VANCOUVER, April 17, 2018 /CNW/ - Bonterra Resources
Inc. (TSX-V: BTR, OTCQX: BONXF, FSE: 9BR1) (the "Company" or
"Bonterra") is pleased to announce that it has received highly
positive results for its preliminary metallurgical testwork, which
forms part of its ongoing Resource Development Program at its 100%
controlled Gladiator Gold Deposit in Quebec, Canada. Results to date show total
gold recoveries of up to 99.4%, including 76.1% from the Gravity
circuit.
"The outstanding metallurgical results, when compared
to the overall average lower recoveries within our industry peer
group, are a significant milestone for the Gladiator Gold Deposit.
The exceptional gravity recovery rates of up to 76.1%,
combined with a simple flotation circuit, may reduce capital
requirements related to a future potential milling operation,"
commented Nav Dhaliwal, CEO of
Bonterra. "Potentially not requiring a cyanide leaching
circuit minimizes the environmental footprint of any future mining
operation and could also improve potential future process
economics of the project."
Highlights and Observations:
- The combination of gravity and gravity-cyanide tests resulted
in significant gold recoveries of 99.0% to 99.4%.
- The combination of gravity and gravity-tail flotation tests
resulted in significant gold recoveries of 96.8% to
97.3%.
- Excellent gravity concentrate recoveries, ranging from 68.3%
to 76.1%, are well above the average of Bonterra's industry
peers and confirm the presence of a significant amount of
free gold in the mineralized system.
- Average >70% of the gold reported to the Gravity
circuit at all grinding test sizes, indicating substantial
potential capital and operating savings in the grinding
circuits.
- A cyanide leaching circuit may not be required, noting
the high recovery of the gold from the gravity and
gravity-tail flotation tests.
- Head assay results from the metallurgical testing ranged from
8.0 g/t Au to 10.0 g/t Au and showed excellent grade reconciliation
with initial drill hole assays.
"As expected, preliminary metallurgical test results
confirmed excellent gold recoveries. On average, greater than 70%
of the gold reports to the gravity circuit at all grinding sizes,
which potentially contributes to substantial capital reductions in
the grinding circuits, potential lower reagent consumption, and
highlights an opportunity for significant savings in the future
processing parameters at Gladiator," commented Peter A. Ball, VP Operations. "The simple
metallurgy, consisting of potentially only a crushing and grinding
circuit to achieve 76.1% recovery, provides a low CapEx/OpEx
process to pour gold bullion on site. Adding a flotation circuit
could yield up to 97.3% recovery and deliver a very high grade gold
concentrate, making material very compatible and easily transported
to a local or a centralized standard milling facility."
Metallurgical Program Review
ALS Metallurgy ("ALS") of Kamloops, British Columbia, was contracted to
complete Gravity Concentration, Flotation and Cyanide leach testing
for the Gladiator Gold Deposit. The studies included grind
optimization, gravity separation, flotation, and cyanide leach
testing, and were intended to provide an initial look at the
characteristics of mineralization to help guide future optimization
test work and processing flow sheet specifications.
Overall, the metallurgical testing and microscopic analysis
indicate that the mineralization is relatively simple with no
deleterious elements, and pre-concentration could potentially be
achieved by a low capital intensive processing sequence, which will
likely include crushing, grinding, gravity concentration and
flotation. The process is a relatively benign one, and also offers
potential environmental permitting advantages, as well as
significant savings in transportation costs. These results are part
of an ongoing comprehensive metallurgical program
designed to define the processing parameters, establish
grade-recovery relationships and optimize gold recovery for a
potential future Gladiator milling facility.
ALS completed testing on approximately 35 kg of composite sample
from the Main Zone with an average head grade of 9.0 g/t Au from
two wide diameter holes MT-18-01 and MT-18-02. The composite sample
was selected to be representative of the deposit mineralization
based on mineralogy, grade and location. Head assay results from
the metallurgical testing ranged from 8.0 g/t Au to 10.0 g/t Au and
showed excellent grade reconciliation with initial drill hole
assays.
Four kg of the sample, at three different grind sizings, were
submitted for gravity separation using a Knelson concentrator. Gold
recovery by the Knelson gravity separation was followed by hand
panning to produce a final gravity concentrate mass that is more
representative of plant operation. The pan concentrate, pan
tailings, and Knelson concentrator tails were assayed for gold and
determined that gold in the samples were highly amenable to gravity
recovery.
Results of the Gravity concentration gold recovery tests are
summarized below:
Test
|
Size
|
Feed
Grade
(g/t
Au)
|
Knelson
Tails
(%)
|
Pan
Tails
(%)
|
Pan
Concentrate
(%)
|
Pan
Concentrate
(g/t
Au)
|
1
|
169 mm
K80
|
9.19
|
20.0
|
11.7
|
68.3
|
3,627
|
2
|
136 mm
K80
|
9.86
|
13.6
|
11.9
|
74.5
|
4,437
|
3
|
83 mm
K80
|
8.70
|
13.0
|
10.8
|
76.1
|
6,461
|
Results of the Flotation concentration gold recovery tests are
summarized below:
Test
|
Size
|
Feed
Grade
(g/t
Au)
|
Gravity
Recovery
Distribution %
|
Rougher
Recovery
Distribution
%
|
Total Recovery
-
Distribution %
|
Au
|
S
|
Au
|
S
|
Au
|
S
|
4
|
169 mm
K80
|
10.0
|
73.0
|
18.8
|
23.5
|
72.0
|
96.5
|
90.8
|
5
|
136 mm
K80
|
8.00
|
70.9
|
17.1
|
26.0
|
73.9
|
96.8
|
91.0
|
6
|
83 mm
K80
|
8.28
|
73.8
|
13.0
|
23.5
|
78.5
|
97.3
|
88.2
|
Results of the Cyanide concentration gold recovery tests are
summarized below:
Test
|
Size
|
Leach Feed
(Gravity Tails)
|
Au
Recovery
Gravity
(%)
|
Leach
Extraction
(%)
|
Au Recovery
Gravity Tails
(%)
|
Au
Recovery
Total
(%)
|
7
|
169 mm
K80
|
Test 1
|
68.3
|
30.7
|
30.7
|
99.0
|
8
|
136 mm
K80
|
Test 2
|
74.5
|
24.9
|
24.9
|
99.4
|
9
|
83 mm
K80
|
Test 3
|
76.1
|
23.1
|
23.1
|
99.2
|
A kinetic rougher test was included in each flotation feed
sizing. This test determined that gold in the samples is highly
amenable to recovery using a standard froth flotation circuit.
Gravity plus cyanidation leach tests were completed, and it was
determined that gold in the samples responded excellent to
conventional leaching. Three of the tests were conducted on the
samples at each grind sizing, and three of the tests were conducted
on the rougher flotation tailings.
Bonterra is currently completing a Resource Development Program
in 2018 at the Gladiator Gold Deposit, including approximately
70,000 m of drilling, metallurgical
studies, and a Mineral Resource update.
Bonterra Resources Quick Facts:
- Well financed with approximately $60
million raised in past 14 months.
- Strong Shareholder Base including: Eric Sprott, Van
Eck, Kirkland Lake Gold
- Gladiator Gold Deposit:
-
- Deposit extension and resource expansion underway with
60,000 m completed in 2017 and
70,000 m planned for 2018.
- Advancing to the completion of an updated NI 43-101 Mineral
Resource Estimate in the second half of 2018.
- Drilled dimensions of the Gladiator Gold Deposit are currently
outlined to a depth of 1,000 m below
surface, and a strike length of 1,200
m.
- Gladiator remains open in all directions, where at least six
distinct sub-parallel zones or mineralized horizons have been
identified.
- Drilling is currently focused on the continued expansion of
Gladiator Gold Deposit and exploration targets within the
10,541-hectare Urban-Barry property.
- Larder Lake Gold Property:
-
- 100% controlled 2,221-hectare in the Cadillac-Larder Break camp
in Ontario (refer to March 17, 2016 news release highlighting
historical gold resource).
- Excellent access to three high grade gold deposits between
Kirkland Lake and Virginiatown.
Robert Gagnon, P.Geo., has
approved the information contained in this release. Mr.
Gagnon is a director of Bonterra and is a Qualified Person as
defined by NI 43-101.
ON BEHALF OF THE BOARD OF DIRECTORS,
Nav Dhaliwal, President &
CEO
Bonterra Resources Inc.
Neither TSX Venture Exchange nor its Regulation Services
Provider (as that term is defined in the policies of the TSX
Venture Exchange) accepts responsibility for the adequacy or
accuracy of this release.
This press release contains "forward-looking information"
that is based on Bonterra's current expectations, estimates,
forecasts and projections. This forward-looking information
includes, among other things, statements with respect to Bonterra's
exploration and development plans. The words "will", "anticipated",
"plans" or other similar words and phrases are intended to identify
forward-looking information. Forward-looking information is
subject to known and unknown risks, uncertainties and other factors
that may cause Bonterra's actual results, level of activity,
performance or achievements to be materially different from those
expressed or implied by such forward-looking information. Such
factors include, but are not limited to: uncertainties related
exploration and development; the ability to raise sufficient
capital to fund exploration and development; changes in economic
conditions or financial markets; increases in input costs;
litigation, legislative, environmental and other judicial,
regulatory, political and competitive developments; technological
or operational difficulties or inability to obtain permits
encountered in connection with exploration activities; and labour
relations matters. This list is not exhaustive of the factors that
may affect our forward-looking information. These and other factors
should be considered carefully, and readers should not place undue
reliance on such forward-looking information. Bonterra disclaims
any intention or obligation to update or revise forward-looking
information, whether as a result of new information, future events
or otherwise.
SOURCE Bonterra Resources Inc.