Method for producing diammonium phosphate by concentrating semi-acidic slurry and secondary ammonization and concentration integrated device

The invention discloses a method for producing diammonium phosphate by concentrating semi-acidic slurry. Diammonium phosphate is prepared by using dehydrate wet-method phosphoric acid as a raw material and comprising the steps of concentrating, settling, separating, aminating for four times, drying and screening. The invention also discloses a secondary ammonization and concentration integrated device used in the process which not only can obtain a traditional-method diammonium phosphate composite fertilizer in nitrogen and phosphorus ratio of 0.32-0.40, but also can further reduce the ammonia consumption and energy consumption, thereby being suitable for high-quality phosphorus ores and phosphorus concentrates formed by the single repeated selection magnesium treatment of mid-low quality phosphorus ores with high content of impurities. The secondary ammonization and concentration integrated device is more energy-saving and environment-friendly and simplifies the process equipment.