 g/t gold, 1 g/t silver, 0.087% copper, 24 ppm
molybdenum, and 0.33% sulphur. The life-of-mine average plant feed
grade is projected to be 0.55 g/t gold and 0.1% copper, a slightly
higher grade than the 2022 Master Composite. The 2022 Master
Composite has been subjected to comminution testing, whole-ore
cyanidation, gravity concentration, bulk rougher and concentrate
cleaner flotation, copper-molybdenum separation flotation, and sand
flotation. Tests incorporating cyanidation of scavenger cleaner
tails and sand concentrates are in progress. Testing of the
variability composites is also in progress with comminution and
whole-rock cyanidation tests recently completed.
Whole-ore flotation tests, using optimized conditions and
reagents, yielded gold, copper and silver recoveries into rougher
flotation concentrates of 81%, 88% and 68%, respectively.
Flotation of a sand concentrate from the rougher tails recovered an
additional 4% of the gold for a combined recovery in rougher
flotation of 85%. Once cyanidation of the scavenger cleaner tails
and the sand concentrates occurs, the overall gold recovery into
concentrates and doré is projected to be 84%. Cleaned copper-gold
flotation concentrates assayed 15% copper, 70 g/t gold and 101 g/t
silver, compared to the average concentrate grade estimated in the
2020 PEA of 17% copper, 75 g/t gold and 72 g/t silver.
Cleaner flotation testing indicates that regrinding to 20
microns, versus 38 microns assumed in the 2020 PEA, is required to
achieve the 15% copper concentrate grade. Lock-cycle rougher and
cleaner flotation testing is in progress on all composites to
determine concentrate grades and metal recoveries in concentrates
and doré.
Copper-molybdenum separation flotation testing on copper-gold
flotation concentrates yielded a potentially saleable molybdenum
concentrate that assayed 48% molybdenum while recovering
approximately 50% of the molybdenum. The Company has
determined that producing a molybdenum concentrate is not currently
economically viable when accounting for operating and capital costs
and will therefore eliminate the processing circuit from the PFS
flowsheet.
Whole-ore gravity concentration tests on the 2022 Master
Composite average gold and silver recoveries of 29% and 5%,
respectively, into concentrates that weigh 0.26% of the feed weight
and assay 60 g/t gold and 18 g/t silver.
Whole-ore cyanidation can be used to process the mineralized
materials and produce a doré, but no copper is expected be
recovered using this process. Cyanidation tests on all composites
indicate average gold and silver recoveries of 89% and 34%,
respectively, which are similar to historic test results. Cyanide
consumption for the tests averaged one kilogram per tonne of
material processed.
Comminution tests on the 2022 Master Composite indicate that the
mineralized materials have average Bond Ball Mill Work Index values
of 16 kWh/mt. This would classify the material as medium-hard to
hard, which is similar to historic test results. JK-SMC test
results of A * b = 24.6 confirmed the 2020 PEA results and
classified the material as hard. These results confirm the
advantage of using a high-pressure grinding roll as the primary
grind in the comminution circuit.
Quality Assurance
The metallurgical tests detailed above were conducted by
independent commercial laboratories and the samples used for
testing were selected to be representative of the material that is
currently planned for processing. Lumina is not aware of any
drilling, sampling, recovery or other factors that could materially
affect the accuracy or reliability of the data referred to
herein.
Qualified Person
Nelson King, SME Registered
Member and Metallurgical Consultant to Lumina, is a "Qualified
Person" as defined by National Instrument 43-101 - Standards of
Disclosure for Mineral Projects. Mr. King has assisted Lumina
in the development and direction of the metallurgical testing
program for the Cangrejos Project, has visited the Cangrejos
Project and Plenge's laboratory in Lima to observe the testing program, and has
reviewed and approved the scientific and technical information
contained in this news release. Mr. King also verified the data
disclosed underlying the scientific and technical information in
this news release.
About Lumina Gold
Lumina Gold Corp. (TSXV: LUM) is a Vancouver, Canada based precious and base
metals exploration and development company focused on the Cangrejos
Gold-Copper Project located in El Oro Province, southwest
Ecuador. Cangrejos is being
advanced to a Pre-Feasibility Study and is the largest primary gold
deposit in Ecuador. Lumina has an
experienced management team with a successful track record of
advancing and monetizing exploration projects.
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Further details are available on the Company's website at
https://luminagold.com/. To receive future news releases please
sign up at https://luminagold.com/contact.
LUMINA GOLD CORP.
Signed: "Marshall Koval"
Marshall Koval, President
& CEO, Director
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.
Cautionary Note Regarding
Forward-Looking Information
Certain statements and information herein, including all
statements that are not historical facts, contain forward-looking
statements and forward-looking information within the meaning of
applicable securities laws. Such forward-looking statements or
information include but are not limited to statements or
information with respect to potentially converting mineral
resources to mineral reserves, potential recoveries used in future
economic studies, the potential economic viability of molybdenum
concentrate when accounting for operating and capital costs, and
the elimination of the processing circuit from the PFS flowsheet,
expected copper recovery from whole-ore cyanidation, and timing for
completion of the PFS study. Often, but not always, forward-looking
statements or information can be identified by the use of words
such as "will" or "projected" or variations of those words or
statements that certain actions, events or results "will", "could",
"are proposed to", "are planned to", "are expected to" or "are
anticipated to" be taken, occur or be achieved.
With respect to forward-looking statements and information
contained herein, the Company has made numerous assumptions
including among other things, assumptions about general business
and economic conditions, the prices of gold and copper, and
anticipated costs and expenditures. The foregoing list of
assumptions is not exhaustive.
Although management of the Company believes that the
assumptions made and the expectations represented by such
statements or information are reasonable, there can be no assurance
that a forward-looking statement or information herein will prove
to be accurate. Forward-looking statements and information by their
nature are based on assumptions and involve known and unknown
risks, uncertainties and other factors which may cause the
Company's actual results, performance or achievements, or industry
results, to be materially different from any future results,
performance or achievements expressed or implied by such
forward-looking statements or information. These factors include,
but are not limited to: risks associated with the business of the
Company; business and economic conditions in the mining industry
generally; the supply and demand for labour and other Cangrejos
Project inputs; changes in commodity prices; changes in interest
and currency exchange rates; risks relating to inaccurate
geological and engineering assumptions (including with respect to
the tonnage, grade and recoverability of reserves and resources);
risks relating to unanticipated operational difficulties (including
failure of equipment or processes to operate in accordance with
specifications or expectations, cost escalation, unavailability of
materials and equipment, government action or delays in the receipt
of government approvals, industrial disturbances or other job
action, and unanticipated events related to health, safety and
environmental matters); risks relating to adverse weather
conditions; political risk and social unrest; changes in general
economic conditions or conditions in the financial markets; and
other risk factors as detailed from time to time in the Company's
continuous disclosure documents filed with Canadian securities
administrators. The Company does not undertake to update any
forward-looking information, except in accordance with applicable
securities laws.
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SOURCE Lumina Gold Corp.