Wollastonite (β-CaSiO
3) was synthesized by the TW method from the mixed solutions of Si(C
2H
5)
4 and CaC1
2 with both the small amount of 2M-HC1 as catalyst and separately the desired quantity of each aqueous solution made up of additives such as MnC1
2, FeC1
3, NiC1
2 or CuC1
2. In the case of the sample obtained without the additives, pure β-CaSi0
3 in a single phase was not obtained at any heat treatment temperature of this study. The acceleration effects of additives on the formation of β-CaSiO
3 were arranged in the order of MnC1
2 > NiC1
2 > CuC1
2 > FeC1
3 at the temperature of 1100°C. MnC1
2 was most effective for the acceleration of β-CaSiO
3 formation among the additives, and in the case of each sample obtained with the addition of MnCl
2 with 7.8 × 10
-3 mole or 9.3 × 10
-3 mole, pure β-CaSiO
3 in single phase was obtained at 1100°C. It was thought that β-CaSiO
3 was formed by reaction of β-Cristobalite with Ca
3Si
2O
7, simultaneously according to the phase transition from α-CaSiO
3 to β-CaSiO
3.
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