So reading about Bingham open-pit mine brought me to reading about electrolytic copper purification.
I understand the general process wherein pure copper from your impure copper anode migrates to the cathode, but one thing I didn’t understand and couldn’t find more information about is why they have moved from pure copper cathodes to stainless steel cathodes in a lot of places.
It seems to me to add a few steps and potential contamination - if you use a pure copper cathode, then the copper from your anode migrates over and you end with a 99.99% pure larger copper cathode which you can sell as-is with little further processing.
If you use stainless steel, you then have to chemically or mechanically separate the copper and stainless steel prior to selling, with potential contamination near the copper-steel interface bringing the purity down from 99.99%.
The people and businesses doing this purification aren’t stupid, so I’m sure they have good reasons to do it with stainless steel cathodes, I just can’t find anywhere on line talking about the why of it rather than the fact of it - and so I turn to you gentle Dopers; does anyone here have a good answer on the “why” of it?