Reduction of electric arc furnace dust pellets by mixture containing hydrogen

Abstract The large amount of dust generated in electric arc furnace aligned with its chemical composition makes this dust a potential source of iron in the direct reduction iron process. Thus, the aim of this research is to investigate the reduction of pellets produced with electric arc furnace dust using hydrogen as the reducing agent. The kinetic investigation was examined applying the differential method. In addition, the influence of reducing gas stream and temperature in the reduction process were investigated applying the Forced Stepwise Isothermal Analysis technique. The temperature studied varied from 500 to 1000°C with isothermals in each 50°C. The reducing gas was a mixture of 10% of hydrogen and 90% of argon. Then, the product characterization was carried out via scanning electron microscope and X-ray analysis. A thermogravimetric test showed a mass loss of 42 wt% due to the reduction of iron and zinc oxides. Besides this, the reduction occurred in three steps: 550-650°C, 700-800°C, 850-950°C. Between 550-650°C, the reduction was controlled by a nucleation mechanism with an Ea of 41.1 kJ/mol. In the second step (700-800°C), a mixed control between nucleation and diffusion was obtained with an Ea of 89.1 kJ/mol. Furthermore, a crust of iron was formed around the pellet, which hindered the reducing gas diffusion into the pellet. In the third stage (850-950°C), the formation of a sintered structure was noted, which decreased pore volume. The internal diffusion of reducing gases was determined as the controlling mechanism, with an Ea of 130.9 kJ/mol.

搜集汇总

背景与挑战

背景概述

该数据集研究电炉粉尘颗粒在含氢混合物中的还原过程，重点关注使用氢作为还原剂的动力学行为和温度影响（500-1000°C）。实验结果表明还原过程分为三个步骤，涉及不同控制机制和活化能，并通过扫描电子显微镜和X射线分析进行产品表征，为电炉粉尘的资源化利用提供科学依据。