Mechanochemical Synthesis of Kaolin-Potassium Phosphates Complexes for Application as Slow-Release Fertilizer

<p>In the current study the effects of the addition, by mechanochemical treatment, of KH₂PO₄, K₂HPO₄and K₃PO₄ to kaolin for the synthesis of new complex compounds to be offered as candidates for slow-release fertilizers are investigated. It is clear that after the characterization of the ground kaolin, two hours of milling is sufficient to achieve the distortion of the crystalline network of kaolin in order to insert additives. The quantity of KH₂PO₄ inserted is not as much as those of K₂HPO₄ and K₃PO₄. This is due to the acid character of those compounds. The amounts of K⁺ and PO₄^3- released when using KH₂PO₄ are larger than those when using the others additives.