Also, after rinsing, how easy is it to recover the rinsed metal from the acidic solution if they want to gather something like cobalt for re-use, which they imply might be something they'd want to do?
It was slightly outside the scope of our research to discuss utilization of that metal ion, but it is a mostly solved engineering problem. Ideally, the sponge would be regenerated after it was full/at capacity with a metal like Co, with a small volume of water, to generate a high concentration solution of Cobalt, which could then be precipitated out as a metal or Cobalt salt using a strong base, or utilized in applications that require Cobalt in solution, or, with certain metals, incorporated into another mineral straight from solution for use in, say, a battery cathode or other material.