Screening and mixture design applied to formulate anti-caking compositions for reducing the caking tendency of granular phosphate fertilizers

The demand for fertilizers in the agricultural sector has increased drastically with the world's exponential growth. Moreover, solid granular fertilizers remain by far the most requested. The granular fertilizers production presents several kinds of problems, especially the ternary fertilizers family. The caking is a severe issue that affects granules' physical quality, particularly during storage and transport. It makes them unsuitable for their intended uses. In this work, a new anti-caking agent has been developed to cope with the granular fertilizer caking problem and improve their physical quality. First of all, thanks to the screening design of Plackett-Burman, the effect of seven anti-caking components on the phosphate fertilizer caking trend was evaluated only by eight trials. Next, a mixture design was used to formulate a new anti-caking agent from three components (glycerol, calcium carbonate, and molasses). The screening design was chosen as the most effective components. Finally, from the mixture design results, a special cubic model was postulated and statically validated. The model delivered a wide range of compositions formulated from the three components mentioned above, capable of reducing the caking tendency of ternary granular fertilizer.