Next Article in Journal
Study on Sulfur Transfer Behavior during Refining of Rejected Electrolytic Manganese Metal
Previous Article in Journal
Controlling Variability in Mechanical Properties of Plates by Reducing Centerline Segregation to Meet Strain-Based Design of Pipeline Steel
Open AccessArticle

Nucleation and Growth of Iron Whiskers during Gaseous Reduction of Hematite Iron Ore Fines

State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Xueyuan Road No.30, Haidian district, Beijing 100083, China
*
Author to whom correspondence should be addressed.
Metals 2019, 9(7), 750; https://doi.org/10.3390/met9070750
Received: 18 June 2019 / Revised: 1 July 2019 / Accepted: 2 July 2019 / Published: 4 July 2019
A high-temperature confocal scanning laser microscope and an online reduction–water quenching experiment system were used to systematically study the generation of iron whiskers during the reduction of hematite ore particles with CO/CO2 gas. The "blooming" phenomenon of the surface during the reduction of iron ore particles was found in this experiment. The orientation of the grain on the longitudinal section of an iron whisker was measured to be uniform by applying the electron back-scattered diffraction technique, which proved that the iron whiskers are most likely to exist in single crystal form. According to the in-situ online experimental video, the average diffusion flux of iron atoms when the layered iron completely covers the surface of the ore particle is about 0.0072 mol/(m2·s). While the iron atom diffusion flux at the root of the iron whisker during the pre-growth process is much larger than the flux when the layered iron is produced, which are defined to be 0.081 mol/(m2·s), 0.045 mol/(m2·s), 0.013 mol/(m2· s), and 0.0046 mol/(m2·s), respectively during the four stages of the growth of an iron whisker. The quantitative relationship between the chemical driving force and the whisker growth is established as Δ G θ + R T ln p CO 2 p CO + 2 n 0.056 r ρ E s T = 0 . View Full-Text
Keywords: whisker; in-situ observation; iron ore; reduction; FeO whisker; in-situ observation; iron ore; reduction; FeO
Show Figures

Graphical abstract

MDPI and ACS Style

Guo, L.; Zhong, S.; Bao, Q.; Gao, J.; Guo, Z. Nucleation and Growth of Iron Whiskers during Gaseous Reduction of Hematite Iron Ore Fines. Metals 2019, 9, 750.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map

1
Back to TopTop