The Board of Directors of Russian gold mining major Polyus has made a final investment decision on the construction of Mill-5 at the Blagodatnoye gold mining complex in Krasnoyarsk region, 25 km away from its Olimpiada operation. The company has successfully completed the Feasibility Study (FS) for the construction of a new mill at the Blagodatnoye complex. The FS findings assume that the most efficient option for the long-term development of Blagodatnoye is continued open pit mining down to the bottom elevation of -70 mrl (so 70 m deeper than the current 240 m deep operation) with simultaneous throughput expansion.
In terms of the pit development, Polyus expects to further increase the proportional use of large-scale mining equipment. The FS also assumes the introduction of a 20 Mt/y capacity in-pit crushing and conveying (IPCC) system, as opposed to conventional truck delivery. IPCC will start delivering ore to both Mill-4 and Mill-5. This will see an edge of pit crushing station consisting of a primary gyratory crusher buried in the pit wall being fed -1,000 mm material which will be crushed to -250 mm feeding a reclaim conveyor then an underground conveyor then a surface conveyor to feed a covered crushed ore stockpile. The 3,300 kW (3 x 1,100 kW) conveyor length will be 1.64 km with a belt width of 1,400 mm.
According to the FS, the nominal processing capacity of Mill-5 stands at 8 Mt/y, increasing total throughput capacity at the Blagodatnoye complex to 17 Mt/y combined. The company expects to apply a conventional gravity-flotation flowsheet at Mill-5, similar to the flowsheet at Mill-4. There will be some additional improvements including high-performance concentrators at the mills discharge (previously at cyclones underflow), screens at the SAG mill discharge, larger equipment (scavenger flotation, CIL) and an additional ore feed line to the ore milling circuit via the secondary crushing building.
The grade in ore processed at Mill-5 is expected to average 1.4 g/t or the life of mine. The anticipated decline in grades compared to current levels at Mill-4 is attributable to the processing of mix of in-situ and the low-grade stockpiled material. During the first five years of operations the estimated recovery rate at Mill-5 is 87.9%. TCC is estimated to average $320/oz.
Construction capex for Mill-5 is now estimated at approximately $600 million. This figure includes construction of the new mill and IPCC as well as the upgrade of the mining fleet and relevant infrastructure spending. Construction is to due to start by end 2021 with commissioning by 2025.
In accordance with the current construction schedule, the launch of the Mill-5 is anticipated in 2025. Post the ramp-up, Mill-5 is expected to provide 390,000 oz of incremental gold volumes.
