• GEOLEACH™
• Process Description
• Design Concept
• Pad and Ponds
• Agglomeration and Stacking
• Solution Management
• Aeration and Temperature Control
• Solution Treatment
• Heap Reclaim
• Water Balance
• Inoculum
• Air Requirements
• GEOCOAT^®
• HotHeap™

GEOLEACH™ Overall Design Concept

In a GEOLEACH™ circuit, the pad is loaded with agglomerated ore in individual panels. Irrigation with a barren leach solution is started in the first panel to achieve the desired pH, and then the panel is inoculated with a microbial culture in solution to begin the biooxidation process.

The temperature, off-gases and pH continue to be monitored, and the aeration and irrigation rates continue to be adjusted based on a real-time feedback loop to achieve optimum activity of the bacteria within the heap.  Agglomerated ore continues to be placed in adjacent panels, with the conditions in each panel monitored separately and the operating parameters adjusted accordingly.

Once the pre-determined oxidation level is reached within the first panel, the leached ore is transported to a tailings containment area, and the panel is re-loaded. The overall result is a "moving slot" within the heap where reclaiming and reloading takes place.

Pregnant leach solution (PLS), containing the base metal values, is collected in ponds, and then sent for downstream metal recovery. For copper recovery, a solvent extraction-electrowinning circuit is typically used. The stripped solution, or "raffinate", is then returned to the heap, with a bleed of this solution goes to a neutralization circuit. Residue from the neutralization circuit is sent to disposal.