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本文提出了稳态数学模型以描述一水硬铝石型铝土矿的溶出反应。该模型反映了一水硬铝石铝土矿溶出过程的主要特征,并以动力学稳态原理为基础。其积分数学式表述如下:式中 p——一水硬铝石比重; M——一水硬铝石分子量; V——溶液体积; K_E——一水硬铝石溶解平衡常数; k——速度常数; r_0——铝土矿中一水硬铝石的形貌特征参数; W_0——一水硬铝石初始重量; η——铝土矿溶出率; C_(NO)、C_(AO)——分别为氢氧根及铝酸根的初始摩尔浓度。 该模型用以测定平果铝土矿溶出表观活化能E。在224～241℃,E=83.5kJ/mol,溶出过程为表面化学反应控制。温度达241～268℃,E的测定值为41.7kJ/mol,此时溶出为表面化学反应和离子扩散联合控制。 表面正、逆向化学反应的离子反应级数均为一级。
This paper presents a steady-state mathematical model to describe the digestion reaction of diasporic bauxite. The model reflects the major characteristics of the diaspore dissolution process and is based on the kinetic steady-state principle. The integral mathematical formula is as follows: Where p - diaspore proportion; M - diaspore molecular weight; V - solution volume; K_E - diaspore dissolution equilibrium constant; k-- R_0 is the morphological characteristic parameter of diaspore in bauxite; w_0 is the initial weight of diaspore; η is the dissolution rate of bauxite; C_ (NO) and C_ (AO) - the initial molar concentrations of hydroxide and aluminate, respectively. The model was used to determine the apparent activation energy E in bauxite dissolution. At 224 ~ 241 ℃, E = 83.5kJ / mol, dissolution process for the surface chemical reaction control. The temperature reached 241 ~ 268 ℃, the measured value of E was 41.7kJ / mol, then the dissolution of the surface chemical reaction and ion diffusion joint control. Surface positive and negative chemical reaction ion reaction series are all level.