The Suzdal Gold Mine displays similarities to Carlin type deposits typified by development in an extensional environment such as rift settings in which orogenic activity has occurred. These types of deposits are hosted along major deep crustal structures such as the Char-Gornostai-Zimunai and Suzdal faults. Mineralising fluids in Carlin deposits are similar to the metamorphic mineralising fluids that occur in orogenic deposits. Precipitation of the mineralisation is through the neutralisation of the fluids through carbonate dissolution typically through a reaction with host rocks such as limestones (Robb, 2005). Argillic alteration, silicification and sulfidisation also play a part in the precipitation of mineralisation.

Similarities between the Suzdal Gold Mine and typical Carlin type deposits includes mineralisation being stratiform similar to other large Carlin deposits as well as gold mineralisation being associated with arsenopyrite, marcasite, and pyrite often with grain sizes in microns. The Suzdal Gold Mine does however, have some noticeable differences from Carlin deposits these include the presence of free gold, a lack of minerals such as cinnabar and realgar, and differing sulphur isotropic compositions as reported by Kovalev.K.R. et al, 2008.

Four SW-oriented en echelon orebodies are recognised, with dips of 40° to 90° SE. Combined orebodies 1/3 and 2 in the northeastern part of the Suzdal Gold Mine possibly merge at depth and are hosted by a predominantly calcareous facies, whilst orebody 4 to the south west is hosted by sandstone and carbonaceous siltstone. The orebodies intersect or are subconcordant with bedding. Individual orebodies extend to a depth of 400m, are 1.5 to 2km in length and 20 to 150m thick, and can be traced for 200 to 800m at the surface, with a thickness of 1 to 40m.

Suzdal underground mine comprises three main ore zones, Zone 2, Zone 4 and Zone 137. Workings currently extend to 610 m below surface and will reach 800 m depth upon depletion of the current Ore Reserves.

Development mining is achieved using modern electro-hydraulic single and twin boom drill jumbos to drill blastholes, diesel powered load-haul-dump loaders (“LHD”) to clean the blasted rock from each blasted advance, and diesel powered articulated dump trucks (“ADT”) to haul broken rock to surface (ore) or to underground voids to be used as backfill.

Production is achieved using variants of the long-hole sub-level open stoping method, either top-down “uphole benching” with eventual backfilling, or bottom-up “Avoca” progressively backfilling each sublevel.

Blastholes are drilled using dedicated electro-hydraulic long-hole drill rigs, blasted ore is removed with LHD and ore is transported to surface with ADT.

Surface is accessed through four transport declines with 8° inclination. Three declines exit the mine through previously mined open pits, while the fourth, from Zone 4, exits through a dedicated box-cut excavation. Development waste is used for backfilling and is transport from development faces to filling locations by LHD or truck.

Stability of the workings is maintained by the installation of ground support (friction anchors, mesh sheets, shotcrete), leaving supporting pillars of ore unmined, for later extraction, and filling mined stopes with development waste as backfill when strategically required.

Crushing
The crushing circuit consists of three stages, a primary jaw crusher and secondary and tertiary cone crushers. The jaw crusher is in open circuit, and there are scalping screens ahead of each of the cone crushers, which otherwise operate in open circuit. The product from the crushing circuits is nominally -15 mm.

Grinding
The grinding circuit consists of three 2.7 m diameter, 3.6 m long ball mills (380 kW each). Two are configured as primary mills and operate in parallel. These mills operate in closed circuit with a screw classifier. Classifier undersize reports to hydrocyclones, the overflow of which reports to flotation. Cyclone underflow reports to the third ball mill, which also operates in closed circuit with a screw classifier. The grind size feeding flotation is approximately 50% -75 ?m.

The Suzdal process plant treats refractory sulphide-hosted gold ore through a plant incorporating flotation and bacterially assisted oxidation of the sulphide ahead of gold recovery using a carbon-in-leach (“CIL”) circuit. Doré is produced on site.

Following an earlier heap leach facility on site, the sulphide plant commenced operation in 2005 with a plant capacity of 300 ktpa of ore. In 2010, the plant capacity was expanded to its current capacity of approximately 575 ktpa of ore.

Flotation
The flotation circuit consists of two roughing stages, scavenging and two stages of cleaning. The first rougher stage uses two parallel trains of three 16 m3 mechanically agitated cells, producing final concentrate. Tailings from this stage are reground using two 2.7 x 3.6 ball mills in closed circuit with cyclones, with a target product size of 75-80% -
75 ?m. The second rougher stage consists of eight 16 m3 cells, which is followed by scavenging, using six 40 m3 ce ........