Hydroxyapatite (HA) Synthesis from Leg Bone By-Product of Beef Cattle: Structural and Optical Characteristics for Various Sintering Temperatures

Bone is one of the by-products of the livestock industry. Bones from slaughtered cattle are easily subjected to the process of decay, so they require quick and precise handling which can be a source of the spreading harmful microorganisms. Beef bone by-product has potential as a high nano-calcium source for hydroxyapatite (HA) material. This study aims to characterize the by-product of bovine leg bone (Os metacarpus) as HA material. We used three stages of the HA production process: calcination, precipitation, and sintering. HA production results were then evaluated. The calcination process uses a temperature of 900°C for 5 h followed by a precipitation process with 0.3M phosphoric acid (H₃PO₄) and then is continued with various sintering temperatures. All samples were evaluated by X-ray diffraction, Fourier transform infra-red, and scanning electron microscopy. The research results indicate that the sintering method significantly alters the structural and optical properties of HA. Kramers-Kronig analysis shows that the stable bonding of the annealed sample is characterized by the widening of the \(\Delta ({\text{LO}}-{\text{TO}}\) $\mathrm{\Delta }(\text{LO}-\text{TO}$ ) and has good agreement with the crystallinity alteration. Significant changes in the number of pores are also evaluated on the HA surface indicating higher surface area allows more interaction.