How does flocculation in paint work?

I recently learned that you can clean up latex paint wash-up water by flocculating it: adding aluminum sulfate and hydrated lime. I vaguely remember how flocculation works in clay slurries (change in pH changes the electrostatic charge on kaolin plates, causing them to attract and then precipitate). Does flocculation in paint work the same way? (Is it exactly the same? Is there kaolin in paint?) What exactly is happening when you add aluminum sulfate and hydrated lime to the paint?


