|Location||Sverdlovsk Region, Russia|
|Operating mines||Voro, Saum|
|Key exploration projects||Andrey, Aramashevsky, Maslovsky|
|Processing||1.05 Ktpa CIP circuit|
|Ore reserves (JORC)||1.0 Moz GE at 2.5 g/t|
|Mineral resources (JORC)||1.0 Moz GE at 2.6 g/t|
|Production start date||2000 (HL), 2005 (CIP)|
|Life of mine||2043 (CIP)|
Voro is one of the very first key assets acquired in 1998, which consists of an open pit, a carbon-in-pulp plant (CIP) with a capacity of 950 Ktpa and a seasonal heap leach (HL) with a capacity of 1 Mtpa. By combining various processing methods, Voro can use both primary and oxidized ore as feed. Since the start of production, the asset has demonstrated sustainable operational and financial results and made a significant contribution to free cash flow.
In 2022, production at Voro was stable at 91 Koz. CIP plant recorded higher grade but lower recoveries due to the processing of transitional ore from Peshernoye.
Mining at Saum was discontinued on the back of deteriorating economics (strong Rouble and higher rail tariffs).
Voro flotation plant is 90% completed. Start-up is expected in Q2 2023 (previous plan was 2027). It will help to bring forward cash flows from high-grade polymetallic deposits, such as Peshernoye, Galka and Saum.
- At the flotation plant, major processing equipment has been installed and the concentrator building has been fully winterised
- Modernisation of the equipment at the heap leach area in order to increase the productivity for tailings processing at the new plant.
- At Andrey deposit, the initial mineral resource estimate amounted to 252 Koz of gold with an average grade of 2.9 g/t. In 2023, Polymetal will complete a feasibility study according to the Russian GKZ standards along with ore reserves estimate.
- In 2023, at Pavlov deposit, Russian-standard feasibility study will be completed and ore reserves will be reported. The Company also plans to continue prospecting at the Aramashevo group of licensed areas.
- Purchased up to 95% of electricity from renewable energy sources
- 99% of water used on site is in a closed cycle or treated wastewater
- 100% of tailings are now dry-stacked.
- Flotation plant start-up in Q2 2023 and ramp-up
- Preparation for underground mining at Peshernoye.
The deposit was first discovered in 1985. In 1998, the Group acquired the company that held the mining licence for Voro. In 1999 mining resumed and heap leaching circuit for oxidised ore was launched in 2000. In 2005, the CIP plant was commissioned with a capacity of 450 ktpa. The plant was expanded to 600 ktpa in 2007 by replacing three-stage crushing with one-stage crushing and SAG milling. The plant was further expanded to 940 ktpa in 2008 by removing bottlenecks from thickening, leaching and filtration sections. In 2010, mining started on the new southern pit to extract ore from an extension of the main deposit.
The Voro deposit is a fracture zone where the ore body generally lies in the footwall of the fault.The main mineralised zones occur within brecciated limestone and are erratic in shape, not visually identifiable and require dense grade control drilling for final delineation prior to mining. A highly variable weathering pattern is developed across the deposit, with a broad oxidation surface developed to a depth of 65 m, but zones as deep as 100 m are developed where karstic features have formed in the limestone. An extension to the main Voro deposit of mainly oxide material has been outlined in the south.
Oxidised gold at Voro occurs mostly in free form. In primary ore, gold occurs in a variety of forms. These include free, inter grown with host minerals, associated with pyrite and attached to silicates. The highly variable mineralogy of primary ore requires careful selection of processing regimes.
The Voro deposit is mined solely by open-pit mining methods and this is expected to continue until the end of its mine life. Ultimately, the mine design is the excavation of two pits: a 240 m deep pit to the north; and an 80 m shallow pit to the south. A conventional truck-and-shovel method is employed with drilling and blasting primarily used in the deep pit. Both primary and oxidised ore are stockpiled and blended near the pit and then transported to the processing facilities located 6 km away. Waste dumps are located 1 to 2 km from the pit.
Two processes are used to extract gold from the two types of ore mined at Voro. Oxidised ore is processed by heap leaching with a capacity of 1,000 ktpa, while primary ore is processed by milling/CIP with a capacity of 950 ktpa.
The primary ore is crushed in a jaw crusher and further treated in a three-stage milling circuit (one SAG mill and two ball mills). A standby circuit, which operated before the expansion (three-stage crushing), is available during the SAG mill downtime. After milling, slurry is thickened and leached (approximately 48 hours residence time) in a CIP circuit. Further processing includes desorption, electrolysis and smelting to doré. Tails are filtered and transported to a dry-stacking tailings storage facility immediately adjacent to the plant.
|Ore Reserves||Tonnage, Mt||Gold grade, g/t||Silver grade, g/t||Copper grade, %||GE grade, g/t||Gold, Koz||Silver, Moz||Copper, Kt||GE, Koz|
|Mineral Resources||Tonnage, Mt||Gold grade, g/t||Silver grade, g/t||Copper grade, %||GE grade, g/t||Gold, Koz||Silver, Moz||Copper, Kt||GE, Koz|