TORONTO, ONTARIO -- (Marketwire) -- 07/20/10 -- Virgin Metals Inc. (TSX VENTURE: VGM) is pleased to provide an update on the ongoing work program at its Los Verdes copper-molybdenum project, located in Sonora, Mexico. The work program, based upon recommendations made in the 2008 National Instrument ('N.I.') 43-101 compliant Pre-Feasibility Study completed by Mine and Quarry Engineering Services, Inc., Chlumsky, Armbrust & Meyer, LLC, and The Mines Group, Inc., is being undertaken to advance Los Verdes towards a full Feasibility Study.
We are currently advancing the work program on two fronts,' said Darren Koningen, a Director at Virgin Metals Inc. 'Not only are we completing additional metallurgical testing to improve existing data on copper and molybdenum recoveries but as well we are revising the current resource estimate to now include silver and tungsten; additions we feel will significantly improve our financial model.'
Virgin Metals engaged SGS Lakefield Research to perform QEMSCAN X-Ray Diffraction (XRD) analysis and optical microscopy on the Los Verdes mineralization. This technique, used to create an image of the individual mineral grains in the sample, provides an understanding of the minerals present and the grind sizes required to unlock the individual particles.
Highlights
-- Essentially all of the molybdenum was present as molybdenite (MoS2)
which is relatively coarse grained and should be easily recoverable by
flotation;
-- No significant quantities of copper were found in oxide minerals only in
sulphides which, by flotation, should enable high copper recoveries;
-- The only other significant sulphide mineral present is pyrite which
should simplify the elimination of impurities during the concentration
process;
-- Silver was present in all samples with grades ranging from 2 to 50 g/t.
The 2008 Pre-Feasibility Study notes that the Los Verdes 'deposit contains silver and tungsten at grades that may be of economic interest as byproducts' and recommended that 'both tungsten and silver be included in future Resource estimates'. Virgin Metals is pleased to report that it is working to advance an internal resource estimate to include both the silver and tungsten, and plans to complete an updated NI 43-101 compliant resource estimate, including silver and tungsten, in the fourth quarter of 2010.
QEMSCAN X-Ray Diffraction Analysis
Six different samples were taken from existing Los Verdes drill core using visual observations and drill logs. The samples were selected to include the major variations in host rock (quartz versus tourmaline), alteration intensities, and the quantities of copper and molybdenum minerals contained. Copper grades in the samples varied from 0.02 percent to 11 percent and molybdenum grades varied from 0.005 percent to 1.7 percent.
Essentially all of the molybdenum was present as molybdenite (MoS2). Molybdenite grain sizes were relatively consistent through all of the samples with +80% of the grains liberated at a size of 200 microns (medium-coarse size). As verified by previous work, the molybdenite is relatively coarse grained and should be easily recoverable by flotation.
No significant quantities of copper were found in oxide minerals. Essentially all copper was contained in sulphides, which should enable good copper recovery by flotation. A relatively wide range of sulphide minerals are present, ranging from primary sulphides (chalcopyrite) to secondary minerals (bornite, chalcocite, covellite). The size of copper sulphide grains is generally finer (medium-fine) than for molybdenite, and the range is more variable. Generally +80% are liberated at 50-100 microns, although one sample required a finer size. The conclusion of the analysis is that the copper should be amenable to flotation, although finer grinds will be necessary to produce good concentrate grades.
The only other significant sulphide mineral present is pyrite. Grains are relatively coarse and similar in size to molybdenite. These 'waste' sulphides are essentially coarse pyrite which should separate from copper minerals by utilizing normal techniques for base metals flotation, with options including 'reverse floating' the pyrite to eliminate it. A number of these types of techniques were not tested during previous metallurgical work.
Silver was present in all samples with grades ranging from 2 to 50 g/t. Silver appears to be primarily associated with copper in the mineral tetrahedrite. Samples with elevated copper contained elevated silver (10 to 50 g/t Ag in samples with highest copper content of 1 to 11 percent). This silver content in the ore should be readily recoverable to a copper concentrate with high payable metal values at a copper smelting facility.
As a follow-up to the QEMSCAN program, Virgin Metals intends to perform a metallurgical program to obtain the final details for processing the Los Verdes ore. This program is anticipated to be completed by early 2011.
This press release has been reviewed by Mr. Darren Koningen, P. Eng., a Director of Virgin Metals. Mr. Koningen is a Qualified Person under National Instrument 43-101.
About Virgin Metals
Virgin Metals is a junior exploration and development company; its projects include two copper-molybdenum porphyry properties in Sonora, northern Mexico. One of these, Los Verdes, has been the subject of a pre-feasibility study and while the other, Cuatro Hermanos, has been the focus of an intense exploration effort.
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Contacts:
Virgin Metals Inc.
Lucas Ewart
(416) 488-2590
www.virginmetals.com
