Can be iPhone detected in 'Find my iPhone' service after recover? I lost my iPhone and while it was turned on I could lock it and put in 'Lost mode' through  Apple 'Find My iPhone' service.

Unfortunately almost one month it's not found and until now I had hope to find it.

If somebody found it and recovered or re-installed iOS on that phone, can it be detected after turning on in my iCloud service anyway? or I lost it forever?
I assume since it was a month ago that you had iOS 6 on there? If someone found it and wiped it from scratch, your Find My iPhone will not work.

In iOS7, Activation Lock could prevent them from re-activating your phone if they found it, and you might have a chance to find something.