Closed cycle cement combined grinding system

The utility model discloses a closed cycle cement combined grinding system. A discharge outlet of a weighing storehouse right faces a feed inlet of a roller press below the weighing storehouse, raw materials enter the roller press to be rolled and pressed, an elevator lifts the rolled and pressed raw materials and conveys the raw materials to a powder concentrator through an upper outlet, the powder concentrator is connected with the weighing storehouse and a cyclone, the powder concentrator carries out power selecting and feeds qualified raw materials into the cyclone and unqualified raw materials into the weighing storehouse, the cyclone is provided with a circulating fan in a matched mode, the circulating fan supplies air to the cyclone, air supplied by the circulating fan removes water in the raw materials, the cyclone feeds the dried raw materials into a ball mill for ball grinding, the ball mill feeds the grinded raw materials to an air chute after the raw materials are lifted by an outlet grinding elevator, at the moment, ultra-fine fly ash and mineral powder of a certain ratio are added in the air chute to be stirred, and finished cement is obtained. The closed cycle cement combined grinding system has the advantages of being simple in structure and convenient to maintain.