Since I understand French and “flocon” is a flake (like a snowflake: flocon de neige, or a cornflake: flocon de mais), I’m going to guess that flocculation means to make something flaky.
edit: Hmm. I just realized that “flocking” in English probably comes from the same root. Since flocking is made of lots of little fibres stuck to something, and “flocon” is French for flake, I’m going to modify my answer somewhat. I think “flocculation” might mean combining lots of little things into a flake the same way corn meal is turned into cornflakes and water molecules are grown into snowflakes.