Synthesis and characterization of wollastonite from egg shell and diatomite by the hydrothermal method

Wollastonite was synthesized using calcium oxide from egg shells and silica from diatomite by being calcined at 800 degrees C. The calcium oxide and silica was synthesized in a molar ratio of 1:1 using the hydrothermal method at 100, 150, and 200 degrees C for 24 hours and then calcined at 1,000 degrees C for 24 hours. The morphology of wollastonite which was characterized by SEM indicated that the particles were an agglomerate consisting of small particles with sizes less than 1 mu m. The FTIR spectra showed that the carbonate band at 1459 cm(-1) was absent from calcination product and that was further confirmed by a thermogravimetric analysis. The nu(Si(OSi)(3)O-Ca wollastonite band presented as a band at 930 cm(-1). The XRD results clarly show the structural formation of wollastonite. This method used to synthesize wollastonite is simple and able to function using cheap starting materials.