Natural and artificial wollastonite is used in the production of ceramics, devitrified glass (sitall), and as a polymer filler. Wollastonite additives decrease the firing temperature of ceramics, improve their strength, decrease the firing and drying shrinkages and the temperature of formation of the vitreous phase. Due to the high dielectric parameters, wollastonite ceramics are used in electrical and radio engineering. The use of wollastonite in the ceramics industry has good prospects.

Wollastonite raw materials and their applications (a review)

The development of a fast fired body, incorporating 5% wollastonite in place of quartz powder in a stoneware composition, resulted in early maturing by 50°C, decrease in the fired shrinkage by around 26.67%, increase in strength by around 18.69% and bulk density by 3.93% along with reduction in percent thermal expansion by 22.12% (at 600°C) of the test specimen fired at 1200°C in comparison to those of a conventional body. The substantial decrease in the shrinkage and thermal expansion would favourably influence the final product output by reducing losses due to deformation, thermal shock, dunting etc. The reduction in the maturing temperature will be helpful to conserve energy during firing.

Development of fast fired body using wollastonite suitable for crockeryware

Low-loss ceramics of L-6 or better grade have been developed using indigenous wollastonite. The composition consisted mainly of wollastonite, clay and a flux. It was observed that a combination of several heavy metal modifiers such as Pb, Ba, etc gave a better result when incorporated in the flux. The maturing tempeiature of the wollastonite body was much less than that of conventional steatite and other low-loss ceramics. Â© 1984 Taylor & Francis Group, LLC.

D. Chattopadhyay

Papers

Low-loss ceramics from wollastonite