Dry stacking: right for the

environment. Right for us.

Dry stacking is the most sustainable method used to store filtered tailings — the silty, sandy material that’s left over once the metals are extracted. In the dry stack method, tailings are placed and compacted in a mound that is concurrently reclaimed with native soil and vegetation. There’s no need for a dam to hold them in place, no possibility of dam failure, and no long-term storage issues. What’s more, due to the deposit’s geology, the tailings will be non-acid generating.

Shows both active and reclaimed dry stack tailings storage at the Greens Creek Mine located near Juneau, Alaska.

How the process works.

  1. Large rocks crushed in the underground mine
  2. Minerals are separated into concentrates
  3. Tailings are dewatered
  4. Water is reused in the processing plant
  5. Filtered tailings are transported to the dry stack facility adjacent to the processing plant
  6. Tailings are compacted into a mound that is engineered for stability
  7. Dry stack facility is concurrently reclaimed with native soil and vegetation
Shows active dry stack tailings storage at the Pogo Gold Mine located near Delta Junction, Alaska.

Benefits at-a-glance.

  • Dry stacking filtered tailings means there is no need for a dam – dam failure is impossible
  • The water generated from filtering is reused in the processing plant
  • Stacked tailings will be placed on a liner, reclaimed on top with native soil and vegetation
  • Tailings will be reclaimed in stages, not all at once — a process called progressive reclamation
  • Significantly smaller footprint than conventional wet tailings storage