Mechanochemical synthesis of eco-friendly fertilizer from eggshell (calcite) and KH2PO4

The present article, based on reverse logistic, provides an environmentally beneficial and cost-effective method of producing calcium phosphate bioceramics (potassium calcium phosphates) aimed for soil conditioning, by a free-solvent mechanochemical process between eggshell waste and KH2PO4. The K3CaH(PO4)2 and possibly CaKPO4 phases formed provide better nutrient management of P, K and Ca, when applied in soil system the material first release K and form hydroxyapatite and important P and Ca bioavailable source at pH ~ 5, which comprises a large part of many countries soils.