72 hour free transit when entering from north korea and flying out of dalian

i am currently in china on a single entry 30 day visa (i am an aussie on an australian passport) and in 2 weeks time i am going on a tour to north korea, the tour brings us back to dandong and we cross back into china, i want to then fly out of dalian within 72 hours to south korea, is this posible?
cheers