低品位硫精矿富氧焙烧反应动力学计算  

Reaction kinetics calculation of low grade sulphur concentrate roasting under oxygen enrichment

作　　者：祖刚[1] 李解[1] 李保卫 王介良[1] 杨仲禹 

机构地区：[1]内蒙古科技大学内蒙古自治区白云鄂博矿多金属资源综合利用重点实验室,内蒙古包头014010

出　　处：《钢铁研究学报》2015年第12期16-24,共9页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(50974073);内蒙古自然科学基金资助项目(2015MS0559)

摘　　要：针对硫精矿中硫的脱除问题，研究了低品位硫精矿在富氧条件下焙烧反应的动力学过程。利用XRD、SEM和EDS分析了硫精矿氧化焙烧过程的矿相变化规律。同时，根据其热分析的DSC和TG曲线，采用Achar-Brindley-Sharp-Wendworth微分法和Coats-Redfern积分法分别计算了脱硫反应的动力学参数，确定了硫精矿不同温度段脱硫的反应机制。结果表明：随着温度的升高，复杂的硫精矿逐渐被氧化成赤铁矿，其中伴随着中间产物硫酸铁的生成与分解；而且焙烧矿的硫含量也随温度升高而逐渐降低。动力学计算结果表明，在430～975℃的温度范围内，硫精矿氧化焙烧分为4个阶段进行，在前3个阶段，脱硫反应机理均符合Avrami-Erofeev方程，为随机成核和随后生长的化学反应控制，只是反应级数和表观活化能在不同阶段各不相同；在第4阶段，脱硫反应机理符合Z_卜T方程，为残余硫化物的三维扩散控制，反应的表观活化能分别为10．812和9．920kJ／mol，在4个温度段中是最低的。For the problem of desulfurization from sulphur concentrate, the reaction kinetics process of low grade sulphur concentrate roasting under oxygen enrichment was studied, and the changes of mineral phases in sulphur concentrate roasting during the course of oxidation were analyzed by SEM, XRD and EDS. At the same time, ac- cording to DSC and TG curves, the kinetic parameters of desulfurization reaction were calculated by Achar-Brind- ley-Sharp-Wendworth differential method and Coats-Redfern integral method, and the desulfurization mechanism of sulphur concentrate was determined at different temperature stages. The results show that with the rising tem- perature, the complex sulphur concentrate gradually becomes hematite, accompanied by the formation or the de- composition of the intermediate ferric sulfate~ and sulfur content of roasting ores decreases. The kinetics calcula- tion results show that in the temperatures of 430--975 ~C, oxidation roasting of sulfur concentrate has four tem- perature stages. In the first three stages, desulfurization reaction mechanisms all accord with Avrami-Erofeev e- quation, belonging to the chemical reaction control of the random nucleation and then growth, only the reaction or- der and the apparent activation energy of reaction vary in different temperature stages~ In the fourth stage, the desulfurization reaction mechanism accords with Z-L-T equation, belonging to the reaction control of the three-di- mensional diffusion of the residual sulphide. In addition to this, the apparent activation energies of reaction are 10. 812 and 9. 920 kJ/mol respectively, and are the lowest in four temperature stages.

关 键 词：硫精矿 氧化焙烧 脱硫动力学 活化能 

分 类 号：TF046.2[冶金工程—冶金物理化学]