The inside portion of the tour
Continuing our tour of the ASARCO open-pit copper mine tour, we headed inside where they break down the ore to get to the copper.
Here they are crushing the ore into smaller pieces, a two or three step process that uses iron balls in the drums. As the drums rotate, the balls crush the ore and then sieves screen for the piece size they want.
After that, they add water and other ingredients, including pine oil, to make a slurry. They use pine oil because the copper in the slurry binds to the pine oil and then floats to the top. The whole building smelled like Pinesol!
The shiny stuff on the top is the copper bound to the pine oil.
Next the copper slurry is sent outside and aerated, reducing the water content in a couple of different holding ponds. Then the whole mixture is loaded onto trucks or railcars and sent to a refinery to continue extracting the copper. Eventually the copper from this mine will end up in a plant in Texas where they make 99.999% pure copper anodes.