TORONTO, July 9, 2019 /CNW/ - Anaconda
Mining Inc. ("Anaconda" or the "Company") (TSX: ANX) (OTCQX: ANXGF)
is pleased to announce that a metallurgical test program (the "Met
Program") that is being conducted as part of the planned
feasibility study for the Goldboro Gold Project ("Goldboro", or the
"Project") has returned extremely high processing recoveries in a
range of 87%-99%. The Met Program was completed at Base
Metallurgical Laboratories Ltd. in Kamloops, BC and under supervision of Ausenco
Engineering Canada Inc., which is leading the Goldboro mineral processing plant design.
Highlights of the metallurgical testing program include:
- High overall gold recoveries from samples tested averaged 97%
with a range from 87% to 99%, with a range of 8% to 97% recovered
by the gravity circuit;
- All tests showed low reagent consumption;
- No deleterious elements were found within the Goldboro samples which contained approximately
3% sulphide minerals;
- In more than 70% of the samples (5 out of 7), the calculated
head grade exceeded the value returned from the samples' metallic
screen assays;
- This testing confirmed that cyanide destruction and arsenic
removal systems would achieve water quality that meets the Federal
Environmental Code of Practice for Metal Mines and the Metal Mining
Effluent Regulations (MMER) discharge criteria.
"We are excited to see that the metallurgical testing
completed to support the Goldboro
feasibility Study is confirming even higher recoveries than testing
performed in 2017 as part of the previously released positive
Preliminary Economic Analysis. This is a very important milestone
that paves the road to finalizing the Goldboro plant design and overall project
feasibility, which is expected to be completed mid Q4
2019. We look forward to further progress in 2019 with
the continuation of permitting, with the aim of obtaining the
requisite permits to begin construction in 2020."
~ Kevin Bullock, Chief
Executive Officer, Anaconda Mining Inc.
The objective of the Met Program was to determine a flow sheet
that optimizes gold recovery while minimizing reagent consumptions
via gravity processing followed by leaching, as well as to assess
the effect of grind on gold recovery by gravity and leach-CIP
processes. The Met Program included comminution testing, grind
optimization, gravity concentration, leach testing, cyanide
destruction and arsenic precipitation. Cyanide destruction and
arsenic precipitation development was also completed to generate
samples for environmental and geotechnical characterization studies
in support of continued environmental permitting. No deleterious
elements were found within the Goldboro samples which contained approximately
3% sulphide minerals.
Anaconda obtained seven samples from the Boston Richardson (Low,
Medium and High Grade) and East Goldbrook (EG1, EG2, EG3 and EG4)
mineral resource areas and made composites by grade and to
spatially represent their respective resource areas. The gold feed
grades of the samples, determined by screened metallics protocol,
ranged from 0.6 grams per tonne ("g/t") to 12 g/t Au. The purpose
of testing a wide range of gold grades was to ascertain plant
recoveries over the entire project life as grades will be
relatively lower during the open pit mining period as compared to
the higher-grade underground mining portion, which represents the
majority of the mine life.
Crushing and Grinding Testing:
Detailed comminution testing characterized ore hardness by Bond
Low Energy Impact Crushing Work Index (CWI), SMC Test, and Bond Rod
Mill Work Index (RWI), Bond Ball Mill Work Index (BWI) and Bond
Abrasion Index (AI). The composites tested fell in the range of
36.8 to 79.4 A x b through SMC tests, with a Bond Ball Mill Work
Index median of 15.7 kWh/t which spanned the medium to medium hard
range of hardness.
Gravity Testing:
Samples from the Boston Richardson zone were tested with the
Extended Gravity Recoverable Gold (E-GRG) protocol to determine
their amenability to gravity concentration. The results showed very
high Gravity Recoverable Gold (GRG) numbers, which ranged from 78
to 98% Au. The GRG value does not directly predict or correlate
gold recovery results from a closed-circuit milling operation. It
is indicative of gravity gold amenability and in this scenario all
three samples would benefit from the inclusion of a gravity
circuit.
Leach Testing:
Leach conditions were evaluated over a range of grind sizes
(from 80% passing 250 μm to 80% passing 60 μm) and leach retention
times up to 48 hours. Leach tests were preceded by batch gravity
concentration to replicate plant conditions. The optimal grind size
was found to be 80% passing 100 to 110 μm. Leach recovery was not
overly sensitive to fineness of grind. Under optimized conditions
(cyanide maintained at 0.5 g/L as NaCN) reagent consumption is low,
with sodium cyanide (NaCN) and lime (CaO) averaging 0.14 kg/t and
0.53 kg/t, respectively.
Initial kinetic screening tests include batch gravity recoveries
ranging from 8% Au to 97% Au and overall leach recoveries ranging
from 86% to 98% for overall recoveries ranging from 87% Au to 99%
Au. Leach tests were run over 48 hours.
Optimization Testing and Detailed Results:
Optimization tests were run at the optimal grind and at reduced
cyanide concentrations of 0.5 g/L NaCN at 50% solids for 24 to 36
hours. The results show in the table below combined gravity/leach
gold extractions of 94% Au to 99% Au with a final residue values of
0.07 g/t Au to 0.46 g/t Au for the Boston Richardson Ore types and
87 to >99% with final residues 0.04 g/t Au to 0.20 g/t Au for
East Goldbrook samples. Calculated head grades ranged from 5.0 g/t
Au to 17.1 g/t Au for the Boston Richardson samples and from 0.90
g/t Au to 21 g/t Au for the East Goldbrook samples. The
metallurgical testing shows an increase of 44 % in the calculated
head grade versus samples Screen Metallics.
|
|
|
|
|
Au
Grade
|
Recovery
(%)
|
Zone
|
Sample
ID
|
NaCN
(g/L)
|
Grind
(µm)
|
Consumption (kg/t)
|
Screen Metallics
Head Grade
|
Calc. Head
Grade
|
Residue
|
Batch
Gravity
|
Leach Kinetics
(hours)
|
Combined
|
NaCN
|
CaO
|
g/t
|
|
g/t
|
Au
|
2
|
6
|
24
|
48
|
Au
|
Boston
Richardson
|
LG Comp
|
1.0
|
121
|
0.41
|
0.36
|
11.1
|
2.24
|
0.09
|
53.6
|
46.1
|
74.1
|
91.4
|
91.4
|
96.0
|
LG Comp
|
1.0
|
108
|
0.54
|
0.45
|
11.1
|
3.34
|
0.07
|
37.8
|
35.2
|
55.4
|
86.6
|
96.4
|
97.8
|
MG Comp
|
1.0
|
118
|
0.58
|
0.47
|
3.07
|
4.97
|
0.13
|
18.3
|
28.3
|
46.6
|
82.6
|
96.7
|
97.3
|
MG Comp
|
1.0
|
101
|
0.47
|
0.59
|
3.07
|
3.66
|
0.06
|
14.3
|
27.0
|
68.3
|
98.4
|
98.1
|
98.3
|
MG Comp
|
1.0
|
118
|
0.45
|
0.52
|
3.07
|
4.97
|
0.15
|
18.3
|
60.4
|
78.0
|
94.1
|
92.4
|
93.8
|
HG Comp
|
1.0
|
121
|
0.86
|
0.46
|
12.0
|
12.9
|
0.27
|
18.4
|
40.9
|
57.5
|
96.5
|
97.4
|
97.9
|
HG Comp
|
1.0
|
121
|
0.55
|
0.40
|
12.0
|
23.9
|
0.46
|
45.2
|
33.6
|
49.4
|
78.4
|
96.5
|
98.1
|
HG Comp
|
1.0
|
99
|
0.99
|
0.46
|
12.0
|
17.1
|
0.25
|
60.9
|
42.9
|
60.8
|
96.5
|
96.3
|
98.5
|
HG Comp
|
1.0
|
99
|
0.52
|
0.49
|
12.0
|
17.1
|
0.29
|
60.9
|
43.4
|
59.9
|
96.5
|
96.4
|
98.6
|
East
Goldbrook
|
EG1 Comp
|
1.00
|
104
|
0.26
|
0.58
|
2.62
|
2.13
|
0.14
|
16.0
|
37.1
|
50.9
|
92.1
|
94.6
|
95.4
|
EG1 Comp
|
0.50
|
104
|
0.12
|
0.53
|
2.62
|
2.13
|
0.07
|
16.0
|
54.0
|
64.7
|
91.4
|
93.2
|
94.3
|
EG2 Comp
|
1.00
|
105
|
0.24
|
0.58
|
2.34
|
3.01
|
0.20
|
44.6
|
58.0
|
75.5
|
89.6
|
89.9
|
94.4
|
EG2 Comp
|
0.50
|
105
|
0.15
|
0.52
|
2.34
|
3.01
|
0.10
|
44.6
|
61.8
|
74.5
|
89.4
|
93.2
|
96.2
|
EG3 Comp
|
1.00
|
80
|
0.27
|
0.56
|
4.84
|
21
|
0.15
|
85.0
|
66.0
|
80.7
|
95.0
|
95.2
|
99.3
|
EG3 Comp
|
0.50
|
80
|
0.18
|
0.60
|
4.84
|
21
|
0.09
|
85.0
|
57.8
|
72.7
|
97.2
|
97.2
|
99.6
|
EG4 Comp
|
1.00
|
103
|
0.23
|
0.44
|
0.62
|
0.90
|
0.12
|
7.7
|
68.5
|
81.1
|
85.5
|
86.3
|
87.4
|
EG4 Comp
|
0.50
|
103
|
0.10
|
0.46
|
0.62
|
0.90
|
0.04
|
7.7
|
59.8
|
76.3
|
94.3
|
95.3
|
95.6
|
Bulk
|
Bulk Comp
|
1.0
|
150
|
0.42
|
0.84
|
-
|
143
|
0.22
|
97.0
|
63.1
|
97.8
|
103
|
94.7
|
99.8
|
Bulk Comp
|
1.0
|
100
|
0.53
|
0.86
|
-
|
3.12
|
0.08
|
32.4
|
52.6
|
81.3
|
88.4
|
96.1
|
97.4
|
Bulk Comp
|
1.0
|
75
|
0.57
|
0.78
|
-
|
4.55
|
0.08
|
57.0
|
67.2
|
97.9
|
104
|
95.8
|
98.2
|
The Bulk Composite was assembled from the Boston Richardson
samples and three of the East Goldbrook samples (EG1, EG2 and EG3)
to provide a large sample for continuous cyanide destruction
tests.
Plant recoveries for the Feasibility Study will be estimated
using grades from the Mine Plan along with typical plant
losses.
Cyanide Destruction:
Cyanide destruction using the SO2/air method testing
with batch and continuous testing demonstrated that a weak acid
dissociable cyanide (CNWAD) below 3 mg/L could be
achieved with 45 minutes of retention time using a conventional
ratio of 5g SO2/g CNWAD.
Arsenic precipitation of the Cyanide Destruction product with
ferric sulphate reduced arsenic in solution to below 0.5 mg/L and
less than 0.1 mg/L can be attained. Addition rates of ferric
sulphate were in line with industrial practice at 10:1 iron to
arsenic. This testing confirms that cyanide destructions and
arsenic removal systems would achieve water quality that meets the
Federal Environmental Code of Practice for Metal Mines and the
Metal Mining Effluent Regulations (MMER) discharge criteria.
This news release has been reviewed and approved by
Robert Raponi, P. Eng. of Ausenco
Engineering Canada Inc., a "Qualified Person", under National
Instrument 43-101 Standard for Disclosure for Mineral
Projects.
ABOUT ANACONDA
Anaconda is a TSX and OTCQX-listed gold mining, development, and
exploration company, focused in Atlantic
Canada. The company operates mining and milling operations
in the prolific Baie Verte Mining District of Newfoundland which includes the
fully-permitted Pine Cove Mill, tailings facility and deep-water
port, as well as ~11,000 hectares of highly prospective mineral
lands including those adjacent to the past producing, high-grade
Nugget Pond Mine. Anaconda is also developing the Goldboro Gold
Project in Nova Scotia, a
high-grade resource and the subject of an on-going feasibility
study.
FORWARD-LOOKING STATEMENTS
This news release contains "forward-looking information"
within the meaning of applicable Canadian and United States securities legislation.
Forward-looking information includes, bit is not limited to,
information with respect to the Offering, the use of proceeds and
the TSX acceptance of the Offering. Generally, forward-looking
information can be identified by the use of forward-looking
terminology such as "plans", "expects", or "does not expect", "is
expected", "budget", "scheduled", "estimates", "forecasts",
"intends", "anticipates", or "does not anticipate", or "believes"
or variations of such words and phrases or state that certain
actions, events or results "may", "could", "would", "might", or
"will be taken", "occur", or "be achieved". Forward-looking
information is based on the opinions and estimates of management at
the date the information is made, and is based on a number of
assumptions and is subject to known and unknown risks,
uncertainties and other factors that may cause the actual results,
level of activity, performance or achievements of Anaconda to be
materially different from those expressed or implied by such
forward-looking information, including risks associated with the
exploration, development and mining such as economic factors as
they effect exploration, future commodity prices, changes in
foreign exchange and interest rates, actual results of current
production, development and exploration activities, government
regulation, political or economic developments, environmental
risks, permitting timelines, capital expenditures, operating or
technical difficulties in connection with development activities,
employee relations, the speculative nature of gold exploration and
development, including the risks of diminishing quantities of
grades of resources, contests over title to properties, and changes
in project parameters as plans continue to be refined as well as
those risk factors discussed in Anaconda's annual information form
for the year ended December 31, 2018,
available on www.sedar.com. Although Anaconda has attempted to
identify important factors that could cause actual results to
differ materially from those contained in forward-looking
information, there may be other factors that cause results not to
be as anticipated, estimated or intended. There can be no assurance
that such information will prove to be accurate, as actual results
and future events could differ materially from those anticipated in
such information. Accordingly, readers should not place undue
reliance on forward-looking information. Anaconda does not
undertake to update any forward-looking information, except in
accordance with applicable securities laws.
SOURCE Anaconda Mining Inc.