Effect of Alkali Metals on the Preferential Geopolymerization of Stilbite/Kaolinite Mixtures

✍ Scribed by Xu, H.; van Deventer, J. S. J.; Lukey, G. C.

• Book ID: 125967522
• Publisher: American Chemical Society
• Year: 2001
• Tongue: English
• Weight: 96 KB
• Volume: 40
• Category: Article
• ISSN: 0888-5885
• DOI: 10.1021/ie010042b

✦ Synopsis

Stilbite is used as the main aluminosilicate oxide source to determine the effect of various factors on the extent of geopolymerization of stilbite/kaolinite mixtures. Increasing the M 2 O/H 2 O ratio (where M ) Na and/or K) results in an increase in the dissolution of aluminum and silicate species from stilbite and kaolinite, which therefore leads to an improvement in the compressive strength of the geopolymer. The SiO 2 /M 2 O ratio affects significantly the degree to which polymerization between Al(OH) 4 -and Si complexes can occur. The results also show that Na + compared with K + enhances the dissolution of aluminum and silicate species. However, K + improves the compressive strength of the geopolymer compared with Na + . It has been established for the first time that kaolinite and stilbite react differently with different alkali metals. The successful geopolymerization of stilbite/kaolinite mixtures can occur only by homogeneously dispersing condensed Na 2 SiO 3 in a MOH solution prior to adding solids.