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采用热重分析法(TG)和研究阿尔及利亚Tamazarte高岭土的热分解动力学。差热分析(DTA)和TG实验在室温~1400°C下进行,加热速率为10~40°C/min。采用JMA和Ligero法由等温处理测得的活化能,以及采用OFW和KAS法由非等温处理测得的活化能,分别约为151和144 kJ/mol。采用非等温处理确定的生长形貌Avrami参数约为1.57,而采用等温处理时该值约为1.35。数值因数与晶体生长的维度有关,采用Matusita方程确定的值为1.53。采用等温处理时,计算得到的频率因子为1.55×10~7s~(-1)。结果表明,块体形核之后伴随偏高岭土的三维生长,偏高岭土具有受扩散控制的多面体结构,以一定数量的晶核开始生长。
Thermogravimetric analysis (TG) was used to investigate the thermal decomposition kinetics of Tamazarte kaolin in Algeria. Differential thermal analysis (DTA) and TG experiments were performed at room temperature ~ 1400 ° C at a heating rate of 10-40 ° C / min. The activation energies measured by the isothermal treatment using the JMA and Ligero methods and the activation energies measured by the non-isothermal treatment using the OFW and KAS methods are about 151 and 144 kJ / mol, respectively. The Avrami parameter of growth morphology determined by non-isothermal treatment was about 1.57, whereas this value was about 1.35 when isothermal treatment was used. The numerical factor is related to the dimension of crystal growth. The value determined by the Matusita equation is 1.53. When isothermal treatment is used, the calculated frequency factor is 1.55 × 10 ~ 7s ~ (-1). The results show that with the three-dimensional growth of metakaolin after nucleation, metakaolin has a diffusion controlled polyhedral structure and begins to grow with a certain number of nuclei.