In modern fertilizer production, the disc granulator, with its efficient and stable granulation capabilities, has become a key piece of equipment for converting bulk raw materials into granular fertilizer. The production process involves four key steps: raw material pretreatment, mixing and conditioning, disc granulation, and drying and cooling. These steps are closely linked to ensure fertilizer quality.
First, raw material pretreatment. Basic fertilizer raw materials such as urea, monoammonium phosphate, and potassium chloride are first crushed to 80-100 mesh in a crusher to remove impurities. If the raw materials have a high moisture content, they are then passed through a dryer to reduce the moisture content to 8%-12% to prevent clumping or loose granules during subsequent granulation. This step lays a solid foundation for “shaping” and ensures that the raw materials meet granulation standards.
Next, the mixing and conditioning stage begins. After pretreatment, the raw materials are fed into a blender and thoroughly mixed according to the formulated ratio. An appropriate amount of binder (such as bentonite) and water are added, and the moisture content is adjusted to 15%-20%. This forms a uniform wet mass with good plasticity, preparing it for subsequent granulation. This process is similar to kneading dough, adjusting the moisture and viscosity to achieve the optimal “shaping” of the material.
Disc granulation is the core of the entire production process. The prepared wet material is conveyed to the granulation discs, which are tilted at an angle of 35°-55° and rotate at a speed of 15-25 rpm. Under the combined effects of centrifugal force, gravity, and friction, the material continuously tumbles within the discs, gradually absorbing surrounding fine particles and forming small spheres. Operators can adjust the disc speed and feed rate to control the granule diameter to between 2 and 5 mm, meeting the specifications of different fertilizer products.
The final step is drying and cooling. Initially wet granules enter a drum fertilizer dryer, where they are dried in a hot air environment at 60-80°C, reducing the moisture content to below 10%. They are then sent to a drum fertilizer cooler, where they are rapidly cooled to room temperature by cold air to prevent the granules from clumping and deteriorating. The cooled granules are screened to remove unqualified particles. Qualified granules are then packaged and stored as final commercial fertilizer.
Through this precise process, the disc granulator not only achieves standardized fertilizer production, but also reduces raw material waste, improves fertilizer utilization, and provides a stable and reliable fertilizer supply for agricultural production.