Pit wall disclosed on May 4 thMining With the strategic stockpile of 1.6 million tonnes, which is equivalent to five months of production, now in place as well as the dual ramp system, ore mining rates dropped during the quarter to more optimal levels. Ore mining rates for the quarter averaged 339,096 tonnes per month at an average mining grade of 1.8 g/t. Waste mining took place on the interim western cutback in preparation for the next sequence of ore mining in the centre of the pit. The next pushback sequence will commence during Q2 2017; this pushback sequence is planned to take place on the western side of the pit and will continue for the balance of 2017.
Consistent with the Company’s DPP and risk management philosophy, the Company has now built a 1.6Mt strategic stockpile of ore. This stockpile, in conjunction with the fully operational dual ramp system in the Nkran pit, allows the Company to maintain steady processing rates even in the event of a temporary impact on inpit access or mining rates.
The Nkran pit has a history of side wall failures, even during the Resolute operating days. Since mining recommenced in 2015, there have been several partial side wall failures. During the quarter, there was a partial failure on the western wall of the Nkran pit, however due to the mitigation measures which have been put in place, as well as the slope stability radar (which has been instrumental in predicting geotechnical issues in the walls of the pit since mining began) there was no impact on either production or safety in the pit.
The grade for the quarter was lower as a result of mining through a planned lower grade section of the orebody. The increase in the strip ratio this quarter was driven by the implementation of the new CSA Global resource model midway through the quarter. Going forward, the life of mine strip ratio for Nkran is expected to be around 6:1, which will be confirmed by the new life of mine plan that will be included in the Expansion Definitive Feasibility Study due to be published in Q2 2017.
Sedar May 4 MD&A