Treatment facilities at the first major greenfields mine to be developed in North America in almost a decade are starting to take shape, with an Australian processing equipment manufacturer providing critical assistance during the design and construction phase.
Located in Eastern Alaska, the Pogo gold project is scheduled to be up and running in the first quarter of 2006, and will take the form of a 2,500t per day mine and a mill producing 350,000oz-500,000oz per annum.
The flowsheet for the Pogo mill was developed by project operator Teck Cominco and is designed to minimise the environmental impact of the gold recovery process. It consists of a SAG/ball mill grinding circuit, gravity concentration, intensive cyanidation, sulphide flotation with ultra fine regrinding of the flotation concentrate and leach/CIP recovery of gold from reground concentrate.
After working closely with Ballarat-based Gekko Systems for several years during the planning process, Teck Cominco recently selected the company to supply the intensive cyanidation unit for the project.
Gekko’s inline leach reactor will be used to treat gravity cleaner scavenger tailings, and is expected to achieve recoveries of 97% or higher based on test work results.
According to Gekko, Teck Cominco chose the ILR 2000 batch automatic because of its ability to leach very fine gold at ambient temperatures and the increased recoveries achieved by its well-mixed reaction zone.