Abstract
The effect of some fluoro compounds on the dehydroxylation and crystallization of kaolinite was investigated using thermal analysis. Samples were prepared starting from the raw kaolin (K-0) by adding 1 mass% fluorine, introduced as LiF (K-Li), NaF (K-Na) and CaF2 (K-Ca), respectively. The results show that the peak temperatures of the dehydroxylation process are less influenced by the fluorides presence, whilst the peak temperatures of the crystallization process decrease in the presence of fluorides, which confirm the mineralizer effect of fluorides on the crystallization process. The activation energies of the dehydroxylation and crystallization processes were calculated using the isoconversional methods described by Kissinger–Akahira–Sunose and Vyazovkin. For the dehydroxylation process, the values of the activation energy calculated as a function of the conversion extent are not significantly influenced by the fluorides presence. For the crystallization process, all the samples with fluorides show values of the activation energy higher than those of the sample without fluorides on the entire range of the conversion extent.
Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
