Reduction Behavior of Blast Furnace Dust Particles during In-Flight Processes

Abstract

Blast furnace (BF) dust can be recycled as one of excellent secondary sources, in view of the valuable amounts of iron and carbon contents, and the in-flight reduction technology is considered to allow processing the fine metallurgical dusts efficiently. In this work, the reduction behavior of BF dust particles during in-flight process was studied using a high-temperature drop-tube furnace in laboratory scale. The effects of temperature and gas composition on the reduction degree were remarkable. Based on the morphological observation and phase diagram analysis, the product layer of the reduced BF dust particle was confirmed in molten state at 1673–1723 K. Kinetic analysis showed that the gas-molten particle reduction during in-flight process was a mixed control of the chemical reaction and diffusion of Fe3+ and O2– ions through the molten product layer, and the corresponding chemical reaction constant (k r) and the diffusion coefficient (D) was also obtained.

Review and data evaluation for high-temperature reduction of iron oxide particles in suspension

“…Xu et al. [6] applied the suspension reduction technology to recycle blast furnace dust. The XRD pattern showed that the dust mainly contained haematite, wustite, metallic iron and calcium ferrite.…”

“…Moreover, researchers are developing other sustainable metallurgical processes based on high-temperature suspension reduction technologies as well. Xu et al [6,7] studied the reduction behaviour of blast furnace dust during the suspension reduction process to explore the possibility of this technology in treating solid wastes.…”

“…Xu et al. [6,7] studied the reduction behaviour of blast furnace dust during the suspension reduction process to explore the possibility of this technology in treating solid wastes.…”

In-flight iron ore reduction and nanoparticle formation in an atmospheric pressure hydrogen microwave plasma

“…This approach has the advantage of maximizing the particle-to-plasma contact area, thus better leveraging the thermo-kinetic advantages offered by the plasma. Despite this advantage, the in-flight plasma reduction technique has received limited attention, with many of the studies using carbon as the reduction agent [28][29][30][31], rather than hydrogen. The major challenge is posed by the short residence times of a few tens of ms to a few seconds available for the reduction under typical conditions.…”