Kinetics of AlOOH dissolving in caustic solution studied by high-pressure DSC  

利用高压DSC研究—水铝石在碱液中的溶出动力学(英文)

作　　者：鲍丽[1] 张廷安[1] 豆志河[1] 吕国志[1] 郭永楠[1] 倪培远[1] 吴许建[1] 马佳[1] 

机构地区：[1]东北大学材料与冶金学院,沈阳110004

出　　处：《Transactions of Nonferrous Metals Society of China》2011年第1期173-178,共6页中国有色金属学报（英文版）

基　　金：Project(2007BC13504)supported by the National Basic Research Program of China;Project(20050145029)supported by Research Fund for the Doctoral Program of Higher Education;Project(2005221012)supported by the Science and Technology Talents Fund for Excellent Youth of Liaoning Province,China

摘　　要：Mechanism functions and kinetic parameters of AlOOH（boehmite or diaspore） dissolving in sodium hydroxide solution were researched.The mixture of boehmite or diaspore and caustic solution was scanned by high-pressure differential scanning calorimetry（DSC） instrument with heating rate of 10 ℃/min,and differential equation method was used to analyse the DSC curves,combining with iterative method and linear least square method.The most probable mechanism functions for both boehmite or diaspore and caustic solution reactions were logically selected from 30 types of non-isothermal kinetics differential equations,according to the calculated results obtained by Matlab program.The most probable differential mechanism function of boehmite dissolving in caustic solution is f（α）=1-α,which reveals the first-order reaction with apparent activation energy of 79.178 kJ/mol and the preexponential constant 1.031×108 s-1.The function,f（α）=2（1-α）3/2,can describe the dissolution of diaspore sample in sodium hydroxide solution.The calculated results of kinetic parameters are apparent activation energy of 73.858 kJ/mol,preexponential constant of 5.752×107 s-1 and reaction order of 1.5.研究一水铝石(包括一水软铝石和一水硬铝石)在氢氧化钠溶液中溶出过程的机理函数并确定相应的动力学参数。将一水铝石矿和氢氧化钠溶液在高压DSC设备中以10℃/min的速度加热,用微分方程法分析得到DSC曲线,同时借助Matlab程序利用迭代法和线性最小二乘法计算微分方程,从30种机理函数的微分形式中分别逻辑地选择了两种一水铝石矿和苛性碱溶液的反应过程的最可能的机理函数。计算结果表明:一水软铝石溶解于苛性碱溶液的最可能的机理函数为f(α)=1-α,表观活化能为79.178kJ/mol,指前因子为1.031×108mol/s,反应级数为1;一水硬铝石在苛性碱溶液中溶解的最可能的机理函数为f(α)=2(1-α)3/2,表观活化能为73.858kJ/mol,指前因子为5.752×107mol/s,反应级数为1.5。

关 键 词：differential mechanism function BOEHMITE DIASPORE apparent activation energy preexponential constant 

分 类 号：TF821[冶金工程—有色金属冶金]