In order to characterize calcination of eggshell, Thermal
gravimetric analyzer (TGA-951 DuPont Instruments Co.,
USA) was used. A portion of the dried eggshell previously
removed impurity and interference material such as organics
and salts was loaded in the TGA analyzer and then
pyrolysis was performed up to 900°C at an elevation of
temperature 40°C/min with continuous injection of N2.
X-ray fluorescence (XRF-1500, Shimadzu, Japan) was
used for the qualitative and quantitative analyses of the inorganic
compositions in the natural and calcined eggshells.
The mineralogy of the natural and calcined eggshells was
characterized by X-ray Diffractor (X-ray Diffractometer,
Rikaku PMG-S2, 30 kV × 16 mA). The image of the
surface of natural and calcined eggshell was obtained by
Scanning electron microscope (SM-300, Topcon, Japan).