Numerical Analysis of Flash Ironmaking Process in a Newly Proposed Counter-Current Downer

• Published in: JOM (1989) Vol. 74; no. 4; pp. 1499 - 1508
• Main Authors: Yang, Yiru, Shen, Zhongjie, Xu, Jianliang, Liu, Haifeng
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2022; Springer Nature B.V
• Subjects: Catalytic cracking; Chemistry/Food Science; Coal gasification; Computational fluid dynamics; Computational Modeling of Metallurgical Furnaces; Earth Sciences; Engineering; Environment; Fluid dynamics; Gas flow; Iron oxides; Ironmaking; Laboratories; Mathematical models; Numerical analysis; Physics; Reacting flow; Reactors; Reynolds number; Temperature; Turbulence models; Velocity; Viscosity
• ISSN: 1047-4838; 1543-1851
• DOI: 10.1007/s11837-021-05003-3

A counter-current downer is proposed as a new structure to improve the flash ironmaking technology (FIT). A computational fluid dynamics (CFD) model was established to predict the dilute gas–particle reacting flow, and a core–annulus structure was observed. Furthermore, counter-current and cocurrent downers have been compared in similar conditions. As a result, reduced iron of the counter-current downer had a higher reduction degree (99.8%) than that of the cocurrent downer (70.1%). The first two reaction steps (Fe 2 O 3  → Fe 3 O 4 and F 3 O 4  → FeO) were swift, while the subsequent step (FeO → Fe) in the counter-current downer showed a significant difference due to the preponderant reduction potential and temperature. Different gas velocities (0.167–0.667 m/s) were also investigated, and the high-speed gas flow brought more particles with decreasing metal yield from 89.3% to 27.5%. However, more gas amounts always led to a higher reduction degree separately of captured and escaped particles.