Samapleu-Grata Nickel-Copper project in Côte d’Ivoire, West Africa is a 60:40 joint venture between US-based technology and mineral exploration company Ivanhoe Electric and Canada-based Sama Resources.
The results of the new Preliminary Economic Assessment (PEA) for the Samapleu-Grata project were announced in March 2024.
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The PEA study, which is based on the Grata, Main and Extension Deposits and the Sipilou Sud Laterite Deposit, supported a conventional open pit mining operation at the site.
With a 16 year-life of mine, it is projected to deliver approximately 38,627 tonnes (t) of 26% copper concentrate and 55,119t of 13% nickel concentrate annually on an average.
Initial capital costs were estimated to be $338m, including $61m for contingencies.
Samapleu-Grata Project Location
The Samapleu-Grata Nickel Copper Project is located in western Côte d’Ivoire, around 600km from the capital Abidjan.
It includes five exploration permits- PR838 (Samapleu-Est), PR839 (Samapleu-Ouest), PR300 (Zérégouiné), PR604 (Grata), and PR837 (Zoupleu), encompassing a total area of 839 km².
History
Base metals mineralisation at the site was discovered in the 1970s.
Sama Nickel Corporation (SNC), a subsidiary of Sama Resources, is active at the site since 2009. It has carried out geophysical surveys, geochemical surveys, and diamond drill programmes at the property.
This was followed by geochemical sampling, geophysical surveying and several phases of diamond core drilling from 2010 to 2023.
The resource base of the project was periodically updated since 2012.
In June 2023, Sama Resources announced an increase in Indicated and Inferred mineral resources at Samapleu-Grata Project. A reclassification led to further increase in indicated mineral resources.
In March 2024, Ivanhoe Electric became a joint venture partner by acquiring a 60% interest in the Samapleu-Grata Nickel-Copper Project. Ivanhoe became the majority stakeholder by completing the terms of the earn-in which included spending C$25m within the specified time period.
Separately, Ivanhoe Electric also owns 22.7% of Sama’s common shares.
Geology and Mineralisation
The western Côte d’Ivoire represents the eastern limit of the WestAfrican Archean craton. The Samapleu-Grata Nickel-Copper Project is located within the Yacouba complex, an ancient igneous complex that has intruded older gneisses of the West African Craton.
Samapleu and Grata exploration properties feature different rocks underneath including gneissic granulite, mafic granulite, charnockite, aluminous garnet, and magnetite gneiss, garnet jotunite/underbite, biotite and granite.
Mineralisation in the two deposits includes primarily pyrrhotite, pentlandite and chalcopyrite, with some amounts of pyrite, platinum-group element, and chromite.
Sulphide mineralisation types were described as matrix textures, net-textures, droplets, breccia, dragged sulphide sometimes with semi-massive sulphides, massive, veins, and veinlets.
Samapleu-Grata Project Mineral Resource Estimate
Samapleu Project Indicated Mineral Resource total 19.4Mt averaging 0.26% Ni for 112.3 million pounds (Mlbs) of Ni metal, 0.23% Cu for 100Mlbs of Cu metal, 0.02% Co for 7.2Mlbs of cobalt (Co) metal, 0.32g/t Pd for 199,800 ounces of palladium (Pd) and 0.1g/t Pt for 64,700 ounces of platinum (Pt).
Inferred Resources stand at 99.49Mt averaging 0.25% Ni for 544.7Mlbs of Ni, 0.23% Cu for 514.6Mlbs of Cu, 0.01% Co for 32.5Mlbs of Co, 0.29g/t Pd for 928,300 ounces of Pd and 0.09g/t Pt for 302,000 ounces of Pt.
Mining at Samapleu-Grata Project
The PEA stated that the conventional owner-operated open pit mining methods will be used to mine the designed pits of the Grata, Main, and Extension deposits. The mine plan is based on Indicated and Inferred Mineral Resources.
Open pit mining will involve drilling and blasting and then using a combination of a backhoe-type excavator and front-end loader-type excavator to load blasted material into haul trucks.
The trucks will then carry the material to run-of-mine (ROM) stockpile, and take waste to waste stockpiles.
Mining will commence at Main deposit followed by Extension and Grata during the first half of the LOM. The activity will continue at Grata for the second half of the life of mine.
Average mining rate of mill feed and waste over the life of mine will be approximately 14.3Mt/y, with total mill feed is estimated to be 86.5Mt.
Overall, the project will need 17 haul trucks, two hydraulic excavators, one wheel loader, and three production drills, along with support and service equipment during full production.
It will employ 236 employees at peak operations.
At Sipilou Sud, a mining contractor will carry out traditional loading and hauling (free-dug) mining and then ship mineable laterite resource material to the port.
Recovery
The surface infrastructure and processing plant will be developed near the Grata Deposit.
The processing plant will treat 5.475Mt/y of ROM mineralised material to produce 55,119t/y of nickel concentrate at 13.0% Ni grade and 38,627 t/y of copper concentrate at 26.0% copper grade.
It will comprise crushing, grinding, rougher flotation, and cleaner flotation circuit with the back end of the concentrator featuring tailings and concentrate thickening, concentrate filtration, and material handling.
The tailings from the concentrator would be thickened and disposed to the Tailings Storage Facility (TSF).
Contractors Involved
A historical mineral resource of the site was estimated by WSP in July 2012 and updated in December 2012. It was further updated in May 2015 and March 2020 with DRA/Met-Chem.
The PEA for the Samapleu Main & Extension, Grata, and Sipilou Sud deposits was prepared by BBA International. Knight Piésold and Chris Martin also contributed.
Metallurgical test work on composites from the Samapleu and Grata deposits was completed by Blue Coast Research.
