Pad and Ponds
Biooxidation takes place on an impermeable "on-off" pad, lined with an HDPE membrane. A one-meter thick layer of drain rock, incorporating solution collection piping and air distribution piping, protects the liner. The effluent from the heap is collected in one or more ponds from which the solution is recycled to the heap for irrigation, or bled to neutralization and/or base metal recovery circuits.
The area required for a GEOCOAT® pad depends on coating ratio, processing rate, stacking height, and the required biooxidation time. 