The largest undeveloped primary silver deposit in Russia

Key facts

Location Verkhoyansk, Republic of Sakha, Yakutia. Russia
Ownership 5% with an option to increase stake to 50% (investment decision no later than Q1 2020)
Mining Open-pit (5-8 years) followed by underground
Processing Flotation
Mineral Reserves (JORC) TBD
Mineral Resources (JORC) 292 Moz of silver at 586 g/t, 3% lead
Production start date 2023


Prognoz is the largest undeveloped primary silver deposit in Russia and currently one of the world’s top silver development projects that may potentially succeed Dukat. The property comprises a very large high-grade resource of 292 Moz of silver at 586 g/t with excellent exploration upside that estimated at 119 — 273 Moz of silver contained at 469 g/t. Polymetal envisions a relatively low-capital and fast development approach for the asset that is based on open-pit mining and conventional processing. Production from the property is estimated at 20 Moz of silver per annum based on a 100% share in the property.

Polymetal entered into the project in 2017, acquiring a 5% indirect stake for US$ 3 million with an option to increase its interest to 50%, subject to certain conditions. Polymetal is obligated to undertake 25 km of diamond drilling in order to complete a technical study that will result in an externally audited JORC-compliant reserve estimate in Q3 2019. Total capital expenditures required to perform the drilling and complete the technical study are expected at US$ 10 million per annum during FY 2017-2019. Upon completion of the technical study and the reserve estimate, but no later than 31 March 2020, Polymetal will have the right to exercise the option for the remaining 45% stake.

Location History Geology Mineral Resources Estimate

The 56 km2 licence area for Prognoz is situated in the Verkhoyansk municipal district of the Republic of Sakha (Yakutia), 444 km north of the regional centre of Yakutsk (population of approximately 300,000) and approximately 220 km southwest of the municipal centre of Batagai (population of approximately 3,700). The site is remote with seasonal access from Batagai by winter-unpaved road. There is no infrastructure at or near the property.

First data concerning the silver-polymetallic mineralization on the Prognoz property were obtained during geological mapping by the Central Geological Survey Expedition from 1968 to 1971. From 1973 to 1977 additional geological mapping was completed at the property, along with an extensive exploration program comprised of soil sampling using two grids (250×100 m and 250×50 m) and 6,500 m of trenches. Exploration activities yielded positive results with 11 mineralized zones with high grades of silver, lead and zinc identified. Between 1987 and 1990, the Yanskaya Exploration Expedition carried out additional exploration works, identifying the mineral composition and main parameters of the mineralised zones. From 1990 to 1998, Prognoz was explored by Yangeologia, which conducted further trenching, core drilling, soil and bedrock sampling, as well as geophysical surveying.

Between 2006 and 2008, an intensive in-fill drilling program with with 873 drill holes totaling 78,925 m was completed, confirming the historical trenching and drilling results. In 2009, the property’s first JORC-compliant resource estimate was prepared by Micon. As part of the resource estimate, pilot plant testwork was performed, demonstrating robust silver recovery levels into both gravity and flotation concentrates. Since 2009, the asset was on care and maintenance until Polymetal’s involvement in the project in the beginning of 2017.

The licence area is located within the Verkhoyansk mobile belt of north-eastern Yakutia and is structurally determined by a set of joints of various hierarchy levels at the intersection of the Allah-Nel’gesinskiy fault and the Sredne-Sartang fault zone. Silver-lead-zinc mineralization represented by quartz-carbonate-sulphide veins is located in a sequence of sedimentary rocks composed of Triassic sandstones and siltstones with thicknesses varying from 2 to 5 m, and in some cases up to 10 m. Nine mineralised zones have been defined with Glavnaya and Boloto being the largest ones (strike length of up to 2 km) and explored in more detail. The average vein thickness is 3 m.

A JORC-compliant resource estimate for the deposit was prepared by Micon in 2009. Resources were estimated up to the depth of 400 metres.

Prognoz Mineral Resources estimate as at 30 May 2009
Tonnes Ag Grade Ag Content
(Mt) (g/t) (Moz)
Indicated 5.86 773 146
Inferred 9.64 473 147
Indicated+Inferred 15.5 586 292

Notes: Silver cut-off grade of 100 g/t

In addition to the resource estimate, Micon performed an evaluation of the conceptual mineral potential for 18 of the other known mineralised zones which were not included in the resource estimate. The additional mineral potential is estimated between 7.9 — 18.1 Mt of ore at 469 g/t silver for 119 — 273 Moz of silver contained.