TORONTO,
April 17, 2013 /CNW/ - Sierra
Metals Inc. (TSX-V:SMT) (BVL:SMT) ("Sierra Metals" or the
"Company" previously Dia Bras Exploration) is pleased to announce
that a pre-feasibility study has been completed by Gustavson
Associates, LLC of Lakewood,
Colorado, for its Bolivar copper-zinc-silver mine located in
Chihuahua State, Mexico. The
study, mine plan and reserve estimate are based on Gustavson's work
and mine plan on a lower-grade portion of the resources, mainly at
its El Gallo Inferior deposit. The evaluation of the higher
grade portions of the mine still require further technical studies,
which should result in additional resources and continued feed of
ore to its processing plant and potentially lead to future reserve
additions over the next 10 months.
Press Release Highlights:
- Bolivar now has Proven and Probable ore reserves totalling
7,456,806 tonnes at 1.044% Cu-Equivalent averaging 19.5 g/t silver,
0.759% Cu, 0.329% Zn. Gold contents average 0.226 g/t but
were not included in the CuEq calculation, but were included within
the project's economics.
- These reserves are in the Gallo Inferior deposit, which is the
lower-grade portion of resources defined in the October 15, 2012 NI
43-101 Technical Report. The October 2012 report defined
15,404,000 tonnes of Measured and Indicated Resources averaging
19.4 g/t silver, 0.79% copper, and 1.01% zinc at a cut-off grade of
0.66% CuEq. Gold contents averaged 0.226 g/t and were added
to the Resource model in January 2013 using the same data used to
do the NI 43-101 Technical Report.
- Out of the 15.4 million tonnes of Measured and Indicated
Resources, 6.1 million tonnes of the highest grades deposits (i.e.
Alta Ley and portions of Gallo Superior deposits) were not included
at this stage in the reserve calculation because more data are
required for mine planning purposes. Additional drilling is
underway to complete mine planning in order to convert these
Measured and Indicated resources to Proven and Probable
Reserves.
- Of the modelled tonnage of 9 million tonnes of the lower grade
Measured and Indicated Resources, approximately 80% were converted
to ore reserves.
- At a production rate of 2,000 tonnes per day, these reserves
provide a 10-year mine life with an additional year of processing
from the stockpile for a total of 11 years.
- Bolivar is currently in commercial production at an ore
throughput rate of 1,000 tons per day and should double its
production capacity to 2,000 tons per day by the end of May
2013.
|
Daniel Tellechea,
President and CEO of Sierra Metals, commented: "Sierra
Metals advances another major step in the Company's evolution with
the completion of this pre-feasibility study that defines for the
first time in the history of the Bolivar mine a formal proven and
probable reserve. Not only does Bolivar have reserves now for
the next 10 years at its expanded 2,000 ton per day mill, but we
are conducting additional significant drilling in two areas to add
to its mine life. First, we are drilling those portions of
the Gallo Superior and Alta Ley that did not have sufficient
density of drilling for mine planning purposes to generate a
reserve. It is important to note that the Gallo Superior and
Alta Ley measured and indicated resources are higher grade than
Gallo Inferior. Second, we are focusing our exploration
drilling in target areas that have been defined by geophysics and
fault extensions from the Alta Ley mine in order to
increase resources and grade. These faults controlled
high-grade copper-zinc mineralization in the Superior portion of
the Alta Ley area, and during 2005-2011 we processed 681,305 tonnes
averaging 1.65% copper and 8.47% zinc. Our new targets are
mineralized zones of similar grade."
Sierra Metals has conducted exploration,
development and mining at the Bolívar Mine since 2004.
Exploration includes geologic mapping and diamond core drilling in
the El Gallo, Increíble and Alta
Ley areas, which are located within the area of resource modeling,
and in the La Narizona, La Montura, La Pequeña and El Val areas,
which are located outside the area of resource modeling.
Pilot mining has been conducted and has provided valuable
information regarding metallurgy, recovery rates, smelter treatment
and refining charges, etc.
Bolivar built its new Piedras Verdes ore processing mill in
2010-2011 and declared commercial production in November 2011 with a processing capacity of 1,000
tonnes per day. The data of prior production were used in the
development of the pre-feasibility study preparation and as a guide
to continued mining as well as doubling of production capacity to
2,000 tons per day, which will be effective by the end of
May 2013.
This work resulted in a NI 43-101 and CIM
compliant resource estimate (see press release of August 30, 2012), which is the basis for this
pre-feasibility study. Table 1 shows the Measured and
Indicated Resources of the compliant resource estimate.
Table 1: Deposit M+I with Tonnes and
Grade
Zone |
Tonnes |
Ag (gpt) |
Cu (%) |
Zn (%) |
CuEq (%) |
Au (gpt) |
El Gallo Superior |
2,041,527 |
30.920 |
1.226 |
0.468 |
1.663 |
0.208 |
El Gallo Inferior |
8,550,959 |
20.820 |
0.757 |
0.366 |
1.064 |
0.243 |
Increible |
- |
- |
- |
- |
- |
Not Modeled |
Alta Ley |
4,811,788 |
12.161 |
0.649 |
2.530 |
1.446 |
Not Modeled |
Total |
15,404,274 |
19.454 |
0.785 |
1.055 |
1.263 |
0.236 |
Note: CuEq>0.66 AND M&I
Gustavson received diamond drill data for 683
drill holes located within the area of the underground mine
workings, and in the Bolívar III, Bolívar IV, and Piedras Verdes concessions to characterize the
skarn-type mineralization. Data from these holes as well as
underground mapping and sampling were included in the study.
The recovered tonnes, including dilution, for
each area were then scheduled for production. The total
tonnes and grades shown in Table 2 constitute the Reserve Statement
for the Bolivar Project as of the date of this pre-feasibility
report. These tonnes are from only portions of the El Gallo
Superior and El Gallo Inferior. Additional information,
namely additional drill holes, is required to upgrade the Measured
and Indicated tonnes at Alta Ley plus un-mined areas of Gallo
Superior to reserves.
On an overall recovery of the Gallo Deposits,
7.46 million tonnes are mined from the Gallo Superior and Inferior
deposits (2.04 + 8.55 million tonnes for a total of 10.59 million
tonnes). This is an overall recovery of 70.5% of the material
modeled. However, from the economic model where only the
final logical mine layout was used, the recoveries of the mineable
Resources range from 76.0 % to 83.5%. Essentially the mine plan
recovers 70.5% of the M+I, but recovers 76-83% of the mineable
M+I.
This Reserves Statement has an effective date of
December 31, 2012 and was completed
by Gustavson as an independent report under the supervision of
Karl D. Gurr, Qualified Person as
defined by NI 43-101.
Table 2 Combined Reserve Statement for
the Bolivar Project
RoM Tonnes + Diluted Grades |
Tonnes |
Ag gpt |
Cu % |
Zn % |
CuEq % (no Au) |
Au gpt |
Waste |
0 |
0.00 |
0.00% |
0.00% |
0.00% |
0.000 |
RoM - Measured - Proven |
4,339,914 |
22.52 |
0.84% |
0.19% |
1.11% |
0.223 |
RoM - Indicated - Probable |
3,116,893 |
15.35 |
0.65% |
0.52% |
0.95% |
0.231 |
Waste - Inferred |
102,002 |
14.56 |
0.62% |
0.56% |
0.91% |
0.234 |
Total P+P |
7,456,806 |
19.52 |
0.76% |
0.33% |
1.04% |
0.226 |
Total P+P+Waste |
7,558,808 |
19.45 |
0.76% |
0.33% |
1.04% |
0.227 |
RoM = Run of mine
Gustavson believes that these deposits may have
additional potential as data collection and interpretation
continue, but this reserve statement provides a snapshot at this
point in time. Continued exploration success at the mine may
justify further production expansion in the future.
Quality Assurance
The technical content of this news release has
been approved by Thomas L. Robyn,
Ph.D., CPG, RPG, a Qualified Person as defined in NI 43-101 and
Senior Vice President, Exploration, for Sierra Metals, Inc.
About Sierra Metals
Sierra Metals Inc. is a Canadian mining company
focused on precious and base metals from its Yauricocha mine in
Peru and its Bolivar mine in
Mexico. The Company is also
advancing its Cusi silver project in Mexico from advanced development into
commercial production. In addition, Sierra Metals is xploring
several precious and base metal targets in Peru and Mexico. Projects in Peru include Adrico (gold), Victoria (copper-silver) and Ipillo
(polymetallic) at the Yauricocha Property in the province of
Yauyos. Projects in Mexico include
Bacerac (silver) in the
state of Sonora, La Verde (gold) at the Batopilas Property in
the state of Chihuahua, and
Las Coloradas (silver) at the
Melchor Ocampo Property in the
state of Zacatecas.
The Company's shares trade on the Bolsa de
Valores de Lima and TSXV under the
symbol "SMT".
This press release does not constitute an
offer to sell or solicitation of an offer to buy the securities in
the United States or any other
jurisdiction. The Common Shares will not be and have not been
registered under the United States Securities Act of 1933, as
amended, and may not be offered or sold in the United States absent registration or an
applicable exemption from the registration requirements.
Neither the TSXV nor its Regulation Services
Provider (as that term is defined in policies of the TSXV) accepts
responsibility for the adequacy or accuracy of this
release.
Forward-Looking Statements
Except for statements of historical fact
contained herein, the information in this press release may
constitute "forward-looking information" within the meaning of
Canadian securities law. Other than statements of historical fact,
all statements are "forward-looking statements", which involve
various known and unknown risk and uncertainties and other factors,
including market conditions that may affect the Company's ability
to execute its current business plan. Actual results might
differ materially from results suggested in any forward-looking
statements. The Company assumes no obligation to update the
forward-looking statements, or to update the reasons why actual
results could differ from those reflected in the forward-looking
statements unless and until required by securities laws applicable
to the Company. Additional information identifying risks and
uncertainties is contained in filings by the Company with the
Canadian securities regulators, which filings are available at
www.sedar.com.
SOURCE Sierra Metals Inc.