열처리 카올린 분말의 알칼리활성화 반응에 미치는 가열온도의 영향 |
김성곤, 송태웅 |
경남대학교 나노신소재공학과 |
Effect of the Heating Temperature on the Alkali-activation Reaction of Calcined Kaolin Powder |
Sung Gon Kim, Tae Woong Song |
Department of Nano Materials Engineering, Kyungnam University |
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ABSTRACT |
The alkali-activation reaction of two types of typical kaolin calcined at various lower temperatures was investigated at room temperature and at elevated temperatures. For the assessment of the reactivity, the temperature increase and the setting time of pastes prepared with calcined kaolin and sodium/potassium hydroxide solution were measured. Unlike raw kaolin, calcined kaolin samples prepared at various temperature showed an alkali-activation reaction according to the different aspects of the changes in the mineral phases. The reactivity with alkaline solutions was exceedingly activated in the samples calcined at $600-650^{circ}C$, but the reactivity gradually decreased as the temperature increased in a higher temperature range, most likely due to the changes in the crystal structure of the dehydrated kaolin. The activation effect of the calcination treatment was achieved at reaction temperatures that exceeded $60^{circ}C$ and was enhanced as the temperature increased. The reactivity of the calcined kaolin with an alkaline solution was more enhanced with the solution of a higher concentration and with a solution prepared from sodium hydroxide rather than potassium hydroxide. |
Key words:
Geopolymer cement, Calcined kaolin, Alkali-activation reaction, Curing temperature, Setting time |
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