Argentina Mining's Blog I Latest news on Mining in Argentina

Este blog fue creado para publicar novedades sobre la mineria en Argentina, complementando así nuestro web y presencia en redes sociales. Como todas nuestras actividades, apunta a conectar a la comunidad minera argentina y establecer un ámbito de promoción de la actividad en el mundo, generando oportunidades de negocios.
---
This blog was created to publish news on argentinean mining, thus complementing our website and presence in social networks. As all of our activities, it intends to connect the mining community in Argentina and provide a place to promote the activity in the world, developing business opportunities.

29 jul 2009

San José mine reserves increased by 8% in contained silver and 16% in contained gold between June 30, 2008 and December 31, 2008

SPOKANE, WA, July 29 /CNW/ - Minera Andes Inc. (TSX: MAI and US OTC:
MNEAF) is pleased to announce the results of an independent NI 43-101
Technical Report that includes a review of the mineral resource and reserve
estimates as of December 31, 2008 at the San José mine in Santa Cruz province,
southern Argentina. Compared to the June 30, 2008 estimate as reported by the
Corporation on June 5, 2009, the contained silver in the proven and probable
mineral reserves increased by 8% and the contained gold increased 16%. Gold
and silver ounces at the mine increased compared with those reported in the
previous technical report because the grades of the mineral reserves
increased, primarily due to the utilization of higher metal prices and a
higher cut-off value reflecting actual cost experience, as well as the
addition of mineral reserves through exploration.
The Technical Report entitled "Technical Report on the San José
Silver-Gold Mine, Santa Cruz, Argentina", was prepared by P&E Mining
Consultants Inc. ("P&E") and authored by Mr. Eugene Puritch, P.Eng. Mr. Al
Hayden, P.Eng., Mr. James L. Pearson, P.Eng., Mr. Antoine Yassa, P.Geo, Mr.
Fred H. Brown, MSc(Eng) CPG PrSCiNat, and Ms. Kirstine Malloch, MAusIMM, all
of whom are qualified persons for the purposes of NI 43-101.

Mineral Resources

The December 31, 2008 San José mineral resource and mineral reserve
estimates disclosed herein are based on work from our joint venture partner
that was audited and adjusted by independent qualified persons James L.
Pearson, P.Eng., Mr. Eugene Puritch, P.Eng. and Mr. Fred H. Brown, MSc(Eng)
CPG PrSCiNat of P&E. The mineral resources and reserves remain open along
strike and at depth in some areas.
P&E used a gold price of US$800 per ounce (oz) and a silver price of
US$12.00 per oz for estimating mineral resources and reserves, which reflect
the price levels at the end of 2008. The average Life of Mine cash operating
costs are estimated at US$106.51/tonne (t) of ore processed, or
US$4.16/equivalent ounce of silver. The Corporation's 49% attributable share
of the base case Net Present Value (NPV), using long-term metal price
estimations of US$900 per ounce of gold and US$13.00 per ounce of silver and a
discount rate of 7%, is US$103.4 million. On an undiscounted basis, the
Corporation's share is US$116.3 million.
At December 31, 2008 total Measured and Indicated Mineral Resources at
the San José Mine were 575,000 ounces of gold and 38.0 million ounces of
silver, contained in 2,240,300 tonnes grading 7.98 grams/tonne (g/t) gold and
527 g/t silver, or 72.5 million ounces of silver on a silver equivalent basis
(see table below). An additional 191,000 ounces of gold and 11.3 million
ounces of silver, contained in 1,049,900 tonnes, grading 5.66 g/t gold and 334
g/t silver are classified as Inferred Resources. A marginal cutoff grade of
240 g/t of silver equivalent, representing the variable operating cost, was
used to estimate the mineral resources (using a price of US$800/oz for gold
and US$12.00/oz for silver).


The San José mineral resource estimate is based on 507 surface and
underground drill holes and 6,640 channel samples. Channel samples were taken
from underground operations at Huevos Verdes Sur, Frea, and Kospi.
The resource models were developed using industry-accepted methods. P&E
validated the model estimates and found them to reasonably estimate grade and
tonnage. The mineral resource estimates are compliant with CIM Definition
Standards for Mineral Resources and Mineral Reserves as incorporated by
reference in NI 43-101.

Mineral Reserves

At December 31, 2008 the Proven and Probable Mineral Reserves, based on
an overall economic cutoff value of US$126.47/t (using a price of US$800/oz
for gold and US$12.00/oz for silver), are 1,626,000 tonnes at 523 g/t silver
and 7.89 g/t gold, containing 27,323,000 ounces of silver and 412,000 ounces
of gold. The mineral reserves also take into account marginal blocks of ore
located within or on the periphery of higher grade zones. The marginal cutoff
for these blocks was US$60.84/t. The marginal cutoff was defined by the value
of ore that meets the variable costs, but not the fixed costs.

The increase in the silver and gold content of the mineral reserves from
June 2008 to December 2008 is due to the utilization of higher metal prices
and a higher cut-off value as well as the addition of mineral reserves through
exploration, which overall has had a positive impact on both silver and gold
grades as well as the metal contained in the mineral reserves. At the current
mill capacity of 1,500 tonnes per day, the reserves have a life of 3.1 years.
The following table provides a reconciliation of the December 2008
mineral reserves to the June 2008 mineral reserves taking production during
the period into account. The percentage gain is calculated by dividing the
depleted mineral reserve tonnes and ounces as of December 31, 2008 by the
amount gained. The amount gained is the mineral reserve reported on December
31, 2008 less the depleted mineral reserve resulting from production.


The following summarizes the key assumptions, parameters and methods used
in the mineral resource and mineral reserve estimates:

- Drillhole assay values and channel samples were combined for mineral
resource estimation;
- Bulk density values used for the estimate are 2.60 tonnes per cubic
meter (t/m(3)) for Huevos Verdes Sur, 2.60 t/m(3) for Frea, and
2.60 t/m(3) for Kospi;
- Assays values manually identified as ore-grade were composited to
length-weighted composite samples;
- Prior to block estimation, gold composite samples were cut to 150 g/t
at Huevos Verdes Sur, 70 g/t at Frea and 40 g/t at Kospi. Silver
assays were cut to 10,000 g/t at Huevos Verdes Sur, 4,200 g/t at
Frea, and 4,400 g/t at Kospi;
- Estimation was done using oriented search ellipses and Ordinary
Kriging where sufficient resolution was available for variography, or
by Inverse Distance Cubed weighting of composite values where the
resolution was poor;
- Mineral resource estimation was confined to areas considered to have
a reasonable degree of geological confidence.
- The mineral reserve cut-off value ("COV") is based on historical
January to October 2008 geologic, mining, plant and mine
administration variable and fixed costs, and November and December
2008 estimated costs. Economic Cut-off Values ("ECOV") were estimated
using both variable and fixed costs and Marginal Cut-off Values
("MCOV") were estimated using variable costs only. The mineral
reserve estimate is primarily based on the ECOV. Ore with a grade
above the MCOV and less than the ECOV are included in the mineral
reserve estimate if it was necessary to develop through them in order
to access ore grades above the ECOV. A total of 84% of reserves are
at or above the ECOV and 16% of mineral reserves are between the ECOV
and the MCOV. The ECOV and the MCOV are US$126.47/t and US$60.84/t,
respectively.
- The economic and marginal cut-offs used to estimate mineral reserves
are 499 g/t Au and 240 g/t Ag Equivalent, respectively.
- Mineral reserves are estimated to a minimum 0.8 meter (m) mining
thickness. This adds 1.2% to the initial measured and indicated
mineral resources used to estimate mineral reserves.
- Within the boundaries of this 0.8 m minimum thickness there is some
material that contains combined Ag and Au grade values below the MCOV
cut-off value that must be mined. This material is referred to as
planned internal dilution. Planned internal dilution is estimated to
be 4.4 %, 0.6 % and 0.6 % by tonnes, contained Ag and contained Au,
respectively.
- Mine recovery is estimated based on the mine plan and design. Mine
recovery losses includes pillars not recovered, losses due to bad
ground and blasted ore left in stopes. Of the initial measured and
indicated mineral resources used to estimate mineral reserves an
estimated 24.6% of these mineral resources will not be recovered.
- Planned external dilution is estimated, based on the mine plan and
design. This planned external dilution is estimated based on
historical reconciliation data gathered, including excavation
surveys, and includes slough and blasted waste rock from both the
hanging and footwalls, mined backfill and blasted waste sent to the
mill. Planned external dilution is estimated to be 13.2%.

A technical report, prepared in accordance with NI 43-101 will be filed
on SEDAR (www.sedar.com) shortly.
This news release was prepared under the supervision of Brian Gavin, CPG,
Vice President Exploration of Minera Andes, a "qualified person" within the
meaning of NI 43-101. For (i) the mineral resource/reserve estimate contained
herein; (ii) a description of the key assumptions, parameters and methods used
to estimate the mineral resource/reserve referred to in this news release; and
(iii) a general discussion of the extent to which the estimate of mineral
resources/reserves may be materially affected by any unknown environmental,
permitting, legal, title, taxation, socio-political, marketing, or other
relevant issues, please refer to the technical report to be filed as noted
above.

Minera Andes is a gold, silver and copper exploration company with a 49%
interest in the San José silver-gold mine in Santa Cruz, Argentina. The San
José mine is owned by Minera Santa Cruz S.A. ("MSC"), which in turn is owned
49% by Minera Andes and 51% by Hochschild Mining plc. Hochschild is the
operator of the San José mine. The Corporation also owns the Los Azules copper
project in San Juan province, where a scoping study has been completed and the
Corporation is awaiting a decision by its joint venture partner, Xstrata
Copper Company, if it will exercise its right to back into a 51% ownership of
the project. Also, in addition to the San José mine and the Los Azules
project, the Corporation holds or has an interest in approximately 304,000
acres of mineral exploration land in those areas. The Corporation presently
has 230,688,851 shares issued and outstanding.

Caution Concerning Forward-Looking Statements:

This news release contains forward-looking statements and forward-looking
information within the meaning of applicable US and Canadian securities laws.
Such forward-looking statements or information include expected production at
MSC's San José Mine. In making the forward-looking statements and providing
the forward-looking information, we have made numerous assumptions. Although
our management believes that the assumptions made and the expectations
represented by such statements or information are reasonable, there can be no
assurance that the forward-looking statements will prove to be accurate.
Forward-looking statements and information involve known and unknown risks,
uncertainties and other factors that may cause our actual results to be
materially different from that expressed or implied by such forward-looking
information. Such risks, uncertainties and other factors include among other
things, declines in the price of gold, silver, copper and other base metals,
capital and operating cost increases, changes in general economic and business
conditions, including changes in interest rates and the demand for base
metals, economic and political instability in Argentina, discrepancies between
actual and estimated production and mineral reserves and resource, operational
and development risk, and the speculative nature of mineral exploration and
regulatory risks.
Readers should not place undue reliance on forward-looking statements or
information. We undertake no obligation to reissue or update forward-looking
statements or information as a result of new information or events after the
date hereof except as may be required by law. See our annual information form
for additional information on risks, uncertainties and other factors relating
to the forward-looking statements and information. All forward-looking
statements and information made in this news release are qualified by this
cautionary statement. Minera Andes' joint venture partner, a subsidiary of
Hochschild Mining plc, and its affiliates do not accept responsibility for the
use of project data or the adequacy or accuracy of this release.

Cautionary Note to U.S. Investors:

The United States Securities and Exchange Commission (the "SEC") permits
mining companies, in their filings with the SEC, to disclose only those
mineral deposits with "mineral reserves" that a company can economically and
legally extract or produce. We use certain terms in this news release, such as
"mineral resources", that the SEC guidelines strictly prohibit us from
including in our filings with the SEC, because these terms are common usage in
Canada and form part of our Canadian filing requirements. U.S. Investors are
urged to consider closely the disclosure in our Form File No. 40F, which may
be secured from us, or from the SEC's website at
http://www.sec.gov/edgar.shtml.

For more information on Mining in Argentina, visit our website: http://www.argentinamining.com/

No hay comentarios:

Publicar un comentario

Thanks for your interest on Argentina Mining's Blog. Please leave your comment on this article in spanish or english. / Gracias por su interés en el Blog de Argentina Mining. Por favor deje su comentario sobre este artículo en español o inglés.