Pad and Ponds
The area required for a GEOLEACH™ pad depends on processing rate, stacking height, operating system (On-Off or Permanent pad), number of lifts, and the required biooxidation time.
Pad design and construction is the same as that employed for conventional acid leaching. Biooxidation takes place on an impermeable pad, lined with an HDPE membrane. A one-meter layer of drain rock that incorporates solution collection piping and air distribution piping protects the liner.
The pad is sloped to the solution collection ditch that runs the length of one or more sides of the heap. The collected solution is directed to the PLS or ILS solution pond. Return solution from metal recovery (raffinate) is also stored in a pond equipped with organic recovery. An emergency overflow pond may be required in high rainfall areas. Pond and solution configurations are dependent on the pad design, ore type and leaching rates.
