Conventional open pit mining methods using drill, blast, load, and haul mining are applicable to the Chandalar Mine because the gravel is frozen (permafrost).
The pit shell was segregated into six separate pits or pit pushbacks designated as Lower Pit A, Lower Pit B, Lower Pit C, Upper Pit A, Upper Pit B, and Upper Pit C. Each pit was designed with haul roads.
A preliminary mining schedule was generated from the base case pit resource estimate:
• Process Material Production Rate: 4,000 bcy per day (ypd) for the first year (with one wash plant) and 8,000 bcy per day for subsequent years (with two wash plants)
• Mine Operating Days per Week: 7
• Mine Operating Period per Year: All of first three quarters (January 1 through October 31), with processing of mined material occurring only between May 17 and September 13 (120 days).
• Mine Operating Shifts per Day: 2
• Mine Operating Hours per Shift: 12
Additional design work and phasing of the pits/pushbacks will likely better balance the annual process and waste stripping and metal production. Likewise, adding more blasting and waste stripping days to the seasonal schedule will help smooth out the production schedule.
High-grade material stockpiled during the first- and second-year ramp ups to full production and lowgrade stockpiled material was scheduled to be processed after completion of regularly scheduled highgrade material processing.
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