大粒径石灰石热分解动力学研究

主要研究大粒径石灰石的煅烧特性，采用热重分析仪研究了5种不同粒径石灰石的煅烧过程。石灰石粒径分布在0.5~10 mm，煅烧温度在900~1 050 ℃。研究结果表明，粒径越小温度越高石灰石分解速率越快，而且粒径和煅烧温度对石灰石热分解机理也有明显的影响。粒径小温度高时反应符合随机成核和随后生长机理模型，粒径大温度低时反应符合相界面反应机理。当粒径为0.5~1 mm时反应活化能很小，随着粒径的增大反应活化能有所增加，粒径在1~5 mm时活化能变化不大，粒径继续增大（5~10 mm）活化能增大了1倍。

Study on thermal decomposition kinetics of limestone with large particle size

Thermal decomposition experiments of limestone with five different particle sizes were conducted through thermo gravimetric analyzer to study its calcined characteristics with large particle size.The limestone particle sizes were distributed in the range of 0.5~10 mm，and the temperature was controlled at 900~1 050 ℃ during the experiments.Rresults revealed that the smaller the particle size，the higher the temperature and the faster the decomposition.And the particle size and calcining temperature made an obvious influence on the thermal decomposition mechanism.When the particle size was small and the temperature was high，the reaction was in accordance with the randomly nucleating and nucleus growth model，but in contrast，reaction was in accordance with the phase interface mechanism.When the particle size was  at 0.5~1 mm， reaction activation energy was very small，and with the increase of particle size，reaction activation energy increased，while in the range of 1~5 mm，activation energy fluctuated，with the continuous increase of particle size to 5~10 mm，the activation energy doubled.