VANCOUVER, April 12 /CNW/ - Bear Creek Mining (TSX Venture: BCM) ("Bear
Creek" or the "Company") is pleased to announce the positive test results
performed and confirmed by three separate laboratories on 10 representative
samples from the Santa Ana Silver deposit. The samples were selected from five
diamond drill holes spaced throughout the area of mineralization at various
depths from the deposit representing average grade ranges indicated by the
Andrew Swarthout, President/CEO stated, "As we anticipated from the
dominance of oxide silver mineralization observed to the depths drilled, the
test work confirms that the Santa Ana material responds very well to cyanide
leaching. Given the guidance from the preliminary metallurgical work and the
size of the under-explored silver anomaly, Santa Ana has excellent potential
to be a low-cost, heap leach, pure-silver deposit. Santa Ana is becoming an
exciting addition to Bear Creek's discovery stream."
Given the positive leach testing results, Phase 3 drilling comprised of
2,500 meters will commence on April 17th. This program is designed to evaluate
the bulk-tonnage, low cost heap leaching potential of the Santa Ana silver
deposit using lower cut-off grades, as well as expanding the higher-grade
intercepts, which remain open along the limits of the anomaly.
Preliminary cyanide leach amenability tests were performed at ALS-Chemex,
Lima, Peru where the ten samples were agitated for 24 hours. As previously
reported, the results indicated that leaching would perform well and that
further testing was warranted (see news release 2 March '07). Subsequent
testing was performed by Plenge Labs, Lima, Peru, and McClelland Labs, Sparks,
Nevada on ground core samples (coarse assay rejects) from the same ten drill
hole samples. Cyanide and pH were monitored throughout the test periods in
order to maintain the proper test conditions.
Plenge Laboratory Test Summary
The samples were ground to approximately 50% passing 200 mesh
(76(micro)m) and bottle roll tested for 96 hours under supervision of Adam
Johnston of Transmin (a consulting metallurgist for the Company). The tests
showed silver recoveries ranging from 72% to 96% Ag with an average of 85%.
These results are indicative of potential recoveries in a vat leach recovery
plant suitable for the treatment of higher-grade material.
McClelland Laboratory Test Summary
Bottle roll tests were performed on material from the same ten drill hole
intervals at McClelland Labs in Sparks, Nevada. The material was crushed to
70% passing 2mm material and was leached for 168 hours. The tests show the
average recovery of silver on this coarser material to be 71% and ranges from
54% to 88%. Importantly, recoveries were still increasing when the testing was
terminated. These results give guidance on potential leach recoveries at
coarser crush size.
Phase II Metallurgical Testing
The test results indicate excellent potential for a "Pulp Agglomeration"
heap leaching technique, a method where higher grade material is milled and
vat leached to achieve higher recoveries, then mixed with crushed lower grade
material and placed in a heap leach. McLelland Labs has commenced a column
leach test program to evaluate expected recoveries in actual heap leach
conditions and define optimal crush size as well as the cyanide and lime
consumption. The testing involves three- 6 inch by 10' columns utilizing
approximately 300 kg of drill core from the same drill hole intervals so that
comparisons can be made to bottle roll leach performance. Column leaching is a
long-term test intended to predict heap leach performance; results are
expected in 2-3 months.
The TSX Venture Exchange does not accept responsibility for the adequacy
or accuracy of this release.
For further information, please visit the Company's website
All of Bear Creek's exploration programs and pertinent disclosure of a
technical or scientific nature are prepared by or prepared under the direct
supervision of David Volkert, P.Geo., Bear Creek's Vice President of
Exploration or Marc Leduc, P. Engr., Vice President Technical Services, and
the President and CEO, Andrew Swarthout, P.Geo., the President and Chief
Executive Officer, who serve as the Qualified Persons under the definitions of
NI 43-101. All diamond drilling has been performed using HQ diameter core with
recoveries averaging greater than 95%. Core is logged and split on site under
the supervision of Bear Creek geologists. Sampling is done on two-meter
intervals and samples are transported by Company staff to Cusco, Peru for
direct shipping to ALS Chemex, Laboratories in Lima, Peru. ALS Chemex is an
ISO 9001:2000-registered laboratory and is preparing for ISO 17025
certification. Silver, lead, and zinc assays utilize a multi-acid digestion
with atomic absorption ("ore-grade assay method"). The QC/QA program includes
the insertion every 20th sample of known standards prepared by SGS
Laboratories, Lima. A section in Bear Creek's website is dedicated to
sampling, assay and quality control procedures.
Certain disclosure in this release, including management's assessment of
Bear Creek's plans and projects, constitutes forward-looking statements that
are subject to numerous risks, uncertainties and other factors relating to
Bear Creek's operation as a mineral exploration company that may cause future
results to differ materially from those expressed or implied in such
forward-looking statements. (*)Any reference to the potential quantity & grade
of mineralization is conceptual in nature, there has been insufficient
exploration to define a mineral resource on the property and it is uncertain
if further exploration will result in discovery of a mineral resource on the
property. Readers are cautioned not to place undue reliance on forward-looking
statements. Bear Creek expressly disclaims any intention or obligation to
update or revise any forward-looking statements whether as a result of new
information, future events or otherwise.
For further information:
For further information: Andrew Swarthout, President and CEO, or Patrick
De Witt, Investor Relations, Phone: (604) 685-6269, Direct: (604) 628-1111,