Savkino Gold Mine is located 400km east of Chita in the Zabaikalsky Province of South Siberia. The mine is owned and operated by UK-based company White Tiger Gold. The property lies in the south appendage of the Ildikan license area and has a surface area of 3.1km2.
The exploration and production of hard-rock gold license was approved to Ildikangold, a Russian subsidiary of White Tiger Gold, by the Federal Ministry of Natural Resources in July 2006. In May 2008, permission was granted to develop and begin operations at the mine.
Production at the Savkino mine commenced in October 2008. The mine produced 18,261Oz of gold in 2012.
Geology and mineralisation of the Savkino mine area
The deposit lies within the Smirnovsko-Mikhailovsky Mineral district. It is hosted between the Smirnovskaya and Mikhailovskiy regional fault zones.
The geology at the mine is prevailed by the Savkino anticline which is confined by the Savkino and Mihkailovskiy thrust faults. The Savkino thrust fault contains lower Cambrian carbonate rocks that are penetrated over lower Jurassic terrigenous units.
The mine also hosts igneous rocks such as lower permian granite, Jurassic granodiorite and Cretaceous rhyolite. Most of the gold is contained in the north-east-trending Jurassic granodiorite and syenite porphyries dykes that are positioned by significant hydrothermal revision of the calcareous rocks.
The gold mineralisation is hosted in the gold placer lying in the Lower Borzya, Ildikan and North Ildikan River valleys. It is also hosted in the hanging wall of the anticline. High rated gold deposits are situated in the upper Jurassic dykes along with silica, sericite, pyrite and barite.
Stretching up to 3km long, the mineralisation exists at a depth of 175m. The width varies between 30m and 50m.
Savkino mine reserves
According to the latest reserve estimate released in 2014, the mine contains proven and probable reserves of approximately 2.8 million tonnes (Mt) graded at 1.31g/t Au, which is equivalent to 119,350kOz of contained gold. The measured and indicated resources are estimated at 3.95Mt graded at 1.36g/t Au, which is equivalent to 173,220Oz of contained gold. The inferred resources are estimated at 15,660Oz.
Open-pit mining methods
Savkino has been developed as an open-pit mine and is being mined using truck and shovel method. The pit was dug to a depth of 178m. The strike length and width of the pit are 1,100m and 400m respectively. The open-pit hosts approximately 12,000m3 of overburden with strip ratio of 4.2.
Ore processing at the Siberian mine
The run of mine ore is transferred to the primary jaw crusher by conveyors.
The crushed ore is carried to the second crusher for next stage of crushing. The output is conveyed to a surge bin and then to an agglomeration drum containing leach pregnant solution (PS).
The leach solution is prepared by processing the leach solution of cement, lime and barren with dilute cyanide solution. It is disseminated over the heap surface from an array of pipes, wobblers and drip emitters to create the pregnant solution (PS).
The PS comprising dissolved gold passes via the heap surface and accumulates in the pregnant solution pond. The resulting solution from the pond is pumped to a adsorption, desorption and recovery (ADR) building. The gold is absorbed on to actuated carbon from the barren solution and stored in two pachuca tanks.
The gold accumulated carbon is stockpiled in the first pachuca tank and transmitted to a elution and electrowinning circuit. The resultant cathode is smelted with fluxes in an induction chamber and transported to the refinery for acidic and caustic washing and then conveyed to the adsorption circuit. The gold is retrieved from the carbon by using a hot solution of caustic soda.
Expansion of the Savkino gold mine
Phase 2 expansion of the mine increased the processing plant’s capacity from 650,000tpa to 1.7Mtpa and involved the construction of a second pit in the southwestern area of the mine, expansion of existing gold recovering plant, mining fleet, and construction of new heap leach pads.
A new power line was installed, and a new crushing and screening plant with a capacity of more than 9,000tpd was commissioned in January 2013 as part of the expansion.
Financing the Savkino gold mine expansion
IFC-Bank provided a revolving credit facility to Ildikangold in February 2011 for the expansion of the Savkino mine.
Ildikangold entered into an agreement with Sberbank in August 2011 for a $10m non-revolving credit facility for the expansion project. A senior secured term loan facility obtained through VTB was also used for the expansion.