蛇纹石酸浸渣碱溶脱硅反应动力学  

Kinetics of alkali-dissolving desilication reaction of serpentine acid leaching slag

作　　者：高凌宇 杨喜云 吴玉楼 陈莹丽 童丽嵘 GAO Ling-yu;YANG Xi-yun;WU Yu-lou;CHEN Ying-li;TONG Li-rong(School of Metallurgy and Environment,Central South University,Changsha 410083,China)

机构地区：[1]中南大学冶金与环境学院,长沙410083

出　　处：《中国有色金属学报》2023年第8期2718-2728,共11页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51574286)。

摘　　要：以蛇纹石酸浸渣为原料,系统研究了碱溶脱硅反应动力学。通过X射线衍射(XRD)、X射线荧光(XRF)、热重-差热(TG-DTA)和场发射扫描电镜-能谱(FESEM-EDS)对蛇纹石酸浸渣物相、化学组成、热稳定性及形貌结构进行了详细分析。利用单因素变量法对蛇纹石酸浸渣碱溶脱硅反应过程进行了研究,详细讨论了NaOH质量分数、反应温度、液固比、搅拌速度和粒度对酸浸渣中SiO_(2)溶出率的影响,并分别采用收缩核模型及Avrami方程拟合动力学,并建立了反应动力学方程。结果表明:在该体系中,蛇纹石酸浸渣碱溶过程动力学不符合传统的收缩核模型,而符合Avrami方程且拟合相关性较高;整个溶出过程受扩散控制,模型特征参数n_(1)=0.21,反应表观活化能E_(a)=8.62 kJ/mol。Using serpentine acid leaching slag as raw material,the kinetics of alkali-dissolving desilication reaction was systematically studied.The phase,chemical composition,thermal stability and morphological structure of serpentine acid leaching slag were analyzed in detail by X-ray diffraction(XRD),X-ray fluorescence(XRF),thermogravimetric-differential thermal(TG-DTA)and field emission scanning electron microscopy-energy spectroscopy(FESEM-EDS).The single-factor variable method was used to study the reaction process of alkali dissolution and desilication of serpentine acid leaching slag.The effects of mass fraction of NaOH,reaction temperature,liquid-solid ratio,stirring speed and particle size on the dissolution rate of SiO_(2 )in acid leaching slag were discussed in detail,and the kinetics were fitted by shrinking core model and Avrami equation,respectively,and the reaction kinetic equations were established.The results show that,in this system,the kinetics of the alkaline dissolution process of the serpentine acid leaching slag does not conform to the traditional shrinking core model,but is consistent with Avrami equation and the fitting correlation is very high.The whole dissolution process is controlled by diffusion model,the characteristic parameter(n_(1))is 0.21,and the apparent activation energy(E_(a))of the reaction is 8.62 kJ/mol.

关 键 词：蛇纹石 酸浸渣 碱溶 硅 动力学 

分 类 号：TF80[冶金工程—有色金属冶金]