Mineralization at the Empire Mine is representative of a polymetallic skarn deposit.

Copper-gold-zinc-silver mineralization at the Empire Mine falls into the skarn-hosted, polymetallic deposit type. In fact, historical results and mining records suggest that skarn mineralization at Empire may exhibit depth zonation with copper giving way to zinc and finally tungsten mineralization. The exact process of this zonation is as yet unknown. This skarn has been overprinted by a later epithermal event along pre-existing structures resulting in the gold and silver mineralization encountered.

Both copper-oxide (carbonates, malachite and azurite) and sulphide (chalcopyrite/chalcocite) mineralization is developed to varying degrees within exoskarn in rafted limestone fragments and endoskarn in porphyry. The copper oxide mineralization occurs as veinlets, stockworks, and disseminated oxide/sulphides. The sulphides have similar characteristics, but also occur as massive lenses, both copper sulphides and magnetite, along skarn-hosted fault breccias. In both breccia types, the degree of mineralization appears to be a function of the amount of contained skarn fragments. The copper and iron were apparently introduced into the skarn during the latter stages of the skarnification processes (Chang, 2003). Brittle faulting/shearing and ductile deformation during the skarnification process likely provided the conduits for mineralizing fluids. These conduits may be exemplified ........

There were no constraints on land boundaries, allowing the pit shell and design pit to encompass and capture the majority of the MI&I resources. The PEA-level phased pit design was based on slopes recommended by Call and Nicholas of 45-degrees in the oxide breccia rock type and 51 degrees in all other rock types.

The pit designs are based on PEA-level operating cost assumptions and appear to be consistent with current labour, fuel, reagent, and general processing costs.

Operating costs were calculated assuming CAT 777 trucks and CAT 992 loaders and DM45 production drills. The work schedule assumes two-12 hour shifts per day, 365 days per year at an assumed 92% availability for haul trucks and loaders, and 85% availability for all other equipment.

The PEA mine plan was designed as a series of four phased push-backs to achieve a balanced production of ore and waste rock over the life of the mine. The mine preproduction requirements at the project are minimal given the presence of mineable mineralization near the bedrock surface. The first pit phases are planned near the crusher area to minimize haulage distances at the beginning of the mine life. Waste material from the pit areas will be utilized for construction of the heap leach pad, crusher area and other infrastructure.

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