NOVELTY - A system for extracting rubbish derived fuel (RDF) from city rubbish comprises a rubbish receiving facility (1), a one-time crusher (2), a biological fermentation pond (3), a first iron remover (4), a sieving machine (5), a gravity force separator (6), a second iron remover (7), a vortex separator (8), an inertia material storage (9), a sorting belt (10), a vibrating sieve (11), a second crusher (12) and a RDF storage (13).    USE - System for extracting rubbish derived fuel from city rubbish, including protogenic rubbish.    DETAILED DESCRIPTION - A system for extracting RDF from city rubbish comprises a rubbish receiving facility (1), a one-time crusher (2), a biological fermentation pond (3), a first iron remover (4), a sieving machine (5), a gravity force separator (6), a second iron remover (7), a vortex separator (8), an inertia material storage (9), a sorting belt (10), a vibrating sieve (11), a second crusher (12) and a RDF storage (13). A conveying device is set between a light particle material output hole of the gravity force separator and the RDF storage. An oversize output hole of the sieving machine is arranged above the input end of the sorting belt. Output end of the sorting belt communicates with input hole of the vibrating sieve. A conveying device is set between an oversize output hole with grain size greater than 75 mm of the vibrating sieve and input hole of the second crusher. A conveying device is set between output hole of the second crusher and input hole of the vibrating sieve. A conveying device is set between the siftage output hole of the vibrating sieve and the RDF storage.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic block diagram illustrating the system for extracting rubbish derived fuel from city rubbish (Drawing includes non-English language text).    Rubbish receiving facility (1)    One-time crusher (2)    Biological fermentation pond (3)    First iron remover (4)    Sieving machine (5)    Gravity force separator (6)    Second iron remover (7)    Vortex separator (8)    Inertia material storage (9)    Sorting belt (10)    Vibrating sieve (11)    Second crusher (12)    RDF storage (13)