Amorphization of wollastonite and diopside by ball milling

The amorphization of wollastonite (CaSiO3) and diopside (CaMgSi2O6) crystals by conventional ball milling under the dry condition and the atomic-scale structures of their amorphous phases were investigated by powder X-ray diffraction (XRD) analysis and Fourier transformed infrared (FT-IR) spectroscopy. The obtained results indicate that both wollastonite and diopside crystals were almost amorphized by ball milling. Moreover, the wollastonite crystal amorphized faster than the diopside crystal. The atomic-scale structures of the amorphous phases in the milled wollastonite and diopside obtained by X-ray radial distribution analyses were approximately similar to those in the fused glasses of wollastonite and diopside, respectively. However, FT-IR data may indicate that the single chains of SiO4 tetrahedra remained as the dominant species even in the wollastonite and diopside subjected to prolonged ball milling.