EFFECT OF ALKALINE ELEMENTS ON COKE STRUCTURE UNDER BLAST FURNACE PROCESS CONDITIONS

1 BHATTACHARYYA Anrin
Co-authors:
1 SCHENK Johannes 2 LETOFSKY-PAPST Ilse 3 ALBERING Jörg
Institutions:
1 Montanuniversität Leoben, Chair of Ferrous Metallurgy, Leoben, Austria, EU
2 Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology and Graz Centre for Electron Microscopy, Graz, Austria, EU
3 Graz University of Technology, Graz, Austria, EU
Conference:
25th Anniversary International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, May 25th - 27th 2016
Proceedings:
Proceedings 25th Anniversary International Conference on Metallurgy and Materials
Pages:
78-83
ISBN:
978-80-87294-67-3
ISSN:
2694-9296
Published:
14th December 2016
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
168 views / 63 downloads
Abstract

Presence of alkaline elements such as sodium and potassium are highly detrimental for blast furnace operations. Even a trace amount of alkali affects the performance of raw materials considerably. The performance of coke in the process suffers significantly in presence of alkalis by the catalysis of Boudouard reaction during its descent through the shaft and subsequent deterioration of its strength in the lower zone of the furnace, leading to various furnace operating problems. The aim of this work is to investigate the impact of these harmful elements on the coke structure in micro as well as nano level. The Coke Reactivity Index (CRI) and Coke Strength after Reaction (CSR) values of coke are determined for original industrial coke samples as well as the same samples artificially impregnated with alkaline elements in different amounts. The original and CRI-method treated samples (with and without added alkali) are characterized using X-Ray Diffractometry (XRD) and Transmission Electron Microscopy (TEM) to look into the lattice and crystalline structure of the constituent graphite of coke. The results demonstrate pronounced disturbance in the graphite lattice caused by alkali. An attempt has been made to explain the mechanism of the deterioration of coke properties under the influence of alkalis in terms of the difference in atomic radii of the constituent elements.

Keywords: Blast furnace, Coke, Alkaline elements, CRI/CSR tests, Characterization

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Scroll to Top