To minimize granule breakage in NPK blended fertilizers during storage, the key lies in a holistic optimization of the entire NPK blending machine production process—encompassing equipment design, configuration, conveying procedures, and finished product handling—thereby enhancing granule stability at the source.

During the batching stage of the NPK blending fertilizer production lines, raw materials for nitrogen, phosphorus, and potassium should be selected based on granule uniformity and comparable hardness; this prevents mutual crushing and abrasion caused by significant disparities in material hardness. The adoption of a static, high-precision batching system minimizes repetitive material agitation, thereby reducing initial granule breakage in the raw materials. For the mixing stage, a horizontal mixer featuring low shear and low impact should be employed; by carefully controlling mixing duration and rotational speed, the risk of granule pulverization caused by internal collisions and friction is effectively mitigated.

Conveying and elevating operations represent high-risk zones for granule damage. Consequently, the production line should be designed to minimize conveying distances and reduce material drop heights. A transition to gentle belt conveying systems is recommended to reduce the high-velocity impact associated with bucket elevators. Furthermore, the angles of chutes should be optimized, and buffering devices installed, to prevent granule fragmentation caused by direct impact. Prior to packaging, a buffer hopper should be incorporated to prevent the crushing of bottom-layer granules under the immense pressure of a large material column; concurrently, a finished product screening machine should be installed to promptly remove any fine dust or broken fragments.

During the finished product storage phase, the silo structure should be optimized through the adoption of a "shallow bin, multi-bin" design. This approach reduces the height of the material column, thereby minimizing crushing caused by the material's own weight. Flow-guiding devices should be installed within the silos to ensure a "First-In, First-Out" (FIFO) inventory rotation, preventing material stagnation and prolonged accumulation. In the post-packaging palletizing area, a ventilated and dry environment must be maintained, and pallet stacking heights carefully controlled, to prevent packaging bags from deforming under pressure—a condition that can lead to granule breakage.

By systematically reducing impact forces, minimizing compressive stress, optimizing buffering mechanisms, and ensuring stable batching ratios across the entire production line, the damage rate of NPK blended fertilizers—both during production circulation and subsequent storage—can be drastically reduced, thereby guaranteeing the integrity of the granules and the overall aesthetic quality of the finished product.