RE:I look at it this way too...
Short answer, Pond evaporation takes up to a year. This type of extraction maybe a day or hours. So what's the big deal if ya have to run the product thru extraction a 2nd time? Your looking at hours not months. The faster extraction is really going to change things. AMY American Manganese extracts all the ingredients of used batteries in a similar process...They make 3-4 passes thru to get high 90s% recover rates and doesn't affect the final cost that much. As always, My opinion only.