NPK compound fertilizer, as a high-efficiency fertilizer containing the three major nutrients—nitrogen, phosphorus, and potassium—requires multiple stages in its production, including raw material processing, batching and mixing, granulation, and drying and cooling. Each stage relies on specialized equipment. The configuration of a complete production line directly determines the quality and efficiency of the fertilizer, and also affects the safety and environmental friendliness of the production process.

Raw material pretreatment equipment is the foundation of production, mainly including crushers and screening machines. Cage crushers are commonly used, offering stable operation and excellent crushing effect. They can break up agglomerated raw materials such as urea, phosphate rock powder, and potassium chloride to below 3-5mm, completely breaking up agglomerates and ensuring the uniformity of subsequent mixing processes. Screening machines are responsible for separating qualified particle sizes from impurities and large particles, effectively improving the purity of the raw materials and laying a solid foundation for the smooth operation of subsequent processes, preventing impurities from affecting fertilizer quality.
Batching and mixing equipment is crucial for ensuring the balanced nutrient content of the fertilizer. The automatic batching system employs precise gravity sensing technology, with metering errors strictly controlled within ±0.5%. It can accurately proportion nitrogen, phosphorus, potassium, and various trace elements according to the fertilizer requirements of different crops, ensuring that the nutrient content of each batch of fertilizer meets standards. The double axis paddle mixer ensures uniform mixing without dead zones, guaranteeing thorough material mixing and effectively preventing uneven nutrient distribution in the fertilizer, thus ensuring its effectiveness.
The granulation equipment is the core of the production line. Commonly used types include rotary drum granulators and roller extrusion granulators. Rotary drum granulators use a wet granulation method, suitable for large-scale continuous production, producing high pellet rates and uniformly rounded granules, meeting the production needs of most NPK fertilizers. Roller extrusion granulators eliminate the need for additional drying steps, resulting in significant energy savings and ease of operation. They are suitable for producing various NPK fertilizer formulations, especially for small and medium-sized production enterprises.
Drying, cooling, screening, and coating equipment are used to optimize product properties. The drum dryer dries the moisture content of the granulated wet granules to within industry standards, preventing mold growth. The cooler quickly lowers the temperature of the dried granules to room temperature, preventing clumping due to high temperatures and facilitating subsequent storage and transportation. The finished product screening machine separates substandard granules and returns them for reprocessing, improving raw material utilization. The coating machine forms a protective film on the granule surface by spraying a special coating agent, extending the fertilizer release time. Finally, the automatic packaging system completes metering, sealing, and coding, ensuring standardized product delivery.
These devices work together to form a complete NPK fertilizer production line. With technological upgrades, the equipment is developing towards intelligence, efficiency, and environmental friendliness, improving production efficiency while reducing energy consumption and pollution, providing a high-quality and stable fertilizer guarantee for modern agriculture.