Effects of Alkali Oxides on the Cristobalitization of Quartz in Whiteware Body

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J. Korean Ceram. Soc. > Volume 29(12); 1992 > Article

Journal of the Korean Ceramic Society 1992;29(12): 981.

자기소지에서 Quartz의 Cristobalite화에 미치는 알칼리 금속산화물의 영향

정창주, 김남일, 오경영¹

전남대학교 무기재료공학과
¹동신대학교 무기재료공학과

Effects of Alkali Oxides on the Cristobalitization of Quartz in Whiteware Body

ABSTRACT

This is a study on the effects of cristobalite transition of quartz in semi-vitrious whiteware body, as addition of alkali and alkali earth oxides, prepared by pottery stone, feldspar, kaolin and clay minerals. The amounts of ${alpha}$-quartz to ${alpha}$-cristobalite transition, F.O.C. (fraction of cristobalite), were increased with firing temperature. In MgO added body, ${alpha}$-quartz was decreased and the formation of cristobalite was increased. Effects of K2O addition was remarkably decreased the formation of cristobalite. Additive effects of MgO and K2O were confirmed that it was very different to variation of transition temperature of metakaolinite to Si-Al spinel structure in thermal reaction of kaolinite minerals. Result CaO addition was ineffective to transition temperature, and the transition temperature in Na2O added body was decreased, but relative intensity of quartz and cristobalite crystal in XRD results was decreased. This was characterized by the effects on the formation of liquid phase much more.