Overview
Stage | Production |
Mine Type | Tailings |
Commodities |
|
Mining Method |
|
Processing |
- Centrifugal concentrator
- Flotation
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Carbon in pulp (CIP)
- Carbon adsorption-desorption-recovery (ADR)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 2028 |
During the year ended December 31, 2018 the True North underground mine operations transitioned to care and maintenance. On October 5, 2019, the 1911 Gold Corporation temporarily suspended ongoing care and maintenance of the underground infrastructure. Access to the True North mine has been temporarily closed.
1911 Gold is currently reprocessing historic tailings on a seasonal basis. |
Latest News | 1911 Gold Commences Tailings Reprocessing Operations May 6, 2020 |
Source:
p. 2, 3
1911 Gold Corporation is a junior gold producer and explorer that owns the True North mine and mill complex at Bissett, Manitoba.
Until July 19, 2018, the 1911 Gold Corporation (formerly Havilah Mining Corporation) operated as a subsidiary of Klondex. With the completion of the Arrangement on July 20, 2018 the 1911 Gold Corporation operated as a separate entity.
Summary:
The True North Gold Deposit is a classical Archean orogenic gold deposit, consisting of quartz-carbonate vein systems hosted by brittle-ductile shear zones and faults in volcanic and sedimentary rocks (greenstones). The deposit is hosted by a north-younging, moderately inclined, succession of volcanic and sedimentary rocks, belonging to the 2.73–2.72 Ga Gem assemblage. At Rice Lake, this assemblage includes volcanic sandstone and conglomerate, tholeiitic basalt flows and gabbro sills and dacitic volcaniclastic rocks, intruded by various felsic porphyry dikes.
Tailings Management Area
The Tailings Management Area (TMA) is located approximately 1-mile (1.6 km) north of the process plant in an area naturally defined by bedrock ridges around the perimeter of a previously flat boggy area. The original ground surface of the bog was near elevation 889 feet above sea level (asl) (271 m asl) (geodetic) with bedrock ridges on the south and west sides up to 920 feet above sea level (asl) (280 m asl) and bounded to the north by bedrock up to elevation 985 feet asl (300 m asl).
The TMA currently consists of eight dykes with a number of the embankments separated by bedrock outcroppings such that they follow an A/B nomenclature. The embankments have been designed and constructed in various stages and phases from 1997 onwards to the most recent raises and improvements completed from 2012 to 2014. The current configuration of the TMA consists of a tailings pond and polishing pond, separated by dyke 7. The west half (approx.) of the tailings pond has reached its capacity, with tailings placed up to the crest of dykes 1, 2, 8, and a portion of dyke 3, while the east half of the tailings pond contains tailings submerged beneath water ranging in depth from less than 3 feet (1m) to several feet (meters). No spillway or low-level outlet structures are present in the TMA. It is understood that the TMA has been designed to safely retain water from the mill discharge, runoff, and storm events.
In order to increase the capacity to retain tailings, the former Operator began development of a new area termed the East Tailings Management Area (ETMA). The ETMA is located directly east of the TMA and currently consists of dyke 9 along its south perimeter, with dyke 6 of the TMA forming the containment along the west side. The natural contours to the north and east provide containment of the remainder of the ETMA.
Dyke 9 has an overall length of nearly 5,000 feet (1,500 m) and at its current constructed elevation, has a height of 10 feet to 13 feet (3m to 4 m). No spillway or low-level outlet structures are present in the ETMA. It is understood that the TMA has been designed to safely retain water from the process plant discharge, runoff, and storm events.
Summary:
1911 Gold is a junior gold producer and explorer that owns the True North mine and mill complex at Bissett, Manitoba, and is currently reprocessing historic tailings on a seasonal basis.
Tailings reprocessing commenced in 2016. From 2016 to 2018 reprocessing of the tailings was carried out concurrently with processing of underground ore when weather allowed.
During the year ended December 31, 2018 the True North underground mine operations transitioned to care and maintenance as a result of ongoing negative cashflows. On October 5, 2019, the 1911 Gold Corporation temporarily suspended ongoing care and maintenance of the underground infrastructure. Access to the True North mine has been temporarily closed.
The primary mining method at the True North mine was long hole stoping.
For the year ended December 31, 2019, the Company operated for 188 days, commencing tailings operations on April 26, 2019, and suspending operations on October 31, 2019.
North Tailings Operation utilizes an excavator to windrow tailings within the Tailings Management Area (TMA) for dewatering and to load the material onto 36-tonne trucks for transport to the processing facility. Tailings are off-loaded into a screened feed hopper and conveyed directly to the grinding circuit, bypassing the crushing circuit. Tailings are processed at a rate of 50 tonnes per hour with a target rate of 1,200 tonnes per day.
Crusher / Mill Type | Model | Size | Power | Quantity |
Gyratory crusher
|
.......................
|
|
|
1
|
Jaw crusher
|
|
30" x 42"
|
|
1
|
Vertical shaft impact crusher (VSI)
|
.......................
|
|
|
1
|
Ball mill
|
|
12.5' x 14'
|
933 kW
|
1
|
Summary:
In 2011, the process crushing plant was expanded by adding a new primary 30 inch by 42 inch (760mm by 1067mm) jaw crusher, a GP300 gyratory crusher as a secondary breaker and a Barmac B8000 VSI (vertical shaft impact) crusher as a tertiary unit. There units are all in line with a 7 foot by 20 foot(2.1m by 6.1m) triple deck vibrating screen.
The process plant feed is ground in an AC 12 ½ foot by 14 foot (3.8m by 4.3m), 1,250 HP (933 kW) ball mill to 67% passing Tyler 200 mesh (74 microns).
Tailings are off-loaded into a screened feed hopper and conveyed directly to the grinding circuit, bypassing the crushing circuit. Tailings are processed at a rate of 50 tonnes per hour with a target rate of 1,200 tonnes per day.
Processing
- Centrifugal concentrator
- Flotation
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Carbon in pulp (CIP)
- Carbon adsorption-desorption-recovery (ADR)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The original processing facility at the True North site, constructed in 1931–32, was destroyed by fire in 1980 and was subsequently reconstructed in 1996–97, with an operating capacity of 900 tonnes per day. Mill capacity was increased to 2,300 tonnes per day in 2011; however, it has since been scaled back to 1,300 tonnes per day to optimize gold recoveries from the tailings reprocessing operation.
The True North Complex includes a modern, fully-permitted 1,300 tonnes-per-day ore processing facility, comprised of crushing, milling, centrifugal gravity concentration and flotation circuits. Concentrates from the gravity circuit are upgraded on a shaker table for direct-smelting, whereas flotation concentrates are reground, thickened and then leached in a three-stage leach circuit. Dissolved gold is recovered by six-stage carbon-in-pulp (CIP) circuit, followed by conventional pressure strip, electrowinning and smelting in an electric induction furnace. Gold is poured into doré ........

Recoveries & Grades:
Commodity | Parameter | 2019 | 2018 | 2017 | 2016 |
Gold
|
Recovery Rate, %
| ......  | ......  | ......  | ......  |
Gold
|
Head Grade, g/t
| 0.9 | 0.04 | 0.1 | 0.11 |
Gold Equivalent
|
Head Grade, oz/ton
| | | 0.1 | 0.11 |
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Reserves at March 31, 2018:
Underground Mineral Resources have been calculated at a Au cut-off grade of 0.100 opt;
Tailings Mineral resources have been calculated at a Au cut-off grade of 0.015 opt.
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Measured
|
In-Situ (UG)
|
599 k tons
|
Gold
|
0.209 oz/ton
|
125 koz
|
Indicated
|
In-Situ (UG)
|
1,409 k tons
|
Gold
|
0.219 oz/ton
|
308 koz
|
Indicated
|
Tailings
|
1,971 k tons
|
Gold
|
0.0243 oz/ton
|
48 koz
|
Measured & Indicated
|
In-Situ (UG)
|
2,007 k tons
|
Gold
|
0.216 oz/ton
|
433 koz
|
Measured & Indicated
|
Tailings
|
1,971 k tons
|
Gold
|
0.0243 oz/ton
|
48 koz
|
Inferred
|
In-Situ (UG)
|
3,586 k tons
|
Gold
|
0.169 oz/ton
|
605 koz
|
Inferred
|
Tailings
|
31 k tons
|
Gold
|
0.0235 oz/ton
|
0.7 koz
|
Heavy Mobile Equipment as of May 8, 2018:
HME Type | Size | Quantity |
Drill (long hole)
|
|
2
|
Drill jumbo (single boom)
|
|
3
|
Scissor Lift
|
|
1
|
Scoop Tram
|
3.5 cu. yd
|
4
|
Scoop Tram
|
2.5 cu. yd
|
5
|
Truck (boom)
|
|
1
|
Truck (haul)
|
13 tons
|
2
|
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Aerial view:
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