​Project details

The Oyu Tolgoi mine, located 550km south of the Mongolian capital of Ulaanbaatar and 80km north of the Mongolia-China border, is one of the largest copper-gold projects in the world.

CWA performed engineering and procurement services for the finished product export system at the mine including the world’s largest bagging system for cohesive bulk materials. The heart of the bagging system consists of four bulk bagging units designed to load concentrate at a rate of up to 320 metric tonnes per hour with some built-in redundancy. Each unit is capable of loading two-tonne bags at a rate of up to 80 metric tonnes per hour.

The system is designed to operate 24 hours per day throughout the year, except for scheduled maintenance, and is equipped with accessories including bag inflators, neck sealers to prevent/minimize dust emissions, dust collectors, label printers, and pallet feeders.

The 4,000m3 bagging building includes 590m2 of commercial space with facilities including a laboratory, a sample area, offices, washrooms, and a lunch room.


The decision to implement a bagging plant was made at a late stage of the project. The design, procurement, and construction needed to be completed within 12 months.


CWA successfully met the project’s aggressive schedule requirements. Within 11 months, CWA:

  • Issued over 435 engineering drawings.
  • Reviewed over 5,000 shop drawings.
  • Answered over 150 RFIs.
  • Reviewed over 200 vendor documents.
  • Issued and evaluated over 50 procurement packages.

Within one month, CWA completed the preliminary engineering including six alternative layouts, a time and motion study, a schedule, and a capital cost estimate. CWA then performed the detailed design of:

  • The material handling systems including a dump hopper, a transfer conveyor from the storage building, a shuttle conveyor, the complete bagging system, overhead cranes, bag loadout conveyors, and the truck loadout station.
  • The dust collection, HVAC, and fire protection systems.
  • Structural and electrical elements.

CWA investigated sourcing across the world and pulled together a team of suppliers to fast-track fabrication and equipment supply in Asia, Europe, and North America. CWA assisted with procurement on all three continents, including placing staff in China for quality assurance and expediting purposes.

CWA also provided tendering, construction support, and commissioning support services.