Dia Bras Obtains 85% Recovery of Silver From Cusi Rocks
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MONTREAL, QUEBEC, Jun 10 (MARKET WIRE) --
Dia Bras Exploration Inc. (TSX VENTURE: DIB) is pleased to report the
results of metallurgical testing on silver-mineralized rock from its Cusi
project. The testing was done under the direction of an independent
engineer, Sr. Pedro Castillo C., at the Centro de Investigation de
Materiales Avanzados (CIMAV) located in Chihuahua City, Chihuahua.
A representative sample was collected under the supervision of Sr.
Castillo from 1,500 tonnes of rock (mined from the Santa Eduwiges and
Santa Marina veins) stockpiled at the Company's Malpaso mill. The sample
was reduced to 5 kg mass and processed using a combination of flotation
and cyanidation methods. The results are shown in the tables below:
Flotation Method
Mass Mass Assay Results Percent Recovery
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Product grams % Ag, g/t Pb% Ag Pb
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Concentrate 232.8 4.62 3743.2 53.91 54.96 59.6
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Flotation tails 4808.7 95.38 148.5 1.77 45.04 4041
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Cyanidation Method
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Pregnant Solution 99.0 66.7
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Residual Tails 4808.7 95.38 49.5 33.30
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Total Recovery 85.00 59.6
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Calculated Head 5041.5 100.0 314.5 4.18 100.0 100.0
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Sr. Castillo also took photomicrographs of flotation concentrates that
show grains about 100 microns in size (-140 mesh or 0.1 mm) of
interlocked sphalerite and galena. From this information, it has been
determined that the best economic grind for Cusi rock is 50% passing 200
mesh (-0.074 mm) and that reagents of zinc sulfate and cyanide during
flotation recovery will reduce zinc contents in the lead-silver
concentrates.
Bottle roll tests of cyanide leaching show that 80% of silver in the
tails is recovered in 16 hours, and that continuing the tests to 48 hours
resulted in 83% recovery of silver, an increase of only 3%. These results
indicate that cyanide-recoverable silver is captured in a short time and
that longer residence time is not worth the cost.
Based on these metallurgical data, management has decided to re-start
pilot mining at Cusi during August, 2009, and process the mineralized
rock by flotation method and stockpile the flotation tails while
cyanidation vats are being constructed. The vats will be completed within
6 months from the start of construction. Application for permits for
cyanidation processing has been made and management expects approval
within six months.
Similar metallurgical tests have been initiated on rock from the
Promontorio mine as management expects to initiate pilot mining of this
deposit during the third quarter of 2010.
Bolivar Production
Further to its May 29, 2009 news release, the transportation of
mineralized rock from the Bolivar Mine to the Malpaso mill has been
resumed Tuesday. The management revised its production forecast for
Bolivar pilot-mining production to approximately 100,000 tonnes at
average grades of 1.47% Cu and 9.16% Zn for 2009.
The technical content of this news release has been approved by Thomas L.
Robyn, Ph.D. Chairman of the Board of Dia Bras, a Qualified Person as
defined in NI43-101.
Annual General Meeting of Shareholders
The Company invites you to attend its Annual General Meeting of
Shareholders to be held at the Delta Hotel, 475 President Kennedy Avenue,
Mozart Room, Montreal, Quebec, at 10:00 a.m. (local time) today. The
Company will present a review of the past year, its first quarter 2009
results and will also provide an update on its business strategy and
development projects. The presentation will also be available on Dia
Bras' Website, www.diabras.com.
About Dia Bras
Dia Bras is a Canadian exploration mining company focused on precious and
base metals in the State of Chihuahua, in northern Mexico. The
Corporation is committed to developing and adding value to its assets -
the Bolivar copper-zinc project and the Cusi silver mining camp. The
Corporation trades on the TSX Venture Exchange under the symbol "DIB".
Neither the 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.
Forward-looking statements
Except for statements of historical fact, all statements in this news
release, without limitation regarding new project acquisitions future
plans and objectives are forward-looking statements that involve risks
and uncertainties. There can be no assurance that such statements will
prove to be accurate; actual results and future events could differ
materially from those anticipated in such statements.
Contacts:
Dia Bras Exploration
Daniel Tellechea
President & CEO
514-393-8875
www.diabras.com
Dia Bras Exploration
Nathalie Dion
Investor Relations
514-393-8875 ext. 241
Copyright 2009, Market Wire, All rights reserved.
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