黄铵铁矾渣热分解反应机理及其动力学解析
Thermal decomposition reaction and kinetic analysis of ammonium jarosite residues
崔雅茹 1李邓 1王国华 1李小明 1赵俊学 1王正民 2桂海平2
作者信息
- 1. 西安建筑科技大学 冶金工程学院,西安 710055
- 2. 汉中锌业有限责任公司,汉中 724204
- 折叠
摘要
针对黄铵铁矾渣侧吹熔炼熔渣稳定控制研究需求,采用热重-差热-质谱联用仪结合XRD、SEM-EDS等分析方法对其热分解过程及动力学特性进行研究.结果表明:黄铵铁矾渣中主要化合物为铵铁矾(NH4)Fe3(SO4)2(OH)6、铁锌尖晶石(Zn,Fe)Fe2O4及硫酸铅PbSO4、CaSO4(H2O)2等硫酸盐.在热分解过程中,铵铁矾在380℃左右发生了脱氨、脱羟反应,生成各种硫酸盐,其机理函数为减速型α-t曲线;Fe2(SO4)3在610℃时发生了分解,反应表观活化能E为153.07 kJ/mol,强化气体产物的扩散有助于推进反应进程;硫酸铅在1080℃左右发生分解,其反应机理遵循三维扩散,表观活化能较高(555.90 kJ/mol);硫酸铅分解的主要限制性因素是分解产物PbO在渣中的扩散,可通过降低渣系的熔点及黏度促进反应进行.
Abstract
To meet the demand of process stability control in side-blowing smelting for treating ammonium jarosite residues,the thermal decomposition and kinetic characteristics of the ammonium jarosites were investigated by means of TG-DSC-MS combined with XRD and SEM-EDS analysis.The results show that the main phases discovered in the researched slag are those of ammonium jarosite(NH4)Fe3(SO4)2(OH)6,spinel(Zn,Fe)Fe2O4,sulfates of PbSO4 and CaSO4(H2O)2.During thermal decomposition,the dehydroxylation and deamination reaction occur at about 380℃,resulting in various sulfates,the mechanism function of the dehydroxylation-deamination reaction is the decelerating α-t curve.In addition,the decomposition of Fe2(SO4)3 occurs at about 610℃,with a corresponding activation energy of 153.07 kJ/mol,which means strengthening the diffusion of gaseous product may contribute to the reaction.And the decomposition of PbSO4 occurs at about 1080℃with a high activation energy of 555.90 kJ/mol,whose reaction kinetic mechanism follows the three-dimensional diffusion.The main limiting factor of PbSO4 decomposition depends upon the diffusion of PbO product in the slag,which can be promoted by reducing the melting temperature and viscosity of the slag system.
关键词
黄铵铁矾渣/热分解/反应机理/动力学特性/表观活化能Key words
jarosite residue/thermal decomposition/reaction mechanism/kinetic characteristics/apparent activation energy引用本文复制引用
基金项目
陕西省科技厅重点研发计划资助项目(2022GY-160)
陕西省博士后科研资助项目(2023BSHEDZZ275)
出版年
2024
NETL
NSTL
万方数据