Abstract
RECENTLY, Wiegmann and Horte1 have discussed the exothermic reaction of metakaolin and concluded that it is due to the formation of sillimanite. Opinion on this question has long been divided. Some2 ascribe the reaction to the crystallization of γ-Al2O3, whereas others3 ascribe it to the formation of mullite by rearrangement of the metakaolin lattice, yielding a residue of γ-Al2O3 and amorphous silica. The claim that sillimanite rather than mullite forms at the exotherm re-introduces a hypothesis that has long gone out of favour4,5. The evidence put forward by Wiegmann and Horte is difficult to dispute but nevertheless the results of our work do not agree with theirs.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
