VANCOUVER, June 6, 2018 /CNW/ - Marlin Gold Mining Ltd.
(TSX-V: MLN) ("Marlin" or the "Company") is pleased to announce
that it has received encouraging preliminary results from the
latest metallurgical testing program being conducted on its wholly
owned Commonwealth gold and silver property in Cochise County, Arizona (the "Commonwealth
Project"). The results indicate that the gold and silver
mineralization is amenable to processing by heap leaching or
milling and recovery by industry standard
methods.
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Akiba Leisman, Executive Chairman
and Interim CEO states that, "Over the past nine months, Marlin has
been conducting extensive metallurgical testing to help define the
parameters and process flowsheet for the Commonwealth
Project. The entire resource is in oxidized material, and
both heap leach and milling scenarios were investigated. The
results received to date meet or exceed management's expectations
for recoveries and engineering has commenced to determine the
optimal capacity and processing method for the project."
Samples for the metallurgical test program were selected from 26
large diameter PQ (8.5cm diameter) core holes drilled in 2016 and
2017 along with various exploration assay rejects to represent 28
variations in the style of mineralization identified by the
exploration work. McClelland Laboratories Inc. ("MLI") was engaged
to conduct a bench scale metallurgical test program to guide the
development of the Commonwealth Project. A series of columns tests,
and cyanidation tests by bottle roll and agitation were carried out
to determine the metallurgical response to heap leaching and a
conventional whole ore milling process. The flowsheets for a mill
operation considered cyanidation with carbon recovery as well as a
flotation concentration and gravity concentration as possible
processing options to demonstrate gold and silver recoveries that
can be expected from either a heap leach operation or a whole ore
milling operation.
The test work used a range of size distributions to determine
the optimum crushing and grinding sizes for each of the processing
options in conjunction with testing the metallurgical response of
the 28 variations in the style of mineralization that have been
identified by the exploration program to date. The depth of the
samples as well as higher grade mineralization was given
representation in the variability samples to help guide future mine
planning considerations. Composite groupings were defined
based on host rock, alteration, mineralization style and either or
both gold and silver assays.
Heap Leaching
Fifty-four column tests have been initiated to test the
potential to apply heap leaching as the process route for the
Commonwealth Project. Although only 11 of the column tests have
reached completion and reporting, the preliminary results to date
provide good insight into the results to be expected from this type
of processing.
The average gold recovery after a 75-day leach cycle was
80.4% on all samples crushed to minus 3/8 inch with recoveries
ranging from 83% to 88% on finer material depending on the style of
mineralization. Results indicate improved extractions
with finer crush sizes by as much as 5% to 15%. The main process
consumables range from 1.17 to 3.24 kg/tonne of cyanide and 1.0 to
2.5 kg/tonne of lime. The consumption of cement added to
agglomerate the finer material was 2.0 kg/tonne. The leach
cycle times being tested range from 75 to 100 days with up to 175
days to complete the total leach and rinse times required. The
column tests yielded low silver extractions averaging
15.2%.
The Company plans to report on the column test results as soon
as the full test results report is received from MLI.
Whole Ore Cyanidation
A series of bench scale tests were carried out to test the
metallurgical response to a standard gold mill employing
cyanidation with recovery of the gold and silver by carbon in pulp
or carbon in leach. This included rolling bottle testing and
agitated leach tests with cyanide and pH adjustment with lime. As
possible variations to whole ore cyanidation, testing of gravity
concentration was carried out as well as flotation concentration to
provide preliminary indications of the probable metallurgical
response of all variations of the processing options. These
variations may possibly reduce grinding costs, reduce consumption
of major consumables, and improve overall metal recoveries as well
as guide the final selection of the process flowsheet.
Bottle roll testing was completed on all composites in a total
of 88 tests keeping the cyanide levels and pH constant. The
results showed good gold extractions ranging from 85.7% to 97.2%
with silver extractions improved over the column testing ranging
from 19.0% to 55.1%. Historical mineralogical studies indicated
that low silver recovery may be attributed to very fine silver
encapsulated in the silica matrix, very fine silver included in
jarosite and silver contained within manganese oxides. Ultrafine
grinding testing showed improved extractions for both gold and
silver but is probably not economic due to the increased power cost
as well and probable increased reagent costs associated with the
finer material that would have to be handled.
Agitated leach tests were carried out on samples which for the
most part compared with the bottle roll tests and conclusions
reached. The leach kinetics indicated that most of the leachable
gold and silver were in solution after 24 hours supporting the
normal design parameters of 36 hours retention time in a commercial
flowsheet. The cyanide consumption ranged from 0.83 to 1.29
kg/tonne with lime requirements at 1.6 to 2.6 kg/tonne. There was
an indication that cyanide consumption was higher on the deeper
composites that were tested.
Analysis for organic carbon as a potential metal loss from
solution showed 0.12% with considerably less in the drill core
samples. The exception to the low levels was in two zones with
sedimentary material that will require closer analysis in the
mining plan and any potential inclusions in the mineralized
zones.
Scoping level flotation tests were completed on three higher
grade composites to test the metallurgical response to single stage
rougher flotation. The three composites were ground to 80%
passing 100, 150 and 200 mesh (150, 106 and 75 microns). Results
indicated that gold recovery to the flotation concentrate would
range from 82.8% to 89.1% while silver recovery would range from
10.6 % to 54.9%. As with the bottle roll testing, the finer
grind showed improved recoveries of both metals.
The tailings from the flotation circuit were subjected to
cyanidation tests and indicated the overall recovery of gold would
be comparable to the whole ore cyanidation results. This would make
the overall process decision on the inclusion of flotation rest on
the operating costs of the two options and any potential savings
that could be achieved with reagents and grinding costs.
The scoping level bench testing of gravity concentration on
samples at 80% passing 200 mesh (75 microns) showed 12.2% to 27.7%
of the gold and 1.9% to 11.2% of the silver reporting to a gravity
concentrate as expected by the metallic assay results.
Quality Assurance and Quality Control
All sample preparation, compositing, and test work was performed
or overseen by McClelland Laboratories Inc. in Sparks, Nevada. Their processes and assaying
results met the requirements of the Company and its consultants,
including Sr. Metallurgist Craig L.
McKenzie, and are traceable and well documented.
Qualified Person
Ross MacFarlane P. Eng Watts,
Griffis and McOuat Limited, Associate Metallurgist and Joe Hinzer, P.Geo., the President and Director
of Watts, Griffis and McOuat Limited both independent of Marlin and
"Qualified Persons" under NI 43-101 have reviewed and approved the
written scientific and technical disclosure contained in this
presentation.
About Marlin Gold
Marlin is a growth-oriented gold and silver mining company
focused on the Americas. The company owns three properties located
in Mexico and the USA and a portfolio of royalties. Marlin's
priority is to profitably operate its La Trinidad Mine, conduct
further exploration on its other projects and enhance shareholder
value through a strategic relationship with Sailfish Royalty Corp.
(TSX-V:FISH). Marlin is backed by a well-funded investor with a
successful track record in the resources sector. The La Trinidad
Mine in Sinaloa, Mexico declared
commercial production on November 1,
2014 and is one of the highest grade open pit heap leach
gold mines in Mexico.
Neither the TSX Venture Exchange nor its Regulation Services
Provider (as the term is defined in the policies of the TSX Venture
Exchange) accepts responsibility for the adequacy or accuracy of
this release.
Cautionary statement regarding
forward‐looking information
This news release contains "forward-looking statements"
within the meaning of applicable securities laws. Forward-looking
statements are statements that are not historical facts and are
generally, but not always, identified by words such as the
following: expects, plans, anticipates, believes, intends,
estimates, projects, assumes, potential and similar expressions.
Forward-looking statements also include reference to events or
conditions that will, would, may, could or should occur, including,
without limitation statements relating to: the anticipated access
to mineralized material, including any potential mining thereof;
the timing and scope of certain drilling programs; the receipt of
assay results; statements regarding the perceived merit of
properties, exploration programs and budgets; anticipated capital
expenditures; mineral resource estimates; timelines; strategic
plans; and other statements that are not statements of fact. These
forward-looking statements are necessarily based upon a number of
estimates and assumptions that are based on management's
expectations and considered reasonable at the time they are made,
including among others: that work proceeds in accordance with the
timing and scope anticipated by management and that anticipated
market prices for precious and base metals are achieved. Investors
are cautioned that all forward-looking statements are inherently
subject to a variety of risks and uncertainties which could cause
actual events or results to differ materially from those reflected
in the forward-looking statements, including, without limitation:
uncertainties related to raising sufficient financing to fund
planned work in a timely manner and on acceptable terms; changes in
planned work resulting from logistical, technical or other factors;
the possibility that results of work will not fulfill
projections/expectations and realize the perceived potential of the
Company's projects; uncertainties involved in the interpretation of
drilling results and other tests and the estimation of gold
resources; risk of accidents, equipment breakdowns and labour
disputes or other unanticipated difficulties or interruptions; the
possibility of environmental issues at the Company's projects; the
possibility of cost overruns or unanticipated expenses in work
programs; the need to obtain permits and comply with environmental
laws and regulations and other government requirements;
fluctuations in the price of gold; and other risks and
uncertainties, including those described in the Company's annual
management's discussion and analysis filed on SEDAR at
www.sedar.com. As a result, readers are cautioned not to place
undue reliance on these forward-looking statements. The
forward-looking statements contained in this news release are made
as of the date of this release. Unless required by law, Marlin has
no intention to and assumes no obligation to update or revise any
forward-looking statements, whether as a result of new information,
future events or otherwise.
SOURCE Marlin Gold Mining Ltd.