Tectonic Reports GOLD Recoveries to 96.8% from Coarse Crush Bottle Rolls Warranting Investigation into Heap Leaching
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TECTONIC REPORTS GOLD RECOVERIES TO 96.8% FROM COARSE CRUSH BOTTLE ROLLS
WARRANTING INVESTIGATION INTO HEAP LEACHING
VANCOUVER, B.C., February 16, 2023 – Tectonic Metals Inc. (TECT: TSX-V; TETOF: OTCQB;
T15B: FSE) (the "Company" or "Tectonic") today announced metallurgical test results from the
Company’s Flat Gold Project (“Flat”), an intrusion -hosted, bulk tonnage gold system located in
southwestern Alaska. As part of the Company’s first year exploration program at Flat,
metallurgical samples were selected by Tectonic from historically drilled diamond core
determined to be representative of the known drilled mineralization and f ive c omposites
comprising of f our oxide and one fresh sulphide were formed . The composites were then
subject to conventional bottle roll, gravity , combined gravity and bottle roll and flotation
metallurgical test work with the goal of de -risking the project and to provide insight into what
metallurgical processing methods might be ideal. The metallurgical results from the five
composites returned gold recoveries averaging 95.6%, with one test returning a high of 99.1%,
all with conventional cyanide leaching (bottle roll) of 75µm material. These exceptional results
prompted Tectonic to conduct a follow-up bottle roll test at a coarser crush (6 mesh, 3360 µm),
which potentially can be used as a proxy for heap leaching, and an average gold recovery of
88.5% was achieved with four of the five composites returning an average gold recovery of
94.0% and a high of 96.8% . The metallurgical results also demonstrate that the mineralization
presently known at Flat is not grind sensitive, is extremely low in sulphur, non preg robbing and
favourable to various gold extraction methods. The success of Tectonic’ metallurgical program
warrants investigating column leach testing as a next step to determine if the mineralization at
Flat is amenable to heap leaching.
Tony Reda, Tectonic President & CEO, commented: We are very pleased with the results of our
initial metallurgical testing at Flat, which undoubtedly demonstrates the non-refractory nature of
known mineralization to date as evidenced by the exceptionally high gold recoveries through
bottle roll testing with minimal cyanide consumption. The baseline test work clearly de-risks the
Flat project with respect to metallurgy and gives Tectonic confidence to aggressively explore for
and develop resources on the project. Most importantly, the high gold recoveries from the 6
mesh bottle rolls coupled with the fact that mineralization begins at surface significantly endorses
the potential amenability for open-pit, heap leachable mineralization at Flat. Heap leaching is a
processing and extraction technology becoming increasingly popular over recent years due to
the potential cost advantages and lower environmental impact it can offer to miners especially as
the average grade of gold deposits has decreased over the past decade. Tectonic is excited to
evaluate heap leaching as a viable metallurgical processing method at Flat as the next value
creating opportunity.”
Metallurgical Highlights
• Conventional bottle roll tests with 48-hour leach kinetics of material ground to a K80 of 75
µm yields an average gold recovery of 95.6% with a range of 88.3% to 99.1%
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• Conventional gravity + bottle roll tests with 48-hour leach kinetics of material ground to
a K80 of 75µm yield an average gold recovery of 97.2% and a high of 98.7% across the
5 composites. The fresh sulphide composite yielded a highly favourable gold recovery
of 94.7%
• Given the initial favourable results, Tectonic then elected to do a coarser crush (6 mesh
coarse crush, K100 of 3360µm) bottle roll test on all five composites with leach kinetics
over a 192-hour period as a proxy for heap leach amenability ahead of future column
leach testing. Bottle roll testing on this coarser crush material achieved an average
gold recovery of 88.5% with 4 of the 5 composites averaging 94.0% at 3360µm vs
97.5% at 75µm indicating the majority of the tested material is not grind sensitive
• Strong and rapid leach kinetics demonstrated throughout the various metallurgical tests
• Very low cyanide consumption with an average of 0.22 kg/t for both the 75µm bottle and
3360µm coarse bottle rolls tests
• Low sulp hur content with 4 of 5 compos ites averaging 0.02% and 0.06% in the fifth
composite
• No preg robbing identified
• The various metallurgical tests and their positive results indicate that Tectonic may have
several metallurgical processing options available at Flat
• To learn more about the metallurgical program and view accompanying maps and
images please click here. Please also see Tectonic’s news release of September 07, 2022
Flat Metallurgical Program – Composites
Tectonic’s Metallurgical Test Work Program focused on Flat’s primary target known as the
Chicken Mountain Zone (“CMZ”) comprised of intrusion -related gold mineralization hosted
within a zoned monzonitic intrusion, which forms part of the more extensive Late Cretaceous Flat
volcano-plutonic complex intruding Cretaceous -aged Kuskokwim sediments. 55 drill holes
(diamond and reverse circulation) were historically drilled at CMZ, all of which encountered gold
mineralization. Five composites (four oxide and one fresh non-oxidized sulphide) derived from
41 samples collected from 9 drill holes for a total weight of 119 kilograms were formed and
determined to be representative of the known gold mineralization at Flat. The five composites
were then subject to an array of metallurgical testing, including bottle roll testing at various crush
sizes, gravity testing, combined bottle roll + gravity testing and flotation testing, to provide
insight on what metallurgical processing methods might be ideal going forward.
In total 5 composites were created from historic drill core samples taken from representative
examples of mineralization from various intrusive phases, alteration assemblages and oxidation
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profiles within the two main historically drilled areas on Chicken Mountain. Composites were
blended following geochemical characterization, fire assaying and cyanide shake tests of each
individual sample. Table 1 summarizes each composite.
Table 1: Flat Metallurgy Composites
Flat Metallurgical Program – Baseline 75um Metallurgical Test Work
Following gold (Au), sulphur (S) and carbon (C) head grade characterization of the 5 composites,
aliquots were ground to K80 at 75µm and subjected to 1Kg tests for cyanide (CN) gold extraction
(bottle roll), gravity concentration, combined gravity bottle roll and flotation recovery. Results
of the 75µm test work are summarized in Tables 2, 3 and 4 below.
Table 2: 75µm grind 48 hr bottle roll tests
Bottle roll results in Table 2 above and below in Figure 1 show excellent Au recoveries through
CN leaching for composites UFA, UFB, HCA1 and HCA2 which averaged 97.5% Au extraction
after the 48-hour test. Composite HCB achieved a slightly lower Au extraction of 88.3%. Cyanide
consumption for all 5 tests was low averaging 0.22 kg/tonne milled.
Au g/t Sulphur % Carbon %
UFA Upper Flat 11 3 30-49 Biotite Syenite Oxide 1.10 0.02 0.01
UFB Upper Flat 9 3 70-119 Biotite Syenite Oxide 0.65 0.02 0.26
HCA1 Main Chicken Mtn 7 1 4-64 Quartz Monzonite Oxide 0.53 0.02 0.02
HCA2 Main Chicken Mtn 6 2 26-41 Quartz Monzonite Oxide 1.08 0.02 0.42
HCB Main Chicken Mtn 8 1 120-132 Quartz Monzonite Fresh-Sulphide 1.14 0.06 0.42
Assayed Composite Head
Composite Zone Samples Drill Hole Drill Hole Sample depth
range (m) Host Rock Mineralization
Type
Au g/t NaCN Ca(OH)2 2 6 24 48 Total
UFA Oxide 1.66 0.24 2.57 90.9 98.1 99.4 96.7 96.7
UFB Oxide 0.68 0.19 1.23 90.4 98.8 101.6 97.1 97.1
HCA1 Oxide 0.75 0.28 2.91 58.0 76.0 96.0 99.1 99.1
HCA2 Oxide 1.05 0.17 2.89 84.5 96.7 95.8 97.0 97.0
HCB Fresh-Sulphide 1.32 0.23 0.92 74.8 83.7 88.2 88.3 88.3
Mineralization
TypeComposite Calculated
Head Grade Consumption (kg/t) Au Recovery %
Leach Kinetics (hour)
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Figure 1. 48 Hour leach kinetics of 75µm grind bottle roll tests. Gold recoveries averaged 95.6%
with a range of 99.1-88.3%.
Table 3: 75µm gravity gold concentration
Gravity Au recovery (Table 3) for composites UFA, UFB, HCA1 and HCA2 was low averaging
17.3% with an average gravity concentrate grade of 89 g/t Au. Composite HCB showed good
gravity Au recovery of 43.7% with an excellent concentrate grade of 409 g/t Au.
Calculated Head
Grade
Au g/t Au g/t Au Recovery %
UFA Oxide 1.16 192 35.8
UFB Oxide 0.79 62 15.2
HCA1 Oxide 0.61 81 12.7
HCA2 Oxide 1.05 20 5.5
HCB Fresh-Sulphide 1.13 409 43.7
Composite Gravity ConcentrateMineralization
Type
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Table 4: 75µm flotation
Flotation test work (Table 4) for UFA, UFB, HCA1 and HCA2 returned an average of 71.2% Au
recovery and 39.3% S recovery, which suggests flotation may not be the best processing option
for Flat oxide mineralization given the high gold recoveries obtained through conventional
bottle roll and the combined gravity and bottle roll testing. Composite HCB, which comprised
fresh sulphide mineralization , returned 97.4% Au recovery with 76.3% S recovery indicating
excellent amenability for gold recovery through flotation of Flat sulphide mineralization.
Further test work of the K80 75µm grind comprising gravity concentration followed by bottle roll
cyanide extraction of gravity tails was conducted specifically to address the high gravity recovery
and lower bottle roll recoveries in composite HCB. Results of the combined gravity – bottle roll
tests are summarized in Table 5.
Table 5: 75µm gravity + bottle roll
Results indicate that high recoveries at a K80 of 75µm grind utilizing gravity pre -concentration
followed by cyanide leaching are attainable for Flat sulphide mineralization with composite HCB
returning a total of 94.7% gold recovery. Composites UFA, UFB, HCA1 an d HCA2 showed a
marginal increase in recovery utilizing gravity prior to leaching with the four composites
averaging 97.9% gold recovery versus 97.5% gold recovery in the 75µm bottle roll only test.
Calculated
Head Grade Recovery %
Au g/t Wt. % Au g/t Ag, g/t Au Rec % S Rec %
UFA Oxide 1.19 27.5 3.66 1.09 84.8 45.0
UFB Oxide 0.81 16.4 3.52 3.43 71.1 27.9
HCA1 Oxide 0.52 17.7 2.19 0.61 74.6 42.7
HCA2 Oxide 1.06 10.7 5.39 1.45 54.3 41.8
HCB Fresh-Sulphide 1.33 14.6 8.87 1.90 97.4 76.3
Composite Concentrate SpecsMineralization
Type
Total
Au g/t Au g/t Recovery % NaCN Ca(OH)2 2 6 24 48 Grav+CN
UFA Oxide 1.11 127 17.8 0.2 3.23 76.3 82.7 82.5 80.8 98.7
UFB Oxide 0.94 52.1 10.0 0.16 2.74 73.3 80.8 83.5 86.2 96.3
HCA1 Oxide 0.77 81.5 18.2 0.11 2.57 79.3 80.3 83.4 80.5 98.7
HCA2 Oxide 1.13 12.9 2.4 0.14 1.79 82.4 90.2 96.8 95.4 97.8
HCB Fresh-Sulphide 1.12 200 34.3 0.17 1.2 58.1 60.2 59.6 60.4 94.7
Calculated
Head
GradeComposite
Gravity Concentrate
Bottle Roll Au Recovery (%)
Consumption (kg/t) Leach Kinetics (hour)
Mineralization
Type
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Flat Metallurgical Program – 6 mesh (3360µm) Metallurgical Test Work
As a proxy for and to investigate the amenability of further column leach testing of Flat
mineralization, bottle rolls were conducted on all five composites on 6 mesh coarse crush ( K100
of 3360µm) material with leach kinetics over a 192-hour period. Results are summarized in
Table 6 below.
Table 6: 6 mesh (3360µm) gravity +bottle roll.
Gold recovery averaged 88.5% for all five composites with composites UFA, UFB, HCA1 and
HCA2 (oxidized mineralization) averaging 94%, while sulphide mineralization represented by
composite HCB achieved an Au recovery of 66.5% at 6 mesh.
Results of the 6-mesh bottle roll clearly demonstrate that column leach testing of the Flat
mineralization is clearly war ranted to test the overall amenability to heap leaching, particularly
in the oxide portions of the deposit. Additional column leach testing of sulphide bearing
mineralization is also warranted due to the low sulphide content, low cyanide consumption and
non-preg robbing nature.
Flat Metallurgical Program – Metallurgist and Laboratory
The metallurgical test work was undertaken by Base Metallurgical Laboratories (Base Met Labs),
Kamloops, British Colombia, under the supervision of Jake Lang , Principal Metallurgist.
Additionally, the program was conducted under the guidance of Tectonic ’s consulting
Metallurgical Advisor, Jeet Basi , who has over 15 years of technical leadership experience in
global public mining companies , includin g Newmont, Goldcorp and Teck Resources. Base
Metallurgical Laboratories is a fully integrated mineral processing laboratory located in
Kamloops BC. The facility incorporat es metallurgical, mineralogy and analytical capabilities.
Base Met Labs is backed by experienced metallurgists with regards to flotation and cyanidation
process flowsheet development and interpretation of mineralogical analyses.
Au g/t NaCN Ca(OH)2 24 48 72 96 192 Total
UFA Oxide 1.50 0.24 4.02 71.4 81.4 88.6 88.6 92.8 92.8
UFB Oxide 0.65 0.28 3.20 87.5 88.7 88.3 88.3 94.2 94.2
HCA1 Oxide 0.50 0.19 3.16 90.0 97.3 95.5 95.5 96.8 96.8
HCA2 Oxide 1.01 0.19 2.08 87.3 87.0 91.1 91.1 92.3 92.3
HCB Fresh-Sulphide 0.97 0.19 1.34 58.9 64.8 65.6 65.6 66.5 66.5
Au Recovery (%)
Leach Kinetics (hour)Composite
Calculated
Head Grade Consumption (kg/t)Mineralization
Type
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About The Flat Gold Project
The Flat Gold Project is an intrusion-hosted, bulk tonnage gold project located in southwestern
Alaska, just 40km north of the giant Donlin Gold Project, which is owned equally by Barrick and
NOVAGOLD.
Flat consists of 92,160 acres of mostly Native-owned land belonging to Doyon, Limited, a
leading Alaska’s Native Regional Corporation and the largest private landholder in the State of
Alaska. Doyon and Tectonic have formed a mutually beneficial mineral lease property
agreement covering all aspects of exploration through to production, including royalties and
ESG provisions. The resulting agreement aligns the interests and expectations of both parties
involved, reduces risk, and creates a process that can advance a project from discovery through
development and production to final reclamation.
Flat represents a rare opportunity in a tier one jurisdiction:
• A large scale, intrusion-hosted gold system with mineralization
• Documented as the 4th largest placer mining district in Alaska with over 1.4Moz of
recorded gold produced via placer mining*
• 55 historical drill holes , all of which hit mineralization and 25 of which bottomed in
mineralization
• Mineralization begins at surface, average drill depth is only 100m vertical, open in all
directions
• Located in close proximity to a world-class gold deposit (Donlin)
• +4km long, +200ppb gold-in-soil anomaly (open for expansion)
• Historical mineralized trenches, some of which remain untested by drilling
• Situated predominantly on Native Owned Land with a full scale mineral lease property
agreement covering all aspects of exploration through to production, including royalties
and ESG provisions
To learn more about Tectonic’s Flat Gold Project, click here.
End Note : *Mineral Occurrence and Development Pote ntial Report, Locatable and Salable
Minerals, Being Sea-Western Interior Resource Management Plan, BLM-Alaska Technical Report
60, prepared by the U.S. Department of the Interior, Bureau of Land Management, November
2010
Qualified Person
Tectonic’s disclosure of a technical or scientific nature in this press release has been reviewed,
verified, and approved by Peter Kleespies, M.Sc., P.Geo., Tectonic’s Vice President Exploration,
who serves as a Qualified Person under the definition of National Instrument 43-101.
To learn more about Tectonic, please click here.
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On behalf of Tectonic Metals Inc.,
Tony Reda
President and Chief Executive Officer
For further information about Tectonic Metals Inc. or this news release, please visit our website
at www.tectonicmetals.com or contact Tony Reda, President & CEO of Tectonic, or Bill Stormont,
Investor Relations, at toll-free 1.888.685.8558 or by email at [email protected].
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Certain information in this news release constitutes forward-looking information and statements under applicable securities law. Any
statements that are contained in this news release that are not statements of historical fact may be deemed to be forward -looking
statements. Forward-looking statements are often identified by terms such as “may”, “should”, “anticipate”, “expect”, “intend” and
similar expressions.
Forward-looking information is not a guarantee of future performance and is based upon a number of estimates and assumptions of
management at the date the statements are made including, among others, assumptions about future prices of gold and other metal
prices, currency exchange rates and interest rates, favourable operating conditions, political stability, obtaining governmen tal and
other approvals and financi ng on time, obtaining required licenses and permits, labour stability, stability in market conditions,
availability of equipment, accuracy of any mineral resources, successful resolution of disputes and anticipated costs and expenditures.
Many assumptions are based on factors and events that are not within the control of Tectonic, and there is no assurance they will prove
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Although Tectonic considers these beliefs and assumptions to be reasonable based on information currently available to it, they may
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strategies; risks associated with mineral exploration and production; risks associated with general economic conditions; adverse
industry events; marketing and transportation costs; loss of markets; volatility of commodity prices; inability to access sufficient capital
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intentions, or expectations upon which they are placed will occur. Such information, although considered reasonable by management
at the time of preparation, may prove to be incorrect and actual results may differ materially from those anticipated. Forward-looking
statements contained in this news release are expressly qualified by this cautionary statement. Although Tectonic has attempt ed to
identify important factors that could cause actual results to differ materially from those contained in forward-looking information, there
may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such
information will prove to be accura te, as actual results and future events could differ materially from those anticipated in such
statements. Accordingly, readers should not place undue reliance on forward -looking information. Tectonic does not undertake to
update any forward-looking information, except in accordance with applicable securities laws.
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