铬酸钠碳化生产重铬酸钠工艺的热力学模拟研究  

Thermodynamic simulation of manufacture of sodium dichromate by carbonization of aqueous sodium chromate

作　　者：韩晓英[1] 余志辉[1] 曲景奎[1] 齐涛[1] 周恩年[1] 

机构地区：[1]中国科学院过程工程研究所,湿法冶金清洁生产技术国家工程实验室,北京100190

出　　处：《计算机与应用化学》2011年第11期1357-1361,共5页Computers and Applied Chemistry

基　　金：国家自然基金资助项目(21006119);国家重点基础研究发展计划(863)(2009AA035001);国家高技术研究发展计划(863)(2011AA060704);国家杰出青年科学基金(51125018)

摘　　要：铬酸钠碳化生产重铬酸钠工艺是高压反应,且泄压后会发生强烈的逆反应,因此实际反应过程的机理及受控条件的影响状况难以用实验来测定。OLI使用非常先进的热力学和数学模型来预测化学体系平衡过程的性质,并且利用OLI预测电解质溶液热力学已成为工业预测标准。本文应用OLI-Analyzer对铬酸钠碳化生产重铬酸钠工艺进行了热力学模拟,包括一次碳化、二次碳化、碳酸氢钠分离以及碳酸氢钠湿法分解。探索压力、温度、浓度等因素对碳化工艺各平衡过程的影响。从热力学的角度确定了各平衡过程的最佳条件,为实际工业应用提供指导意义。经过模拟得出各平衡过程的最佳条件为:(1)一次碳化:温度为40℃,压力为1MPa,铬酸钠初始浓度10mol/kg;(2)二次碳化:温度为40℃,压力为1MPa,预碳化率66.7%;(3)碳化液中碳酸氢钠分离:温度为40℃,压力为1MPa,铬酸钠初始浓度10mol/kg;(4)碳酸氢钠湿法分解:温度为7℃,压力为0.001MPa,此时分解率98.89%。The manufacture of sodium dichromate by carbonization of aqueous sodium chromate is a high-pressure reaction.However,when it returns to atmospheric pressure,the reverse reaction will occur strongly.Therefore,it is difficult to measure the real reaction mechanism and the affection of controlled conditions by experiment.OLI can predict the characters of chemical equilibrium process based on some very advanced thermodynamic and mathematic models.And it becomes industrial predictive standard in the thermodynamic area of electrolyte aqueous solutions.The paper simulated the process of the manufacture of sodium dichromate by carbonization of aqueous sodium chromate,including first carbonization,second carbonization,the separation of NaHCO_3 and the evaporation of sodium dichromate from carbonization liquid.The paper also discussed the affection of pressure,temperature,concentration to each equilibrium process of carbonation.From the point of thermodynamic view,it is determined the optimal condition of each equilibrium process,which provided a guide for the actual industry.The optimal condition of each equilibrium process is that,temperature is 40℃,pressure is 1 MPa,the concentration of Na_2CrO_4 is 10 mol/kg for the first carbonization;temperature is 40℃,pressure is 1 MPa,the expected rate of carbonation is 66.7%for the second carbonization;temperature is 40℃,pressure is 1 MPa,the concentration of Na_2CrO_4 is 10 mol/kg for the separation of NaHCO_3 from the carbonization liquid;temperature is 7℃,pressure is 0.001 MPa for the wet decomposition of NaHCO_3,here the decomposition rate is 98.90%.

关 键 词：OLI-Analyzer 热力学 铬酸钠 重铬酸钠 碳化 

分 类 号：TP319[自动化与计算机技术—计算机软件与理论] TQ115[自动化与计算机技术—计算机科学与技术]