2026/07/09
Next, the batched materials enter a mixer, where high-speed agitation ensures macroscopic uniformity, laying the groundwork for subsequent granulation. Granulation is the core stage of the process. Rotary drum granulators are the most widely used equipment; inside the rotating drum, materials—aided by steam and binders—adhere layer by layer and grow into rounded granules as they roll. Alternatively, double-roller extrusion granulators compress the powder directly under high pressure without adding water, making them particularly suitable for high-concentration or water-soluble formulas. Wet granules exiting the granulator have high moisture content and must be sent to a rotary dryer to remove excess moisture using high-temperature flue gas; they are subsequently cooled to prevent caking. A screening process—using either rotary or vibrating screens—then separates finished granules that meet size specifications, while undersized or oversized materials are crushed and returned to the system for re-granulation. To enhance product performance, some plants add a coating step, applying anti-caking agents or slow-release coatings.
Finally, the finished granules are weighed and bagged using electronic quantitative packaging scales. The complete NPK fertilizer production process enables continuous, fully automated operation from batching to the finished product, with production capacity flexibly adjustable from 5 to 20 tons per hour. Advanced control systems monitor temperature, pressure, and electrical current in real-time, automatically adjusting steam flow and rotation speeds to ensure consistent product quality. This process offers exceptional flexibility, allowing for rapid adjustments to formulation ratios to meet the diverse needs of field crops, fruits and vegetables, and turf. Amidst mounting global pressure on food security, efficient and precise NPK fertilizer production technology is emerging as a vital technical cornerstone for boosting yields and increasing returns in modern agriculture.