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

Project Descriptionthe first phase of the Main Zone pit will finish in Year 8. The second phase of the Main Zone pitwill start in Year 4 and will be completed in Year 13. Mining of the first phase of the EastCleaver pit will commence in Year 2 of the schedule with the second phase of that pit starting thenext year. The East Cleaver open pit will be completed in Year 9. The prefeasibility study willconsider alternate open pit phasing and sequencing options during the review of the preliminaryoperating philosophy noted above.2.4.4.2 High Grade OreHigh grade ore from the open pits will be hauled by truck to the surface crusher locatedimmediately adjacent to the mill facilities. The currently proposed mill site is located on atopographic high point approximately 500 metres north east of the Boot Lake deposit. During thecourse of the prefeasibility study alternate locations for the milling and or surface crushingfacilities will be explored and evaluated in order to optimize ore haulage routes and costs.2.4.4.3 Waste Rock and Tailings StorageSuitable waste rock from the initial mining of the Main Zone open pit will be used to constructthe initial tailings facility. The remaining waste rock from both the Main zone pit and the EastCleaver pit will be hauled by truck and placed in a waste rock storage facilities.An acid rock drainage (ARD) model will be developed for each deposit as part of theprefeasibility study, which will allow the potential for acid rock drainage to be addressed.Strategies will be developed once the waste rock materials are categorized and quantified, theresults of which will be properly incorporated into the design of the waste storage facility and thestarter dams required for the tailings facility. If waste rock is required for backfilling inunderground stopes, it will be acquired from the waste rock storage facility rather than bequarried if the quality of waste rock is suitable.During the course of the prefeasibility study alternate locations for the waste rock and tailingsstorage facilities will be evaluated in order to strike a balance between minimizing theenvironmental disturbance of the project and minimizing capital and operating costs. Theevaluation will include the potential to provide a separate waste rock storage facility near oradjacent to the East Cleaver open pit.2.4.4.4 Low Grade OreLow grade ore mined over the life of the Main Zone and East Cleaver open pits will be hauled bytruck and placed in a single low grade stockpile facility located within the confines of the wasterock storage facility. The prefeasibility study will evaluate the potential to provide a separate lowgrade ore stockpile facility near or adjacent to the East Cleaver open pit.2.4.4.5 GroundwaterThe influence of groundwater inflows and pressures on pit slope stability, pit dewateringrequirements and open pit operating conditions has been considered to be negligible due topermafrost conditions. The prefeasibility study will assess the potential for the existence of atalik under Camp Lake, quantify the possible extent of such a feature, determine how that willaffect the hydrological and geotechnical conditions of that part of the Main Zone pit locatedJanuary 2008 Hackett River Project – Project Proposal Sabina Silver CorporationReport Version B.1 2–13 Rescan Environmental Services Ltd. (Proj. #833-2)