Searchlight Minerals Corp. announces results of metallurgical testing on Searchlight gold project
29 Gennaio 2007 - 3:00PM
PR Newswire (US)
HENDERSON, NV, Jan. 29 /PRNewswire-FirstCall/ -- Searchlight
Minerals Corp. (OTC BB: SRCH) (the "Company"), today announced that
it has received the initial results of metallurgical testing
conducted by its independent mining consultants Arrakis, Inc
("Arrakis") on chain-of-custody surface samples collected from the
Company's Searchlight Gold Project in southern Nevada.
Metallurgical testing by Arrakis using the process of total
digestion has consistently revealed a feed grade of 0.37 ounces per
ton (opt) gold or better in the Searchlight Project samples.
Preliminary tests indicate that the "head" ore grade may be
concentrated. Metallurgical extraction, using autoclave leaching,
has been successful in extracting 80% of the gold into solution.
Work is continuing to optimize these processes and finalize a
potential commercial extraction protocol for the Searchlight Gold
Project. Once this is completed, drilling for reserves is expected
to determine the commercial feasibility of the project. The table
below provides an overview of the results from hundreds of
metallurgical tests completed, to date, by independent mining
consultants Arrakis: Chain of Custody Results Summary
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COC Tests Feed Grade Extracted Grade (SP4) Gold (opt)(xx) Gold
(opt)(xx) Leach Method
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Bench Leach Tests
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SP4 - 500 grams 0.58 0.24 - 0.42 48 hr Leach
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SP4 - 50 lbs head 0.54 Con 1 1.56 0.36 96 hr leach Con 2 0.93 0.75
96 hr leach
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Bulk Leach Tests
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BL1 - 1,000 lbs 0.58 0.25 48 hr Leach
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BL2 - 1,000 lbs 0.58 0.22 48 hr Leach
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BL3 - 9,000 lbs head 1,674 lbs cons 0.90 0.21 72 hr Leach
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Autoclave Tests
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TP2-12 - 200 grams 0.34 - 0.39 0.03 - 0.26 1.5 hr Autoclave
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TP8 - 200 grams 0.37 0.16 1.5 hr Autoclave TP9 (TP8 tails) 0.14 1.5
hr Autoclave ------ ------------------ Total 0.30 3.0 hr Autoclave
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(x) Gold analysis was performed by Arrakis, Inc. under
chain-of-custody parameters. Analysis of all head ore samples was
done by 3 acid digestion in a Milestone Ethos Plus microwave sample
digester and analyzed by a Perkin Elmer 5100 graphite furnace
atomic adsorption (GFAA) system with Zeeman background correction.
Pregnant solutions from all bench and bulk tests were analyzed for
Au using calibration blanks and standards corrected with matching
sample matrix to the specific solution being read. (xx) Feed Grade
is the initial gold content in the sample. ExtractedGrade is the
amount of gold leached into solution. Discussion of Work Program
The Company has been working on the Searchlight property for the
past 20 months. In May 2005, Arrakis, Inc., a Denver-based
independent mining consultancy that specializes in refractory or
problematic gold ore extraction techniques, was engaged by the
Company, to collect preliminary chain-of-custody ("COC") surface
samples from the Searchlight property (located near Searchlight,
NV) and analyze such samples for gold content. Results of the
surface samples are provided below:
-------------------------------- Feed Grade Surface Sample I.D. Au
(opt) -------------------------------- SS5 0.39
-------------------------------- SS6 0.48
-------------------------------- SS7 0.55
-------------------------------- SS8 0.69
-------------------------------- While the feed grade of the
preliminary samples indicated significant gold content, the grade
recovered into solution from sample SS8 in a somewhat standard
bottle roll leach test approximated 0.19 opt gold. Following this
initial sampling, Arrakis tested a variety of bench scale leach
methods in order to improve extraction of the gold. The bench
testing and optimization of leach conditions improved the
extraction efficiency to 72% and outlined a protocol for bulk leach
testing. To further the work program, six tons of COC bulk samples
were collected from the Searchlight property on September 14, 2005.
Results from analyses of the bulk samples were as follows:
-------------------------------------------- Feed Grade Extracted
Grade Bulk Test I.D. Au (opt) Au (opt)
-------------------------------------------- BL 1 0.58 0.25
-------------------------------------------- BL 2 0.58 0.22
-------------------------------------------- BL 3 0.90 0.21
-------------------------------------------- "While the bulk test
did not optimize extraction of the gold from the ore, it
demonstrated that metal can be produced from this refractory ore
and that analytical techniques now exist to allow the optimization
of its recovery," stated Jim Murray, President of Arrakis Inc.
"While more work is required to optimize and define the recovery
process, results to date indicate the potential for an economically
viable precious metal resource. Information developed from the
extensive bench and bulk scale test activities should allow process
optimization to proceed more rapidly, subject to quantifying the
deposit size and quality through a drilling program." Arrakis has
begun work on examining pressure leaching via autoclave to enhance
both the kinetics and extraction efficiency of gold from solution.
A series of 11 autoclave tests were conducted at John E. Litz &
Associates using 200-gram samples in a Parr 1 liter pressure
reactor. Solution analysis was completed by Arrakis, Inc. The
results of such tests are summarized in the following table:
------------------------------------------------- Feed Grade
Extracted Grade Autoclave Test I.D. Au (opt) Au (opt)
------------------------------------------------- TP2 0.37 0.07
------------------------------------------------- TP3 0.39 0.08
------------------------------------------------- TP4 0.38 0.03
------------------------------------------------- TP5 0.37 0.15
------------------------------------------------- TP6 0.34 0.19
------------------------------------------------- TP7 0.37 0.03
------------------------------------------------- TP8 0.37 0.16
------------------------------------------------- TP9 0.37 0.14
------------------------------------------------- TP10 0.37 0.23
------------------------------------------------- TP11 0.37 0.26
------------------------------------------------- TP12 0.37 0.15
------------------------------------------------- All samples
approximated 200 grams in 1 liter of solution. Leach time for all
samples approximated 90 min and the sample for TP7 was dead roasted
prior to leaching. "We are very pleased with our progress, to date,
and continue to pursue a focused and detailed metallurgical program
to develop a commercially viable process for this gold project,"
stated Ian McNeil, President and Chief Executive Officer of
Searchlight Minerals Corp. "We have outlined a detailed work
program with Arrakis for the first part of 2007 to further move
this project towards feasibility. If future results continue to be
encouraging, we expect to drill the property later this year."
About Searchlight Minerals Corp. Searchlight Minerals Corp. is a
dynamic mineral exploration company focused on the acquisition and
development of projects in the southwestern United States. The
Company is currently involved in two projects: (1) the Clarkdale
Slag Project, which seeks to recover precious and base metals from
the reprocessing of slag material produced from the smelting of
copper ores from former mines in the Jerome, Arizona area; and (2)
the Searchlight Gold Project, which involves exploration for
precious metals on mining claims near Searchlight, Nevada. The
Clarkdale Project is the more advanced of two ongoing projects that
the Company is pursuing. The Searchlight Gold Project is an
early-stage gold exploration endeavor on 3,200 acres located
approximately 50 miles south of Las Vegas, Nevada. Searchlight
Minerals Corp. is headquartered in Henderson, Nevada, and its
common stock is listed on the OTC Bulletin Board under the symbol
"SRCH". For further details, please visit the Company's website at
http://www.searchlightminerals.com/ or contact the Investors
Relations Department at: Ph: (702) 939-5247 Fax: (702) 939-5249
email: Forward-Looking Statements This Press Release may contain,
in addition to historical information, forward-looking statements
within the meaning of Section 27A of the Securities Act of 1933, as
amended, and Section 21E of the Securities Exchange Act of 1934, as
amended. Statements in this news release that are forward-looking
statements are subject to various risks and uncertainties
concerning the specific factors disclosed under the heading "Risk
Factors" and elsewhere in the Company's periodic filings with the
U.S. Securities and Exchange Commission. When used in this news
release, the words such as "could," "plan", "estimate", "expect",
"intend", "may", "potential", "should", and similar expressions,
are forward-looking statements. The risk factors that could cause
actual results to differ from these forward-looking statements
include, but are not restricted to the Company's limited operating
history, uncertainties about the availability of additional
financing, geological or mechanical difficulties affecting the
Company's planned geological work programs, uncertainty of
estimates of mineralized material, operational risk, environmental
risk, financial risk, currency risk, dependence on joint venture
partners and other statements that are not historical facts as
disclosed under the heading "Risk Factors" and elsewhere in the
Company's periodic filings with securities regulators in the United
States. CONTACT: please visit the Company's website at
http://www.searchlightminerals.com/ or contact the Investors
Relations Department at: Ph: (702) 939-5247, Fax: (702) 939-5249,
email: DATASOURCE: Searchlight Minerals Corp. CONTACT: please visit
the Company's website at http://www.searchlightminerals.com/ or
contact the Investors Relations Department at: Ph: (702) 939-5247,
Fax: (702) 939-5249, email:
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