Nouveau Monde Graphite is developing the Matawinie graphite project in Saint-Michel-des-Saints near Quebec, Canada. Credit: James St John.
The project will use CAT haul trucks and hydraulic excavators for mining operations. Credit: Harfang.
Power required by the mine will be sourced from Hydro-Québec’s 34.5kV distribution line. Credit: of Azumanga1.

The Matawinie graphite project is located in Saint-Michel-des-Saints, approximately 130km north of Montreal, Canada. Nouveau Monde Graphite is the developer of the high-purity flake graphite deposit.

The property consists of 250 map-designated claims forming nine main claim blocks spread over 13,694ha. The Tony block is the most prominent and consists of 145 contiguous map-designated claims spread over 7,543.86ha.

NMG completed the prefeasibility study of the Matawinie graphite project, which is mainly focused on the West Zone of the Tony claim block, in October 2017.

The mine is estimated to produce an average of 52,000t of graphite concentrate a year through its life of 27 years.

In 2021, the project, which subsequently incorporated sustainability and community goals, was given the green light to proceed by the Québec Government in Canada.

Matawinie graphite project geology

The Tony block is located within the Morin Terrane, a part of the deformed and transported Allochthonous monocyclic belt of the Grenville geological province.

It consists of a 14km circular conductor within highly metamorphosed sedimentary rocks surrounding a topographic high associated with a magmatic pluton.

Most of the lithologies on the Tony block are typical metasedimentary rocks, assigned to be a part of the ‘Grenville Series’ of Logan. The principal lithologies found at the Grenville Supergroup include aluminous paragneisses, marble, quartzite, amphibolite, and other related rocks.

The aluminous paragneiss is the most abundant rock type encountered in the area and is also host to the graphite mineralisation on the Tony claim block. The paragneisses are derived from the metamorphism and deformation of the original politic sedimentary rocks that took place during the Grenville Orogeny.

Graphite mineralisation

Crystalline flake graphite mineralisation is found at the Tony claim block mostly aligned parallel to the main foliation and is disseminated in the marbles and rusty biotite paragneisses of the Grenville Supergroup in the central metasedimentary belt in Quebec and Ontario.

The graphitic horizons are embedded with garnet paragneiss units, which display low graphite content.

Matawinie graphite project reserves

In 2017, the Canadian graphite project  was estimated to contain probable reserves of 33Mt grading 4.39% Cg.

Mining and ore processing

Conventional open-pit mining method will be performed at the Matawinie graphite project, including trucking and shovelling followed by drilling and blasting.

Major mining equipment proposed for the site includes CAT 775 haul trucks, CAT 6015 hydraulic excavators, 988K wheel loader, and D6T track dozer.

The ore processing facility or concentrator will consist of a crushing area, beneficiation, dewatering, bagging and tailings processing areas.

The concentrator is designed to produce a graphite concentrate containing 97% Cg from an ore containing 4.39% Cg. The beneficiation process will include crushing, grinding, conventional flotation, polishing, and column flotation to achieve the concentrate.

The graphite concentrate will then undergo filtration, drying, and classification to produce four high-purity products.

Plant rejects will undergo flotation and magnetic separation to produce sulphide and non-sulphide tailings. The streams will be thickened and filtered for dry-stacking.

Matawinie graphite project demonstration plant

Nouveau Monde Graphite commissioned a demonstration plant in 2020, which aimed to evaluate and enhance the graphite concentration before commercial launch. It followed the natural graphite processing procedures, and initially transform the ore by liberating and concentrating the natural graphite flakes.

The demonstration plant  is located on an existing industrial property in Saint-Michel-des-Saints, and  was estimated to produce 1,000t of graphite concentrate a year, including 250t of battery-grade biggest graphite.

In 2021, the Québec government in Canada issued a ministerial decree, authorizing Nouveau Monde Graphite’s Matawinie mining project for high-purity graphite concentrate production of 100,000tpa.

According to NMG, the experience in extracting and concentrating the ore in the plant, paired with the geological knowledge of the Metawinie property have significantly de-risked the project.

Infrastructure facilities

Power supply for the mine will be provided by Hydro-Québec through a new 34.5kV distribution line from Hydro-Québec nearest post (Poste Prevost).

Access to the mine will be through an 8.3km-long road from Pit à Midas to the main gate.

Key players involved

Nouveau Monde Graphite has engaged DRA Americas’ division Met-Chem to prepare the pre-feasibility study (PFS) for the Matawinie graphite project.

Independent engineering firms MET-Pro, SNC-Lavalin and WSP assisted NMG in preparing the engineering study for the demonstration plant.

Journeaux Associates conducted a geotechnical analysis of the West Zone deposit as part of the PFS to evaluate the pit slope design recommendations for the open-pit mine.