In the fertilizer industry, diammonium phosphate (DAP) and NPK compound fertilizer are often considered two different product lines. However, with flexible process design, a single NPK compound fertilizer production line can effectively handle DAP processing, achieving "one line for multiple uses."

The core lies in process switching. Both are produced using rotary drum ammoniation granulation. When switching from NPK to DAP (e.g., 18-46-0), the key is adjusting the neutralization method: using a tubular reactor or pre-neutralization tank, phosphoric acid and gaseous ammonia react fully to generate ammonium phosphate slurry, replacing the previously added potassium salts and fillers, thus meeting the high concentration requirements of DAP.

Precise nutrient control. DAP has a total nutrient content as high as 64%, and even slight deviations in the ratio result in a large amount of waste. Modern NPK fertilizer production lines solve this problem through "online acid mixing" technology: clean acid and sludge acid are stored separately, and the mixing ratio is dynamically adjusted based on real-time nutrient data. Nutrient stabilization time is reduced from several hours to within one hour, significantly reducing waste.

Equipment Universality and Fine-tuning: Core equipment such as fertilizer granulators, dryers, and screening systems are completely universal. Only the addition of a slag acid tank and optimization of the ammonia distributor at the raw material end, along with the selection of corrosion-resistant materials to cope with high-temperature and high-pressure environments, are required.

This flexible switching allows companies to quickly respond to the market: during the spring planting season, they can primarily produce DAP, and after the seasonal change, switch to NPK compound fertilizer production. One set of equipment meets the needs of different crops, reducing costs and increasing efficiency.