The McIlvenna Bay project is an underground copper and zinc mine located in Saskatchewan, Canada.
Canada-based mining company Foran Mining initially developed the project. A pre-feasibility study for the project was completed in April 2020, while a feasibility study was published in April 2022 and was later updated in March 2025. The study highlighted a mine life of 18 years for an initial investment of approximately C$987.4m ($696.7m).
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In April 2026, Eldorado Gold completed the acquisition of Foran Mining, valuing the company at approximately C$3.8bn. Following the transaction, Foran became a wholly owned subsidiary of Eldorado.
In June 2026, Eldorado Gold announced the production of the first copper concentrate at the McIlvenna Bay project.
The site team is now concentrating on ramping up operations towards commercial production, anticipated in the third quarter of 2026, and a nameplate throughput capacity of 4,900 tonnes per day (tpd).
The project is expected to produce an average of 41 million pounds (mlb) of copper, 20,000oz of gold, 444,000oz of silver and 54mlb of zinc annually.
McIlvenna Bay project location and geology
The McIlvenna Bay project is located in north-eastern Saskatchewan within Foran’s McIlvenna Bay property. The project area is located approximately 1km south of Hanson Lake and comprises 113 claims covering an area of 140,445 hectares (347,047 acres).
Geology and mineralisation
The McIlvenna Bay property lies on the western edge of the Paleoproterozoic Flin Flon Greenstone Belt, which forms part of the Reindeer Zone. The host terrain of McIlvenna Bay is the Hanson Lake Block.
The McIlvenna Bay Formation is the host formation of the sulphide deposit, which is approximately 200m thick. The formation hosts the massive and semi‐massive sulphides and copper‐rich stringer zones of the McIlvenna Bay deposit, including altered felsic volcanic rocks, volcaniclastics, and/or volcanic‐derived sediments of rhyolitic composition.
The McIlvenna Bay is a volcanogenic massive sulphide deposit and features two types of mineralisation, including massive to semi-massive sulphide mineralisation and stockwork-style sulphide mineralisation.
Copper and/or zinc, with lower concentrations of silver, gold and lead, occur in the massive to semi-massive sulphides, while elevated copper and gold occur in the stockwork-style mineralisation.
McIlvenna Bay reserves
The McIlvenna Bay deposit is estimated to contain mineral reserves of 29.7 million tonnes (mt), grading 2.17% zinc and 1.21% copper, 0.44 grams per tonne (g/t) gold and 14.4g/t silver as of June 2026.
Mining methods
Conventional long-hole mining methods including sub-level transverse and longitudinal stoping and Avoca stoping are being used to develop the mine. Underground access to the McIlvenna Bay deposit is through a ramp from the surface.
Lateral development is being carried out with conventional trackless mining equipment to access the ore body during the initial four years of operations. The initial production areas, underground infrastructure and ventilation system are also being developed during this period.
A 2.43m × 7.32m rectangular production and service shaft will be constructed in year five of operations to reduce the haulage distance and access time for the lower levels. A total of 35 underground levels are due to be developed, with each level spaced at 30m intervals sill to sill.
Drilling activities are being carried out with a top hammer drill, blasted, and mucked using battery-electric (BEV) load-haul-dump vehicles.
The ore haulage plan during the early mine life involves the use of BEV haul trucks, while during the latter stages, the ore will be hauled to the rock breaker stations upon commissioning of the rectangular shaft.
Waste will be hauled to the surface or to an active production level for use as backfill.
Processing at the McIlvenna Bay project
The McIIvenna Bay project’s processing plant is designed for a processing capacity of 4,900tpd.
Ore from the underground mine is hauled to the surface and dumped into a surface crushing facility. A shaft hoisting system will be constructed for the lower mining levels in year five.
The run-of-mine ore undergoes crushing in a single-stage jaw crusher to a nominal 100% passing 245mm (80% passing 125mm) and is stockpiled.
The crushed ore is then fed to a grinding circuit consisting of a semi-autogenous grinding and a ball mill. The grinding circuit reduces the particle size to a nominal 80% passing 75 micrometres (µm) for flotation.
The cyclone overflow slurry from the grinding circuit then undergoes flotation to recover copper and zinc concentrates. The flotation circuits for copper and zinc are similar in design, and both will produce rougher concentrates before regrinding in horizontal IsaMills to a P80 of approximately 25µm and 20µm, respectively.
The zinc and copper concentrates are then dewatered using a dedicated vertical pressure filter for both to produce two stockpiles of product filter cake at 9% moisture for transportation to toll smelters.
Infrastructure facilities
The project site is accessible through the SK-106 public road, from where an existing all-season 18km gravel road connects to the project area. A 1,100m2 helipad will be constructed adjacent to the mine site entrance for emergency access.
An on-site co-generation liquefied natural gas power plant consisting of a total of 14 internal combustion generators initially provided 11MW of power for the site, with supplemental power provided by an existing 25kV distribution line from the Saskatchewan provincial grid.
SaskPower constructed a new 110/138kV transmission line, fed from the Pelican Narrows substation, providing secure, reliable power for the project.
Potable water is trucked to the site and stored in a freshwater tank. A containerised Potable Water Treatment Plant is being installed to treat water drawn from two on-site wells.
Contractors involved in the McIlvenna Bay project
The feasibility study was prepared by the international professional services company Stantec Consulting.
Micon International, a mining consultancy, was responsible for the mineral resource estimate.
Metallurgical research and test work company Blue Coast Research was responsible for the process metallurgy, while metallurgical test work was provided by Base Metallurgical Laboratories.
Canada North Environmental Services was engaged for the hydrology and environmental studies.
Canada-based engineering consultant Halyard provided the surface infrastructure and process plant design and costs, while consultancy Knight Piesold was responsible for the tailings storage facility design and costs.
The underground mine geotechnical designs were prepared by Canadian mining consultant RockEng, while MineFill Services, a mine backfill solutions provider, prepared the design of underground backfill reticulation.
In May 2022, Foran engaged Boart Longyear to deliver TruScan services using an Energy Dispersive X-Ray Fluorescence system, which generates continuous measurements of elemental abundance for selected elements alongside automated collection of structural information and core photography.
DRA Americas, a subsidiary of DRA Global, was engaged to lead detailed engineering and procurement work. G Mining Services is providing project execution and specialised consultancy services for the project.
McKeen’s Trucking Service is responsible for on-site crushing and hauling services, with drilling services handled by Hy-Tech Drilling, and Procon is providing the underground mining services.
A2SKI Industrial, Burnco, MA Ironworks and McIlvenna Bay Catering are also involved in the project.
