DENVER, Jan. 9, 2019 /PRNewswire/ -- Vista Gold
Corp. (TSX & NYSE American: VGZ) ("Vista" or the "Company")
today announced that recent high pressure grinding roll ("HPGR")
crusher and ore sorting tests on high-grade samples confirm
previous test results. The Company also announced its plans
to complete fine grinding and leaching tests in the 1st
quarter of 2019 and to follow these results with updated
preliminary feasibility study ("PFS") economics in the
2nd quarter of 2019.
Interim Met Testing Results Confirm Benefits of Ore
Sorting
Additional HPGR and ore sorting tests were completed on two, 2.5
tonne samples from Mt Todd's Batman deposit containing 1.39 and
1.70 grams of gold per tonne ("g Au/t"), respectively. This
testing program confirmed two important results:
- HPGR crushing followed by screening results in increased
concentration of gold in the fine fraction, and
- the small amount of gold lost in the rejected material is
proportionally lower when sorting higher-grade material.
As with previous tests, the samples were HPGR crushed at the
facilities of Thyssen Krupp Industries in Germany and screened at 16 millimeters ("mm"),
approximately 5/8 inches. The coarse fraction (+16mm) was
sent to the facilities of Tomra Sorting Solutions in Germany, where 2-stage (x-ray transmission and
laser) sorting tests were completed using production-sized and
commercially available equipment. The following table
summarizes the results of the testing program for each of the
samples and compares these results to previous bulk tests on
low-grade samples.
Sample
(g
Au/t)
|
Sorter Feed
(+16mm)
|
Sorter
Product
|
Sorter
Reject
|
Gold Loss
(%)
|
Fraction of Total
Sample (%)
|
Grade
(g
Au/t)
|
Fraction of Total
Sample (%)
|
Grade
(g
Au/t)
|
Fraction of Total
Sample (%)
|
Grade
(g
Au/t)
|
1.39
|
17.8%
|
0.731
|
9.4%
|
1.238
|
8.4%
|
0.158
|
1.0%
|
1.70
|
18.6%
|
0.737
|
10.3%
|
1.239
|
8.3%
|
0.110
|
0.7%
|
Previous
Results
|
0.63
|
17.5%
|
0.533
|
10.5%
|
0.817
|
7.0%
|
0.103
|
1.1%
|
0.34
|
17.8%
|
0.255
|
11.0%
|
0.365
|
6.8%
|
0.075
|
1.5%
|
0.67
|
18.7%
|
0.619
|
11.3%
|
0.901
|
7.4%
|
0.192
|
2.0%
|
Frederick H. Earnest, President
and Chief Executive Officer commented, "These tests confirm the
value-adding benefit of ore sorting for the Mt Todd gold project
and demonstrate lower gold losses with higher grade crusher
feed. We attribute these results to the favorable
characteristics of the Batman deposit. Simply stated, the
gold-containing sulfide minerals and quartz/calcite veining are
more easily broken into small particles than the non-mineralized
host rock. Where this breakage does not result in clean
separation from the host rock in the first pass of HPGR crushing,
the gold-bearing minerals are easily identified and separated in
the ore sorting circuit. These results complement our
previously announced fine grinding and leaching test results
(please refer to our August 2, 2018
press release) and we expect that these results will support
additional improvements in the economics of the Mt Todd gold
project when we complete the PFS economics expected in the
2nd quarter of this year."
Met Testing and PFS Update Schedule
The crushed and sorted samples have been transported to the
facilities of Resource Development Inc., where sample preparation
has been completed for assaying and additional fine grinding,
leaching and tailings characterization tests. Samples are
being sent to Core Metallurgy Pty Ltd to obtain additional fine
grinding data simulating grinding in the horizontal IsaMill and to
the FLSmidth Minerals Testing and Research Center to obtain data
simulating grinding in the vertical VPX Mill. Both tests will
target a final product size of 38-45 microns and will generate a
sufficient volume of material for subsequent leach tests. The
fine grinding and leach tests are expected to be completed in the
1st quarter of 2019 with final results expected to be
available in the 2nd quarter of 2019.
The Company has completed additional tailings characterization
tests and concluded that no material design changes are required to
proceed to the economic analysis using a final grind size of 38-45
microns. At this time, the Company anticipates announcing the
results of an updated PFS in the 2nd quarter of
2019.
Mr. Earnest added, "We expect the combination of the recently
improved gold prices, weaker Australian dollar, and improved gold
recovery to have a positive impact on the economics of the Mt Todd
gold project. We anticipate that the planned testing programs
will confirm our ability to achieve a nearly constant tail grade at
the target grind size, which has previously demonstrated gold
recoveries better than 90% with no increase in process area power
requirements."
Qualified Person
Deepak Malhotra, on behalf of
Prosolv Consulting LLC, an independent Qualified Person as defined
by Canadian National Instrument 43-101, supervised the preparation
of the information that forms the basis for the scientific and
technical information disclosed herein and has reviewed this press
release and consented to its release.
For further information on the Mt Todd Gold Project, see the
Technical Report entitled "NI 43-101 Technical Report Mt Todd Gold
Project 50,000 tpd Preliminary Feasibility Study Northern
Territory, Australia," dated
March 2, 2018 with an effective date
of January 24, 2018, which is
available on SEDAR as well as on Vista's website under the
Technical Reports section.
About Vista Gold Corp.
The Company is a well-funded gold project developer. The
Company's principal asset is its flagship Mt Todd gold project in
Northern Territory, Australia. Mt Todd is the largest
undeveloped gold project in Australia.
For further information, please contact the Company at (720)
981-1185.
Forward Looking Statements
This press release
contains forward-looking statements within the meaning of the U.S.
Securities Act of 1933, as amended, and U.S. Securities Exchange
Act of 1934, as amended, and forward-looking information within the
meaning of Canadian securities laws. All statements, other
than statements of historical facts, included in this press release
that address activities, events or developments that we expect or
anticipate will or may occur in the future, including such things
as our plans to complete fine grinding and leaching tests in the
1st quarter of this year and update the PFS economics in
the 2nd quarter of this year; our expectation that with
the combination of the recently improved gold prices, weaker
Australian dollar, and improved gold recovery the updated PFS will
disclose improvements in the economics of the Mt Todd gold project;
our belief that no material design changes are required to proceed
to the economic analysis using a final grind size of 38-45 microns;
our belief that ore sorting for the Mt Todd gold project will
result in lower gold losses with higher grade crusher feed; our
anticipation that the planned testing programs will confirm our
ability to achieve a nearly constant tail grade at the target grind
size, which has previously demonstrated gold recoveries better than
90% with no increase in process area power requirements; our
anticipation that the Company will announce the results of an
updated PFS in the 2nd quarter of this year, are
forward-looking statements and forward-looking information. The
material factors and assumptions used to develop the
forward-looking statements and forward-looking information
contained in this press release include the following: no change to
laws or regulations impacting mine development or mining
activities, our approved business plans, mineral resource
and reserve estimates and results of preliminary economic
assessments, preliminary feasibility studies and feasibility
studies on our projects, if any, our experience with regulators,
our experience and knowledge of the Australian mining industry and
positive changes to current economic conditions and the price of
gold. When used in this press release, the words
"optimistic," "potential," "indicate," "expect," "intend,"
"hopes," "believe," "may," "will," "if," "anticipate," and similar
expressions are intended to identify forward-looking statements and
forward-looking information. These statements involve known
and unknown risks, uncertainties and other factors which may cause
the actual results, performance or achievements of the Company to
be materially different from any future results, performance or
achievements expressed or implied by such statements. Such
factors include, among others, uncertainty of resource and reserve
estimates, uncertainty as to the Company's future operating costs
and ability to raise capital; risks relating to cost increases for
capital and operating costs; risks of shortages and fluctuating
costs of equipment or supplies; risks relating to fluctuations in
the price of gold; the inherently hazardous nature of
mining-related activities; potential effects on our operations of
environmental regulations in the countries in which the Company
operates; risks due to legal proceedings; risks relating to
political and economic instability in certain countries in which
the Company operates; uncertainty as to the results of bulk
metallurgical test work; and uncertainty as to completion of
critical milestones for Mt Todd; as well as those factors discussed
under the headings "Note Regarding Forward-Looking Statements" and
"Risk Factors" in the Company's latest Annual Report on Form 10-K
as filed on March 6, 2018 and other
documents filed with the U.S. Securities and Exchange Commission
and Canadian securities regulatory authorities. Although we
have attempted to identify important factors that could cause
actual results to differ materially from those described in
forward-looking statements and forward-looking information, there
may be other factors that cause results not to be as anticipated,
estimated or intended. Except as required by law, we assume
no obligation to publicly update any forward-looking statements or
forward-looking information; whether as a result of new
information, future events or otherwise.
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SOURCE Vista Gold Corp.