Coro Mining Corp. ("Coro" or the "Company") (TSX:COP) is pleased to
announce the results of an updated, independent, National
Instrument 43-101 compliant resource estimate for its Berta copper
leach project, located approximately 20km west of the village of
Inca de Oro, in the III Region of Chile. Coro is also pleased to
announce the results of confirmatory metallurgical column test work
completed for the Berta Central deposits.
On May 8th 2013, the Company announced that it had signed a
Letter of Intent ("LOI") with ProPipe SA, ("ProPipe") an
engineering firm based in Santiago, Chile, giving ProPipe the right
to earn up to a 50% interest in the Berta property by funding the
further development of the project.
Alan Stephens, President and CEO of Coro commented, "We continue
to make excellent progress at Berta, where we have demonstrated a
significant increase in in-pit resources, by re-assessing the
economic parameters of Berta Sur and by incorporating the Berta
Central deposits into the resource model. The updated in-pit
resource estimate for the project now stands at 17,604,000t at a
grade of 0.37%CuT, equivalent to 64,000t of contained copper, and
with a low overall stripping ratio of 0.49:1. The results of the
column test work from Berta Central confirm the encouraging results
previously obtained from Berta Sur. Coro and ProPipe are currently
optimising the development plan for Berta, with the objective of
placing it into production at the rate of 5,000-10,000 tonnes per
year of copper cathode, as soon as possible."
Updated Resource Estimate
This updated resource estimate includes the Berta Sur deposit,
and the Berta Central deposits, which comprise 5 individual but
adjacent deposits which have been subject to prior small scale open
pit mining. The resource estimate was completed by independent
consultants, Geoinvestments SpA, at a variety of total copper
(%CuT) grades, as shown on Table 1, below.
Table 1: Resource Estimate
----------------------------------------------------------------------------
Berta Project Resource Estimate
----------------------------------------------------------------------------
Measured Indicated
Zone Cutoff kt % CuT % CuS kt % CuT % CuS
----------------------------------------------------------------------------
0.10 16,498 0.34 0.23 8,653 0.23 0.14
--------------------------------------------------------
0.15 13,275 0.39 0.27 5,780 0.27 0.18
--------------------------------------------------------
Berta Sur & Central 0.20 10,487 0.45 0.31 3,336 0.35 0.23
--------------------------------------------------------
0.25 8,355 0.51 0.36 1,961 0.44 0.30
--------------------------------------------------------
0.30 6,791 0.56 0.40 1,289 0.52 0.36
----------------------------------------------------------------------------
--------------------------------------------------------
0.10 10,972 0.32 0.21 4,423 0.18 0.11
--------------------------------------------------------
0.15 8,853 0.37 0.25 2,800 0.21 0.13
--------------------------------------------------------
Berta Sur 0.20 6,892 0.42 0.29 1,332 0.26 0.16
--------------------------------------------------------
0.25 5,385 0.47 0.33 561 0.31 0.20
--------------------------------------------------------
0.30 4,288 0.53 0.37 261 0.36 0.24
----------------------------------------------------------------------------
--------------------------------------------------------
0.10 5,526 0.38 0.26 4,230 0.27 0.17
--------------------------------------------------------
0.15 4,422 0.45 0.31 2,980 0.33 0.22
--------------------------------------------------------
Berta Central 0.20 3,594 0.51 0.36 2,003 0.41 0.27
--------------------------------------------------------
0.25 2,969 0.57 0.40 1,401 0.49 0.34
--------------------------------------------------------
0.30 2,503 0.63 0.45 1,028 0.56 0.39
----------------------------------------------------------------------------
----------------------------------------------------------------------------
Berta Project Resource Estimate
----------------------------------------------------------------------------
Measured & Indicated Inferred
Zone kt % CuT % CuS kt % CuT % CuS
----------------------------------------------------------------------------
25,150 0.30 0.20 4,845 0.24 0.15
--------------------------------------------------------
19,055 0.36 0.24 3,249 0.30 0.20
--------------------------------------------------------
Berta Sur & Central 13,822 0.43 0.29 2,039 0.38 0.25
--------------------------------------------------------
10,316 0.50 0.35 1,402 0.45 0.31
--------------------------------------------------------
8,080 0.56 0.39 932 0.53 0.37
----------------------------------------------------------------------------
--------------------------------------------------------
15,394 0.28 0.18 2,105 0.18 0.11
--------------------------------------------------------
11,653 0.33 0.22 1,296 0.22 0.13
--------------------------------------------------------
Berta Sur 8,225 0.39 0.27 720 0.26 0.16
--------------------------------------------------------
5,946 0.46 0.32 343 0.29 0.18
--------------------------------------------------------
4,549 0.52 0.36 127 0.33 0.21
----------------------------------------------------------------------------
--------------------------------------------------------
9,756 0.33 0.22 2,740 0.29 0.19
--------------------------------------------------------
7,402 0.40 0.27 1,953 0.35 0.24
--------------------------------------------------------
Berta Central 5,598 0.47 0.33 1,318 0.44 0.30
--------------------------------------------------------
4,370 0.55 0.38 1,059 0.50 0.34
--------------------------------------------------------
3,531 0.61 0.43 805 0.57 0.40
----------------------------------------------------------------------------
In order to demonstrate the potential economic viability of the
Berta Sur and Central resources, a series of pit optimizations
using the Lersch & Grossmann algorithm was completed utilizing
appropriate operating costs, results obtained from the
metallurgical test work, and a variety of copper prices. For a
$3.00/lb copper price and a 0.14% CuT cut-off grade, the optimum
pits were determined to contain 17,604,000t at a grade of 0.37% CuT
and an overall stripping ratio of 0.49:1, as detailed in Table 2,
below.
Table 2: In-Pit Resource Estimate
----------------------------------------------------------------------------
Berta Project In Pit Resource
----------------------------------------------------------------------------
Measured Indicated
------------------------------------------------
Zone Pit kt % CuT % CuS kt % CuT % CuS
----------------------------------------------------------------------------
Berta Sur Berta Sur 8,929 0.35 0.23 1,427 0.19 0.11
----------------------------------------------------------------------------
Trinchera-
Salvadora 2,242 0.48 0.30 527 0.47 0.29
--------------------------------------------------------------
Carmen-Gemela 982 0.51 0.36 562 0.38 0.26
--------------------------------------------------------------
Berta Central Nueva 219 0.43 0.29 295 0.34 0.22
--------------------------------------------------------------
Berta II 853 0.37 0.24 150 0.36 0.23
--------------------------------------------------------------
Chico 900 0.30 0.18 518 0.25 0.14
----------------------------------------------------------------------------
Berta Sur &
Central Total 14,125 0.38 0.25 3,479 0.29 0.18
----------------------------------------------------------------------------
----------------------------------------------------------------------------
Berta Project In Pit Resource
----------------------------------------------------------------------------
Measured & Indicated Waste Strip
------------------------------------------------
Zone Pit kt % CuT % CuS kt Ratio
----------------------------------------------------------------------------
Berta Sur Berta Sur 10,356 0.33 0.21 2,609 0.25
----------------------------------------------------------------------------
Trinchera-
Salvadora 2,769 0.48 0.30 2,499 0.90
--------------------------------------------------------------
Carmen-Gemela 1,544 0.47 0.32 1,852 1.20
--------------------------------------------------------------
Berta Central Nueva 514 0.38 0.25 375 0.73
--------------------------------------------------------------
Berta II 1,003 0.37 0.24 572 0.57
--------------------------------------------------------------
Chico 1,418 0.29 0.17 762 0.54
----------------------------------------------------------------------------
Berta Sur &
Central Total 17,604 0.37 0.23 8,669 0.49
----------------------------------------------------------------------------
The copper grade distribution for Berta Sur and Central is shown
on Figure 1 and the proposed open pits are shown on Figure 2.
Parameters Used in the Construction of the Mineral Resource
An updated mineral resource block model was produced for the
Berta Sur and Central deposits, using information from Coro's 2011
and 2012 drilling campaigns and from earlier Anglo American, Grand
Cru Resources and Outokumpu drilling. The resource estimate was
based on 152 drill holes for a total of 22,213m, as shown on Table,
below.
Table 3: Drill holes
----------------------------------------------------------------------------
Berta Sur & Central Drilling
Campaigns Berta Sur Berta Central
----------------------------------------------------------------------------
Av TD Total Av TD Total
Company Date Type Holes (m) m Holes (m) m
----------------------------------------------------------------------------
Outokumpu Mar-Sept 1994 RC 4 25 100 28 44 1,221
----------------------------------------------------------------------------
Anglo American Sep-Dec 1997 RC 19 112 2,126 16 121 1,930
----------------------------------------------------------------------------
Grand Cru Res Feb-Jul 2007 DDH 3 435 1,305 6 335 2,007
----------------------------------------------------------------------------
CORO Phase 1 Jul-Aug 2011 RC 23 181 4,160
----------------------------------------------------------------------------
CORO Phase 2 Mar-Jun 2012 RC 14 300 4,198 3 379 1,136
----------------------------------------------------------------------------
CORO Infill Jul-Aug 2012 RC 29 112 3,264 7 109 766
----------------------------------------------------------------------------
Total 92 15,153 60 7,060
----------------------------------------------------------------------------
----------------------------------------------------------------------
Berta Sur & Central Drilling
Campaigns Berta Sur + Central
----------------------------------------------------------------------
Company Date Type Holes Av TD (m) Total m
----------------------------------------------------------------------
Outokumpu Mar-Sept 1994 RC 32 41 1,321
----------------------------------------------------------------------
Anglo American Sep-Dec 1997 RC 35 116 4,056
----------------------------------------------------------------------
Grand Cru Res Feb-Jul 2007 DDH 9 368 3,312
----------------------------------------------------------------------
CORO Phase 1 Jul-Aug 2011 RC 23 181 4,160
----------------------------------------------------------------------
CORO Phase 2 Mar-Jun 2012 RC 17 314 5,334
----------------------------------------------------------------------
CORO Infill Jul-Aug 2012 RC 36 112 4,030
----------------------------------------------------------------------
Total 152 22,213
----------------------------------------------------------------------
The mineral resource estimate has been generated from drill hole
sample assay results and the interpretation of a geologic model
which relates to the spatial distribution of copper in the deposit.
Grade estimates were made using ordinary kriging with nominal block
size measuring 5 meters long, 5 meters wide and 5 meters in height
and resources have been classified by their proximity to sample
locations. The small open pit workings at Berta Central were
topographically surveyed and their volumes subtracted from the
model. The in-pit mineral resource was constructed according to
technical and economic parameters shown in Table 4.
Table 4: Technical and Economic Parameters
----------------------------------------
Mining $2.09/t
----------------------------------------
Processing $4.74/t
----------------------------------------
SXEW $0.102/lb
----------------------------------------
G & A $0.045/lb
----------------------------------------
Sales & Marketing $0.041/lb
----------------------------------------
Metallurgical Recovery 80%
----------------------------------------
Inter ramp Pit Slope 50 degrees
----------------------------------------
Copper Price $3.00/lb
----------------------------------------
The mineral resources in this news release were estimated using
current Canadian Institute of Mining, Metallurgy and Petroleum
(CIM) standards, definitions and guidelines. An updated NI 43-101
technical report detailing the mineral resource estimate will be
completed and filed on SEDAR (www.sedar.com), and Coro's website
(www.coromining.com), within 45 days.
Metallurgical Testwork
A sample was taken from outcrop and pit walls from each of the
Berta II - Nueva - Chico and Gemela - Salvadora old workings, and
submitted to the Hydrometallurgy Laboratory of the Department of
Metallurgical Engineering, University of Santiago de Chile (USACH)
for compositing and column test work. The principal objective of
this test was to ascertain if there were any material differences
in the metallurgical characteristics of the Berta Central deposits
and those from the previously announced Berta Sur deposit test work
carried out by Geomet.
A total of three 2m column tests, with the same column
dimensions used for the previous Berta Sur test work, and with
granulometry of 80% - 1/2", were completed. The cur ing dosage was
10kg acid/t with a curing time of 24 hours and a specific flow rate
of 10 l/hm2. The head grade of the sample was 1.4%CuT/1.1%CuS, and
the three columns were run at 10, 15 and 20g/l of acid
concentration in the irrigation solution.
The results from the three columns showed very similar leach
kinetics to that observed for the Berta Sur tests with best results
obtained with concentrations of plus 15g/l acid. A summary of the
Berta Sur and Berta Central test work is shown on Table 5, below.
As with the previous test work for Berta Sur, recoveries in excess
of 100% of the theoretical solubilities have been obtained for
Berta Central, indicating recovery of copper from copper wad
species.
Table 5: Metallurgical Column Test Work
----------------------------------------------------------------------------
Theore
Column Sample Location Head assays -tical Actual Days NAC
----------------------------- -----
Rec Rec
% CuT % CuS % Sol CuT CuS kg/t
----------------------------------------------------------------------------
P80 3/8" Comp A BDH07-07 Drill
Geomet Core (Berta Sur) 0.84 0.59 70 91.0 130 26 21
----------------------------------------------------------------------------
P80 3/8" Comp B Surface trench,
Geomet partially
leached (Berta
Sur) 0.66 0.36 55 68.0 126 28 24
----------------------------------------------------------------------------
P80 3/8" Comp C Surface trench,
Geomet partially
leached (Berta
Sur) 0.38 0.14 37 56.0 150 28 22
----------------------------------------------------------------------------
P80 1/2" (10 g/L Berta Central
H2SO4) USACH 1.40 1.10 79 51.5 66 28 22
----------------------------------------------------------------------------
P80 1/2" (15 g/L Berta Central
H2SO4) USACH 1.40 1.10 79 80.0 113 28 20
----------------------------------------------------------------------------
P80 1/2" (20 g/L Berta Central
H2SO4) USACH 1.40 1.10 79 87.0 120 28 28
----------------------------------------------------------------------------
About Berta
Berta is a near surface, copper oxide deposit, with
mineralization, as defined by drilling, mapping and geochemistry,
occurring in three principal areas; Berta Sur, Berta Central and
Berta Norte. It is associated with sub-vertical, elongate,
potassically altered porphyry intrusive bodies and related
hydrothermal and intrusive breccias, emplaced into a tonalite
stock. Oxidation extends from surface to depths of 50m to 100m.
Berta Sur comprises a single, coherent body of mineralization that
has not been previously mined, while Berta Central comprises
several smaller bodies, located immediately north of Berta Sur,
which were the focus for previous small scale artisanal copper
oxide production. Berta Norte comprises several, discreet, NW
oriented zones of mineralization, individually 25-85m in width,
100-250m in strike length and largely gravel covered. A resource
estimate has not yet been completed for Berta Norte. Coro has
identified potential for additional copper oxide resources
elsewhere on the property, and in the surrounding district.
Coro announced a NI43-101 compliant resource estimate for the
Berta Sur area, in its news release NR12-19, dated December 6th
2012 and the results of preliminary metallurgical test work in its
news release NR12-17, dated November 5th 2012. The shareholder's
agreement for the new operating company, SCM Berta, formed by Coro
and ProPipe, is being finalized and additional time has been
granted to ProPipe to present an Environmental Impact Declaration
for the project and to complete a Preliminary Economic Evaluation,
in order to accommodate an optimal development plan for the
project, as a result of the resource increase.
About ProPipe SA
ProPipe is a Chilean supplier of consultancy, engineering and
project management services to its customers in the mining process,
infrastructure and environment markets. ProPipe have relevant
experience in conceptual and basic design, preliminary feasibility
and feasibilities studies, and detailed engineering for mining
companies in Chile. Some of its principal clients are BHP Billiton
(Minera Escondida), Antofagasta Minerals (Minera Los Pelambres,
Minera El Tesoro, and Minera Esperanza), Minera Las Cenizas and
Algorta Norte. ProPipe's recent projects include the Camarones
7,000 tonne per year copper cathode plant, the Algorta Norte 78 km
sea water pipeline, and Minera Escondida's Coloso filter plant
expansion project.
Qualified Person Notes
The mineral resource estimates contained in this news release
have been prepared in accordance with National Instrument 43-101
Standards of Disclosure for Mineral Projects ("NI 43-101"). The
technical information in this news release, including the
information that relates to geology, mineralization, drilling, and
mineral resource estimates on the Berta deposit, is based on
information prepared under the supervision of, or has been reviewed
by Sergio Rivera, Vice President of Exploration, Coro Mining Corp,
a geologist with more than 30 years of experience and a member of
the Colegio de Geologos de Chile and of the Instituto de Ingenieros
de Minas de Chile. The foregoing person is a "qualified person" for
the purposes of NI 43-101 with respect to the geology,
mineralization and drilling being reported on. The "qualified
person" responsible for the independent resource estimate at Berta
Sur was Sergio Alvarado Casas, a consultant geologist with more
than 27 years of experience and General Manager and partner of
Geoinvestments SpA. He is a member of CIM, the Chilean Mining
Commission, and the Instituto de Ingenieros de Minas de Chile. The
technical information has been included herein with the consent and
prior review of the above noted qualified persons. The qualified
persons have verified the data disclosed, including sampling,
analytical and test data underlying the information or opinions
contained herein.
All mineral resources have been estimated in accordance with the
definition standards on mineral resources and mineral reserves of
the Canadian Institute of Mining, Metallurgy and Petroleum (CIM)
referred to in National Instrument 43-101, commonly referred to as
NI 43-101. U.S. reporting requirements for disclosure of mineral
properties are governed by the United States Securities and
Exchange Commission (SEC) Industry Guide 7. Canadian and Guide 7
standards are substantially different. This News Release uses the
terms "measured," "indicated" and "inferred" resources. We advise
investors that while those terms are recognized and required by
Canadian regulations, the SEC does not recognize them. Mineral
resources which are not mineral reserves do not have demonstrated
economic viability. The estimate of mineral resources may be
materially affected by copper pricing, environmental, permitting,
legal, title, taxation, socio-political, marketing, or other
relevant issues. Inferred mineral resources are considered too
speculative geologically to have economic considerations applied to
them that enable them to be categorized as mineral reserves.
CORO MINING CORP.
Alan Stephens, President and CEO
About Coro Mining Corp.:
The Company was founded with the goal of building a mining
company focused on medium-sized base and precious metals deposits
in Latin America. The Company intends to achieve this through the
exploration for, and acquisition of, projects that can be developed
and placed into production. Coro's properties include the advanced
Berta copper leach project and the Payen, El Desesperado,
Llancahue, and Celeste copper exploration properties, all located
in Chile and the advanced San Jorge copper-gold project, located in
Argentina.
This news release includes certain "forward-looking statements"
under applicable Canadian securities legislation. Such
forward-looking statements or information, including but not
limited to those with respect to the prices of copper and
molybdenum, metallurgical results and resources, involve known and
unknown risks, uncertainties, and other factors which may cause the
actual results, performance or achievements of the Company to be
materially different from any future results, performance or
achievements expressed or implied by such forward-looking
statements or information. Such factors include, among others, the
actual prices of copper, the factual results of current
exploration, development and mining activities, changes in project
parameters as plans continue to be evaluated, as well as those
factors disclosed in the Company's documents filed from time to
time with the securities regulators in the Provinces of British
Columbia, Alberta, Saskatchewan, Manitoba, Ontario, New Brunswick,
Nova Scotia, Prince Edward Island and Newfoundland and
Labrador.
To view Figure 1, "Berta Sur & Central Cu Grade Distribution
at 1710m Elevation," click the following link:
http://media3.marketwire.com/docs/coro1.jpg.
To view Figure 2, "Berta Proposed Open Pits," click the
following link: http://media3.marketwire.com/docs/coro2.jpg.
Contacts: Coro Mining Corp. Michael Philpot Executive
Vice-President (604) 682 5546investor.info@coromining.com
www.coromining.com
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