I'm not 100% positive on what the mites do, but I'm guessing they're parasitic in nature and feed off of whatever they can through the scorp's intersegmental membranes.
Good luck getting rid of them; an infestation that bad is pretty rough. Other than drying out enclosures and putting a thin layer of vaseline on the mites, you can also move your scorpions into a hospital tank -- really just an empty tank with dry paper towels for substrate and a water dish so the scorpion doesn't dehydrate. The overall dryness should help with the mites.
Also, try finding some predatory mites. It's not easy in winter, but you might find them in the substrate of your other moist tanks, or you can leave out a dead prey item and look for larger, fast-moving mites scavenging it in a few days. Move these mites onto your infested scorpions and they should eat some of the bad mites.
If your emperor scorpion stops eating, don't panic.
Be nice -- you were a noob once, too
"Never ask an engineer to explain something, because he will."