After completing a detailed study, Fluor performed engineering, procurement and construction for a 750,000 t/a silver, lead, zinc concentrator. The project was completed within budget and on schedule and represented a successful breakthrough in the way Mount Isa Mines executes projects. The turnkey contract approach allowed Mount Isa Mines to specify the metallurgical design parameters and then hand over full responsibility for detailed design, procurement and construction to us.

We performed design, engineering, procurement and construction on the silver, lead, zinc concentrator at Mount Isa Mines' NW Queensland mine.

The plant included a reclaim tunnel, coarse ore conveying, grinding, flotation, thickening, concentrate storage and loadout.

Scope Highlights

• Coarse ore from a 4,500t live stockpile is fed to the SAG mill feed conveyor by four plate feeders controlled by a weightometer.

• The 5m x 6.7m grate discharge SAG mill could be converted to a 1,600,000 t/a ball mill in a future expansion.

• An existing ball mill and cyclone cluster were relocated from the Mount Isa Copper Concentrator for use in this plant.

• In addition to lead and zinc concentrates, a lead/zinc middlings product was recovered by flotation.

• Conventional flotation cells were employed for scavenger flotation, column flotation cells were used for cleaning the lead and zinc rougher concentrates, and the Jameson flotation cells were used for cleaning the LGM product.

• A tower mill was used for regrinding combined lead and zinc middlings prior to LGM flotation.

• Two sampling systems were used, one for on-stream analysis, the other for inventory purposes.