Answer: Poor granulation and excessive fines in NPK production generally stem from four key areas: raw material moisture content, spraying/binding efficiency, equipment operating conditions, and raw material formulation. Most issues are not caused by equipment failure and can be effectively remedied through targeted adjustments.

First, moisture imbalance in the materials is the primary cause. If moisture is too low, the powder lacks sufficient tackiness to agglomerate, resulting in excessive fines; conversely, if moisture is too high, the material tends to stick to the walls and clump, leading to uneven granule sizes and unstable formation. Production processes must strictly control moisture levels, keeping NPK granulation moisture within the standard range to ensure adequate material plasticity.
Second, poor spraying and binding performance is a factor. Issues such as clogged granulator nozzles, uneven atomization, or insufficient spray volume prevent the binding agent from evenly coating the powder, making it difficult for the material to agglomerate into granules. Nozzles require regular cleaning to ensure fine atomization; for high-nitrogen or high-potassium formulations that are difficult to granulate, adding an appropriate amount of a specialized binding agent can assist the process.
Finally, equipment and raw material issues play a role. Improper adjustment of granulator rotation speed or tilt angle, as well as material buildup and scaling on the inner walls, can disrupt the material's rolling and granulation trajectory. Additionally, inconsistent raw material particle sizes and inadequate mixing can significantly reduce the granulation rate. Regular cleaning of equipment buildup, calibration of operating parameters, and thorough mixing of raw materials are essential to minimize fines at the source and improve the granulation rate and visual quality of the finished product.