NPK compound fertilizer is a core fertilizer rich in the three essential nutrients for crops: nitrogen, phosphorus, and potassium. With its balanced nutrients and wide applicability, it is widely used in the cultivation of various crops. Its production process is rigorous and standardized. Through standardized assembly line processing, basic raw materials are transformed into finished fertilizers with uniform granules and stable fertilizer effects. The entire NPK fertilizer production process is continuous and refined.

Raw material pretreatment is the first step in production. The raw materials used in production are nitrogen, phosphorus, and potassium sources, commonly including urea, monoammonium phosphate, and potassium chloride. These raw materials often have problems with clumping and uneven particle size, requiring them to be ground into fine powder of 80 to 100 mesh using a pulverizer. Impurities are removed to ensure uniform fineness and purity, laying the foundation for subsequent mixing and processing and avoiding uneven nutrient distribution in the finished product.
Then comes the precise batching and uniform mixing process. Workers set scientific ratios based on the growth needs of different crops and soil fertility characteristics, and accurately weigh various raw materials using an automated batching system. After the proportions are finalized, the raw materials are fed into a mixer for thorough mixing, ensuring uniform integration of nitrogen, phosphorus, potassium, and auxiliary materials. This guarantees consistent nutrient ratios in each batch of raw materials, ensuring fertilizer quality from the source.
Granulation is the core process that determines the fertilizer's form. The industry mainstream uses rotary drum granulation, where the uniformly mixed powder is fed into an inclined rotary drum, with a suitable amount of water or steam sprayed as a binder. Relying on the friction and extrusion force of the continuously rotating drum, the powder gradually agglomerates and binds, forming uniformly sized moist granules. Some production lines also use extrusion granulation technology, which eliminates the need for water addition and uses high-pressure compaction to granulate, adapting to different production needs.
After granulation, drying, cooling, and screening are required. Moist granules have a high moisture content and are prone to clumping and deterioration, so they need to be sent to a drying equipment for constant-temperature dehydration, followed by cooling to set their shape. Afterward, they are screened and graded by a screening device to remove oversized or undersized unqualified granules, retaining only finished granules with the standard particle size. Unqualified granules can be re-crushed and reused, reducing raw material waste.
Finally, the fertilizer undergoes quality inspection and packaging before being stored. Staff randomly sample and test the finished product for nutrient content, moisture, particle size, and contaminant levels to ensure compliance with industry standards. Qualified NPK fertilizer is then sealed and packaged using automated equipment, stored in warehouses, and ultimately used in agricultural production to provide a balanced and long-lasting supply of nutrients for crop growth.