Lac Herbin Mine (Val-d’Or)

 mine, gold mine

The Lac Herbin mine consists of an underground mine using a ramp for access and a ventilation raise as escape way. The Aurbel mill is located approximately 1.5 km east of the mine site and the ventilation raise is located about 1.5 km southwest of the mine site, on the south side of Lac Herbin. There is a tunnel from the main zone area to the old Dumont Mine Shaft.

Most of the mineralized zones are located beneath Lac Herbin. The mineral resources are contained into 12 zones. The ramp portal starts east of the deposit on an outcrop. The ramp (4.7 m x 4.5 m) has been advanced to about 390 m below surface at a grade of -15. The ramp is used as a haulage road, ventilation exhaust and main access for personal and services. Its size allows a use of 30 tonnes low-profile haulage trucks. Lateral development was done extensively on HW, HW2, LH, S1, S3 and WE zones. On level 20, 200 m below surface, the access for the ventilation raise is used for deep exploration drill stations.

The Lac Herbin deposit is a narrow veins deposit type. The mineralization is contained within 12 shear zones. The longitudinal long hole mining method and a variance of it, called “Selective Short Hole” (SSH) is mostly used to mine the reserves. Generally, the mining blocks will be of a maximum dimension of 60 m in length and 60 m in height. The principal access, located at the base of these blocks, will be developed from the main ramp. In certain cases, a secondary ramp will be excavated to reach mineralized zones. These 3.6 m X 3.8 m drifts are excavated with mechanized equipments. These drifts are also for ore and waste transportation between the zones and the main ramp. Thereafter, the ore charged in trucks and hauled to surface.

Either conventional or Alimak raise are driven from the main access to give access to the sub-levels. The lateral ore development (sub-levels) will generally proceed on both side of the vein to the limits of the mineralization. Most of lateral development will be accomplished by conventional method. Conventional rock support will be installed in various developments. Production drilling will be performed by long hole drills mounted on a 4 wheel autonomous carrier. The diameter of drilling will be 2.5 inches and length of hole limited to 15 m. The mucking of the stopes will be done laterally using remote control scoop trams. The ore will be mucked to a secondary mucking point or loaded directly in 30 t haulage trucks.