SAN DIMAS

MINING

Tayoltita Area | Santa Rita area | Central Block Area | Nukay Mine

Underground gold and silver mining operations are carried out at three main centres in the district. The operations employ underground cut-and-fill techniques, with LHD equipment feeding either truck or rail haul to the mills. Primary access takes advantage of the topographic relief, with adits driven at river level to intersect the veins at depth.

The ore is transported from the three areas to the processing plant in Tayoltita. The current operations employ approximately 900 people.

Tayoltita Area

The Tayoltita area includes the oldest operating mine in the San Dimas area. The main access is a 4.4 kilometre tunnel from a portal approximately 400 metres northeast of the Tayoltita mill.

The mining method employs mechanized cut-and-fill mining on vein mineralization using waste rock as backfill. The veins vary from 1 to 3 metres in width and generally dip at 75-80 degrees. Production drilling is largely completed with jackleg drills depending on the vein thickness. Ore is hauled from the stoping areas using LHD equipment, then by rail haulage to surface through the main access tunnel. Tayoltita has the lowest overall operating costs and cut-off grade in the area mainly due to the efficient ore transport system.

The development of the San Luis tunnel to connect the San Antonio area to the Tayoltita area has enabled the development of several additional veins of variable width dipping at 75 degrees. This area is currently being developed as an important new source of ore for Tayoltita.

Santa Rita Area

Main access to the Santa Rita area is by an adit located three kilometres to the northeast of the Tayoltita mill site. The vein dip varies from sub vertical to as low as 35 degrees which allows for a room and pillar mining operation in some of the flatter lying areas. Ore is hauled by LHD equipment to either an internal shaft or directly to rail haulage on the main access tunnel. The shaft employs a double drum hoist with 2.2 tonne skips. Goldcorp plans to connect the rail haulage to the Tayoltita tunnel, which will considerably reduce ore transport costs. Currently, ore is loaded at the portal for surface haulage to the Tayoltita mill.

Central Block Area

The Central Block area is located northwest of Tayoltita. It is linked to it by the San Luis Tunnel, which provides easy access to the area, as well as integration of support services.

Mining operations at Central Block vary according to the width of the veins, since they range from one to six metres. Most are exploited by conventional cut and fill but Roberta and Robertita veins will be exploited by Long Hole system in the second half of this year. Ore haulage is by a combination of LHD equipment and trucking.

Nukay Mine

Mining of the Nukay and La Aguita deposits is by conventional open-pit mining methods utilizing front-end loaders and trucks.  Mine facilities include a mine office, equipment depot, compressed air and a maintenance shop.  Underground mining is carried using traditional cut and fill methods. Ore from the underground mines is trammed to the surface via a 320-metre long adit and trucked to the mill or to a stockpile at the mine site.