Chesapeake Provides Metallurgical Update for Metates
Chesapeake Provides Metallurgical Update for
Metates
Vancouver, British Columbia--(Newsfile Corp. - September 13, 2022) - Chesapeake Gold Corp. (TSXV:
CKG) (OTCQX: CHPGF) ("
Chesapeake
" or the "
Company
") is pleased to provide a metallurgical
update for its world class, Metates gold-silver project located in Durango State, Mexico.
Metallurgical Testwork Program - Initial Column
The sulphide heap leaching metallurgical test program commenced in May 2021 with a sample that had
already been crushed to ½" and stored in Denver for several years.
The sample was placed in a transparent column for the oxidation phase. The column was run for 128
days and achieved an oxidation of approximately 30%.
After the oxidation phase, the column was rinsed
and then leached with a standard lime cyanide solution.
The leach cycle was run for 90 days, similar to a
standard oxide gold heap leach test.
To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/752/136838_baf5e367348198f5_002full.jpg
To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/752/136838_baf5e367348198f5_003full.jpg
The above graph shows that over the 90-day leach period, the gold recovery reached almost 60% and
silver recovery just over 50%.
These results are extremely encouraging as they show significantly higher
precious metal recoveries than
unoxidized
samples from previous test work used to support the 2013
and 2016 prefeasibility studies (PFS).
Phase 1 - Oxidation Testwork
With fresh drill samples, an extensive metallurgical test program commenced in a Vancouver laboratory.
The core material was composited into two bulk samples.
One for the Massive Intrusive mineralisation
and one for the Intrusive Breccia mineralisation.
These two rock types represent the higher-grade core
mineralisation and have been the focus of the testwork program to date.
The initial tests were all run under the same conditions and were aimed at developing time vs' oxidation
vs' gold and silver recovery curves for both the Massive Intrusive and Intrusive Breccia. Two columns
were also run with NO pre-oxidation to determine a baseline "Zero" oxidation gold and silver recovery.
The oxidizing columns were run for 60, 120 and 180 days.
With no pre-oxidation the two mineralization types tested returned approximately 35% gold and 20%
silver recoveries.
The initial intrusive column demonstrated higher recoveries with almost 60% gold
recovery and over 50% silver recovery.
Higher recoveries above these levels are generally a successful
indication that the mineralization when oxidized will give better recoveries in a heap leach environment.
Concurrently, an additional 12 columns were run at the same time as the "Zero" column testing using two
different alkaline oxidation chemistries. These columns generally gave good repeatability in the oxidation
rates when the columns were run under exactly the same conditions.
The oxidation rate, however, when compared to the first sample tested was slower and did not reach a
similar oxidation level.
Alan Pangbourne, President and CEO, commented "the metallurgical results to date confirm that the
fresh core samples being tested from Metates will oxidize in a similar fashion to the first column.
We are
now focusing on optimizing the oxidation rate and achieving sufficient oxidation to achieve the targeted
gold and silver recoveries."
Phase 2 - Variable Testwork
A second round of testing is underway and is designed to investigating ways to speed up the oxidation
kinetics and have multiple columns running under various conditions to improve and optimize the
oxidation rate.
The variables being tested includes crushing finer to ¼", using High Pressure Grinding Rolls (HPGR) to
crush finer, different reagent strengths, different pH's, on/off irrigation, and varying air addition rates.
Initial oxidation response from some of these changes are encouraging and show higher initial oxidation
rates.
Despite the slower oxidation rate of the fresh core samples, Chesapeake remains optimistic that we will
be able to optimize and accelerate the oxidation to achieve the desired recoveries.
Natural Oxidation - Metates Core Samples
Over the time since we started the drilling early 2021, we have observed that the Metates mineralization
will oxidize naturally when exposed to air and moisture.
Figure 1 - Fresh core from the 2021 drilling
To view an enhanced version of Figure 1, please visit:
https://images.newsfilecorp.com/files/752/136838_baf5e367348198f5_004full.jpg
Figure 2- Same core 5 to 6 months later
To view an enhanced version of Figure 2, please visit:
https://images.newsfilecorp.com/files/752/136838_baf5e367348198f5_005full.jpg
The above photographs pertain to the same drill hole and were taken over a period of 5 to 6 months.
The
first (grey) photo above was taken as the core came out of the drill barrel.
The second photo was taken
in November 2021.
The change in colour of the core is an indication of natural oxidation.
Figure 3- Core broken open after 5 -6 months
To view an enhanced version of Figure 3, please visit:
https://images.newsfilecorp.com/files/752/136838_baf5e367348198f5_006full.jpg
Figure 4 Other core after 5 to 6 months
To view an enhanced version of Figure 4, please visit:
https://images.newsfilecorp.com/files/752/136838_baf5e367348198f5_007full.jpg
The core was broken in November and clearly shows that the oxidation is also penetrating the sample.
Additionally, parts of the core have visibly decomposed, as can be seen above in the second photo.
A
sample of this decomposed material was taken for X ray defection analysis (XRD).
The Company had originally planned to commence a PFS in 2022.
Results of the Phase 2 metallurgical
program and an updated mineral resource estimate will form the basis of a new PFS.
Presently, Chesapeake is well funded with almost C$30 million in cash and cash equivalents.
About Chesapeake
Chesapeake Gold Corp. is focused on the discovery, acquisition, and development of major gold-silver
deposits in North and South America. Chesapeake's flagship asset is the Metates project ("
Metates
")
located in Durango State, Mexico. Metates hosts one of the largest undeveloped gold-silver deposits in
the Americas with over 19.8 million ounces of gold and 540 million ounces of silver in the Measured and
Indicated Mineral Resource and a further 0.64 million ounces of gold and 18.0 million ounces of silver in
Inferred Mineral Resource. See technical report titled "Metates Sulphide Heap Leach Project Phase I
dated August 30, 2021.
Chesapeake also has an organic pipeline of satellite exploration properties strategically located near
Metates. In addition, the Company owns 69% of Gunpoint Exploration Ltd. which owns the Talapoosa
gold project in Nevada.
Qualified Persons
Dr. Art Ibrado, P.E., of Fort Lowell Consulting PLLC, is the independent qualified person responsible for
the scientific and metallurgical technical information in this news release in accordance with NI 43-101
and has reviewed and approved the contents of this release.
For Further Information:
For more information on Chesapeake and its Metates Project, please visit our website at
www.chesapeakegold.com
or contact Alan Pangbourne at
or +1 778 731
1362.
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies
of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release.
Forward-looking Statements
This news release contains "forward-looking statements" within the meaning of Canadian securities legislation. These include, without limitation,
statements with respect to the updated MRE, economic and project parameters presented in the PEA and other costs and economic information,
the strategic plans, timing and expectations for the Company's exploration and drilling programs at the Metates Property, including metallurgical
testing,
mineralization estimates and grades for drill intercepts, permitting for various work, and optimizing and updating the Company's resource
model and preparing a pre-feasibility study; information with respect to high grade areas and size of veins projected from underground sampling
results and drilling results; and the accessibility of future mining at the Metates Property. Such forward-looking statements or information are
based on a number of assumptions, which may prove to be incorrect. Assumptions have been made regarding, among other things: the reliability
of mineralization estimates, the conditions in general economic and financial markets; the price of gold and silver; availability and costs of mining
equipment and skilled labour; timing and amount of expenditures related to drilling programs; and effects of regulation by governmental agencies.
The actual results could differ materially from those anticipated in these forward-looking statements as a result of risk factors including: the timing
and content of work programs; results of exploration activities; the interpretation of drilling results and other geological data; receipt, maintenance
and security of permits and mineral property titles; environmental and other regulatory risks; project cost overruns or unanticipated costs and
expenses; and general market and industry conditions. Forward-looking statements are based on the expectations and opinions of the Company's
management on the date the statements are made. The assumptions used in the preparation of such statements, although considered reasonable
at the time of preparation, may prove to be imprecise and, as such, readers are cautioned not to place undue reliance on these forward-looking
statements, which speak only as of the date the statements were made. The Company undertakes no obligation to update or revise any forward-
looking statements included in this news release if these beliefs, estimates and opinions or other circumstances should change, except as
otherwise required by applicable law.
To view the source version of this press release, please visit
https://www.newsfilecorp.com/release/136838