Canadian Malartic mine is an open-pit gold mine located in Quebec, Canada. It is the largest operating gold mine in Canada.
Developed by Osisko Mining, the mine is currently owned and operated by Canadian Malartic General Partnership, formed of Agnico Eagle Mines (50%) and Yamana Gold (50%).
The mine was developed over a period of six years following the first exploration drill holes in 2005. It produced first gold in April 2011 and began commercial production in May 2011. Canadian Malartic has an estimated mine life of 20 years.
The mine is being extended under the Malartic Extension Project, with mining activities expected to begin in 2020.
Canadian Malartic General Partnership is also exploring the potential of the Odyssey, East Malartic, Sheehan and Sladen zones.
Canadian Malartic mine location, geology and mineralisation
The Canadian Malartic gold mine is located within the Canadian Malartic property in north-west Quebec, Canada.
The property is located 25km west of Val-d’Or, within the Municipality of Malartic. It spreads across a 16km-long portion of the Cadillac-Larder Lake fault zone and lies in the southern part of the Archean-age Abitibi greenstone belt that falls along the Ontario-Quebec border.
It is situated predominantly within the Pontiac Group of metasedimentary rocks and is dominated by mafic-ultramafic metavolcanic rocks of the Piché Group and metasediments of the Cadillac Group.
The mine contains disseminated gold-bearing pyrite mineralisation, hosted by porphyritic felsic to intermediate intrusions and altered Pontiac Group metasediments.
Canadian Malartic mine reserves
The Canadian Malartic gold mine was estimated to contain total proven and probable mineral reserves of 66.9 million tons (Mt) graded at 1.11 grams per ton (g/t) of gold (Au) as of December 2019.
The mine produced 697,200oz of gold and 873,420oz of silver in 2018 while gold production in the third quarter of 2019 stood at 163,145oz.
Mining method at Canadian Malartic mine
Canadian Malartic employs an open-pit mining method, using large-scale excavators and trucks. The mine uses hydraulic excavators as the primary loading tools and a wheel loader as a secondary loading tool.
The mining fleet for Canadian Malartic includes 27 CAT 793 F trucks with a nominal payload capacity of 226t each, three 6060 electrical front shovels, two remote-controlled shovels, three LeTourneau L-1850 wheel loaders, one Caterpillar 994 wheel loader and 30 other support vehicles, along with over 100 pick-up vehicles. A Hitachi EX5600-6 excavator was added to the mining fleet in June 2016.
Exploration activities focused on Odyssey, East Malartic and East Gouldie zones were conducted in 2019 to define and increase underground mineral resources to supplement production from the open-pit operation. Drilling highlights include 8.6g/t gold over 25.8m at a depth of 1,071m.
The mining pit is being extended into the Barnat deposit, which will pave the way for increasing its life by six years. The extension will involve the deviation of Highway 117 to enable access to the Barnat and Jeffrey deposits. The partnership began pre-commercial production from the Barnat deposit.
Processing at Canadian Malartic mine
Ore from the mine is processed at the Canadian Malartic mineral processing complex, which has a daily throughput of 55,000t of ore. The ore is transported to a crushing circuit and stockpiled in a covered pile before being conveyed to the semi-autogenous grinding circuit.
It is then sent to three identical ball mills, which are in closed circuit with hydro-cyclones. The slurry is thickened and fed to the leach tank circuit for conventional cyanidation and carbon-in-pulp processing to extract gold. The final product is gold / silver doré bars.
The tailings are pumped to a tailings impoundment facility following thickening and detoxification, which reduces cyanide levels to below 20 parts per million.
Excess water at the plant is either re-used or treated before being discharged.
Infrastructure at Canadian Malartic mine
The infrastructure at the site includes a process plant, a crushing plant, an administration / warehouse building and a mine office / truck shop building.
The site receives power from the existing Hydro-Québec 120kV Cadillac main substation via a 19km-long electrical transmission line. A 26.4MW diesel-electric power generation plant also supplies power to support site operations.
The process water is supplied from the plant thickener overflows and the freshwater is supplied from underground mine dewatering system. The gland water distribution system, reagent preparation water and the reclaimed water from the South-east Pond area also form part of the plant water systems. The mine also has a connection to the Malartic municipal sewage and potable water systems.
Located north-east of the truck shop, the fuel storage facilities at the site have a total storage capacity of 250,000l.
Promec carried out electrical, mechanical and piping equipment installation for the concentrator along with secondary structural work. The company also installed electrical and instrumentation components and constructed 120kV substations.
Agrégat RN performed drilling / blasting, excavation, transportation and spreading during the construction phase.
VCC General Contractor designed and constructed the gatehouse for the mine site.