overview and location
The Berezovskoye license covers an area of 7.8 sq km and is located 6 km from the tailings processing plant and 2 km from Centralnoye and has full access to existing infrastructure. In 1960s Khinganolovo launched exploration works on Berezovskoye deposit and did more than 30 thousand meters of boreholes including underground drilling and 246 thousand cubic meters of trenching. In late 1980s Soviet enterprises carried out trial mining in preparation for full scale mining operations after the depletion of ore on Khinganskoye deposit.
Berezovskoye deposit is localized in a weakly differentiated massive ore body relative to the array of isotropic rhyolite. Along the related-intersecting microfracturing systems linear metasomatic ore bearing zones of north-west and north-north-east directions have been formed.
Ore columns at the Berezovskoye deposit represent isolated maximum concentrations of tin and polymetals in narrow northwest and north northeast trending steeply pitching zones of fault junctions. The ore contains tin mainly in a form of cassiterite, rarely – stannite and as cryptocrystalline and colloform soluble formations. Tin distribution in the ore of the deposit has a distinctly pocket nature attributable to abrupt variations of thickness and grades. Sulphides in quartz-sulphide ore are represented by galena, sphalerite, stannite, chalcopyrite, bornite, chalcocite. The chemical composition of the ores corresponds with sulfide-cassiterite type, in some cases with the type transitional to the cassiterite-quartz.
The deposit comprises 16 known ore bodies with a length of up to 540 meters hosting high grade cassiterite-silicate tin ore. The drilling operations were limited by 350-500 meters and a number of ore bodies has not been blocked out on that depth. The thickness of ore bodies varies from 0,5 to 2,5 meters.
«RJC Consulting» Ltd. was commissioned by Khingan Resources Limited to perform the mineral resource estimation for Berezovskoye tin deposit and issue a report in accordance with the JORC Code guidelines (2012). RJC Consulting made a detailed evaluation of the historical drilling data and made a site visit. The resource base of Berezovskoye deposit has high growth capacity on Chetvertaya, Tretya and Malutka ore zones. The most advanced is Obeshayshaya ore zone consisting up to 3 perspective ore bodies. In addition to tin Berezvoskoye deposit has resource potential for silver with an average grade of 40 g/t.
The mineral resources for Berezovskoye has been estimated at a rate of 2 mln.tonnes of ore containing 16121 tonnes of tin (average Sn grade - 2.64%). The resources has been classified as Inferred. Estimated potential for mineral resources increase is more than 8 thous.tonnes of tin. The first drilling is planned for 2018.
The mine design for Berezovskoye deposit is based on ramp access to a cut-and-fill mining operation. Cut-and-fill mining is most suitable for mining steeply dipping orebodies, in strata with good to moderate stability, and a comparatively high-grade mineralization.
Development of Berezovskoye cut-and-fill undergound mining operations includes: a footwall haulage drive along the orebody at the main level; an undercut of the stope area, with drains for water; a spiral ramp in the footwall, with access drive to the undercut; and a raise connection to the level above, for ventilation and filling material.
The mining fleet from Centralnoye project will be relocated to the Berezovskoe mine after production has been completed. The annual mining operations are designed for 876kta at 1.6 % Sn. The operation has a mine life of 6 years. Peak production of 260 ktpa is reached in 2nd year.
Confirmation drilling programme for Berezovskoye deposit using underground and surface exploration boreholes. Expected drilling volume is 14 thous. meters.
Launch of the underground mining construction operations. The mine design based on ramp access cut-and-fill mining method.
Commisioning of the underground mining operations on Berezovskoye deposit after production completion on Centralnoye. Average production for Berezovskoye project is 146 ktpa of ore and 6 years of life-of-mine.