Synthesizing calcium phosphate powder from bovine bone wastes using calcination and hydrothermal techniques to evaluate physicochemical properties and mineralogy speciation

This study focuses on developing a sustainable method for producing high-purity, nanocrystalline, ion-substituted natural hydroxyapatite (HA) from bovine bone waste through sequential calcination and hydrothermal treatment, and to characterize its physicochemical and morphological properties for potential biomedical applications. Calcination at 900°C for 8 h removed organic matter and produced 90 wt.% crystalline HA. Hydrothermal treatment with diammonium hydrogen phosphate (pH 7.5–8.0) at 110°C for 12–18 h produced magnesium (Mg) and sodium (Na) ion-substituted carbonated HA with Ca/P ratios of 1.6–1.9. Scanning Electron Microscopy (SEM) analysis showed nanocrystals of 60–80 nm forming non-uniform agglomerates of 0.1–0.5 mm. The combination of high yield, ion substitution, and nanoscale morphology indicates strong potential across various fields, particularly in biomedical applications, environmental sustainability, and agriculture.