Premium
Differential Thermal Calorimetric Determination of the Thermodynamic Properties of Kaolinite
Author(s) -
NICHOLSON PATRICK S.,
FULRATH RICHARD M.
Publication year - 1970
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1970.tb12084.x
Subject(s) - kaolinite , exothermic reaction , mullite , crystallization , enthalpy , differential scanning calorimetry , differential thermal analysis , amorphous solid , quartz , materials science , exothermic process , enthalpy change of solution , calorimetry , extraction (chemistry) , standard enthalpy of reaction , chemistry , chemical engineering , mineralogy , thermodynamics , organic chemistry , metallurgy , adsorption , ceramic , physics , diffraction , optics , engineering
Four samples of kaolinite were investigated to determine the exothermic reaction enthalpy by differential thermal calorimetry. The measured 9 kcal/mol for the 980°C exothermic reaction enthalpy corresponds to the calculated heat of crystallization of silica at this temperature. Literature evidence discounts the crystallization of the other participating phases, mullite and silicon spinel. An NaOH extraction technique was used to remove the amorphous silica from a kaolinite fired at 850°C; this extraction removed the 980°C exotherm. It is tentatively suggested, therefore, that most of the heat release at 980°C on firing kaolinite accompanies the reaction SiO 2 (amorphous) → SiO 2 (β‐quartz).