Tosca Mining releases NI 43-101 Resource estimate and Metallurgical results for Red Hills,
Vancouver, British Columbia, February 22, 2012. Tosca Mining Corporation (TSX.V:TSQ,
OTCQX:TSMNF, FSE:TQ4) announces the completion by Mine Development Associates (“MDA”) of Reno, Nevada of
the first publically reported, NI 43-101compliant mineral resource estimate for the Red Hills Deposit,
located in Presidio County, Texas. The MDA report also summarizes the results of a metallurgical study
completed by METCON Research in Tucson, Arizona. The mineralization of interest at Red Hills occurs
within a porphyry molybdenum deposit and near surface copper enrichment zone (“copper blanket”) that
covers an area about 4,000 ft (1220 m) by 3,000 ft (915 m). The porphyry molybdenum mineralization has a
depth-extent of over 2,000 ft (610 m) though the mineralization is not well-defined past a depth of
1,000 ft (305 m). Both copper and molybdenum mineralization are open to the south under
● Red Hills Mineral Resources
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As a term of reference
according to www.metalprices.com, the price as of February 17, 2012, of Molybdenum was $14.51 per pound
and Copper $3.79 per pound.
●Metallurgy: Results of flotation testing
Sadek El-Alfy, PhD, CEO, commented “The results from the 2011 diamond drill campaign
confirmed that Red Hills is a large porphyry deposit with commercially attractive grades of both
molybdenum and copper. Metallurgical studies have shown that recoveries of this molybdenum/copper
resource are encouraging and straightforward.
In 2012 we will continue to develop Red Hills by
investigating the economic feasibility of molybdenum/copper extraction and recovery on a large scale;
this study will be incorporated in a Preliminary Economic Assessment (“PEA”) currently being prepared by
M3 Engineering in Tucson, Arizona. The company is planning a drill program to upgrade the resources and
to drill test the potential southern extension of the deposit.”
estimate is based on a database of 121 drill holes totaling 60,131 feet (18,328 m) which includes 53,947
feet (16,443 m) of diamond drilling. The copper and molybdenum resources were modeled and estimated by
evaluating the drill data statistically, utilizing the geologic interpretations developed by Tosca and
MDA to interpret mineral domains on 29 cross sections spaced at 100 ft (30.5 m) intervals, resolving the
mineral domain interpretations on longitudinal sections spaced at 20 ft (6.1 m) intervals, analyzing the
modeled mineralization statistically to establish estimation parameters, and interpolating grades into a
three-dimensional block model. Lithology, oxidation, and copper-molybdenum mineral domains models were
created for the Red Hills project. The modeling of the Red Hills Resources was performed using Gemcom
Surpac® mining software.
The stated resource is fully diluted to 20ft (6.1 m) by 20ft by 20ft
blocks. In consideration of the depth limits of any potential open pit mining, the Red Hills resource
was constrained to a bottom elevation of 2,800 ft (853 m) approximately 1,200 ft (366 m) below the
Because of the requirement that the resource exists “in such form and quantity and
of such a grade or quality that it has reasonable prospects for economic extraction,” MDA is reporting
the resources at a cutoff grade (0.025% MoEq) as that is reasonable for deposits mined by open-pit
methods. In determining a reasonable cutoff grade, MDA considered metal prices, extraction costs, and
metallurgical recoveries. The diluted resources have been reported at additional cutoffs in order to
provide a grade distribution. The diluted resources at a 0.05% MoEq cut-off grade is included in the
Mineral Resource highlights on page 1 to show the effect of a higher cut-off grade.
resource is fully contained within the near-surface copper blanket, and there is a significant tonnage
of molybdenum-only material in the resource. The lower copper grades within the Red Hills resource
result from the “spreading” of the copper over the full resource. If the copper mineralization is
evaluated from a copper-only standpoint, the copper resource at a 0.15% Cu cutoff grade (comparable to
0.027% MoEq cutoff grade) contains an Indicated Resource of 8 million tons of 0.35% Cu (56.4 million
lbs. Cu) and an Inferred Resource of 12.7 million tons of 0.25% Cu (63.4 million lbs. Cu).
addition to the molybdenum/copper mineralization, multi-element analyses of Tosca’s drill samples show
elevated rhenium levels associated with molybdenite mineralization. Rhenium concentrations of 0.5 to
>1.0 part per million were encountered over vertical intervals of up to 500 feet (152 m) throughout the
METCON conducted a froth flotation study on seven
composite core samples from Tosca’s 2011 drilling at Red Hills, using assay rejects. The froth flotation
study was conducted at a grind size of approximately 80 percent passing 74 microns, a pulp density of 25
percent solids, and pulp pH at 11. The results of this investigation are tabulated below:
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Head assays of composites 1 to
5 contained significant copper concentrations (0.16% to 0.78% Cu). Copper recoveries from those five
samples ranged from 52.26% to 85.61 % (average: 66.2 %). Composites 6 and 7 did not contain detectable
copper in head assays.
Head assays of Composites 2 to 7 contained significant molybdenum
concentrations (438 ppm to 963 ppm Mo). Molybdenum recoveries from those composites ranged from 81.41%
to 93.23 % (average: 88.8%).
A complete copy of the NI 43-101 for Red Hills Projects is available on
SEDAR and also filed on the OTC-QX website.
The mineral resource estimate was
prepared by Paul Tietz, Senior Geologist at Mine Development Associates (“MDA”) in Reno, Nevada in
accordance with National Instrument 43-101. Paul Tietz is an independent “Qualified Person” as defined
by National Instrument 43-101.
The metallurgical studies were supervised by Rodrigo R. Carneiro, a
metallurgical engineer with METCON Research (“METCON”) and a “Qualified Person” as defined by
The mineral Resource estimate and the metallurgical work were reviewed by Luca Riccio,
PhD, PGeo and Sadek El-Alfy, PhD, respectively. Both are “Qualified Persons” according to the
definitions of NI 43-101. Luca Riccio has supervised the preparation of the technical information and
data included in this News Release.
On Behalf of the board of directors,
further information, please visit the company's website at www.toscamining.com or call 604-687-6562.
Neither 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.
Statements in this press release, other than purely historical information,
including statements relating to the Company’s future plans and objectives or expected results, may
include forward-looking statements. Forward-looking statements are based on numerous assumptions and are
subject to all of the risks and uncertainties inherent in resource exploration and development. As a
result, actual results may vary materially from those described in the forward-looking statements