The Rainy River mine is located approximately 65 kilometres northwest of Fort Frances, Ontario. The site is situated on the traditional lands of Treaty #3 Anishinaabe Communities in Northwestern Ontario.
Exploration in the general area of the property began in 1967. In 1990, the property was acquired by Nuinsco Resources Ltd. who actively explored the ground from 1993 to 2004. The property was sold to Rainy River Resources Ltd. in June 2005, which continued exploration and development of the project until New Gold acquired the property from Rainy River Resources Ltd. in October 2013. Construction began in March 2015 and the mine reached commercial production in October 2017.
Rainy River will utilize both open pit and underground mining through its life of mine.
The open pit mine is a conventional truck and shovel mining operation, with a fleet of 220-ton payload haul trucks combined with diesel-powered hydraulic excavators and large front-end loaders as primary loading units.
The underground is designed as a mechanized ramp access mine that will use longitudinal longhole open stoping techniques to access the underground mineral reserves. The underground mine will be accessed via three portals, including two in-pit portals, as well as the Intrepid zone portal located to the east of the open pit, which significantly reduces capital development spend.
The Rainy River process plant includes crushing, grinding, gravity separation, cyanide leaching, carbon-in-pulp, carbon stripping and regeneration, electrowinning, and doré production. Gold output from the Rainy River Mine operation is in the form of doré bars (doré) containing on average of approximately 40% gold and 60% silver. The doré bars are shipped to refiners for further process. Silver credits are received from the refiners.
Plant tailings are deposited in the Tailings Management Area (TMA) and TMA water is reclaimed and returned to the process plant. Rainy River maintains an Engineer of Record who oversees dam designs, reviews construction, and completes dam safety and monitoring inspections. The Independent Tailings Review Board reviews all aspects of tailings management from a third-party perspective, with the intent of identifying and minimizing any potential risks.
Learn more about New Gold’s approach to tailings management here.
New Gold continues its exploration efforts, focusing on identifying and generating new targets to define additional mineralization within the Company’s broader land package and potentially expand the life of the mine.
Exploration drilling led to the discovery of 17 Zone, 34 Zone and 433 Zone.
2000s – 2010s
Several exploration and infill drilling campaign undertaken, led the delineation of the Rainy River ore body and the additional discovery of the Intrepid Ore Zone.
In March 2021, first phase of reconnaissance drilling program completed within Northeast Trend area, ~15 kilometres north from the Rainy River Mine. Second phase of program commenced in December 2021.
Geology and Land
The property is located within the 2.7 billion year (Ga) old Neoarchean Rainy River Greenstone Belt (RRGB) and encompasses an approximately 30 kilometre long, north-east trending portion of the Belt. In this area, the RRGB is bounded to the north-west by the Sabaskong Batholith, to the east by the Rainy Lake Batholithic Complex and to the south by the Quetico fault.
The Rainy River deposit occurs within a sequence of felsic to intermediate metavolcanic rocks bounded to both the north and south by a lower mafic sequence. These sequences are intruded by the Sabaskong batholith to the north, and the Black Hawk stock to the east and southeast.
The current geometry and plunge of the Rainy River ore deposit are the result of several deformation events, which affect both the hosting lithologies and the features associated with the gold mineralization.
Four main styles of mineralization have been identified on the Rainy River deposit:
- Gold-bearing sulphide ± quartz stringers and veins in felsic quartz-phyric rocks;
- Quartz-ankerite-pyrite shear veins in mafic volcanic rocks;
- Sulphide-bearing silver-enriched quartz veinlets in dacitic tuffs and breccias; and
- Copper-nickel-platinum group metals mineralization hosted in a small younger mafic-ultramafic intrusion situated within the main cluster of gold and silver deposits.
The Rainy River Mine occupies approximately 6,140 hectares, comprising 100 patented mining rights and surface rights claims (including 9 leasehold interest mining rights and/or surface rights claims). In addition, the Company has a land package of approximately 30,644 hectares surrounding the mine site, including patented mining rights and/or, surface rights and unpatented claims.