The Westwood Gold project, developed by IAMGOLD, is located in Bousquet Township, approximately 40km to the east of Rouyn-Noranda, Québec, Canada, one of the top gold producing countries in the world.
Westwood is an underground mining operation extracting gold-containing ore that is treated at Doyon mine’s carbon-in-pulp mill. The gold processing plant at Doyon mine was commissioned in March 2013. Commercial production at the mine began in July 2014. The ore is currently being processed at the Doyon processing plant.
The average annual gold production of Westwood is estimated to be 186,000oz over 20 years of its mine life.
Westwood project location, geology and mineralisation
The Westwood mineral zone, discovered in 2004, is part of the Doyon-Bousquet-LaRonde mining camp and is situated 2km from the Doyon gold mine in the Abitibi sub-province. It extends more than 1,925ha and comprises 120 titles, one mining and surface lease, and three tailings leases.
The deposit is located within the Archaean volcanic and intrusive rocks of the Bousquet Formation. Mineralisation at the gold deposit is categorised into three distinct zones. The Zone 2 extension and north corridor zones comprise quartz-pyrite, chalcopyrite and sphalerite veins and veinlets within a matrix filled with disseminated pyrite. These zones are located within felsic to intermediate volcanic rocks.
The third zone is a gold-rich zone comprising pyrite-sphalerite stringers with massive sulphide bands and minor gold-bearing, sulphide-rich quartz veins.
Westwood gold mine reserves
The Westwood mine holds 301,000t of ore graded at 7.3g/t Au in proven and 2.07 million tonnes (Mt) of ore graded at 7.0g/t Au in probable reserves as of December 2014. As of 31 December 2014, the contained gold reserve at the mine was 539,000oz.
The measured and indicated resources are estimated to be 1.65 million ounces (Moz) of gold, whereas the inferred resources are estimated to be 9.72Mt graded at 10.9g/t (equivalent to 3.39Moz of contained gold).
Construction and infrastructure facilities
IAMGOLD utilises the mill and water management facilities of the Doyon gold mine for the Westwood project.
Major activities included the refurbishment of the existing Doyon mill and the construction of production and ventilation shafts, an administration and services building, a backfill plant and a sewage treatment plant.
The Doyon processing plant currently processes ore from the Mouska and Westwood mines.
Gibraltar copper-molybdenum open-pit mine
The cut-and-fill mining method is applied at the Westwood gold mine. The ore is trucked and transported to the Doyon carbon-in-leach mill complex, where it is grounded using a SAG mill and a ball mill.
The mill complex has a capacity in excess of one million tonnes a year, enabling Westwood to process ore from surrounding goldfields.
The processing complex also has a copper flotation circuit and will be installed with a desulphurisation circuit for tailings reclamation, and a zinc flotation circuit in the second phase. The cyanide destruction capacity at the complex will also be increased.
GB Structures was awarded a contract to build a head frame for the Westwood gold project at Abitibi. Dumas Contracting conducted sinking works of the main concrete-lined shaft at Westwood, in a 50/50 joint venture with IAMROCK.
The contract for the construction of the main ventilation shaft was awarded to Redpath.