But in this image I have 80 icons. What I wanted was to flatten the icons individually.
But without needing to save each icon in a different file ...
Just applying a batch command to all layers individually.
Oh sorry, I misunderstood. I actually have a couple tutorials on a very similar topic that may help out. You would need to have each icon on it's own layer but once that's in place, the process is a snap.
In short, File > Export and choose Layers to Files.