Let gravity do the work for you. We transfer mixed resin to a separation tank ~ 30 feet in height and backwash the bed to expand all the resin. Then you let the beads settle out and they will form layers based on density. Basically you do this three or four times. Cation beads will settle to the bottom, then a small interface layer of mixed cation and anions, and then a top layer of anion. We'll sluice off the three layers to separate tanks regen them (except for the interface layer), and then recombine. That's it in a nutshell and it works great. It all depends on your setup though. If you don't have a separation tank with a enough height to expand the bed enough so it can settle properly then you're looking at a pretty big capital expenditure.
Have you tried contacting other plants through the INPO working groups?