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Thermal reactions of alkali-leached aluminosilicates studied by XRD and solid-state Al-27, Si-29 and Na-23 MAS NMR

IR@CGCRI: CSIR-Central Glass and Ceramic Research Institute, Kolkata

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Title Thermal reactions of alkali-leached aluminosilicates studied by XRD and solid-state Al-27, Si-29 and Na-23 MAS NMR
 
Creator MacKenzie, K J D
Meinhold, R H
Chakravorty, Akshoy Kumar
Dafadar, M H
 
Subject Structural Clay Products
 
Description The interactions of dehydroxylated Zettlitz kaolinite with NaOH solution have been studied using X-ray powder diffraction and solid-state MAS NMR to characterise the crystalline and amorphous products, respectively, and to provide further information about the reaction sequence of kaolinite. Under the present conditions, leaching for very short times (ca. 10 min) preferentially removes uncombined amorphous silica (but not the quartz impurity), and also introduces Na into the remaining amorphous aluminosilicate phase. Leaching for longer times continues to remove Si from the amorphous phase, with a concomitant increase in Na incorporation and an increase in the proportion of available Al. On reheating to 1140 and 1300 degrees C, the resulting crystalline phases reflect the increase in Al and Na content with increased leaching time, forming a-alumina and, in samples leached for > 60 min, a nepheline solid solution at the expense of mullite, residual quartz and cubic spinel-type phase.
 
Publisher Royal Society of Chemistry
 
Date 1996-05
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://cgcri.csircentral.net/1682/1/mackenzie1996.pdf
MacKenzie, K J D and Meinhold, R H and Chakravorty, Akshoy Kumar and Dafadar, M H (1996) Thermal reactions of alkali-leached aluminosilicates studied by XRD and solid-state Al-27, Si-29 and Na-23 MAS NMR. Journal of Materials Chemistry, 6 (5). pp. 833-841. ISSN 0959-9428
 
Relation http://cgcri.csircentral.net/1682/