Development of FDN began in 2017, with first ore produced in 2019, and commercial production achieved in February 2020. The current mining method is longhole transverse stoping in fair to good ground and D&F stoping in poor ground.
The life of mine includes continuing to use longhole and drift-and-fill mining methods as follows:
• North and Central area: transverse longhole open stoping with paste backfill on 25 m levels in fair to good ground conditions, and drift-and-fill in poor ground conditions.
• South area: transverse and longitudinal open stoping with paste backfill on 25 m levels in fair to good ground conditions. Production in the South Zone is currently scheduled to begin in 2028.
Originally designed for a 3,500 tpd underground production rate, the mining rate was increased to 4,200 tpd in 2021, and is currently operating at a production rate of 4,400 tpd. Additional debottlenecking and engineering studies are underway to evaluate going to a production rate of 5,000 tpd.
The host rock for the deposit is competent but the resource zone is less competent with a small portion in poor rock (less than 8%). Geomechanically, the rock mass quality varies from Poor to Fair (RMR range 40 to 55), with the intact rock strength averaging 60 MPa. The deposit is also relatively close to surface (approximately 200 m below surface in some locations).
Given the variable conditions encountered at FDN, a range of methods and/or sup ........
