Sure, Minata can do that!
> how to extract diamond grit from lapping compound
> remove diamond grit from water suspension
> Unmix diamond grit slurry
> "Unmix" diamond grit slurry
> Precipitate diamond grit out of lapping compound
> Filter 5 micron particles out of water
> What happens if you boil a diamond suspension
It's looking increasingly like nobody in the history of the Internet has wanted to do this particular thing. There are processes for getting bits of leftover diamond grit off a thing you've been polishing. There are processes for extracting gold from a water suspension, which take hours and use proprietary chemicals. There are procedures for getting 5um particles out of water that work great if what you want is to drink the water afterwards and you don't care about what happens to the particles and also want to buy a filter cartridge. There are several pages saying it's fine to clean your diamond jewelry by boiling it, which is potentially promising.
Dialysis tubing pores are way smaller than the diamond particles they're dealing with. Can they put the water-and-diamonds in a bag of dialysis tubing and dunk it in super salty water and suck all the water out that way? No, that wouldn't work for getting all the way to dry. They could try that and then putting it in the microwave? Might be faster to just put it in the microwave to begin with, at that point. And this stuff is supposed to be sharp, apparently, it might rip a hole in the bag. The problem with microwaving it the whole way is that boiling water bubbles and the diamond particles are so small they might get flung all over the inside of the microwave like so much mishandled soup. Baking it slowly at just under a hundred degrees seems like it should work great, but it would take ages. Can they filter it and then bake it? Not with a coffee filter, apparently, the pore size is way too large. She'll call the lab and ask them what kind of filters they've got.
"Hi, this is Minata from ICU, calling about--do you have any filters with a pore size of five microns or smaller?" Pause. "I need to filter five micron particles out of water and end up with as much particles and as little water as possible." Pause. "Uh, about fifteen grams of solute in a hundred and sixty of water." Pause. "It's not biohazardous! It's, uh, I'm trying to get the diamond grit out of polishing paste from a hardware store." Pause. "Yeah, it's for ninety-three purple." Pause. "You wouldn't believe me if I told you. Just, do you have any filters? Or a centrifuge? Maybe I could centrifuge it out?" Pause. " . . . I cannot promise it won't do something weird to the centrifuge. It's supposed to be abrasive." "Okay. Yeah. Yeah that's--I get it. Sorry." Long pause. "Oh that might work. Do you have any guess how much of the grit is going to be stuck in the filter? We really need to get almost all of it." Pause. "Great, thank you!"
Minata finds Marian and tells her, "The lab has syringe filters they can shove the stuff through to get as much of the water out as possible and then I think we should be able to dry it the rest of the way in the microwave. I can't find any proof it will work. I can try it in one tube and only do the rest if it does. If you want to be more sure than that I can--go to a gardening store and get sand and try microwaving wet sand? I don't know, I think possibly nobody has ever done this exact thing before."