DENVER, Aug. 13, 2019 /PRNewswire/ -- Vista Gold
Corp. (NYSE American and TSX: VGZ) ("Vista" or the "Company") today
announced the completion of its metallurgical testing program and
reported final leach test results for its Mt Todd gold project
located in Northern Territory, Australia.
Results of this comprehensive metallurgical program are based on
testing completed on 71 samples of material from the Batman
deposit, representing various head grades and a wide range of grind
sizes. Results confirm:
- Average gold recoveries are in the low-90% range, compared to
86.4% in the Preliminary Feasibility Study dated effective
January 24, 2018 (as defined
below);
- Grinding to 80% passing (P80) 40 microns results in higher gold
recoveries across all grade ranges; and
- Additional higher gold recoveries correlate to higher grade
feed material.
Frederick H. Earnest, President
and Chief Executive Officer, commented, "We are pleased with the
results of the comprehensive metallurgical testing program. The
average gold recoveries at a finer grind size continue to reflect
the predictable nature of the deposit observed in previous
programs. We expect these results to positively impact the
economics of the Mt Todd gold project. Our analysis indicates that
each 1% improvement in gold recovery results in approximately a
0.6% increase in IRR and a US$27
million increase in the NPV5%. In addition to the
improvement in gold recovery, this metallurgical program provides
us with the engineering information to make modest changes in the
process flowsheet to reflect the finer grind size. We are now
focused on completing an updated preliminary feasibility study that
will also incorporate current equipment prices, consumable supply
costs, and foreign exchange rates. We have hired an independent
engineering firm to complete a benchmarking study for our internal
use in the review of the preliminary feasibility study results due
to be announced later this quarter."
Metallurgical Testing Program Description and Results
The metallurgical testing program was conducted on bulk samples
from the Batman deposit with gold grades in the following ranges:
greater than 1.5 grams gold per tonne ("g Au/t"), 1.0 to 1.5 g
Au/t, 0.8 to 1.0 g Au/t, 0.6 to 0.8 g Au/t, 0.4 to 0.6 g Au/t, and
less than 0.4 g Au/t (lower than cut-off grade). All samples were
HPGR crushed, screened and sorted at testing facilities in
Germany. Subsequently, they were
shipped to Denver, Colorado where
samples were prepared by Resource Development Inc. ("RDi"). Fine
grinding tests were completed at FLSmidth in Salt Lake City, Core Metallurgical Labs in
Perth, and SGS Laboratories near
Toronto. Fine grinding was
completed to simulate results from VXP mills and IsaMills. In
addition to providing samples for subsequent leach testing, these
tests provided engineering information to support the preparation
of an updated preliminary feasibility study. Standard leach tests
reflective of the proposed Mt Todd process flowsheet were completed
at RDi with assays completed by Florin Analytical Services in
Reno.
The following tables summarize the leach test results of 71
samples:
|
Test
#
|
Particle
Size (P80)
|
% Recovery
(Au)
|
Calc. Head
Grade (Au
g/mt)
|
Residue
Grade (Au
g/mt)
|
|
+1.5g
Au/t
|
|
BR113
|
101
|
86.1
|
1.77
|
0.25
|
|
BR114
|
101
|
85.4
|
1.77
|
0.26
|
|
BR119
|
91
|
87.6
|
1.82
|
0.23
|
|
BR120
|
91
|
88.9
|
1.74
|
0.19
|
|
BR117
|
76
|
87.3
|
1.74
|
0.22
|
|
BR118
|
76
|
87.0
|
1.70
|
0.22
|
|
BR116
|
74
|
87.0
|
1.70
|
0.22
|
|
BR115
|
74
|
86.4
|
1.67
|
0.23
|
|
BR153(1)
|
53
|
93.6
|
1.96
|
0.12
|
|
BR154(1)
|
53
|
93.6
|
1.90
|
0.12
|
|
BR196
|
31
|
90.3
|
1.73
|
0.17
|
|
BR195
|
31
|
90.4
|
1.69
|
0.16
|
|
BR204
|
22
|
93.1
|
1.70
|
0.12
|
|
BR205
|
22
|
93.0
|
1.63
|
0.11
|
|
BR201
|
19
|
91.8
|
1.56
|
0.13
|
|
<53 micron
average values
|
92.3
|
|
0.13
|
|
Test
#
|
Particle
Size (P80)
|
% Recovery
(Au)
|
Calc. Head
Grade (Au
g/mt)
|
Residue
Grade (Au
g/mt)
|
|
>=1.0g Au/t
< 1.5g Au/t
|
|
BR122
|
97
|
84.6
|
1.24
|
0.19
|
|
BR121
|
97
|
86.6
|
1.20
|
0.16
|
|
BR123
|
74
|
89.1
|
1.26
|
0.14
|
|
BR124
|
74
|
87.5
|
1.21
|
0.15
|
|
BR144
|
59
|
84.9
|
1.21
|
0.18
|
|
BR143
|
59
|
84.8
|
1.17
|
0.18
|
|
BR197
|
29
|
90.4
|
1.21
|
0.12
|
|
BR198
|
29
|
90.1
|
1.16
|
0.11
|
|
BR206
|
20
|
92.7
|
1.10
|
0.08
|
|
BR207
|
20
|
92.7
|
1.09
|
0.08
|
|
<53 micron
average values
|
91.5
|
|
0.10
|
|
Test
#
|
Particle
Size (P80)
|
% Recovery
(Au)
|
Calc. Head
Grade (Au
g/mt)
|
Residue
Grade (Au
g/mt)
|
|
>=0.8g Au/t
< 1.0g Au/t
|
|
BR126
|
87
|
85.5
|
0.88
|
0.13
|
|
BR125
|
87
|
86.5
|
0.87
|
0.12
|
|
BR128
|
79
|
88.4
|
0.89
|
0.10
|
|
BR127
|
79
|
87.4
|
0.86
|
0.11
|
|
BR147
|
69
|
85.5
|
0.95
|
0.14
|
|
BR148
|
69
|
85.0
|
0.91
|
0.14
|
|
BR130
|
69
|
86.9
|
0.86
|
0.11
|
|
BR129
|
69
|
89.1
|
0.83
|
0.09
|
|
BR158
|
59
|
87.4
|
0.93
|
0.12
|
|
BR199
|
35
|
89.5
|
0.9
|
0.09
|
|
BR200
|
35
|
89.6
|
0.85
|
0.09
|
|
BR209
|
22
|
91.8
|
0.88
|
0.07
|
|
BR208
|
22
|
91.9
|
0.84
|
0.07
|
|
<53 micron
average values
|
90.7
|
|
0.08
|
|
Test
#
|
Particle
Size (P80)
|
% Recovery
(Au)
|
Calc. Head
Grade (Au
g/mt)
|
Residue
Grade (Au
g/mt)
|
|
>=0.6g Au/t
< 0.8g Au/t
|
|
BR104
|
70
|
85.3
|
0.63
|
0.09
|
|
BR105
|
70
|
84.9
|
0.61
|
0.09
|
|
BR106
|
70
|
84.1
|
0.61
|
0.10
|
|
BR157
|
59
|
88.5
|
0.77
|
0.09
|
|
BR162(1)
|
52
|
92.3
|
0.73
|
0.06
|
|
BR161(1)
|
52
|
91.4
|
0.72
|
0.06
|
|
BR96
|
49
|
89.9
|
0.68
|
0.07
|
|
BR95
|
49
|
89.6
|
0.66
|
0.07
|
|
BR97
|
49
|
89.5
|
0.66
|
0.07
|
|
BR101
|
39
|
90.5
|
0.65
|
0.06
|
|
BR102
|
39
|
90.9
|
0.64
|
0.06
|
|
BR103
|
39
|
90.4
|
0.64
|
0.06
|
|
BR100
|
36
|
92.1
|
0.79
|
0.06
|
|
BR98
|
36
|
88.3
|
0.70
|
0.08
|
|
BR99
|
35
|
89.7
|
0.73
|
0.08
|
|
BR109
|
18
|
94.0
|
0.69
|
0.04
|
|
BR107
|
18
|
89.4
|
0.68
|
0.07
|
|
BR108
|
18
|
93.8
|
0.66
|
0.04
|
|
BR111
|
15
|
91.0
|
0.61
|
0.06
|
|
BR110
|
15
|
92.0
|
0.60
|
0.05
|
|
BR112
|
15
|
90.9
|
0.60
|
0.06
|
|
<53 micron
average values
|
90.9
|
|
0.06
|
|
Test
#
|
Particle
Size (P80)
|
% Recovery
(Au)
|
Calc. Head
Grade (Au
g/mt)
|
Residue
Grade (Au
g/mt)
|
|
>=0.4g Au/t
< 0.6g Au/t
|
|
BR131
|
59
|
84.8
|
0.46
|
0.07
|
|
BR132
|
59
|
86.2
|
0.46
|
0.06
|
|
BR165
|
56
|
83.6
|
0.52
|
0.08
|
|
BR166
|
56
|
85.0
|
0.52
|
0.08
|
|
BR210
|
22
|
88.5
|
0.42
|
0.05
|
|
BR211
|
22
|
89.0
|
0.41
|
0.05
|
|
<53 micron
average values
|
88.8
|
|
0.05
|
|
Test
#
|
Particle
Size (P80)
|
% Recovery
(Au)
|
Calc. Head
Grade (Au
g/mt)
|
Residue
Grade (Au
g/mt)
|
|
< 0.4g
Au/t (below cutoff)
|
|
BR167
|
60
|
81.6
|
0.18
|
0.03
|
|
BR212
|
60
|
80.6
|
0.18
|
0.03
|
|
BR213
|
49
|
85.8
|
0.32
|
0.05
|
|
BR168
|
49
|
78.5
|
0.21
|
0.04
|
|
BR133
|
21
|
87.5
|
0.26
|
0.03
|
|
BR134
|
21
|
86.9
|
0.26
|
0.03
|
|
<53 micron
average values
|
84.7
|
|
0.04
|
|
|
|
(1)
|
Previously reported
in the May 29, 2019 press release.
|
Qualified Person
Deepak Malhotra, on behalf of
Resource Development Inc., 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 (the "Preliminary
Feasibility Study"), 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 gold project developer. Our principal asset is
our flagship Mt Todd gold project in Northern Territory,
Australia. Mt Todd is the largest undeveloped gold project in
Australia.
For further information, please contact Pamela Solly, Vice President of Investor
Relations, 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 belief that recoveries in the low 90% range may be achieved
for the Mt Todd gold project; our belief that the testing results
show higher recoveries at finer grind sizes; timing and completion
of an updated preliminary feasibility study incorporating the
results of the completed metallurgical testing program; and that
actual results will be consistent with test work results 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: test results
are indicative of actual results, 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 it operates; risks due to legal proceedings; risks relating
to political and economic instability in certain countries in which
it 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 in
February 2019 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.
