Quebrada Blanca Copper, Chile

The Quebrada Blanca Mine is located at an elevation of 4400 meters in northern Chile. Teck acquired controlling interest in Quebrada Blanca through the acquisition of Aur Resources in August 2007. The operation mines approximately 10 million tpy of ore from an open pit and leaches the ore to produce copper cathodes via conventional solvent extraction and electrowinning processes. Current overall copper recovery is approximately 65-75% after a 450-day leach cycle. The mineralogy of the ore is gradually changing toward a higher proportion of primary chalcopyrite, and the average head grade is declining as Quebrada Blanca mines the deeper transitional ore.

In 2007, GeoBiotics began a laboratory and field testwork program on the Quebrada Blanca ore with the goal of proving that the GEOLEACH™ process would improve leaching kinetics, increase copper recovery, reduce inventory, and reduce power and acid consumption. In addition, GEOLEACH™ is expected to make treatment of the underlying hypogene ore economical, which would extend the mine life by 20 years.

After successful laboratory testing, a 47 x 66 meter section of the existing pad was isolated for construction of a GEOLEACH™ test pad to biooxidize approximately 40,000 tonnes of ore. Construction of the demonstration plant was completed in early 2009, and adapted microbes were applied to the heap in July 2009. GeoBiotics expects successful completion of the trial by mid-2010, and a decision to convert the entire operation to GEOLEACH™ upon analysis of results.