How to adjust pH of NPK fertilizer by rotary drum granulator

In the process of compound fertilizer granulation by rotary drum granulator, the pH of material is a main factor of fertilizer granulation, and also has an important impact on fertilizer efficiency and NPK production line.

PH is an important indicator of whether the material system is suitable. In the granulation system of ammonium phosphate, the pH value of material should be controlled between 6.0 and 6.5. When the material is slightly acidic, the solubility of the material is large, and the reaction is violent. It is easy for particles to bond into balls and produce large particles. If it is slightly alkaline, the ammonia loss is large, the reactivity of the material is poor, and the material divergence is not easy to form granules. During the operation of the rotary drum granulator, the pH value can be adjusted by adding ammonium bicarbonate and calcium magnesium phosphate fertilizer. If the conditions permit, a small amount of gas ammonia and granulation steam can be added into the material layer to neutralize map, and the reaction heat can increase the granulation temperature at the same time.