Image: Sepon Copper plant expansion

Minerals & Metals1 min read

Sepon Copper plant expansion

OZ Minerals
2005 - 2008
Copper; Gold

The Sepon Copper plant uses 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. The POXII project scope included provision of a duplicate pressure oxidation facility, which formed part of an overall expansion of the plant to increase throughput to 80 000 t/y.

Ausenco’s scope was for the full EPCM of the project. This included EPCM US$40m for a duplicate autoclave facility; 1000m3 of concrete; 700t of structural steel fabricated in Thailand; 160t refractory lined steel autoclave fabricated in Finland and transported through Thailand and Laos to the mine site; complex titanium, monel and super duplex piping and valves; and peak construction workforce of 300 from diverse cultural backgrounds.


  • Project completed on time in a heated market in which human and material resources were in short supply
  • Commissioning and ramp up to full production achieved in two weeks
  • One month performance verification successfully completed following commissioning and ramp up.