VANCOUVER, BC, June 15, 2021 /CNW/ - Zacatecas Silver Corp.
("Zacatecas Silver" or the "Company", (TSXV: ZAC) (OTC Markets:
ZCTSF) (Frankfurt: 7TV) is pleased
to announce it has received positive preliminary metallurgical test
results from SGS Minerals at Lakefield ("SGS").
The work completed by SGS was a first-pass bench-scale scoping
study based on a small bulk sample of historical drill core, being
100 kg. It is the first metallurgical test-work completed at
Panuco and demonstrates robust
gold, silver, lead and zinc recoveries above 90% are
achievable.
The metallurgical test work supports both bulk flotation
flow-path and sequential flotation flow-path, with the bulk
floatation flow-path producing a single gold, silver, lead and zinc
rougher concentrate (15 minutes of floatation and 23% mass pull)
with 697 g/t silver, 0.97 g/t gold, 1.67% zinc and 0.58% lead and
recovering 96.2 % of the silver, 93.6% of the gold, 96.5% of the
zinc and 92.1 % of the lead.
This is an attractive processing option for silver-rich but base
metal-poor material.
Dr. Chris Wilson, Zacatecas
Silver Chief Operating Officer and Director, states, "The
rougher flotation recoveries are extremely encouraging especially
given they have been achieved using historical core. It is
anticipated that optimization work using fresh core will further
enhance metallurgical performance. Mineralization at Panuco is silver-rich but base metal-poor
(<1% combined lead and zinc), as such, producing a silver-gold
dore is ideal rather than separate zinc and lead concentrates. The
fact that over 96% of the silver and almost 94% of the gold has
presented to the rougher concentrate, suggest that regrinding of
the rougher concentrate and tank leaching with cyanide, is likely
to be a highly viable processing option. This flow path would
generate a silver-gold dore."
Sequential Flotation Flow-Path
Even though the material at Panuco has a combined lead and zinc grade of
<1%, intermediate sulphidation systems that exist in the
Zacatecas region are often silver
and base metal-rich. For this reason, a sequential flotation
flow-path was applied to the master bulk sample to produce lead,
zinc and pyrite concentrates.
The lead-silver concentrate graded 2,420 g/t Ag, 2.55% lead and
1.19% Zn that recovered 71.9% of the silver and 87.5% of the lead.
A zinc-silver concentrate grading 2.19% Zn and 190 g/t Ag was
produced that recovered 82% of zinc, while a pyrite concentrate
graded 0.73 g/t Au and 57 g/t Ag and recovered 47.8% of the gold
and an additional 6.5% of the silver. This indicates a clear
association between gold and pyrite.
The lead and zinc concentrates were then submitted to open
circuit cleaner tests. These tests produced saleable silver-lead
and zinc concentrates:
- The lead-silver concentrate graded 37,869 g/t Ag, 50.7% lead,
12.80 g/t Au, 3.93% Zn that recovered 45.2% of the silver and 64.6%
of the lead.
- A zinc-silver concentrate grading 2,218 g/t Ag, 47.4% Zn, 1.54
g/t Au and 1.62% Pb that recovered 39.3% of zinc.
Importantly, the pyrite concentrate submitted to open circulate
cleaner tests graded 1.84 g/t that recovered 15% of the gold.
As a result, gold recovery can occur with the pyrite
concentrate.
Locked cycle flotation tests to recycle the middlings should
improve the grade of the silver-lead and zinc concentrates and thus
overall recovery.
Dr Wilson further comments, "The work completed by SGS has
provided two potentially viable flow-paths for recovery of precious
and base metals, in addition to recovery of gold and silver from
pyrite concentrates. As we have a substantial land package in
the Zacatecas region, it is
important that we evaluate and develop viable options for both
silver-rich base metal-poor systems and silver and base metal-rich
systems."
Zacatecas Silver has retained SGS to compete a second stage of
test work with specific emphasis on optimizing flotation recovery,
determining cyanide recovery of gold and silver in bulk rougher
concentrates, enhanced recover of silver-lead and zinc in lead and
zinc concentrates, and potential to recover silver and gold from
pyrite concentrates.
Bulk Sample Information
The bulk sample used by SGS in the testing described above was
taken from representative intervals of historical Panuco drill core. Significantly, the bulk
sample head grade of 0.25 g/t Au, 169 g/t Ag, 0.41% Zn and 0.14% Pb
is broadly consistent with the grade of the Panuco historical resource estimate
(Van Phu Bui and Michael O'Brien, 2019) of 3,954,729 tonnes at
153 g/t Ag Eq. (136 g/t Ag, 0.14 g/t Au, 0.012 % Pb, 0.11% Zn) for
a total of 19,472,901 ounces Ag Eq. (cut-off 100 g/t Ag Eq.).
This indicates that the bulk sample submitted for metallurgy is
representative of the historical resource estimate. See
"Historical Resource Estimate Information" set forth below.
Table 1 – Rougher Bulk Concentrate
|
Assay
|
Recovery
(%)
|
Product
|
Mass
(%)
|
Au
(g/t)
|
Ag
(g/t)
|
Pb
(%)
|
Zn
(%)
|
Au
|
Ag
|
Pb
|
Zn
|
Rougher Concentrate
(15 min)
|
23.0
|
0.97
|
697
|
0.58
|
1.67
|
93.6
|
96.2
|
92.1
|
96.5
|
Rougher
Tailing
|
77.0
|
0.02
|
8
|
0.015
|
0.018
|
6.4
|
3.8
|
7.9
|
3.5
|
Table 2 – Rougher Sequential Flotation Flow
Sheet Lead and Zinc Concentrate
|
Assay
|
Recovery
(%)
|
Product
|
Mass
(%)
|
Au
(g/t)
|
Ag
(g/t)
|
Pb
(%)
|
Zn
(%)
|
Au
|
Ag
|
Pb
|
Zn
|
Lead Rougher
Concentrate
|
4.8
|
0.77
|
2,420
|
2.55
|
0.64
|
13.4
|
71.9
|
87.5
|
7.7
|
Lead Rougher
Tailings
|
95.2
|
0.25
|
48
|
0.018
|
0.39
|
86.6
|
28.1
|
12.5
|
92.3
|
Zinc Rougher
Concentrate
|
15.3
|
0.35
|
190
|
0.05
|
2.19
|
18.9
|
17.8
|
5.4
|
82.0
|
Zinc Rougher
Tailings
|
4.5
|
4.21
|
373
|
0.22
|
0.94
|
67.6
|
10.3
|
7.1
|
10.3
|
Pyrite Rougher
Concentrate
|
18.3
|
0.73
|
57
|
0.021
|
0.20
|
47.8
|
6.5
|
2.7
|
8.8
|
Pyrite Rougher
Tailings
|
61.6
|
0.09
|
<10
|
<0.01
|
<0.01
|
19.9
|
3.8
|
4.4
|
1.5
|
Table 3 – Cleaner Sequential Flotation Flow
Sheet Lead and Zinc Concentrate
|
Assay
|
Recovery
(%)
|
Product
|
Mass
(%)
|
Au
(g/t)
|
Ag
(g/t)
|
Pb
(%)
|
Zn
(%)
|
Au
|
Ag
|
Pb
|
Zn
|
Lead
3rd Cleaner Concentrate
|
0.2
|
12.80
|
37,869
|
50.7
|
3.93
|
8.9
|
45.2
|
64.6
|
1.7
|
Lead Rougher
Tailings
|
97.2
|
0.22
|
45.2
|
0.02
|
0.23
|
84.9
|
29.8
|
14.7
|
55.2
|
Zinc
4th Cleaner Concentrate
|
0.3
|
1.54
|
2,218
|
1.62
|
47.4
|
2.0
|
5.1
|
4.0
|
39.3
|
Zinc Rougher
Tailings
|
91.5
|
0.19
|
21.8
|
0.013
|
0.05
|
68.8
|
13.4
|
8.6
|
10.3
|
Pyrite 3rd Cleaner
Concentrate
|
2.1
|
1.84
|
220
|
0.088
|
1.01
|
15.0
|
3.1
|
1.3
|
5.2
|
Pyrite Rougher
Tailings
|
85.6
|
0.12
|
13.8
|
0.01
|
0.018
|
40.2
|
8.0
|
6.2
|
3.8
|
Methodology, Quality Assurance and Quality
Control
Historical Panuca drill core is stored in a secure restricted
facility. The bulk sample was collected from by Zacatecas geologists. Drill core intervals
were placed into individually labelled polythene sample bags and
sealed with a single use clip-lock seal. Chain of custody was
maintained by Zacatecas until the
bulk samples was delivered to DHL for courier to SGS.
SGS submitted the sample to QEMSCAN and XRD analysis. The sample
consisted of mainly quartz (46.8%) and moderate amounts of dolomite
(13.5%) and micas (12.9%). Other gangue minerals in minor and trace
levels included: K-feldspar (5.3%), plagioclase (0.77%),
amphibole/pyroxene (3.4%), chlorite/clays (2.34%), calcite (3.3%),
and ankerite (1.2%). Sulphides accounted for about 9.3% of the
sample and consisted of pyrite (7.1%), sphalerite (0.66%),
arsenopyrite (1.34%), and galena (0.15%). Chalcopyrite and other
sulphides were trace. Liberation of the pyrite, sphalerite, and
galena was good at ~80%, 87%, and 96% respectively. Arsenopyrite
liberation was low at 54%.
For the rougher bulk concentrate, a single test was conducted
using soda ash as pH modifier, copper sulphate (sulphide
activator), potassium amyl xanthate (sulphide collector), Aero 241
(dithiophosphate promoter) and methyl isobutyl carbinol (frother).
Timed concentrate samples were collected and assayed to monitor the
recoveries.
For the sequential flotation flowsheet, tests were conducted
using soda ash or sulphuric acid as pH modifiers, copper sulphate
(sulphide activator), potassium amyl xanthate (sulphide collector),
Aero 241 (dithiophosphate promoter), in the lead circuit, Aero 5100
(allyl alkyl thionocarbamate promoter) in the zinc circuit, and
methyl isobutyl carbinol (frother).
The SGS analysis included a quality assurance / quality control
(QA/QC) program. Zacatecas
detected no significant QA/QC issues during review of the data.
Zacatecas 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. SGS Minerals Lakefield is ISO/IEC 17025 accredited.
SGS is independent of Zacatecas.
Qualified Person
The technical content of this news release has been reviewed,
verified and approved by Dr. Chris Wilson, B.Sc
(Hons), PhD, FAusIMM (CP), FSEG. Chief Operating Officer and
Director of Zacatecas Silver, a qualified person as defined by NI
43-101.
About SGS
SGS is the world's leading testing, inspection and certification
company, recognized as the global benchmark for quality and
integrity. SGS's 89,000 employees operate a network of 2,600
offices and laboratories, working together to enable a better,
safer and more interconnected world.
About Zacatecas Silver Corp.
The Zacatecas Silver property is located in Zacatecas State,
Mexico, within the highly
prospective Fresnillo Silver Belt, which has produced over 6.2
billion ounces of silver. The company holds 7826 ha (19,338 acres)
of ground that is highly prospective for low and intermediate
sulphidation silver-base metal mineralization and potentially low
sulphidation gold-dominant mineralization.
The property is 25 km south-east of MAG Silver Corp.'s
Juanicipio Mine and Fresnillo PLC's Fresnillo Mine. The property
shares common boundaries with Pan American Silver Corp. claims and
El Orito which is owned by Endeavour Silver. There are four main
high-grade silver target areas within the Zacatecas concessions: the Panuco Deposit,
Muleros, El Cristo and San Manuel-San Gill. The Property also
includes El Oro, El Orito,
La Cantera, Monserrat, El Peñón,
San Judas and San
Juan silver-base metal vein targets. These targets are
relatively unexplored and will be the focus of rapid reconnaissance
review.
On behalf of the Company
Bryan Slusarchuk
Chief Executive Officer and Director
Historical Mineral Resource Estimate Information
In 2019 Santacruz Silver Mining Ltd. completed an updated
historical resource estimate as set forth in the technical report
titled "Technical Report – Veta Grande Project, Zacatecas State,
Mexico" dated 20th of
August 2019. The report was prepared
by Van Phu Bui, P. Geo and Michael O'Brien, P. Geo, and filed on
www.sedar.com ("2019 Panuco Historical Resource"). The 2019 Panuco
Historical Resource reported 3,954,729 tonnes at 153 g/t Ag Eq.
(136 g/t Ag, 0.14 g/t Au, 0.012 % Pb, 0.11% Zn) for a total of
19,472,901 ounces Ag Eq. (cut-off 100 g/t Ag Eq.). The 2019
Panuco Historical Resource used "inferred mineral resources", which
is a category set forth under CIM Definition Standards for Mineral
Resources & Mineral Reserves adopted on May 10, 2014.
The 2019 Panuco Historical Resource was calculating using 75
drill collars, 866 down hole surveys and 2,607 assayed
samples. A surface trench database totalling 183 trenches
with 1,813 samples was used. Resource blocks were defined
using with dimensions of 20 m along
strike and down dip, and 1 m across
strike. Grades for gold, silver, lead and zinc were
interpolated into blocks using the following estimation algorithms:
central — ordinary kriging and NW and Tres Cruces — inverse distance squared.
Assumptions used in the 2019 Panuco Historical Resource include the
following metal prices: gold price of US $1,350/oz, silver price of US $16/oz, lead price of US $0.90/lb and zinc price of US $1.10/lb. The 2019 Panuco Historical Resource
assumed recovering similar to the Veta Grande System being: gold at
52.2%, silver at 62.1%, lead at 87.9% and zinc at 78.6%. The
Company considers the 2019 Panuco Historical Resource relevant due
to its identification and modelling of the Panuco deposit.
The Company has not done sufficient work to classify the 2019
Panuco Historical Resource as a current mineral resource or mineral
reserves, and the Company is not treating the historical estimate
as current mineral resources or mineral reserves.
Although the historical resource estimate is considered reliable,
8% of the drill core intervals used in the resource calculations
was re-sampled and submitted these to ALS for independent assay.
Further, additional data verification including resurveying of
select diamond drill holes collars; review of graphic drill core
logs, comparison of these logs with remaining half-cut core, and a
cross-check of select geological logs agonist database entries; and
a check of original ALS assay certificates against the assays and
drill hole database. Remodelling of the current Panuco resource is ongoing pending receipt of
check sample assays.
Forward-Looking Statements
Information set forth in this news release contains
forward-looking statements that are based on assumptions as of the
date of this news release. These statements reflect management's
current estimates, beliefs, intentions and expectations. They are
not guarantees of future performance. Zacatecas Silver cautions
that all forward looking statements are inherently uncertain and
that actual performance may be affected by many material factors,
many of which are beyond their respective control. Such factors
include, among other things: risks and uncertainties relating to
Zacatecas Silver's limited operating history, its proposed
exploration and development activities on is Zacatecas Properties
and the need to comply with environmental and governmental
regulations. Accordingly, actual and future events,
conditions and results may differ materially from the estimates,
beliefs, intentions and expectations expressed or implied in the
forward-looking information. Except as required under applicable
securities legislation, Zacatecas Silver does not undertake to
publicly update or revise forward-looking information.
Neither TSX Venture Exchange nor its Regulation Services
Provider (as that term is defined in the policies of the Exchange)
accepts responsibility for the adequacy or accuracy of this
release.
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