NPK fertilizer production technology is a systematic process that transforms various nutrient-bearing raw materials into uniform granular products; each stage, from raw material to finished product, entails specific technical requirements.

Formulation design and raw material pretreatment mark the starting point. Based on the target NPK ratio, the proportions of raw materials—such as urea, monoammonium phosphate (MAP), and potassium chloride—are determined. These materials undergo crushing and screening to ensure uniform fineness and prevent caking, which could otherwise hinder subsequent mixing and granulation.

Granulation is the core stage. Depending on product positioning and production capacity, techniques such as rotary drum, pan, or extrusion granulation may be employed. During granulation, moisture content, temperature, and the dosage of binding agents require precise control: excessive moisture causes material to stick to equipment walls, while insufficient moisture makes pellet formation difficult; temperature affects material plasticity and the granulation rate. Operators must adjust parameters in real-time based on the material’s condition to ensure granule sphericity and strength.

Drying and cooling determine storage stability. Wet granules enter the drum fertilizer dryer, where hot air temperature is maintained within an optimal range to evaporate moisture while avoiding nitrogen loss or granule cracking. After drying, the granules pass through a cooler to bring their temperature close to ambient levels, preventing caking after packaging.

Screening and material recycling ensure uniform particle size. Granules meeting specifications proceed to packaging, while undersized fines and off-spec granules are returned to the granulation system for reuse, thereby minimizing waste and stabilizing quality.

Final product handling and quality control constitute the last critical steps. Qualified granules may undergo coating to enhance anti-caking properties. Each batch undergoes testing for parameters such as nutrient content, moisture, and granule strength; products are released for shipment only after meeting national standards.

NPK fertilizer production process is an integrated system where formulation, granulation, drying/cooling, and quality testing work in concert to ensure the stable production of high-quality compound fertilizers.