The Crean Hill Project is a past-producing open-pit and underground nickel mine owned by Magna Mining and located in the Sudbury Basin nickel district of Ontario, Canada.
The Crean Hill deposit was discovered in 1885 and the first production was reported in 1906. The mine produced nickel and copper for over 80 years under the ownership of Vale (INCO).
Lonmin Canada, a subsidiary of Magna, explored the project from 2003 to 2022 showing high-grade platinum-palladium-gold mineralisation in the footwall of the contact nickel zones.
In April 2024, the project received the Crean Hill Permit to Take Water (PTTW) approval from the Ministry of Environment, Conservation and Parks (MECP).
This permit will enable the dewatering of the existing mine works allowing Magna to further explore the project with an advanced exploration plan.
Crean Hill Location and Site Access Details
The Crean Hill Project is located approximately 30km southwest of downtown Sudbury in the Denison Township within the Greater Sudbury City in Ontario.
The project consists of patented surface and mining claims covering approximately 255.9 hectares (ha) of land.
The project is accessible by Regional Road 4, Highway 17 (a part of the Trans-Canada Highway Network) and Sudbury Regional Airport. Highway 17 is located 7km north of the project.
Crean Hill Ownership History
The Crean Hill deposit was discovered by Francis Charles Crean. From 1906 to 1918, the Canadian Copper Company owned the deposit and commenced operations at a rate of 300 tonnes per day.
The project was purchased by INCO in 1918 followed by the closure of mine in 1919. The mine reopened in 1987 under INCO.
INCO conducted drilling programs from 1987 to 2002 when the mine was again closed and decommissioned.
In 2003, the Lonmin-Vale Joint Venture was initiated followed by drilling, surveys, mapping, and sampling programs till 2005. CVRD acquired INCO in 2006 and changed its name to CVRD INCO and then to Vale INCO and Vale Canada in 2007.
Vale conducted drilling and exploration programs till 2013. A wholly owned subsidiary of Lonmin Plc, Lonmin Canada Inc., became the operator of the Lonmin-Vale Joint Venture and controlled the project till 2018.
In 2018, the joint venture terminated and Loncan (Lonmin) was acquired by Magna Mining in November 2022 as its wholly owned subsidiary.
Crean Hill Project Geology and Mineralisation
The Crean Hill Project hosts a large trough structure at the base of the Sudbury Igneous Complex. The terraces within the trough control the distribution of nickel-copper mineralisation.
The nickel-copper sulphide mineralisation may be hosted within the additional terraces in different orientations.
The mineralisation of the project is contained from east to west in the following zones: 9400 Zone, 109 Foot Wall (FW) Zone, Remnant Zones, 123 (109 FW2) and 126 (109 FW4) Zones, 101 Zones, and 99 FW Zone.
The eastern part of the 9400 Zone hosts nickel, copper, and Platinum Group Metals (PGM) mineralisation containing semi-massive to massive contact-style pentlandite, chalcopyrite, and pyrrhotite.
The FW sulphide mineralisation in the 9400 Zone is dominated by chalcopyrite and pyrrhotite with minor sulphide/arsenide minerals like pentlandite, pyrite, gersdorffite, sphalerite, galena, cobaltite, sperrylite, bornite, chalcocite, michenerite, and merenskyite.
The mineralisation of the 109 FW Zone consists of pyrrhotite, chalcopyrite, platinum, palladium, gold, and gersdorffite.
The Remnant Zones host copper, quartz-rich norite, norite, pyrrhotite, pentlandite, and chalcopyrite. The 123 (109 FW2) and 126 (109 FW4) Zones have the same mineralisation as adjacent zones.
The 101 Zones consist of high nickel and copper minerals. The zones are partially opened from the southwest to the depth.
Crean Hill Mineral Resource Estimate
The indicated in-pit mineral resource estimate of the Crean Hill Project at 0.3% Nickel Equivalent (NiEq) is 16.76Mt containing 2.2 million pounds (Mlbs) nickel at a grading of 0.53%, 2.04Mlbs copper at a grading of 0.49%, and 1.7 million ounces (Moz) of platinum-palladium-gold at gradings of 0.48g/t, 0.37g/t, and 0.25g/t, and 0.02% cobalt.
The inferred in-pit mineral resource estimate is 4.34Mt containing grades of 0.43% nickel, 0.49% copper, 0.02% cobalt, 0.29g/t platinum, 0.14g/t palladium, 0.07g/t gold at 0.3% NiEq.
The indicated underground mineral resource estimate of the mine is 14.53Mt containing grades of 0.96% nickel, 0.84% copper, 0.03% cobalt, 0.88g/t platinum, 1.02g/t palladium, and 0.54g/t gold at 1.1% NiEq.
The inferred underground mineral resources are 1.1Mt containing grades of 0.61% nickel, 0.46% copper, 0.02% cobalt, 0.64g/t platinum, 1.09g/t palladium, and 0.21g/t gold at 1.1% NiEq.
Mining and Processing Methods
For the underground mine, bulk and selective mining methods have been proposed. The primary mining method will be Longitudinal Long Hole Stoping for greenfield areas.
Variations of the Mechanised Cut and Fill (MCAF) method will be used near the historic stopes.
The open pit mine was developed to mine ores located near the surface and will be mined by using a conventional shovel and truck fleet.
As per the PEA, the recovery method is not determined and will depend upon an ore sale agreement with a local mining company.
The mined ores will be accumulated into lots for processing. Via a sampling tower, these lots will be sampled and then transported to the mill owned by the local mining company.
Project Infrastructure
The existing infrastructure of the Crean Hill Project consists of roads, waste rock stockpiles and related facilities.
The infrastructure required for the advanced exploration program is expected to include trailers, maintenance shops, covered storage and outside structure, explosives storage, water supply, diesel generators etc.
For phase two production, the anticipated infrastructure will include a headframe, offices, core shack, mine services, slurry plant, compressed air plant, parking, waste rock dumping facility etc.
Power Transmission
The Crean Hill Project is crossed by a 230kV transmission line from the south and a 115kV transmission line from the west.
An existing substation, located at the project boundary, may supply electricity to the project site at 69kV. The Lockerby Mine power infrastructure may be used to supply the project.
Key Contractors
The PEA for the Crean Hill Project was prepared by Stantec Consulting.
SGS Canada and XPS- Expert Process Solutions were also involved in the preparation of the PEA.
Off-Take Agreement
In March 2024, Magna signed a definitive off-take agreement with Vale Base Metals, a wholly owned subsidiary of Vale Canada.
As per the agreement, the initial production form the project will be shipped to the Clarabelle Mill owned by Vale for processing.
