Novel Coating Technologies to Reduce Rate of Moisture Absorption of Phosphate and Phosphate/Urea Substrates

One of the most significant challenges in handling bulk materials like fertilizer substrates is the affinity of the substrate components to adsorb moisture. This affinity is further exaggerated when blended with other substrates, as well as when stored in regions with elevated humidity. Examples of this are seen when combining phosphate substrates (DAP, MAP, SSP etc.) with nitrogen-containing substrates (ammonium sulfate, urea etc.) to produce various grades of NPK. The combination of these substrates can increase the rate of deliquescence or moisture uptake in granular fertilizers, which can either lead to mushiness observed on the surface of fertilizer granules, mass gain due to absorption into granules, and even increased caking tendencies.