The Oyu Tolgoi Underground Project (OT Underground) site is located in the South Gobi region of Mongolia 550 km south of Mongolia’s capital city, Ulaanbaatar, and approximately 80 km north of the border with China.
The C2S (Conveyor to Surface) decline forms a crucial part of the OT underground project; providing vehicular access to the underground mine for materials, equipment and personnel transportation, and housing a conveyor system for the transfer of crushed ore to the surface.
The C2S Primary Ventilation system is temporary, providing primary air to support mine development until breakthrough with the underground mine. The C2S primary ventilation system is located on the surface adjacent to the boxcut; fans and ducting will provide primary air via the conveyor steel multiplate arch tunnel. The air will reticulate to the underground mine via the conveyor decline and exhaust back up the service decline.
During winter, heaters will heat the intake air to a minimum +2oC.
After the C2S breaks through into the underground mine in approximately four years the primary ventilation system will be decommissioned and both the Conveyor and Service declines will serve as exhaust airways.
The primary function of the C2S Primary Ventilation is to support underground mine development activities
by providing ventilation and consists of:
i) Four (4) off diesel fired mine air heaters;
ii) Two (2) off two-stage primary vent fans;
iii) Ducting including ducts, dampers, duct insulation and weather protection;
iv) MV (10.5kV) substation;
v) LV (<1000V) substation; and
vi) Fuel storage tank and associated piping.
The C2S Primary Ventilation will be decommissioned and removed after breakthrough of the C2S declines
to the underground mine.
Works for the construction of the C2S Primary Ventilation will include the following:
i) Replacement of local fill under equipment foundations with Engineered Fill;
ii) Installation of buried services, including earth grids and electrical conduits;
iii) Construction of cast in-situ concrete foundations;
iv) Installation of equipment, including fans, heaters and tanks;
v) Installation of ducting;
vi) Installation of MV and LV electrical rooms and equipment;
vii) Installation of piping and valves; and
viii) Installation of electrical, instrumentation and control materials and equipment.