500,000 pounds = 250 tons!
It takes a LOT of energy to excavate, transport, process and dispose of the remainder of 250 tons of anything.
Not to mention the social and morality issues.
https://www.dailymail.co.uk/news/article-4764208/Child-miners-aged-four-living-hell-Earth.html
Thankfully Tesla is coming out with a battery that uses little or no cobalt.