Tailings

Tailings are a ground rock waste product that remains after the desired minerals have been removed from the ore. Tailings are very fine powders but usually put into tailings impoundments in a slurry form (see Slurry).

The most common way to prevent Acid Mine Drainage production from tailings is to submerge the tailings under water to limit contact with oxygen (see Acid Mine Drainage). This storage method must be done indefinitely.

Sources:
Mining Watch Canada’s website glossary