080121-08MN006-Sabina Hackett River Project Proposal ... - NIRB

Project Description2.4.5.2 Boot Lake Production PlanThe proximity of the Boot Lake deposit represents an opportunity to extract ore at a relativelyearly stage, either by underground or open pit methods. The current plan is to bring theunderground operation into production as soon as possible at a relatively low rate, and increaseunderground production to a maximum sustainable level upon completion of the permanent oreand waste transport system to surface. This will be realised by accessing the upper portion of theBoot Lake deposit by a decline ramp from surface down to an optimum elevation determined bythe overall project schedule. Production mining will take place in the upper levels whileunderground development for the permanent ore and waste handling system is established. Thepermanent ore and waste handling system will consist of ore and waste passes feeding anunderground crusher located at the ultimate depth of the deposit, a vertical hoisting shaft tosurface and an overland conveyor to the milling facility.Initial ore production from the Boot Lake underground mine will commence in Year 2 at a rate of2,000 t/d. Ore will be loaded into underground haul trucks located on the individual mininglevels and trucked up the decline to the surface crusher located immediately adjacent to the millfacilities. The ore production rate will be increased to 3,000 t/d in Year 4, and 4,000 t/d in Year 5as additional mining areas are developed and mining equipment introduced to the mine. In Year6 ore production will increase to the ultimate rate of 5,750 t/d upon commissioning of thepermanent ore and waste handling system to surface, whereupon truck haulage in the decline willbe limited to the delivery of some bulk materials to the mining areas and some waste haulage tosurface. This production rate will be maintained until the end of the life of mine in Year 12.The initial production rate, as well as the build-up of the production rate and the ultimateproductive capacity of the underground mine, are a function of the mining method, ore and wastehandling system, and capital cost restrictions. The prefeasibility will identify and evaluate anumber of permanent ore and waste handling systems with the view to provide a robust materialshandling system that can allow for a quick build-up to full productive capacity at the lowestcapital and operating cost. The materials handling systems to be evaluated will include shafthoisting as well as conveyor and truck haulage. The prefeasibility study will also evaluate therequirement for an underground crusher. If an underground crusher is required, the prefeasibilitystudy will evaluate potential ore and waste pass arrangements and crusher locations.2.4.5.3 East Cleaver and Main Zone Production PlansThe current plan is to develop stand-alone underground operations at the East Cleaver and MainZone deposits in order to extract mineralization immediately below the respective final pit limitsat the cessation of open pit mining.Each underground mine will be accessed by a decline ramp collared from within the respectiveopen pit and underground development commenced such that stopes are ready to produce uponcessation of open pit mining. Ore production from the East Cleaver deposit is planned to runfrom Year 10 to Year 11 and from the Main Zone deposit from Year 11 to Year 13 at a combinedore production rate of 2,000 t/d.January 2008 Hackett River Project – Project Proposal Sabina Silver CorporationReport Version B.1 2–15 Rescan Environmental Services Ltd. (Proj. #833-2)