Is the waste from extracting further copper /molybdenum from mine tailings environmentally safer than inputs?

I am an investor in Amerigo Resources, a company that has a plant in Chile to extract more copper and also molybdenum from old and fresh mine tailings (from Coldeco’s El Teniente mine). They have a consultant studying laundering the waste product by a pipeline from the extraction (which involves crushing) process back into a [...]

Abandoned mine buildings from the Anaconda Copper Mining Company on the flanks of Mount Ophir, CA – darwin19

Image taken on 2007-10-20 15:35:55 by mlhradio.

Copper mining section between Ducktown and Copperhill], Tennessee. Fumes from smelting copper for sulfuric acid have destroyed all vegetation and eroded the land (LOC)

Image taken on 1940-01-01 00:00:00 by The Library of Congress.