Study on the formation of direct reduced iron by using biomass as reductants of carbon containing pellets in RHF process. (15th December 2017)

• Record Type: Journal Article
• Authors: Yuan, Peng; Shen, Boxiong; Duan, Dongping; Adwek, George; Mei, Xue; Lu, Fengju
• Is Part Of: Energy. Volume 141(2017)
• Page Start: 472
• Page End: 482
• Publication Date: 2017-12-15
• Subjects: Biomass -- Reductants -- Direct reduced iron -- Shrinkage -- Strength -- Metallization; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2017.09.058
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: To investigate the possibility of using biomass reductants instead of fossil fuels in the formation of direct reduced iron (DRI) in rotary hearth furnace (RHF), three kinds of cheap biomass such as bamboo char, straw fiber and charcoal were selected as reductants to compare with anthracite and graphite. The effect of reductants, temperature, dwelling time, C/O ratio and particle sizes on the shrinkage, strength and metallization of the biomass/ore pellets was investigated and discussed. The optimized reduction conditions were obtained as 1200 °C, 20min, C/O = 0.7 and the particle size range of <0.15 mm, 1–2 mm and 0.15–0.3 mm for straw fiber, bamboo char and charcoal respectively. The results showed that straw fiber was considered as an optimal reductant in the formation of direct reduced iron instead of fossil fuels. By the techniques of scanning electron microscope (SEM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD), the mechanism of biomass as reductants was revealed. Volatile matter was confirmed to play an important role in the formation of DRI when biomass used as reductants. Highlights: Charcoal, bamboo char and straw fiber were used as reductants for the formation of DRI. Straw fiber was considered as an optimal reductant instead of fossil materials. Volatile matter was essential during the reduction of pellets with biomass reductants. Reduction mechanism of pellets with biomass reductants was proposed.