Newcore Gold Announces 91.7% Gold Recoveries in Column Testwork for the Sewum and Boin Deposits at the Enchi Gold Project, Ghana Additional Column Tests Completed on Oxide Mineralization from Sewum and Boin
NEWS RELEASE
Suite 1560 - 200 Burrard Street www.newcoregold.com
Vancouver, British Columbia V6C 3L6 [email protected]
Newcore Gold Announces 91.7% Gold Recoveries in Column Testwork for
the Sewum and Boin Deposits at the Enchi Gold Project, Ghana
Additional Column Tests Completed on Oxide Mineralization from Sewum and Boin
October 4, 2023 TSX-V: NCAU, OTCQX: NCAUF
Vancouver, BC – Newcore Gold Ltd. ("Newcore" or the "Company") (TSX-V: NCAU,
OTCQX: NCAUF) is pleased to announce positive results from five additional column tests
completed as part of the ongoing metallurgical program at the Company’s 100%-owned Enchi
Gold Project ("Enchi" or the "Project") in Ghana. An average gold recovery of 91.7% was
achieved from column testwork completed on three composite samples from the Sewum Gold
Deposit ("Sewum") and two composite sample from the Boin Gold Deposit ("Boin").
Highlights from Column Test Results
• Five Column Tests Completed, Average Gold Recovery of 91.7% Achieved.
o A total of five column tests (three from Sewum and two from Boin) returned an average
gold recovery of 91.7%, with a recovery range of 88.4% to 95.6%.
• Testwork Further Advances the Understanding of Processing Options for Enchi.
o Testing completed on representative samples of oxide mineralization from trenches.
o Crush size in testing in-line with modelled crush size for heap leach processing.
o Larger sized samples used in the columns with each sample weighing 30 kg.
• Low Reagent Consumption.
o All samples showed modest cyanide consumption with an average of 1.2 kilograms per
tonne ("kg/t"), with a 1.3 kg/t lime (hydrated) addition to maintain a pH above 10.5.
• Additional Metallurgical Testwork Underway.
o Optimization work continues on results from additional column tests to be completed on
oxide mineralization from the Sewum, Boin, and Nyam gold deposits.
o A pilot heap bench-scale test is underway, to be completed in Q4 2023.
o Additional testing of sulphide mineralization from Sewum is in progress.
Greg Smith, VP Exploration of Newcore stated, "This additional set of column tests completed
on representative oxide material from the Enchi Gold Project returned results that are
consistent with prior results, returning high recoveries for all five compos ite samples.
Metallurgical testwork completed on oxide mineralization confirms the generally modest lime
and cement consumptions. This work continues to highlight the amenability of Enchi to heap
leach gold recovery and the favorable results will be incorp orated into our PEA update
scheduled for H1 2024. This testwork was completed on samples from the two largest deposits
currently identified on the Project, Sewum and Boin, which together compromise
approximately 73% of the Mineral Resource Estimate. We continue to de-risk and advance the
development of the Project with further metallurgical testwork underway on both oxide and
sulphide mineralization at Enchi."
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Metallurgical Testing Summary
A total of five composite samples, three from Sewum and two from Boin, were submitted for
column testwork to the Intertek Lab located in Tarkwa, Ghana, approximately four hours by
paved road from the Enchi Gold Project. Material for the metallurgical samples consisted of
trench material collected for metallurgical sampling. The samples were selected to represent
the two largest deposits on the Project, Sewum and Boin, and consisted of blended oxide
material with individual samples and composites covering a range of gold grades.
Composites BnMetT r1 and BnMetTr2 were prepared using 20 samples each from trench
KBTR_MET_001 at Boin with a total weight of 60 kg per composite sample. Composite
SwMetTr1, SwMetTr2, and SwMetTr3 were prepared using 20 samples each from trench
SWTR_MET_001 at Sewum with a total weight of 60 kg per composite sample.
Recovery for the five samples averaged 91.7%, with a range of 88.4% to 95.6%.
Table 1 - Column Tests Grade and Average Recovery
Sample Deposit Grade Au g/t Recovery Rate
BnMetTr1 Boin 1.79 90.85%
BnMetTr2 Boin 1.04 88.42%
SwMetTr1 Sewum 1.56 88.62%
SwMetTr2 Sewum 0.75 94.67%
SwMetTr3 Sewum 0.57 95.58%
Average 91.70%
Composite samples were homogenized by mixing all material from the individual samples and
crushed to 70% passing 12.5 mm. Each composite sample was then split to provide sub -
samples weighing 4 kg each. Two samples were removed and again split into a further four
fractions of 2 kg for use in screening and grading analysis, head sample analysis, and ten-day
coarse bottle roll leach tests.
Screening and Grading Analysis of Head Samples
A size analysis was done on each of the five composite samples. The samples were tested at
eight screen sizes and included analyses for percent mass.
Table 2 - Size Analysis by Composite Sample
Sieve
BnMetTr1 BnMetTr2 SwMetTr1 SwMetTr2 SwMetTr3
%
mass
Au
g/t
%
mass
Au
g/t
%
mass
Au
g/t
%
mass
Au
g/t
%
mass
Au
g/t
+10.0mm 4.1 4.26 6.3 5.95 3.0 0.10 5.9 0.10 3.3 0.28
+6.3mm 11.6 6.55 17.5 3.19 9.4 0.93 14.1 0.29 18.8 0.40
+2.5mm 19.4 3.27 22.1 1.33 21.0 1.44 28.9 0.57 35.3 1.42
+1.0mm 11.3 2.09 12.7 0.85 13.0 1.36 20.0 0.60 18.5 0.33
+300µm 14.3 1.39 11.5 0.97 10.4 2.62 14.7 0.49 13.9 0.41
+212µm 3.2 1.51 2.3 0.91 2.2 1.63 2.5 0.54 2.4 0.49
+150µm 3.0 1.56 2.2 0.83 2.1 2.99 2.1 0.59 2.0 0.49
-150µm 33.0 1.10 25.2 0.52 38.9 1.17 11.8 0.67 5.9 0.61
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The samples were assayed for gold which showed that gold was present in all size fractions
analysed. The distribution shows relatively consistent gold grades for all size fractions within a
range of 0.28 grams per tonne gold ("g/t Au") to 6.55 g/t Au, with two outliers grading 0.10 g/t
Au. Results include 10% to 43% passing 300 microns indicating that agglomeration is
warranted.
Head Sample Analysis
Using the results of the sizing and grading analysis, a head grade was calculated for each of
the composite samples. The results were then compared to the head grade assays which were
completed on the 50-gram subsamples. The results compared well for the five composites.
Table 3 - Grade Analysis by Composite Sample
Gold Grade g/t BnMetTr1 BnMetTr2 SwMetTr1 SwMetTr2 SwMetTr3 Average
Assayed Grade 2.12 1.04 1.56 0.70 0.59 1.20
Calculated Grade 2.47 1.62 1.40 0.51 0.76 1.35
Average 2.29 1.33 1.48 0.60 0.68 1.28
Ten Day Coarse Bottle Roll Leach
Simulated heap leach testing was conducted on the composite samples using two -kilogram
sub-samples which underwent leaching for ten days. Batch dissolution tests (ten days,
intermittent rolling -bottle) was completed under e xcess leach conditions (grind size – as
received, 50% solids, leach time: ten days, pH 10.5, NaCN (sodium cyanide) addition 1
gram/litre). The final residue was dried, weighed, and assayed for gold. After each 24 hours of
leaching, solution assays were tak en and analyzed, and reagent consumption (cyanide and
lime) was calculated.
For composite BnMetTr1, 66.4% of the gold was recovered on the first day, with recoveries
increasing consistently to 83.6% on the tenth day. For composite BnMetTr2, 66.0% of the gold
was recovered on the first day, with recoveries increasing consistently to 81.6% on the tenth
day. For c omposite SwMetTr1, 74.6% of the gold was recovered on the first day, with
recoveries increasing consistently to 87.6% on the tenth day. For composite SwMetTr2, 77.8%
of the gold was recovered on the first day, completed testing at 89.5% on the tenth day. For
composite SwMetTr3, 66.4% of the gold was recovered on the first day, with a final recovery of
90.3% on the tenth day. In all cases leaching con tinued after the first ten days with ultimate
recoveries expected to continue to increase with additional leaching time.
A graph showing the gold recovery by sample can be viewed at the following link:
https://newcoregold.com/site/assets/files/5829/2023_10-ncau-nr-met-graph-columnvsbottle.pdf
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Metallurgical Testing – Column Tests
Five 30 kg closed -cycle column leach tests were conducted on the samples as received. The
test charge was loaded into 150 mm in diameter by 1.5 -metre-tall PVC columns. 30 kg of the
individual samples were agglomerated in a rolling drum using Portland cemen t at a 10 kg/t
addition rate and then allowed to air dry for three days. After the samples had been air dried,
they were loaded into the columns with the columns tilted at an angle to avoid stacking before
being set upright. The column was then allowed to sit for a day before the initial level was taken
to determine the slump.
The leaching parameters used in these column leach tests included the addition of
approximately 1.4 kg/t of lime which was blended into each feed solution , and a cyanide
concentration of 1,000 ppm. The initial feed solution was prepared by adding lime to tap water
to obtain a solution pH above 10.5 , followed by the addition of one gram of sodium cyanide
per litre of solution with a solution application rate of 10L/h/m 2 for all samples . The column
testwork was conducted under a closed cycle for 60-90 days. All solution samples were assayed
for gold and pH and free sodium cyanide was analyzed and recorded. Leach residue was
thoroughly washed, dried, screened and analyzed for gold by fire assay.
A graph showing the leach curve can be viewed at the following link:
https://newcoregold.com/site/assets/files/5829/2023_10-ncau-nr-met-graph-leach-chart.pdf
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The column tests are aimed at simulating the response to leaching of the sample with the
emphasis on establishing the gold dissolution characteristics (rate and extent), reagent
consumption, and the degree of slumping within the ore bed. All samples showed amenability
to heap leaching, with recoveries averaging 91.7% after 60 to 90 days.
The samples showed low cyanide consumption averaging 1.1 kg/t with a 1.3 kg /t lime
(hydrated) addition to maintain a pH above 10.5. The slumps were moderately above
acceptable industry standards with an overall average of 15.4%. The sample response to a
percolation rate of 10L/m 2/hr resulted in some flooding. The ideal percolatio n rate will be
studied and optimized.
Table 4 - Summary of Column Leach Tests
Composite Leach Time Slump % Reagent Consumption kg/t
NaCN Lime Cement
BnMetTr1 90 days 14.8% 0.77 1.56 10
BnMetTr2 90 days 17.9% 1.39 1.88 10
SwMetTr1 90 days 10.2% 1.09 1.08 10
SwMetTr2 60 days 20.1% 0.82 0.86 10
SwMetTr3 60 days 14.1% 1.51 1.16 10
Average 15.4% 1.12 1.31 10
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The column leach test program has shown that the gold in the ore samples tested is readily
leachable and amenable to heap leaching. The recoveries achieved are considered high and
are interpreted to indicate strong amenability to heap leaching. The particle size distribution
and size by size analysis performed on both the head and residue after leach showed that the
maximum g old recovery occurred in the finer fractions as compared to the coarser size
fractions.
Screening and Grading Analysis of Tails Samples
A size analysis was done on all the tails from the composite sample column tests. The samples
were tested at eight scre en sizes including analyses for percent mass and assayed for gold.
The distribution shows consistently low grades of gold for all size fractions, in line with the high
gold recoveries in the column tests, within a range of 0.00 g/t Au to 0.37 g/t Au with o nly five
samples reporting greater 0.2 g/t Au. Four of the five samples with elevated results are related
to the higher-grade sample which assayed 1.79 g/t Au.
Multi-Element Analyses
The five composites were tested for 33 elements using multi-acid digestion and analysed by
Inductively Coupled Plasma Optical Emission Spectrometry ("ICP"). The five samples show very
similar profiles for all elements analysed. All samples contain no silver with every result below
the detection limit of 0.5 g/t silver. All samples reported low values for lead, zinc, and copper
averaging 11, 21, and 10 ppm respectively and mildly elevated arsenic averaging 313 ppm
with no relationship to the gold grade. Relative to previously analyzed sulphide material , the
concentrations are much lower for the more mobile elements including calcium, magnesium,
sodium, and sulphur, and consistently moderately lower for cobalt, manganese, nickel, and
strontium.
Bond Work Index
The five composite samples were selected for bond index determination. Samples were sent
from Intertek to Jet -Com Engineering in Tarkwa, Ghana and included a range of recoveries
and gold grades. The five as -received samples were crushed to 100% passing 3.3 5mm and
from this a 700 cm3 volume was measured and weighed to be used as feed for the bond mill.
The grindability, defined as the ease at which a mineral particle is reduced to a predetermined
size, of the samples ranged from 1.29 g/rev to 1.73 g/rev aver aging 1.51 g/rev which shows
that the ore requires relatively little energy to crush. The bond work indices range between
8.89 KWh/t and 10.60 KWh/t , averaging 9.58 KWh/t indicative of material defined as soft to
low-medium hardness.
Boin and Sewum Oxide Sample Details
Two trenches were dug for metallurgical test work on the Enchi gold project. The locations of
the trenches were selected in order to allow for wide gold mineralized intercepts in each of the
two largest deposits, Sewum and Boin, currently identified on the Enchi Gold Project. Material
exposed in the trenches is consider representative of the oxide portion for both deposits. A
total of 61 m and 107 m was completed on KBTR_MET_001 from Boin and SWTR_MET_001
from Sewum respectively. Trench KBTR_ MET_001 at Boin was dug -out manually while as
SWTR_MET_001 was dug-out mechanically. Samples were assigned a new unique number and
submitted to the Intertek Lab located in Tarkwa, Ghana.
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Select assay results from the 5 holes of the drill program reported in this release are below:
Table 5 - Enchi Gold Project Trenching Results Highlights
Hole ID Zone/Deposit From (m) To (m) Length (m) Au (g/t)
KBTR_MET_001 Boin 1.0 45.0 44.0 1.43
and 5.0 34.0 29.0 1.97
SWTR_MET_001 Sewum 15.0 107.0 92.0 1.18
including 27.0 40.0 13.0 2.70
including 58.0 81.0 23.0 1.78
Notes:
1. Intervals reported are trench lengths with true width estimated to be 75 - 85%; and
2. Length-weighted averages from uncut assays.
Enchi Gold Project Mineral Resource Estimate
The Enchi Gold Project hosts an Indicated Mineral Resource of 41.7 million tonnes grading
0.55 g/t Au containing 743,500 ounces gold and an Inferred Mineral Resource of 46.6 million
tonnes grading 0.65 g/t Au containing 972,000 ounces (see Newcore news release date d
March 7, 2023). Mineral resource estimation practices are in accor dance with CIM Estimation
of Mineral Resource and Mineral Reserve Best Practice Guidelines (November 29, 2019) and
follow CIM Definition Standards for Mineral Resources and Mineral Reserves (May 10, 2014),
that are incorporated by reference into National Instrument 43-101 ("NI 43-101"). The Mineral
Resource Estimate is from the technical report titled "Mineral Resource Estimate for the Enchi
Gold Project" with an effective date of January 25, 2023, which was prepared for Newcore by
Todd McCracken, P. Geo, of BBA E&C Inc. and Simon Meadows Smith, P. Geo, of SEMS
Exploration Services Ltd. in accordance with NI 43-101 Standards of Disclosure for Mineral
Projects, and is available under the Company’s profile on SEDAR at www.sedar.com. Todd
McCracken and Simon Meadows Smith are independent qualified persons ("QP") as defined
by NI 43-101.
Newcore Gold Best Practice
Newcore is committed to best practice standards for all exploration, sampling and drilling
activities. Drilling was completed by an independen t drilling firm using industry standard RC
and Diamond Drill equipment. Analytical quality assurance and quality control procedures
include the systematic insertion of blanks, standards and duplicates into the sample strings.
Samples are placed in sealed b ags and shipped directly to Intertek Labs located in Tarkwa,
Ghana for 50 gram gold fire assay.
Qualified Person
Mr. Gregory Smith, P. Geo, Vice President of Exploration at Newcore, is a Qualified Person as
defined by NI 43 -101, and has reviewed and approved the technical data and information
contained in this news release. Mr. Smith has verified the technical and scientific data disclosed
herein and has conducted appropriat e verification on the underlying data including
confirmation of the drillhole data files against the original drillhole logs and assay certificates.
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About Newcore Gold Ltd.
Newcore Gold is advancing its Enchi Gold Project located in Ghana, Africa’s large st gold
producer (1). The Project currently hosts an Indicated Mineral Resource of 743,500 ounces of
gold at 0.55 g/t and an Inferred Mineral Resource of 972,000 ounces of gold at 0.65 g/t (2).
Newcore Gold offers investors a unique combination of top -tier leadership, who are aligned
with shareholders through their 20% equity ownership, and prime district scale exploration
opportunities. Enchi’s 216 km 2 land package covers 40 kilometres of Ghan a’s prolific Bibiani
Shear Zone, a gold belt which hosts several 5 million -ounce gold deposits, including the
Chirano mine 50 kilometers to the north. Newcore’s vision is to build a responsive, creative and
powerful gold enterprise that maximizes returns for shareholders.
On Behalf of the Board of Directors of Newcore Gold Ltd.
Luke Alexander
President, CEO & Director
For further information, please contact:
Mal Karwowska | Vice President, Corporate Development and Investor Relations
+1 604 484 4399
www.newcoregold.com
(1) Source: Production volumes for 2022 as sourced from the World Gold Council
(2) Notes for Mineral Resource Estimate:
1. Canadian Institute of Mining Metallurgy and Petroleum ("CIM") definition standards were followed for the
resource estimate.
2. The 2023 resource models used ordinary kriging (OK) grade estimation within a three-dimensional block model
with mineralized zones defined by wireframed solids and constrained by pits shell for Sewum, Boin and Nyam.
Kwakyekrom and Tokosea used Inverse Distance squared (ID2).
3. Open pit cut-off grades varied from 0.14 g/t to 0.25 g/t Au based on mining and processing costs as well as the
recoveries in different weathered material.
4. Heap leach cut-off grade varied from 0.14 g/t to 0.19 g/t in the pit shell and 1.50 g/t for underground based on
mining costs, metallurgical recovery, milling costs and G&A costs.
5. CIL cut off grade varied from 0.25 g/t to 0.27 g/t in a pit shell and 1.5 0 g/t for underground based on mining
costs, metallurgical recovery, milling costs and G&A costs.
6. A US$1,650/ounce gold price was used to determine the cut-off grade.
7. Metallurgical recoveries have been applied to five individual deposits and in each case th ree material types
(oxide, transition, and fresh rock).
8. A density of 2.19 g/cm3 for oxide, 2.45 g/cm3 for transition, and 2.72 g/cm3 for fresh rock was applied.
9. Optimization pit slope angles varied based on the rock types.
10. Reasonable mining shapes constrain the mineral resource in close proximity to the pit shell.
11. Mineral Resources that are not mineral reserves do not have economic viability. Numbers may not add due to
rounding.
12. The Mineral Resource Estimate is from the technical report titled "Mineral Resource Estimate for the Enchi Gold
Project" with an effective date of January 25, 2023, which was prepared for Newcore by Todd McCracken, P.
Geo, of BBA E&C Inc. and Simon Meadows Smith, P. Geo, of SEMS Exploration Services Ltd. in accordance with
National I nstrument 43 -101 Standards of Disclosure for Mineral Projects and is available under Newcore’s
SEDAR profile at www.sedar.com. Todd McCracken and Simon Meadows Smith are independent qualified
persons ("QP") as defined by National Instrument 43-101.
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 release.