Lamaque is an underground gold mining operation located in the Quebec province of Canada. It is 100% owned by Eldorado Gold, following its acquisition of Integra Gold in July 2017.
Lamaque achieved first gold pour in December 2018 and began commercial production in March 2019.
The mine produced 113,940oz of gold in 2019 and is expected to produce 125,000-135,000oz in 2020. It is anticipated to have an initial mine life of seven years with an average production of 117,000oz a year. Annual production is anticipated to reach 150,000oz by 2022.
Lamaque gold mine location
The Lamaque gold mine is situated near Val-d’Or city, 550km north-west of Montréal, the largest city in Quebec.
The site can be accessed via the Provincial Highway 117 or 7e Street and the Chemin Des Gravieres Street.
Geology and mineralisation of Lamaque gold mine
The Lamaque project includes the Triangle gold deposit, situated 2.5km south of the historical Lamaque and Sigma mines.
The Triangle deposit is an Archean greenstone-hosted orogenic lode gold deposit, located at the eastern end of the Southern Abitibi Greenstone Belt. It is underlain by volcanic flows and volcaniclastic rocks of the Val-d’Or formation and is concentrated around a porphyritic diorite known as The Triangle Plug.
The Triangle deposit holds gold inside the quartz-tourmaline-carbonate veins within a sequence of sub-parallel sub-vertical shear zones.
The Lamaque Main Plug intrusion hosting the Lamaque mine is similar in shape, composition and type of mineralisation to The Triangle Plug.
The Val-d’Or region includes a number of shear zones with the Cadillac Tectonic Zone (CTZ) being the major structure for gold mineralisation.
Exploration at Lamaque
A new high-grade gold mineralisation zone called the Ormaque zone was discovered at Lamaque in January 2020. It is equidistant from the historically mined Sigma Deposit and the Triangle Deposit.
The company plans to undertake exploration drilling of 50,000m in 2020, including 29,000m of resource expansion drilling in the lower Triangle Deposit, 10,000m at the Ormaque zone, and 10,000m of drilling to test other targets.
Investments totalling $24m are also being made in the Lamaque decline project, which is expected to be completed in 2022. The company began construction of a decline from the Sigma mill to the Triangle mine in June 2020.
The 3km decline project will eliminate surface rehandling and haulage of the ore from the Triangle mine to the mill, as well as provide underground access for economic exploration in the area between the Triangle deposit and the Sigma and Lamaque mines. It will reduce the energy required for ventilation in the mine while also enabling increased production from the Triangle mine in the future.
The company received a permit from the Quebec Ministry of Environment to proceed with the expansion of production from the Triangle mine to 2,650tpd, in March 2020.
Reserves at Lamaque
Lamaque contains proven and probable gold reserves of 4,09 million tonnes (Mt) containing 9.72 million ounces (Moz) of in-situ gold graded at 7.39g/t.
Mining method at Lamaque
The project employs a haulage ramp system to surface to recover reserves from the Triangle deposit. The ramps are used for hauling ore and waste, and part of the exhaust air circuit. It also provides access for equipment, personnel, and services.
The main ramp is used for communications, power, ventilation, industrial water and dewatering.
Based on the Triangle deposit’s orebody characteristics, a longitudinal retreat long-hole mining method was selected.
Sill pillars are placed temporarily to facilitate the simultaneous operation of a greater number of production areas. The pillars are removed as the mining activity advances upwards to the sill level.
The stopes are backfilled using rockfill and approximately one-third to half of the volume is filled with cemented rockfill (CRF) while the rest of the void is filled with non-cemented rockfill.
Processing at Lamaque gold mine
The extracted ore is processed at the Sigma mill, situated at a distance of 3km from the Triangle zone. The Sigma mill and tailings facility was acquired by Integra in 2014.
The mill’s crushing circuit comprises a cone crusher, jaw crusher and a screen, while the grinding circuit includes a primary rod mill and two ball mills.
The company plans to increase throughput at the Sigma mill following the exploration success at the Triangle deposit.
The mill has a nameplate capacity of 2,200tpd and currently receives 1,800tpd of material from Triangle. Production from the deposit is being increased to 2,200tpd to maximise the throughput of the processing plant.
Promec Mining was contracted to construct the Triangle exploration ramp while the definition drilling programme was performed by Forage Orbit-Garant.
Abibiti Geophysics conducted a high-resolution AeroVision (UAV-MAG) survey on the property in 2017. Geoposition Arpenteurs Géomètre received a contract to survey drill collars.
Alimak was contracted to develop the ventilation raise network.