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

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Vol. 32; no. 11; pp. 4070 - 4077
• Main Authors: Borges, Roger, Soares Giroto, Amanda, Klaic, Rodrigo, Wypych, Fernando, Ribeiro, Caue
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-11-2021
• Subjects: Eggshell; KH2PO4; Nutrient management; Potassium calcium phosphates; Smart fertilizer; Eggshell; KH2PO4; Smart fertilizer; Potassium calcium phosphates; Nutrient management
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2021.09.013

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•Eggshell as a sustainable Ca source;•Mechanochemical convertion of calcite and KH2PO4 into K3CaH(PO4)2 and possibly CaKPO4;•Smart fertilizer production on nutriente management;•Hydroxyapatite formation from calcium potassium phosphates.
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 a 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.