Patented copper leaching process

The Sepon Copper Project is a patented copper leaching process comprised of crushing, acid grinding, acid floatation, pressure oxidation, and a solvent extraction electrotwinning circuit designed to produce 60,000 tpa of cathode copper, which has subsequently been increased by Minerals & Metals to 80,000 tpa.  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.

Our scope was for the full EPCM of the project which including process plant and associated infrastructure.

• EPCM US$235M for a 60,000 tpa SXEW plant and US$31M for gold plant extraction
• First acid milling hard rock grinding circuit in the world - use of large balls and stainless throughout - technical challenge
• 35,000m³ of concrete in the copper and gold plants
• 3,500t of structural steel mostly sourced from Thailand
• 70km for complex piping and 260km of cabling
• 3,000 construction personnel on site from the cultural backgrounds of over six countries.

Project Highlights

• Completed two weeks ahead of a 2.5-year schedule
• Completed 1.8% under budget
• Significant procurement and logistical challenges 
• 6,714,046 man hours at 0.6 LTIFR, peak 3,400 personnel
• Winner of 2005 National Engineering Excellence Award.