In organic fertilizer production lines, granulation is a crucial link between raw material processing and finished product delivery, directly determining the physical properties, nutrient stability, and application effectiveness of the fertilizer. This process uses physical or chemical reactions to process loose organic materials into granular products, not only solving the problems of inconvenient transportation and uneven application of traditional loose organic fertilizers, but also improving nutrient slow-release performance and contributing to sustainable agricultural development.
Currently, the mainstream organic fertilizer granulation technologies mainly include three categories: disc granulation, drum granulation, and extrusion granulation. Disc granulation, with its simple structure and high granulation rate, has become the preferred choice for small and medium-sized production lines. It uses the rotation of an inclined disc to drive the material to roll, gradually forming uniform granules under the action of a binder, with a sphericity of over 90%. Drum granulation is suitable for large-scale production, utilizing the axial rotation of the drum and the flipping of the lifting plates to achieve thorough mixing and granulation of the material. A single production line can produce over 100 tons per day. Extrusion granulation eliminates the need for binders, using high-pressure extrusion to mold the material into its own adhesive form. It is particularly suitable for organic raw materials with high fiber content, producing high-strength granules with minimal nutrient loss.
Smooth operation of the granulation process requires precise control of three key factors. First, the raw material moisture content must be precisely controlled, typically between 30% and 45%. Too high a moisture content leads to granule clumping, while too low a moisture content hinders granulation. Second, the particle size must be controlled between 2-5mm by adjusting parameters such as equipment speed and screen specifications, based on crop requirements and application scenarios. Finally, the choice of binder is crucial. Commonly used natural binders such as starch and humic acid must balance granulation effectiveness with environmental friendliness, avoiding the introduction of harmful components.
Advanced granulation technology not only enhances the practicality of organic fertilizers but also promotes the resource utilization of agricultural waste. Granulated organic fertilizers have a more uniform nutrient distribution and release nutrients slowly after application to the soil, reducing nutrient loss and environmental pollution. Furthermore, granular fertilizers facilitate mechanized application, reducing labor intensity and aligning with modern agricultural development trends. With increasing environmental protection requirements and the upgrading of agricultural technology, granulation technology is developing towards intelligence and energy saving. Through automated control systems, parameters can be adjusted in real time, further improving production efficiency and product quality, and providing stronger technical support for ecological agriculture.
