纳米级碳酸钙煅烧分解特性研究

Characteristics of Calcination Decomposition of Nanoscale Calcium Carbonate

利用热重分析仪研究了纯氮气氛下,升温速率、环境气氛等因素对纳米级碳酸钙的热分解控制途径,并且与两种常规碳酸钙进行了比较,同时对其煅烧分解动力学进行了分析。研究发现,纳米级碳酸钙煅烧分解比常规碳酸钙更加活跃,同等反应条件下分解温度更低,且随着升温速率的增加反应向高温区移动。CO2分压极大影响纳米级碳酸钙的煅烧分解,致其分解温度极大推迟。纳米级碳酸钙煅烧分解受n=1的成核与生长机制控制,活化能总体比其他两种常规碳酸钙要低。

Thermogravimetric analyzer was used to study the factors influence on calcining decomposition of nanoscale calcium carbonate under pure nitrogen atmosphere,the factors included heating rate,environmental atmosphere,etc.The results were compared with two routine calcium carbonates,meanwhile,the calcining decomposition kinetics of nanoscale calcium carbonate were also analyzed.It was found that the decomposition of nanoscale calcium carbonate was more active than that of routine calcium carbonates,and the decomposition temperature was lower under the same reaction condition.The decomposition reaction moved to the high temperature area with the increase of the heating rate.The partial pressure of CO 2 greatly affected the decomposition of nanoscale calcium carbonate,which resulted in a great delay in its decomposition temperature.The decomposition of nanoscale calcium carbonate is controlled by the mechanism of nucleation and growth(n=1).The activation energy of nanoscale calcium carbonateis is generally lower than that of the other two routine calcium carbonates。