the Stillwater and East Boulder Mines both operate on-site concentrators. Once ore is removed from the ground, it goes into a concentrator and the refining process begins.
• Two Concentrators, one at each mine.
• Concentrators capacities:
- Stillwater Mine: 3,000 tons per day
- East Boulder Mine: 2,000 tons per day
The Concentrator Process
• Ore is fed into the concentrator, mixed with water and ground to a slurry. PGM-bearing sulfide minerals are liberated from the rock matrix
• Reagents are added to the slurry to separate the valuable sulfides from the waste rock. Sulfide minerals are floated, recycled, reground and refloated to produce a concentrate suitable for further processing.
• The flotation concentrate, weighing about 2% of the original ore weight, is filtered and transported in bins to the Company’s metallurgical complex in
Columbus, Montana.
• Tailings material from this process is returned to the mines and used for backfill to provide a foundation upon which additional mining activities can occur.
The balance is placed in tailings containment areas.
