Vancouver, B.C., March 22, 2011 - Exeter Resource
Corporation (AMEX:XRA, TSX:XRC, Frankfurt: EXB -
"Exeter" or the "Company") is pleased to report positive results
from its metallurgical test program on sulfide mineralization at its Caspiche project. These results will be used to develop
capital and operating costs for the integrated Oxide-Sulfide pre-feasibility
study ("PFS") scheduled for release in Q3-2011. It is proposed that
gold and silver will be recovered from the surface oxide deposit by
"heap leaching", whereas gold, silver and copper will be recovered
from the underlying sulfide deposit using industry standard
"flotation" technology.
Testwork has confirmed the successful application of both
reduction roasting and pressure oxidation technologies to reduce or eliminate
arsenic from the sulfide concentrates produced by flotation. Highlights of testwork
conducted by independent laboratories include:
- Reduction Roasting: Testwork
by both Outotec (Sweden) AB and Technip USA (Inc) reduced arsenic levels in
concentrate samples to 0.2% arsenic, a level considered commercially
acceptable (without penalties) in most smelter contracts.
- High Temperature/Pressure Oxidation: Testwork solubilised 99%
of the copper, leaving the arsenic as the residue mineral scorodite. Leaching of the residue yielded gold
dissolutions that averaged 96%. These results strongly suggest that high
quality cathode copper and gold-silver bullion can be produced from a
plant that uses pressure oxidation to treat concentrates, and the recoveries
will be very high.
Yale Simpson, Chairman of Exeter stated, "We
have now successfully demonstrated that two widely used and commercially
available technologies can be applied to reduce and/or eliminate arsenic from
Caspiche sulfide concentrates. Our engineering
contractors will now incorporate these processing alternatives into the
integrated Oxide-Sulfide PFS due for completion in Q3-2011.
"The successful completion of this
comprehensive metallurgical campaign on Caspiche
sulfide concentrates is an important development milestone for the
project."
Additional details from the metallurgical testwork are as follows:
- The pilot plant recovered 75 kilograms of
concentrate from approximately 10 metric tons of diamond drill core
representative of Caspiche sulfide
mineralization. The resulting concentrates assayed on average 23.5%
copper, 35 g/t gold, 75 g/t silver and 2.4% arsenic.
- Two suppliers of roaster technology, Outotec and Technip
successfully completed testwork on the
concentrates, reducing the arsenic content to 0.2% (or less), while
retaining a sulfur content of 25%. Roasting did not result in any copper
or gold losses. The "low arsenic" concentrate met a
specification that is readily acceptable to 3rd party smelters.
- Testwork by
SGS Lakefield using high temperature/pressure oxidation
("autoclaves") successfully resulted in 99% copper extraction
from Caspiche concentrates in almost all of
the 8 tests carried out. Conventional cyanide leaching of the pressure
oxidation residues recovered on average 96% or more of the gold.
- The PFS will model 80,000 to
150,000 tonnes/day underground and open
pit mining operations, including capital and operating cost estimates
for the various mining and processing options available to the project.
Discussion of Caspiche
Sulfide Concentrate Testing Program
Much of the Caspiche sulfide ore contains a small
proportion of the copper-arsenic sulfide mineral, enargite,
which elevates the arsenic content of final concentrates to levels not
normally acceptable to copper smelters.. In early 2010, Exeter, through a
study by SNC Lavalin Australia, identified a range
of processes with the capability of addressing the arsenic issue. The Company
selected two of these processes for detailed testwork
on the basis that both are commercially proven and readily available. The two
processes are Reduction Roasting and High Temperature/Pressure Oxidation.
Reduction Roasting was recently selected for Codelco's
new Ministro Hales copper mine in northern Chile.
In November 2010, Exeter commissioned SGS Lakefield
of Ontario, Canada, to operate a flotation pilot plant on approximately 10
metric tons of representative Caspiche sulfide ore
to produce concentrates for testwork. The copper
gold concentrate produced contained approximately 2.4% arsenic.
Reduction Roasting
Two leading roasting technology providers, Outotec
and Technip, independently tested the pilot plant
concentrate. The Outotec tests were carried out in
a rotating kiln and the Technip tests were carried
out in a 4 inch fluidised bed reactor using sand as
an inert medium. Both sets of testwork indicated an
optimum temperature in the range of 675oC and 700oC. Importantly, the testwork showed that residual sulfur in the "cleaned
concentrate" is approximately 25%, a level that is considered acceptable
to smelters in terms of their fuel needs.
High Temperature/Pressure Oxidation
SGS Lakefield carried out a series of batch autoclave tests on the Caspiche sulfide concentrate under different conditions
and between temperatures of 210oC and 225oC.
High Temperature/Pressure Oxidation ultimately
produces cathode copper and gold-silver dore and is
in commercial operation at a number of sites. It uses oxygen injected into
the concentrate slurry in an autoclave. The process simultaneously solubilises the copper, oxidises
virtually all the sulfides and converts the arsenic into the environmentally
stable mineral scorodite, a crystalline ferric
arsenate. Gold is normally leached from the residue after adjusting the pH to
10.5.
The final SGS Lakefield report has yet to be
received, but the Company can report that copper solubilisation
was consistently near 99%, as was sulfide oxidation. Cyanide leaching of the
solid autoclave residues extracted 95% or more of the contained gold.
Jerry Perkins, Exeter's Vice President - Development
commented, "Testwork has demonstrated that Caspiche sulfide mineralization can be successfully
treated using commercially available technologies to produce readily
marketable products. Our consulting engineers for the PFS, Jacobs
Engineering, will apply their in-house expertise to develop capital and
operating costs for both technologies."
Significantly, the Company is also carrying out many
other metallurgical testwork programs aimed at optimising aspects of the Caspiche
resource and flowsheet. McClelland Laboratories is
investigating possible heap leaching of the lower copper grade MacNeill zone, providing the potential to convert up to
60Mt of material currently classified as waste into ore. The Company is also
investigating in detail, up to 160MT of other lower grade material with
similar potential to be converted to ore.
The Company has engaged SGS Lakefield to start the
first program to optimise the flotation reagent
regime for Caspiche sulfides. To date the Company
has used a "standard" flotation regime that may not optimise copper recovery. In addition, the Company will
shortly initiate work to investigate the possible use of High Pressure
Grinding Rolls ("HPGR"), a grinding alternative that has the
potential to reduce power consumption and improve mineral liberation. A
drilling campaign to recover fresh drill core for the HPGR testwork is planned.
Mr. Jerry Perkins, Exeter's Vice President
Operations and Development and a "qualified person" within the
definition of that term in National Instrument 43-101, Standards of
Disclosure for Mineral Projects, has supervised the preparation of the
technical information contained in this news release.
About Exeter
Exeter Resource Corporation, with a treasury of $85 million, is a Canadian
mineral exploration company focused on the exploration and development of the
Caspiche project in Chile. The project is situated
in the Maricunga gold district, between the Refugio
mine (Kinross Gold Corp.) and the giant Cerro Casale
gold deposit (Barrick Gold Corp. and Kinross Gold
Corp.).. The discovery represents one of the largest mineral discoveries made
in Chile in recent years. Exeter has initiated pre-feasibility studies with
the aim of demonstrating the commercial viability of this world class
discovery.
You are invited to visit the Exeter web site at www.exeterresource.com.
EXETER RESOURCE CORPORATION
Bryce Roxburgh
President and CEO
For further information, please contact:
B. Roxburgh, President or
Rob Grey, VP Corporate Communications
Tel: 604.688.9592 Fax: 604.688.9532
Toll-free: 1.888.688.9592
|
Suite 1660, 999 West
Hastings St.
Vancouver, BC Canada V6C 2W2
exeter@exeterresource.com
|
Safe Harbour Statement -
This news release contains "forward-looking information" and
"forward-looking statements" (together, the "forward-looking
statements") within the meaning of applicable securities laws and the
United States Private Securities Litigation Reform Act of 1995, the Company's
belief as to the extent and timing of its PFS, drilling programs, various
studies including engineering, environmental, infrastructure and other
studies, and exploration results, budgets for its exploration programs, the
potential tonnage, grades and content of deposits, timing, establishment and
extent of resources estimates, potential for financing its activities,
potential production from and viability of its properties, permitting
submission and timing and expected cash reserves. These forward-looking
statements are made as of the date of this news release. Readers are
cautioned not to place undue reliance on forward-looking statements, as there
can be no assurance that the future circumstances, outcomes or results
anticipated in or implied by such forward-looking statements will occur or
that plans, intentions or expectations upon which the forward-looking
statements are based will occur. While the Company has based these
forward-looking statements on its expectations about future events as at the
date that such statements were prepared, the statements are not a guarantee
that such future events will occur and are subject to risks, uncertainties,
assumptions and other factors which could cause events or outcomes to differ
materially from those expressed or implied by such forward-looking
statements. Such factors and assumptions include, among others, the effects
of general economic conditions, the price of gold, silver and copper,
availability of water, changing foreign exchange rates and actions by
government authorities, uncertainties associated with legal proceedings and
negotiations and misjudgements in the course of
preparing forward-looking information. In addition, there are known and
unknown risk factors which could cause the Company's actual results,
performance or achievements to differ materially from any future results,
performance or achievements expressed or implied by the forward-looking
statements. Known risk factors include risks associated with the ability to
obtain any necessary approvals, waivers, consents and other requirements
necessary or desirable to permit or facilitate the proposed Arrangement, the
risk that any applicable conditions of the proposed transaction may not be
satisfied, risks associated with project development; the need for additional
financing; operational risks associated with mining and mineral processing;
fluctuations in metal prices; title matters; uncertainties and risks related
to carrying on business in foreign countries; environmental liability claims
and insurance; reliance on key personnel; the potential for conflicts of
interest among certain officers, directors or promoters of the Company with certain
other projects; the absence of dividends; currency fluctuations; competition;
dilution; the volatility of the Company's common share price and volume; tax
consequences to U.S. investors; and other risks and uncertainties, including
those described in the Company's Annual Information Form for the financial
year ended December 31, 2009, dated March 30, 2010 filed with the Canadian
Securities Administrators and available at www.sedar.com. Although the
Company has attempted to identify important factors that could cause actual
actions, events or results to differ materially from those described in
forward-looking statements, there may be other factors that cause actions,
events or results not to be as anticipated, estimated or intended.. There can be no assurance that forward-looking
statements will prove to be accurate, as actual results and future events
could differ materially from those anticipated in such statements.
Accordingly, readers should not place undue reliance on forward-looking
statements. The Company is under no obligation to update or alter any
forward-looking statements except as required under applicable securities
laws.
Cautionary Note to United States Investors - The information contained herein
and incorporated by reference herein has been prepared in accordance with the
requirements of Canadian securities laws, which differ from the requirements
of United States securities laws. In particular, the term
"resource" does not equate to the term "reserve". The
Securities Exchange Commission's (the "SEC") disclosure standards
normally do not permit the inclusion of information concerning "measured
mineral resources", "indicated mineral resources" or
"inferred mineral resources" or other descriptions of the amount of
mineralization in mineral deposits that do not constitute
"reserves" by U.S., unless such information is required to be
disclosed by the law of the Company's jurisdiction of incorporation or of a
jurisdiction in which its securities are traded. U.S. investors should also
understand that "inferred mineral resources" have a great amount of
uncertainty as to their existence and great uncertainty as to their economic
and legal feasibility. Disclosure of "contained ounces" is
permitted disclosure under Canadian regulations; however, the SEC normally
only permits issuers to report mineralization that does not constitute
"reserves" by SEC standards as in place tonnage and grade without
reference to unit measures.
NEITHER THE TSX NOR ITS REGULATION
SERVICES PROVIDER (AS THAT TERM IS DEFINED IN THE POLICIES OF THE TSX
EXCHANGE) ACCEPTS RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THIS NEWS
RELEASE