Specific features of the crystallization of wollastonite

Abstract

The specific features of the separate crystallization of pseudowollastonite (the α phase) and β -wollastonite from an X-ray amorphous iron-free aluminosilicate melt are considered in respect to different methods used for cooling of the melt. It is shown that the phase transition from the amorphous state to the crystalline state is accompanied by the propagation of the heat wave front. Fig. 3. Sequential stages of the propagation of the heat wave front of self-propagating crystallization.

Application of slaker grits industrial waste as a primary calcium oxide source in a ceramic frit formulation

“…The obtained patterns were in accordance with several published papers [9,[18][19][20]. Wollastonite glass-ceramic materials have several advantages compared with natural stones, such as low linear thermal expansion coefficient, high strength, low thermal conductivity, low density, and corrosion resistance [20,21]. It is well known that the calcium monosilicate has three modifications: wollastonite (triclinic at room temperature), α-wollastonite (monoclinic, also 2M or parawollastonite), and β-wollastonite (triclinic, also 4A or pseudowollastonite); these last two forms are produced at elevated temperatures by surface crystallization mechanism [16,21,22]; while β-wollastonite is a lower temperature modification and more easily obtained, α-wollastonite is stable at temperatures above 1100 °C.…”

“…It was also observed a discrete halo in the diffractogram baseline on all groups, indicating the presence of a residual vitreous phase typical of glass-ceramic materials [17]. The obtained patterns were in accordance with several published papers [9,[18][19][20]. Wollastonite glass-ceramic materials have several advantages compared with natural stones, such as low linear thermal expansion coefficient, high strength, low thermal conductivity, low density, and corrosion resistance [20,21].…”

Synthesis and characterization of wollastonite-2Mby using a diatomite precursor

“…Wollastonite is characterized by an acicular crystal shape, whiteness and fluxing properties; these properties lead to its applications in the fields of tile, paint, paper and vinyl tile manufacture. Ceramics based on wollastonite, for example, are characterized by several advantages: low linear thermal expansion coefficient; high strength; low thermal conductivity; and non-wettability with aluminium melts (Pavlov et al , 2008). In compositions of paints, the needle-laminar shape of wollastonite crystals improves the coverage and strength parameters of coatings and allows for substantial savings in the amount of pigments required (Nikonova et al , 2003).…”