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Thermal decomposition of sepiolite and variations in pore structure with and without acid pre‐treatment
Author(s) -
Balci Suna
Publication year - 1996
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/(sici)1097-4660(199605)66:1<72::aid-jctb442>3.0.co;2-t
Subject(s) - sepiolite , specific surface area , thermal decomposition , thermogravimetric analysis , materials science , thermal stability , adsorption , decomposition , chemical engineering , mineralogy , mineral , raw material , chemistry , catalysis , organic chemistry , metallurgy , engineering
Sepiolite is a high surface area clay mineral containing channels of molecular dimensions. In industrial applications as an adsorbent or catalyst support, the mineral should have thermal stability. In this study, the effect of heat treatment on sepiolite structure was investigated. Thermal decomposition of raw sepiolite and acid pre‐activated sepiolite samples were carried out with a thermogravimetric analyser. Approximately 24% weight loss was observed till 900°C. This value decreased to 14% for acid pre‐treated samples. The surface area value of the original sepiolite was 148 m 2 g −1 , and it increased to 263 m 2 g −1 at 100°C. Further increase in temperature caused channel plugging and crystal structure deformation, as a result the surface area values showed a decrease with temperature. On the other hand, acid pre‐treatment caused a change in pore size distribution by increasing the surface area 2·5 times. Acid pre‐treatment also restricted the possible crystal structure deformations during temperature changes. While the surface area of the original mineral which was heated up to 900°C was 60 m 2 g −1 , the corresponding value of the acid pre‐treated sepiolite was 360 m 2 g −1 .