ZnSO_(4)-FeSO_(4)溶液氧压水热强化针铁矿法除铁行为与机理

Iron removal behavior and mechanism of oxygen pressure hydrothermal enhanced goethite method in ZnSO_(4)-FeSO_(4) solution

针对湿法炼锌过程中针铁矿法锌铁分离效率低、沉铁产物性能差等问题,本文提出了在氧压水热环境下开展针铁矿法除铁的方法。结果表明:提高反应温度、氧分压、搅拌转速、晶种用量和pH均有利于针铁矿除铁。在反应温度为110℃、氧分压为0.2 MPa的优化反应条件下,产出的沉铁产物中铁含量为55.2%,锌含量为3.2%,硫含量为1.5%;沉铁产物中生成了结晶度较高的针铁矿晶簇。在氧压水热除铁过程中,反应在0~60 min时符合一级反应动力学特征,在60~100 min时满足二级反应动力学特征,反应活化能为34.50 kJ/mol;在110℃下除铁反应的速率常数(k)为0.021 dm^(3)/(mol·min)。

In order to solve the problems such as the low efficiency of zinc-iron separation and poor performance of iron residues in the process of zinc hydrometallurgy,this paper proposed a method for iron removal using goethite method in an oxygen pressure hydrothermal environment.The results indicate that increasing reaction temperature,oxygen partial pressure,stirring speed,seed addition and pH are all beneficial for iron removal.Under the optimized reaction conditions with a reaction temperature of 110℃and an oxygen partial pressure of 0.2 MPa,the contents(mass fraction)of iron,zinc and sulfur in iron precipitate product are 55.2%,3.2%and 1.5%,respectively.The iron crystal clusters with high crystallinity are formed in iron precipitate product.During the oxygen pressure hydrothermal iron removal process,the iron removal reaction at the time from 0 min to 60 min follows the first order reaction kinetics characteristics,and then follows the second order reaction kinetics characteristics at the time from 60 min to 100 min.The activation energy of the iron removal reaction is 34.50 kJ/mol,and the rate constant(k)of the iron removal reaction is 0.021 dm^(3)/(mol·min)at 110℃.