Sepon Copper - Innovative leaching solutions

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The Sepon Copper project is a patented copper leaching process comprised of crushing, acid grinding, acid flotation, pressure oxidation and a solvent extraction electrowinning circuit designed to produce 60 000 t/y of cathode copper, which has subsequently been increased by Ausenco to 80 000 t/y.

The project scope included all plant services including reagents, oxygen plant, cooling towers and infrastructure such as power supply, water supply, accommodation to house 4 000 personnel, roads, bridges, waste services and tailings storage.

Ausenco’s scope was for the full EPCM of the project which included process plant and associated infrastructure.

  • EPCM US$235m for a 60 000 t/y SXEW plant and US$31m for the gold plant expansion
  • First acid milling hard rock grinding circuit in the World – use of large ceramic balls and stainless throughout – technical challenge
  • 35,000m3 of concrete in the copper and gold plants
  • 3 500 t of structural steel mostly sourced from Thailand
  • 70 km of complex piping and 260 km of cabling
  • 3 000 construction personnel on site from a cultural background of over six countries
  • Completed 2 weeks ahead of a schedule and under budget
  • Significant procurement and logistical challenges
  • 6 714 046 man-hours at 0.6 LTIFR, peak 3 400 personnel
  • Innovative and complex copper leaching process
  • Winner of 2005 National Engineering Excellence Award.

Project details

Business line
Minerals & Metals
Oxiana Resources Limited
2003 - 2005
Solution phase
Create (EPCM with fee)
Project value
Program management, Engineering, Global procurement, Commissioning, EPC/EPCM, Studies and technical solutions