LSE-listed Polymetal has announced an updated mineral resource estimate for the Prognoz silver deposit, in Yakutia, Russia, which the company says has the potential to be one of the world’s largest primary silver deposits.
Prognoz has resources of 256-million ounces of silver-equivalent at 789 g/t.
"In-fill drilling results exceeded our expectations and strengthened our belief that Prognoz may succeed Dukat as one of the largest primary silver deposits in the world,” Polymetal CEO Vitaly Nesis said on Wednesday.
The new estimate incorporates data from 532 additional diamond drill holes (71 276 m) completed by Polymetal in 2017 and 2018.
Compared with the previous mineral resource estimate completed by Micon in 2009, Polymetal added lead and used higher cutoff grades together with conservative extrapolation parameters to ensure a more robust and reliable estimate. The new estimate’s pure contained silver decreased by 19% to 237-million ounces, while the average silver grade increased by 25% to 731 g/t. The average vein width increased by 15%, from 1.9 m to 2.2 m.
Polymetal is busy with a prefeasibility study, which will be completed in the first half of 2020.
The company said that there was a slight delay in the timing of the study, but explained that it was driven by the need to better understand the limits of oxidation in the mineralised material, which was a key input for the selection of the processing plant design criteria.