碱式碳酸钴非等温热分解动力学

Non-isothermal kinetics of thermal decomposition of basic cobalt carbonate

利用热重分析及X线衍射技术,考察不同升温速率下碱式碳酸钴的热分解特性,研究碱式碳酸钴热分解动力学。用模型函数法（Coats-Redfern和Achar法）和非模型法（Kissinger法和Flynn–Wall–Ozawa法）分析计算热分解过程第2阶段的动力学参数。研究结果表明：在空气气氛下,碱式碳酸钴的热分解过程分2个阶段进行（碱式碳酸钴在303 K左右开始失去结晶水;493 K时无水盐分解,至625 K以上基本分解完毕,产物为四氧化三钴）,其中分解过程质量损失率为29.5%,与理论值相符;产物表观活化能E为106.139~144.537 kJ/mol,lg A（A为指前因子）为9.396~11.868,机理函数为成核与长大模型。

Kinetics and thermal decomposition behavior of basic cobalt carbonate was investigated using TG and XRD at various heating rates.Kinetic parameters of decomposition of basic cobalt carbonate for the second-stage was calculated and analyzed using model-fitting（Coats-Redfern method and Achar method） and model-free（Kissinger method and Flynn-Wall-Ozawa method）.The results show that the decomposition process of basic cobalt carbonate is divided into two stages： the crystallization water begins to dehydrate at 303 K,decomposition of basic cobalt carbonate follows at 493 K and changes into Co3O4 powder decomposition completely above 625 K in air atmosphere.The mass loss of decomposition of basic cobalt carbonate is 29.5%,which is in good agreement with the theoretical mass loss.Activation energy E and lg A are 106.139-144.537 kJ/mol and 9.396-11.868,respectively.The mechanism function is nucleation and growth model.