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本文研究了一水硬铝石型铝土矿的溶出动力学。通过对一水硬铝石矿Bayer法溶出过程主要特征的研究,并基于动力学稳态原理,推导了溶出反应速度方程: V=kS[(C_N—C_A)/K_E] 式中,k为表观速度常数;S为反应表面积;C_N,C_A分别为溶液中氢氧根和铝酸根的摩尔浓度;K_E为溶出反应平衡常数。应用等溶出率方法处理了平果铝土矿溶出动力学数据。结果表明,一水硬铝石表面反应有关离子的反应级数为1的假设是合理的。224—242℃之间,平果矿溶出表观活化能为89.5 kJ/mol,反应为动力学控制区;当温度升至242—268℃,表观活化能降至44.4 kJ/mol,溶出过程处于表面化学反应及传质步骤的影响应予同时考虑的过渡区。
In this paper, the dissolution kinetics of diasporic bauxite was studied. Based on the study of the main characteristics of the dissolution process of the diaspore Bayer process and based on the kinetic steady state principle, the dissolution rate equation is derived as follows: V = kS [(C_N-C_A) / K_E] View the rate constant; S is the reaction surface area; C_N, C_A respectively, the molar concentration of hydroxide and aluminate solution; K_E dissolution equilibrium constant. The leaching kinetics data of Pingguo bauxite were processed by the method of dissolution rate. The results show that the assumption that the reaction order of ions on the surface of diaspore is 1 is reasonable. 224-242 ℃, the apparent activation energy of Pingguo ore dissolution was 89.5 kJ / mol, and the reaction was the kinetic control zone. When the temperature reached 242-268 ℃, the apparent activation energy decreased to 44.4 kJ / mol and the dissolution process The effects of surface chemical reactions and mass transfer steps should be considered simultaneously in the transition zone.