Dry flue gas deacidification system and process

The invention belongs to the technical field of solid waste treatment, and relates to a dry flue gas deacidification system and a dry flue gas deacidification process, the dry flue gas deacidification system comprises a flue mixer, a bag-type dust collector and a chimney which are sequentially connected along a flue gas flowing direction, and a fly ash circulation loop is arranged between the bag-type dust collector and the flue mixer. A fly ash steam activation device is arranged on the fly ash circulation loop; the fly ash steam activation device comprises a double-shaft spiral structure rotating oppositely, a feeding section shell, a mixing activation section shell and a discharging section shell, the feeding section shell, the mixing activation section shell and the discharging section shell are communicated in sequence, a feeding port is formed in the feeding section shell, a discharging port is formed in the discharging section shell, a steam inlet is formed in the mixing activation section shell, and a