Lynn Lake Gold Project, Manitoba, Canada
Alamos Gold's Lynn Lake gold project involves the integrated development of the MacLellan property and the Farley Lake property, located within 45km of Lynn Lake, northern Manitoba, Canada.
The preliminary economic assessment (PEA) report for the project was completed in February 2014, by the former owners Carlisle Goldfields (75%) and AuRico Gold (25%), while the feasibility study is scheduled to commence in the last quarter of 2016 and be completed in late-2017.
The project's PEA estimates a production rate of 145,000oz of gold a year and a mine life of 18 years. The pre-production capital for the project is estimated to be C$424m ($381m approximately).
Lynn Lake Gold Project geology and mineralisation
The MacLellan and Farley Lake properties are located in the north belt (Rainbow Trend) of the Lynn Lake greenstone belt, within the Churchill Structural province. The north belt hosts rhyolites, overlain by andesite and basalt, sedimentary rocks and an upper basaltic unit.
Mineralisation at the MacLellan site is hosted within a unique stratigraphic sequence known as the Agassiz Metallotect, which comprises inter-layered siltstones, basalts, iron formations and minor felsic volcanics, whereas mineralisation at the Farley Lake site is hosted in a pre-Cambrian sedimentary iron formation, which is mostly composed of an oxide facies iron formation with additional clastic sediments.
Lynn Lake gold mine reserves
The project is estimated to hold combined measured and indicated resources of 40.3 million tonnes (Mt) grading 2.03g/t Au and containing 2.63 million ounce (Moz) of gold. Inferred resources are estimated to be 50.7Mt grading 1.28g/t Au and containing 2.09Moz of gold.
Mining and processing at the Manitoba gold project
The mining method proposed for the Lynn Lake project is the conventional open-pit mining method integrating drill, blast, truck and shovel operations.
The processing flowsheet conceived for the project includes gravity concentration with an intense 48h cyanide leach, pre-aeration with lead nitrate addition, a six-stage carbon-in-pulp (CIP) adsorption process, and gold elution and electro-winning stages.
Infrastructure at Lynn Lake Gold project
Access to the Maclellan property is through an existing 9km-long, weather-resistant gravel road connecting Lynn Lake, whereas access to the Farley Lake property is via the Highway 391 and a 17km weather-resistant road.
The project will involve the installation of four culverts and a bridge over the Keewatin River, rehabilitation of the aggregate quarry, and access road improvements for access to the Farley Lake site, whereas five culverts and a bridge will be installed over the Lynn River and improvements to access and bypass roads will be performed for access to the MacLellan site.
Power for the project will be sourced from the provincial grid via a high-voltage power line, while a power substation will also be constructed onsite.
Other major infrastructure for the project will include a tailings storage facility (TSF), a covered ore storage facility, a truck shop, a warehouse, an explosives storage facility, a sewage treatment plant, an office complex, a fuel storage facility, an emergency / back-up power generator, a radio communication tower, a maintenance store, and two cofferdams at the Farley Lake site.
Key players involved
The PEA report for the project was compiled by Tetra Tech.