The Idaho-Maryland Mine Project proposes a modern mineral process plant using simple gravity and flotation methods.
The project proposes to produce gold concentrates and does not use Mercury or Cyanide. Sand tailings are used either as cemented paste backfill underground or as dry engineered fill on surface.
The mineral process plant has a closed water circuit and therefore reagents used for flotation in the mineral process plant are not discharged from the project.
Gold removed by gravity methods using water
Sulphide minerals (pyrite) removed by flotation and shipped offsite as concentrate
Sand Tailings Unmineralized quartz and andesite from processing
CEMENTED PASTE BACKFILL
Approximately 50% of the sand tailings is used as cemented paste backfill (CPB) to fill mined voids underground. The use of CPB is a best practice in mining because it is a non-draining, low permeability, material and ensures geotechnical stability.
The project uses filter-presses to remove the water from sand tailings after processing. The greatest environmental risks of mining projects are often related to the disposal (spills) and storage of liquid tailings (dam failures). The production of dry tailings eliminates these risks entirely.