2026/07/06
Control moisture and temperature of the finished product: Granules exiting the dryer should have a moisture content of ≤2%, and the temperature upon exiting the cooler should be ≤40°C. If ambient humidity exceeds 60%, it is recommended to extend the cooling time or use dehumidified air. For high-nitrogen formulations (such as urea-based fertilizers), the discharge temperature from the cooler can be lowered to below 35°C, as the critical relative humidity for urea moisture absorption decreases as temperature rises.
Apply anti-caking agents: Use a spraying system at the cooler outlet or prior to packaging to apply mineral oil or surfactants evenly at a rate of 0.2%–0.5%. This creates a hydrophobic film that effectively blocks moisture migration between granules. Inert materials compatible with the fertilizer should be selected to avoid interfering with nutrient release.
Select appropriate packaging materials: Composite woven bags with polyethylene film liners are preferred to block external moisture. After packaging, bags should be stacked in a cool, dry place; stacking height should not exceed eight layers to prevent deformation of the bottom granules due to pressure. It is recommended to place desiccants in the storage facility or ensure regular ventilation and dehumidification to maintain relative humidity below 50%. Periodically restacking the bags (once a month) can further reduce the risk of caking.