Source:
p. 6
The Back Forty Project is directly owned by the Back Forty Joint Venture LLC (“BFJV”) which controls approximately 3,222 gross acres of surface and mineral rights which are owned or held under lease or option by BFJV.
Summary:
The zinc-copper-gold-silver bearing sulphide mineralization identified on the Property exhibits typical characteristics of VMS mineralization.
Mineralization at the Back Forty deposit consists of discrete zones of: 1) zinc or copperrich massive sulphide (±lead), which may contain significant amounts of gold and silver, 2) stockwork stringer and peripheral sulphide, which can be gold, zinc, and copperbearing (±lead/silver), 3) precious metal-only, low-sulphide mineralization, and 4) oxiderich, precious metal-bearing gossan.
Mining Methods
- Truck & Shovel / Loader
- Mechanized Cut & Fill
- Blast Hole Stoping
- Paste backfill
- Dry waste backfill
Summary:
The Back Forty Project area consists of very subdued terrain and topography. The area, topography and climate are amenable to the conventional open pit mining operations proposed for the Project. No underground mining is planned at this stage although there is future potential for this type of operation.
The mining operation will use a conventional open pit mining method, off-highway trucks, and hydraulic shovels. The waste rock and mineral resource will be drilled and blasted using typical grade control methods and blasthole sampling.
Concepts for underground mining that have been considered to date include:
- Access to the underground workings would be via a portal driven into the high wall of the open pit.
- Development of the portal would commence prior to completion of open pit mining so that the underground mine and open pit would operate concurrently for some period.
- The majority of underground ore would be mined using a bulk method, such as blast hole stoping. For the limited tonnage of ore where greater selectivity was required, mechanized cut and fill would be utilized.
- Mined out stopes would be backfilled with a combination of paste (generated from mill tailings) and waste rock from development. The use of paste fill would minimize the incremental tonnage of tailings delivered to the TSF.
Processing
- Flotation
- Agitated tank leaching
- Counter current decantation (CCD)
- Merrill–Crowe
- Cyanide (reagent)
Flow Sheet:
Summary:
The process plant has been designed to treat a variety of ore types ranging from low sulphur precious metals ore, high copper massive sulphide ore, high zinc massive sulphide ore, stringer base metal ores and high lead tuff ore.
The process plant has been designed to treat a variety of ore types ranging from low sulphur precious metals ore, high copper massive sulphide ore, high zinc massive sulphide ore, stringer base metal ores and high lead tuff ore.
Two separate treatment methods will be employed for processing Back Forty ores:
- Leaching of low sulphide precious metal bearing ore using sodium cyanide, with metal recovery via the Merrill-Crowe process – Oxide Plant.
- Flotation of base metal sulphide ores to produce a bulk (copper or lead) concentrate and a zinc concentrate – Sulphide Plant.
The oxide plant has been designed for a throughput of 800 tpd (dry) at head grades of up to 8.0 g/t gold and 127 g/t silver. The overall flo ........
Reserves at February 6, 2018:
| Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
|
Proven & Probable
|
Total
|
11.65 Mt
|
Gold
|
1.85 g/t
|
|
|
Proven & Probable
|
Total
|
11.65 Mt
|
Silver
|
21.7 g/t
|
|
|
Proven & Probable
|
Total
|
11.65 Mt
|
Copper
|
0.28 %
|
|
|
Proven & Probable
|
Total
|
11.65 Mt
|
Zinc
|
2.64 %
|
|
|
Proven & Probable
|
Total
|
11.65 Mt
|
Lead
|
0.21 %
|
|
|
Measured
|
Mill / Sulphide
|
7,353 kt
|
Gold
|
1.75 g/t
|
414 koz
|
|
Measured
|
Oxide
|
590 kt
|
Gold
|
5.72 g/t
|
109 koz
|
|
Measured
|
Total
|
7,943 kt
|
Gold
|
2.04 g/t
|
522 koz
|
|
Measured
|
Mill / Sulphide
|
7,353 kt
|
Silver
|
19.1 g/t
|
4,507 koz
|
|
Measured
|
Oxide
|
590 kt
|
Silver
|
37.3 g/t
|
707 koz
|
|
Measured
|
Total
|
7,943 kt
|
Silver
|
20.4 g/t
|
5,214 koz
|
|
Measured
|
Mill / Sulphide
|
7,353 kt
|
Copper
|
0.37 g/t
|
60.5 M lbs
|
|
Measured
|
Oxide
|
590 kt
|
Copper
|
0.05 %
|
0.7 M lbs
|
|
Measured
|
Total
|
7,943 kt
|
Copper
|
0.35 %
|
61.2 M lbs
|
|
Measured
|
Mill / Sulphide
|
7,353 kt
|
Zinc
|
3.59 %
|
581.7 M lbs
|
|
Measured
|
Oxide
|
590 kt
|
Zinc
|
0.2 %
|
2.6 M lbs
|
|
Measured
|
Total
|
7,943 kt
|
Zinc
|
3.34 %
|
584.3 M lbs
|
|
Measured
|
Mill / Sulphide
|
7,353 kt
|
Lead
|
0.18 %
|
28.4 M lbs
|
|
Measured
|
Oxide
|
590 kt
|
Lead
|
0.12 %
|
1.6 M lbs
|
|
Measured
|
Total
|
7,943 kt
|
Lead
|
0.17 %
|
30 M lbs
|
|
Indicated
|
Mill / Sulphide
|
6,827 kt
|
Gold
|
1.69 g/t
|
371 koz
|
|
Indicated
|
Oxide
|
1,854 kt
|
Gold
|
2.22 g/t
|
132 koz
|
|
Indicated
|
Total
|
8,680 kt
|
Gold
|
1.8 g/t
|
504 koz
|
|
Indicated
|
Mill / Sulphide
|
6,827 kt
|
Silver
|
22.2 g/t
|
5,633 koz
|
|
Indicated
|
Oxide
|
1,854 kt
|
Silver
|
39.9 g/t
|
2,380 koz
|
|
Indicated
|
Total
|
8,680 kt
|
Silver
|
28.7 g/t
|
8,013 koz
|
|
Indicated
|
Mill / Sulphide
|
6,827 kt
|
Copper
|
0.36 %
|
54.2 M lbs
|
|
Indicated
|
Oxide
|
1,854 kt
|
Copper
|
0.04 %
|
1.6 M lbs
|
|
Indicated
|
Total
|
8,680 kt
|
Copper
|
0.29 %
|
55.8 M lbs
|
|
Indicated
|
Mill / Sulphide
|
6,827 kt
|
Zinc
|
3.64 %
|
547.1 M lbs
|
|
Indicated
|
Oxide
|
1,854 kt
|
Zinc
|
0.41 %
|
16.7 M lbs
|
|
Indicated
|
Total
|
8,680 kt
|
Zinc
|
2.95 %
|
563.8 M lbs
|
|
Indicated
|
Mill / Sulphide
|
6,827 kt
|
Lead
|
0.35 %
|
53.1 M lbs
|
|
Indicated
|
Oxide
|
1,854 kt
|
Lead
|
0.29 %
|
11.7 M lbs
|
|
Indicated
|
Total
|
8,680 kt
|
Lead
|
0.34 %
|
64.9 M lbs
|
|
Measured & Indicated
|
Mill / Sulphide
|
14,180 kt
|
Gold
|
1.72 g/t
|
785 koz
|
|
Measured & Indicated
|
Oxide
|
2,444 kt
|
Gold
|
3.07 g/t
|
241 koz
|
|
Measured & Indicated
|
Total
|
16,623 kt
|
Gold
|
1.92 g/t
|
1,026 koz
|
|
Measured & Indicated
|
Mill / Sulphide
|
14,180 kt
|
Silver
|
22.2 g/t
|
10,140 koz
|
|
Measured & Indicated
|
Oxide
|
2,444 kt
|
Silver
|
39.3 g/t
|
3,087 koz
|
|
Measured & Indicated
|
Total
|
16,623 kt
|
Silver
|
24.7 g/t
|
13,227 koz
|
|
Measured & Indicated
|
Mill / Sulphide
|
14,180 kt
|
Copper
|
0.37 %
|
114.7 M lbs
|
|
Measured & Indicated
|
Oxide
|
2,444 kt
|
Copper
|
0.04 %
|
2.2 M lbs
|
|
Measured & Indicated
|
Total
|
16,623 kt
|
Copper
|
0.32 %
|
116.9 M lbs
|
|
Measured & Indicated
|
Mill / Sulphide
|
14,180 kt
|
Zinc
|
3.61 %
|
1,129 M lbs
|
|
Measured & Indicated
|
Oxide
|
2,444 kt
|
Zinc
|
0.36 %
|
19.3 M lbs
|
|
Measured & Indicated
|
Total
|
16,623 kt
|
Zinc
|
3.13 %
|
1,148 M lbs
|
|
Measured & Indicated
|
Mill / Sulphide
|
14,180 kt
|
Lead
|
0.26 %
|
81.5 M lbs
|
|
Measured & Indicated
|
Oxide
|
2,444 kt
|
Lead
|
0.25 %
|
13.4 M lbs
|
|
Measured & Indicated
|
Total
|
16,623 kt
|
Lead
|
0.26 %
|
94.9 M lbs
|
|
Inferred
|
Mill / Sulphide
|
615 kt
|
Gold
|
2.74 g/t
|
54 koz
|
|
Inferred
|
Oxide
|
514 kt
|
Gold
|
4.24 g/t
|
70 koz
|
|
Inferred
|
Total
|
1,129 kt
|
Gold
|
3.42 g/t
|
124 koz
|
|
Inferred
|
Mill / Sulphide
|
615 kt
|
Silver
|
36.7 g/t
|
726 koz
|
|
Inferred
|
Oxide
|
514 kt
|
Silver
|
51 g/t
|
842 koz
|
|
Inferred
|
Total
|
1,129 kt
|
Silver
|
43.2 g/t
|
1,568 koz
|
|
Inferred
|
Mill / Sulphide
|
615 kt
|
Copper
|
0.57 %
|
7.7 M lbs
|
|
Inferred
|
Oxide
|
514 kt
|
Copper
|
0.09 %
|
1 M lbs
|
|
Inferred
|
Total
|
1,129 kt
|
Copper
|
0.35 %
|
8.7 M lbs
|
|
Inferred
|
Mill / Sulphide
|
615 kt
|
Zinc
|
1.57 %
|
21.2 M lbs
|
|
Inferred
|
Oxide
|
514 kt
|
Zinc
|
0.39 %
|
4.5 M lbs
|
|
Inferred
|
Total
|
1,129 kt
|
Zinc
|
1.03 %
|
25.7 M lbs
|
|
Inferred
|
Mill / Sulphide
|
615 kt
|
Lead
|
0.38 %
|
5.2 M lbs
|
|
Inferred
|
Oxide
|
514 kt
|
Lead
|
0.51 %
|
5.8 M lbs
|
|
Inferred
|
Total
|
1,129 kt
|
Lead
|
0.44 %
|
11 M lbs
|
Corporate Filings & Presentations:
| Document | Year |
|
...................................
|
2020
|
|
...................................
|
2018
|
|
...................................
|
2018
|
|
...................................
|
2018
|
|
Preliminary Economic Assessment
|
2014
|
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