Non-isothermal decomposition kinetics of hydrogarnet in sodium carbonate solution

作者：Zhu, Xiaofeng; Zhang, Tingan^*; Wang, Yanxiu; Lu, Guozhi; Zhang, Weiguang; Wang, Cong; Zhao, Aichun

来源：Chinese Journal of Chemical Engineering, 2015, 23(10): 1634-1639.

DOI：10.1016/j.cjche.2015.07.029

• Hydrogarnet
• Differential scanning calorimetry (DSC)
• Activation energy
• Mechanism function
• Carbonation
• Alumina

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 (HP-DSC) at different heating rates of 2, 5, 8, 10, 15 and 20 K.min(-1), respectively. The activation energy (Ea) 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.

• 出版日期2015-10
• 单位太原科技大学; 东北大学