摘要
Carbonation decomposition of hydrogarnet is a significant reaction of the calcification-carbonation new method for alumina production by using low-grade bauxite.In this work,non-isothermal decomposition kinetics of hydrogarnet in sodium carbonate solution was studied by high-pressure differential scanning calorimetry(HPDSC) at different heating rates of 2,5,8,10,15 and 20 K·min^(-1),respectively.The activation energy(E_α) was calculated with the help of isoconversional method(model-free),and the reaction mechanism was determined by the differential equation method.The calculated activation energy of this reaction was 115.66 kJ·mol^(-1).Furthermore,the mechanism for decomposition reaction is Avrami-Erofeev(n=1.5),and the decomposition process is diffusion-controlled.
Carbonation decomposition of hydrogarnet is a significant reaction of the calcification-carbonation new method for alumina production by using low-grade bauxite.In this work,non-isothermal decomposition kinetics of hydrogarnet in sodium carbonate solution was studied by high-pressure differential scanning calorimetry（HPDSC） at different heating rates of 2,5,8,10,15 and 20 K·min-1,respectively.The activation energy（Eα） was calculated with the help of isoconversional method（model-free）,and the reaction mechanism was determined by the differential equation method.The calculated activation energy of this reaction was 115.66 kJ·mol-1.Furthermore,the mechanism for decomposition reaction is Avrami-Erofeev（n=1.5）,and the decomposition process is diffusion-controlled.
基金
Supported by the Joint Funds of the National Natural Science Foundation of China(U1202274)
the National Natural Science Foundation of China(51204040)
the Research Fund for the Doctoral Program of Higher Education of China(201200421100 11)
the Doctor Start-up Foundation in Taiyuan University of Science and Technology(20142001)
