Fabrication and characterization of tetra-calcium phosphate from natural wastes of eggshell and cockle shell

Abstract

This study focused on the utilization of natural waste materials, specifically eggshell and cockle shell, for extracting calcium carbonate (CaCO₃) as calcium-rich feedstocks for the synthesis of tetra-calcium phosphate (TTCP) via a solid-state reaction. The synthesized TTCP powders were compared with those produced using commercially available CaCO₃. The CaCO₃ powders derived from eggshells and cockle shells were found to exhibit characteristic calcite structures with a high calcium content of 95–96 % and a combination of irregularly shaped amorphous and crystalline morphologies. The TTCP powders synthesized from eggshell- and cockle shell-derived CaCO₃ demonstrated a characteristic high-intensity peak, along with minor phases of hydroxyapatite (HAp) and calcium oxide (CaO). These powders were fine and white with a light-blue tint. It is speculated that the fabricated TTCP powders hold potential for medical applications, such as bone cement.