How to move recovered photos back to the Delete folder?

Immediately after you accidentally Recovered the photos, you could shake the phone and you would see an Undo option. This would have put them back into the Recently Deleted folder. It will likely not work now after doing other tasks, but in the future that would be the first thing to do and it will work. Other than that, there is no way to automatically put them back in the Recently Deleted folder, so you will most likely need to do it again.

Did you perhaps make an iCloud backup, while you still had the photos in Recently Deleted?

If you still have the backup, you could restore the iPhone from your backup - this will restore the Photos Library as well, including the Recently Deleted album. The only problem of restoring from a backup is, that everything on your iPhone will be reverted to the state it has been when you made the backup. It might be more trouble than repeating the selection of the photos to be deleted.

A suggestion - I would not keep more items in Recently Deleted than can be seen at a glance - for two reasons:

1. Most important - if you accidentally move an important photo to Recently Deleted, you may not notice it until it is too late, if there are hundreds of photos in Recently Deleted. With only ten photos or so in Recently Deleted, you will be able to see all photos instantly, that are about to be deleted. It is better to delete the photos you are sure about that they are not needed (bad shots or redundant photos) instantly.
2. Photos may behave strangely, if Recently Deleted is very full. I once had more than thousand photos in Recently Deleted and could not empty the Recently deleted album at all. I had to put all photos back and delete them in smaller groups of a few hundred photos at a time.