Characteristic of Wollastonite Synthesized from Local Raw Materials

摘要

In this study, wollastonite (CaSiO3) has been synthesized by solid state reaction method at temperature range of 1050-1300 ?C from local raw materials e.g. silica sand and limestone with addition of small amount of B2O3 as a mineralizer to activate the reaction process during sintering. The resulting products are investigated employing XRD and SEM techniques. β-wollastonite was obtained at 1050 ?C and transformed to pseudowollastonite (α-CaSiO3) at 1150 ?C. Physical and thermal properties have been evaluated. The batch sintered at 1250 ?C showed the highest value of density of about 1.98 g/cm3 with high shrinkage rate as compared with other batches. The results also revealed that thermal expansion coefficient is more compatible with results obtained from natural wollastonite.