Mining Impacts · impact
Arsenic mobilisation
Water · After closure
- Mitigation
- Capture and stable disposal of roaster dust, arsenic fixation as scorodite, and containment of what has already been produced.
- Category
- Water
- Timescale
- After closure
Case
Giant Mine, Yellowknife holds 237,000 tonnes of arsenic trioxide dust in underground chambers. Canada's remediation freezes the surrounding rock with passive thermosyphons, and is planned to hold for at least a century.
Mechanism
Arsenic rides with gold and copper in arsenopyrite and enargite. Roasting the ore to free the gold drives off arsenic as a trioxide dust that is water-soluble, where the mineral it came from was not — turning a locked-up element into one that travels.
Where
UndergroundOpen pitSmelter
Open on the Mining Impacts shelf — the interactive card, the filters, and everything alongside it.