As said, there are several ...
Published by J.J.P. (Hans) Zijlstra, Director at GeoChemTec
As said, there are several methods available. One wonders if the metal concentrate, remaining after mining waste water treatment, is sufficiently pure to further process economically, as compared to a concentrate produced directly from ore processing. And if so, will you be paid accordingly by the refinery for offering a precious raw material or do they ask you to pay, because what you deliver is actually a waste that you otherwise have to dispose off at great cost?