循环流化床灰中铝的浸出行为及动力学研究

以煤矸石电厂循环流化床粉煤灰(CFB灰)为原料,研究了CFB灰中Al2O3酸浸出行为的影响因素及其酸浸出过程动力学。试验结果表明:盐酸浓度6 mol/L、酸浸温度110℃、酸浸时间180 min、液固比为4:1,KF加入量为15%,Al2O3的浸出率为68.46%。CFB灰中Al2O3的浸出过程受扩散和化学反应控制,符合典型的"未反应核收缩模型"。其反应动力学方程可用1-(1-α)1/3=k’t来描述,反应表观级数为1.0875,反应活化能为21.186 kJ/mol。

Leaching Behavior and Kinetics of Aluminum from Circulating Fluidized Bed Ash

Using circulating fluid bed fly ash(CFB ash) generated in gangue power plant,the influencing factors in the acid leaching behavior and kinetics of aluminum oxide from the circulating fluidized bed ash was studied.The results show that the concentration of hydrochloric acid of 6 mol/L,the temperature 110 ℃,reaction time 180 min,liquid-to-solid ratio of 4:1,and KF addition amount with 15%,the leaching rate of ferric oxide is 68.46%.The acid leaching process of Al2O3 conforms to the typical "shrinking unreacted core model ".Its equation of kinetics of reaction can be described by 1-(1-α)1/3=k′t,the apparent reaction order is 1.0875,the activation energy of the reaction is 21.186 kJ/mol,while the process speed rate is controlled by the diffusion and chemical reaction rate.