机构地区: 东南大学化学化工学院
出 处: 《化学学报》 2006年第7期611-616,共6页
摘 要: 以KNO3-H2O为模型体系,考察了未添加晶种的间歇结晶过程动力学,将历经爆发成核后的结晶体系近似为添加晶种的结晶体系.并结合光学关联方法,推导了可描述历经爆发成核后的晶体形成和生长速率模型.模型中含有可反映结晶固相信息的透光率变量,从而避免了以往模型仅靠液相浓度数据求解模型参数的不便.运用该模型拟合未添加晶种结晶过程的中后期实验数据,得到了KNO3晶体的二次成核和生长动力学参数,参数结果与文献中报道的添加晶种结晶过程的参数值相近.在此基础上,针对添加晶种的结晶过程,提出了晶种添加量的定量设计方法,并得到了实验的初步验证. For researching the kinetics of unseeded batch crystallization process, the KNO3-H2O system was tested and the assumption that the kinetic characteristic after spontaneous nucleation is similar to that of seeded crystallization process was proposed. Responding to the assumption, a kinetic model related to transmittance, as a variable reflecting solid phase information, was established by optical method in order to reduce the relativity between model parameters and concentration data. Using the model, the secondary nucleation and crystal growth kinetics parameters of KNO3 crystal were successfully estimated from the intermediate and final stages' experimental data, and the values of parameters appeared to be in good agreement with those of seeded crystallization process published in literature. Based on it, a quantitative design method of seed load was subsequently put forward for seeded crystallization process, and the corresponding experiment also acquired perfect effect.
关 键 词: 未添加晶种结晶 动力学模拟 透光率 晶种添加量 定量设计
领 域: [化学工程]