The Meliadine mine is located near the western shore of Hudson Bay in the Kivalliq District of Nunavut, about 25 km north of Rankin Inlet and 290 km southeast of our Meadowbank mine. Meliadine includes seven gold deposits, six of which are part of the current mine plan. The 98,222-hectare property covers an 80-km-long greenstone belt.
Facilities at the Meliadine mine include a main camp and an exploration camp. The main camp is located approximately 1.8 km north of the Tiriganiaq deposit and it consists of 14 wings of modular trailers that can accommodate approximately 700 personnel.
Commercial production began at Meliadine in May 2019. The Company anticipates that mining at Meliadine will be carried out through several underground mining operations and open pits over a mine life extending to 2032. There are numerous opportunities to create additional value at Meliadine, both at the mine and on the large regional land package.
Geology
Archean volcanic and sedimentary rocks of the Rankin Inlet greenstone belt underlie the property. The rock layers have been folded, sheared and metamorphosed. They trend west-northwest, dip steeply to the north, and have been overturned. The rock units are truncated by the Pyke Fault, a regional structure that extends the entire 80-km length of the property.
Mineralization
The Pyke Fault and associated secondary structures (i.e., the Lower Fault) appear to control gold mineralization on the property. Along the fault is a series of oxide iron formations that host six of the seven known Meliadine mine deposits. The deposits consist of multiple lodes of mesothermal quartz-vein stockwork, laminated veins and sulphidized iron formation mineralization. The northern, magnetite-rich Upper Oxide iron formation hosts Tiriganiaq — the largest deposit to date with a strike length of approximately 3.0 km at surface and a known depth of 893 metres, as well as the Tiriganiaq-Wolf (North) and Discovery deposits. The southern, weakly magnetic Lower Lean iron formations contain the F-Zone, Pump, Tiriganiaq-Wolf (Main) and Wesmeg deposits. The Wesmeg North deposit is hosted by mafic volcanics and is located between the Wesmeg and Tiriganiaq deposits.
The deposits are all within 5 km of Tiriganiaq except for Discovery, which is 17 km east-southeast of Tiriganiaq. Each of these deposits has mineralization within 120 metres of surface, making them potentially mineable by open pit methods. They also have deeper mineralization that could potentially be mined with underground methods, which are currently being considered in various internal studies.
At December 31, 2022, Meliadine was estimated to host 3.8 million ounces of gold in proven and probable mineral reserves (19.5 million tonnes grading 6.02 g/t gold) mostly at underground depth, as well as 1.6 million ounces of gold in measured and indicated mineral resources (12.4 million tonnes grading 4.13 g/t gold) and 2.3 million ounces of gold in inferred mineral resources (11.1 million tonnes grading 6.39 g/t gold).
Mining
Mining at Meliadine will be carried out through 10 open pits and two underground mining operations. Underground access is by decline, with long-hole mining methods. Each stope is backfilled, with cemented pastefill and/or cemented rockfill used in primary stopes and dry rockfill for the secondary stopes. A conventional truck/shovel operation is used for the open pits. Mining at Tiriganiaq in 2022 was carried out from both underground and an open pit.
In 2021, the Company completed the oxygen expansion (third line), the relocation of the former EWTP process works into the newly constructed water treatment complex and initiated construction of the building for the new saline effluent treatment works within the water treatment complex.
The Company obtained permits in 2022 to construct and operate a waterline to discharge treated saline effluent to Hudson Bay. By replacing the discharge saline water to sea currently done by truck, the waterline is expected to reduce costs and the environmental impact.
In 2023, the Company expects to pursue the saline effluent treatment works, the in-ground works for the power plant expansion, install the structure for the power plant expansion and install the structure for the fourth filter press and CIL expansion works. The Company will also work on the MPEI components for the fourth filter press and the underground western ventilation intake project.
Processing
Initial ore processing commenced in early February 2019 using low-grade stockpiles. The mill employs a conventional gold circuit comprising crushing, grinding, gravity separation and cyanide leaching with a carbon-in-leach circuit, followed by cyanide destruction and filtration of the tailings for dry stacking. In 2022, milling rates averaged 4,814 tonnes per day.
The Phase 2 mill expansion is expected to be completed in mid-2024 and the processing rate ramp-up is expected to increase throughput to achieve 6,000 tpd by year-end 2024.
Exploration
At the Meliadine mine in 2023, the Company expects to spend approximately $12.3 million for 53,100 metres of capitalized drilling, with a focus on conversion drilling at the Tiriganiaq, Pump, Wesmeg North, Wesmeg and F-Zone deposits, and $2.4 million for further development of the exploration drift. An additional $1.9 million is budgeted for 10,100 metres of exploration drilling of the Tiriganiaq, Wesmeg North, Wesmeg and F-Zone deposits, which are all open at depth.
The Company expects to spend an additional $6.7 million for 8,000 metres of drilling to investigate for new, near-surface satellite deposits close to the road and infrastructure around the Meliadine and Meadowbank/Amaruq operations. Any new discoveries at open-pit depths have the potential to extend the life of each mine in conjunction with the extensions of higher-grade underground mineralization at each site.