• Journal of the Korean Ceramic Society
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• v.36 no.3
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• pp.274-283
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• 1999

1.1-nm tobermorite의 수열합성에 SiO2원으로 zeolite광물을 출발물질로하여 소석회와 Ca(Si+Al)의 몰비 0.8~1.0로 150$^{\circ}$~23$0^{\circ}C$,8~48시간 동ㅇㄴ 포화증기압하에서 수열반응을 시킨 결과, 반응초기단계에서 tobermorite가 생성되었고, 고결정성 1.1-nm tobermorite의 최적합성조건은 0.8몰, 23$0^{\circ}C$, 48시간이었다. 출발물질중 Al의 존재로 tobermorite는 Ca/(Si+Al)몰비 0.8이 1.0보다 결정화가 급속히 이루어지고 있으나 Al를 함유치 않은 석영의 경우에는 Ca/Si 몰비 1.0이 0.8에서 보다 결정화가 빠르게 진행되었다 1.1-nm tobermorite는 $700^{\circ}C$에서 일주일간 가열처리하여도 저면간격이 변화하지 않는 열적거동이 이상형임을 보여주었다. 특히 출발물질중 Al의 존재는 1.1-nm tobermorite의 결정화와 안정화를 촉진시켜주며 Al이온이 tobermorite구조중의 Si이온과 동형치환을 한다.

• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.291-299
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• 1993

Hydrothermal synthesis of 1.13nm tobermorite was performed to obtain the mixing ratio of raw materials, the optimum reaction time and the effect of aluminum in two systems, $CaO-SiO_2-H_2O$ and cement sludge-$SiO_2-H_2O$. 1.13nm tobermorite($5CaO{\cdot}6SiO_2{\cdot}5H_2O:C_5S_6H_5$) was synthesized excellently from $CaO-SiO_2-H_2O$ system on each mole ratio (0.4, 0.8) of $CaO/SiO_2$ at $180^{\circ}C$. But a tobermorite crystals had a sign of crystal conversion after 6 hours of reaction times in the case of $CaO/SiO_2=0.4$ and 4 hours of reaction time in the case of $CaO/SiO_2=0.8$. However, a tobermorite synthesized from cement sludge wastes did not show the crystal conversion on each mole ratio(0.4, 0.8) of $CaO/SiO_2$ within 10 hours of reaction times. It is considered that aluminum ions dissolved from cement sludge wastes retarded the recrystallization of tobermorite. This role of aluminum ion was confirmed in $CaO-SiO_2-H_2O+Al$ powder system. According as added amount of Al powder was increased from 0.8% to 3.0%, the crystal had a highly flatter and larger shape. Recrvstallization was not detected within the same reaction times when aluminum was added.