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Prognoz

The largest undeveloped primary silver deposit in Russia

Key facts

Location Verkhoyansk, Republic of Sakha, Yakutia. Russia
Ownership 100%
Mining Open-pit (5-8 years) followed by underground
Processing Flotation
Mineral Reserves (JORC) TBD
Mineral Resources (JORC) 256 Moz of Ag Eq at 789 g/t, 2% Pb
Production start date 2023

Overview

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 256 Moz of Ag Eq at 789 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 and in 2018 increased its interest to 100%. Polymetal provided guidance on its near and long-term plans for Prognoz in the second half of 2018. Project activities for 2018 include 46 km of diamond drilling and extensive in-house metallurgical test work.

  • JORC-compliant reserve estimate in Q4 2019;
  • The results of the Pre-Feasibility Study are expected in H1 2020.
  • Subject to the positive investment decision, the full production run-rate can be achieved in 2024.

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 property is located within the Verkhoyansk mobile belt of northeastern Yakutia. Silver-copper-lead-zinc mineralization, represented by quartz-carbonate-sulphide veins, is located in a sequence of sedimentary rocks composed of Triassic sandstones and siltstones. Nine mineralised zones are defined, with Main and Swamp being the largest (strike length of up to 4 km). Mineralized material is partially oxidised with the depth of weathering varying widely dependent on relief and proximity of water table.

The new estimate incorporates data from 532 additional diamond drill holes (71,276 m) completed by Polymetal in 2017-2018.

Prognoz Mineral Resource estimate in accordance with the JORC Code (2012) as at 01 August 2018
Tonnes Ag Eq Grade Ag Eq Content
(Mt) (g/t) (Moz)
Indicated 5.57 873 156
Inferred 4.50 673 99
Indicated+Inferred 10.07 789 256

Notes: Mineral Resources are reported on the basis of a 106 g/t Ag cut-off for the open pit component (within an optimized pit shell, based on a US$ 16/oz silver price), and a 240 g/t Ag cut-off for the underground component (below the pit shell). A Pb price of US$ 2,200/t was used for the metal equivalent calculation only. For more information please refer to press-release.