Dafadar, M H and Das, S and Chakravorty, A K (1998) Effect of heat on Al2O3-SiO2 gel coprecipitated at different pH. Transactions of the Indian Ceramic Society, 57 (4). 100-102,105. ISSN 0371-750X

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Abstract

In the present studies Al2O3—SiO2 mullite gels have been synthesized in close range of pH between 6 and 9 by co-precipitating technique using dilute NH4OH solution. Both qualitative and semi-quantitative mullite formation studies have been done. Results show that a spinel to mullite formation occurs during heating the co-precipitated gels in the temperature range between 1100° and 1200°C with 2 hours soaking in each case. The quantity of mullite in all the cases increases with the continued increase in temperature. With the increase in pH, during co-precipitation, the approximate yield of mullite decreases from pH 6 to 9. It is concluded that co-precipitated Al2O3—SiO2 gel becomes inhomogeneous with increase in pH during precipitation. The appearance of boehmite at higher pH range is responsible for low mullitization growth during heat treatment.

Item Type:	Article
Subjects:	Engineering Materials
Divisions:	UNSPECIFIED
Depositing User:	Bidhan Chaudhuri
Date Deposited:	13 Jul 2012 12:35
Last Modified:	11 Mar 2014 12:45
URI:	http://cgcri.csircentral.net/id/eprint/1582

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