NPK Fertilizer Granulation Process: Nine Steps to Perfect Particles

Raw Material Preparation According to the target fertilizer formula, precisely weigh raw materials such as urea, phosphate fertilizer, and potassium salt to ensure accurate proportion of nutrient elements. Subsequently, process large raw materials into particle sizes suitable for mixing through crushers, laying a solid foundation for subsequent processes. Raw Material Mixing Feed the proportioned raw materials into dual-shaft paddle mixers or V-shaped mixers to achieve thorough and uniform mixing of raw materials through mechanical force. This step ensures even distribution of various nutrient elements in the fertilizer. Granulation Forming Add appropriate amount of water according to granulation needs to bring raw materials to suitable humidity. Then use disc granulators, drum granulators, or extrusion granulators to form mixed materials into particles of specific sizes and shapes through rotation or pressure. Drying Treatment Send moist particles into fluidized bed dryers or rotary drum dryers to remove moisture from particles through hot air or other drying media, preventing particle agglomeration during storage and transportation. Cooling Process Dried particles have high temperatures and need to be cooled to suitable temperatures through equipment such as cooling drums to prevent high temperatures from affecting fertilizer performance while creating conditions for subsequent processing and packaging. Screening Selection Use screening machines to grade and screen cooled particles, selecting high-quality particles that meet particle size requirements. Oversized particles may need regranulation, while undersized particles can be recycled as dust. Coating Treatment To enhance fertilizer moisture resistance and control nutrient release rate, some production lines apply coating treatment to qualified particles, wrapping organic or inorganic films on particle surfaces. Automatic Packaging Use automatic packaging machines to weigh and package finished fertilizers, forming standardized finished fertilizer bags, making final preparations for storage and transportation. Intelligent Control The entire production line is equipped with advanced PLC control systems and automation instruments to monitor and adjust key parameters such as raw material ratio, granulation humidity, and drying temperature in real-time, ensuring production process stability and product quality.