Question

Why must mine tailings be stored and disposed of carefully

Answer 1

The mining tailings are the leftovers of the porces in which some minerals (the part that they do not want to keep) are separatd from a given ore. This leftovers usually contain some chemical compounds that may be dangerous for the enviroment, and other problem is the fact that some of the separated minerals can be also dangerous, for example things like the arsenic or the mercury.

This is why the mine tailings must be stored and disposed carefully

Answer 2

Mine tailings be stored and disposed of carefully since they contain a lot of chemicals that are very toxic that leaches into aquifers, and they also runoff in the rainwater into streams and lakes.

Tailings, also called mine dumps, culm dumps, slimes, tails, refuse, leach residue or slickens, are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore.