An updated resource estimate for Polymetal International PLC's Prognoz silver project in Russia showed a 25% increase in the average silver grade and a 19% decline in contained silver.
The project hosts total indicated and inferred resources of 10.1 million tonnes at 731 g/t of silver and 2.0% lead, or 789 g/t of silver equivalent, for 237 million ounces of silver and 197,800 tonnes of lead, or 256 million ounces of silver equivalent. The resource used cutoffs of 106 g/t for the open pit component and 240 g/t for the underground component.
According to Polymetal, the updated estimate incorporates data from 532 drillholes totaling 71,276 meters completed in 2017 to 2018.
The company plans to carry out further drilling in 2019 to upgrade the current inferred resources to the indicated category and establish new resources. It also plans to conduct advanced metallurgical testing and mapping as well as geotechnical studies.
These activities will help the company estimate ore reserves at Prognoz and complete a pre-feasibility study, the results of which are expected in the first half of 2020.