Scylla serrata shells calcination using electric furnace and microwave kiln

Abstract

To accommodate the rising demands for artificial bone substitutes, the possibilities of extracting calcium oxide (CaO) as precursor of hydroxyapatite (HAP) from Scylla serrata (crab) shells via electric furnace and microwave kiln heating (calcination) were investigated. The crab shells were obtained from food wastes from local restaurants in Miri, Malaysia. They were treated by calcination with temperatures of 600°C, 800°C, and 1000°C for 3 and 4 hours in electric furnace. The shells were also calcined in microwave kiln at power levels of 60%, 80% and 100% for 1 hour. Characterization on the calcined shell samples were done using Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffractometer (XRD). Based on the FTIR and XRD spectra, it was found that calcium oxide was obtained through calcination at temperatures ≥ 800°C. The results also indicated that a higher calcination temperature and duration would yield CaO with larger crystallite size. Through calcination in microwave kiln, CaO was readily produced when calcination was done at 60% power.