Name: Asacha mine.
Location: The Asacha mine is located in Kamchatka, in Far East Russia.
Mine Owner/s: Trans-Siberian Gold.
Brief Description: Asacha is an established high-grade underground gold mine.
The resource at Asacha occurs in the Main zone, which is being mined, and the East zone, which is yet to be mined.
Brief History: The Asacha deposit was discovered in 1973.
Exploration work was undertaken by State-owned Central Kamchatka Geological Expedition from 1986 to 1990. In 1990, a mining licence was granted to Trevozhnoe Zarevo (TZ), and in 1994 TVX Gold (TVX) acquired a 50% stake in the company. Exploration work was conducted by TVX from 1996 to 1998. In 2001, Trans-Siberian Gold (TSG) acquired TVX’s 50% stake in TZ, and increased this to 90% in 2002. TSG acquired the remaining 10% interest in TZ in 2007 and 2010. TSG conducted geological exploration drilling of the Main zone from 2004 to 2005, and of the Eastern flank during 2012. Mine development started in 2008, and mining (extraction and stoping) started in the mid-2011.
Geology/Mineralisation: Asacha is an epithermal gold/silver deposit located on a tertiary volcanic arc typical of ore systems found along the Pacific Rim. The main ore zone at Asacha consists of five steeply dipping veins with two principal veins averaging more than 2 m wide. Veins are characterised by low sulphidation quartz-adularia occurring predominately in dacite domes.
Mining Method: Sublevel drifts and layer-by-layer stoping methods.
Products: Gold.
Major Infrastructure and Equipment: Asacha is an underground mine. Ore processing at the Asacha plant involves:
- two-stage grinding with semiautogenous grinding at the first stage, ball milling at the second stage, pulp classification in hydrocyclones by 0.75 mm and hydrocyclones’ slurry thickening in a high-capacity thickener;
- a cyanidation and carbon-in-leach process;
- electric elution of loaded carbon by basic solutions under pressure using IPS technology, acid treatment and thermal regeneration of carbon;
- melting of cathode deposits into doré alloy; and
- cyanide destruction of slurry tailings through chlorination and storing the neutralised tailings as diluted slurry.
Resources: Total measured and indicated resources as at December 31, 2017, were estimated at 611 000 t grading 20 g/t gold and 56 g/t silver. Total inferred resources were estimated at 345 000 t grading 23 g/t gold and 48 g/t silver.
Prospects: Trans-Siberian Gold considers the geological nature of the area to be conducive to the formation of high-grade epithermal-style gold/silver metal deposits, and a large number of such occurrences have been identified.
Further exploration of these occurrences may significantly increase the resource base.
Contact Details:
Trans-Siberian Gold
Tel +44 1480 811871
Email enquiries@trans-siberiangold.com
Website http://www.trans-siberiangold.com