2015-Sustainable Industrial Processing Summit
SIPS 2015 Volume 3: Takano Intl. Symp. / Metals & Alloys Processing
| Editors: | Kongoli F, Noldin JH, Mourao MB, Tschiptschin AP, D'Abreu JC |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2015 |
| Pages: | 550 pages |
| ISBN: | 978-1-987820-26-3 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Fume Formation from Liquid Ferromanganese
Ida Kero1; Dmitry Slizovskiy2; Gabriella Tranell2; Bernd Wittgens3;1SINTEF MATERIALS & CHEMISTRY, Trondheim, Norway; 2NORWEGIAN UNIVERSITY OF SCIENCE AND TECHNOLOGY, Trondheim, Norway; 3SINTEF, Trondheim, Norway;
Type of Paper: Regular
Id Paper: 44
Topic: 3
Abstract:
Dust, fume or airborne particulate matter, constitutes a health, safety and environmental challenge for most metal producers, including the ferromanganese alloy industry. To decrease the oxide dust generation of industrial metallurgical processes, more fundamental knowledge about the fume formation mechanisms is necessary. In this study, the active oxidation of a ferromanganese alloy and the resulting fume formation has been investigated. A liquid medium carbon grade ferromanganese alloy was held at different temperatures in the range 1400-1700A°C, while the surface was exposed to an impinging air jet. The resulting fume was multi-coloured and rich in either MnO, MnOx-FeOy or Mn3O4 depending on the deposition temperatures; the Fe/Mn average ratio also varied (0.009 - 0.023) with deposition temperature. Most of the particles were spheres of various dimensions but cubic particles and whiskers were also observed and protoparticle diameter increased with temperature. There were also amorphous phases present in the fume. Silicon, calcium and magnesium were the most common impurity elements with traces of K, Na, Zn, Ni, Cu and P. The use of a graphite crucible most likely had a significant effect on the chemistry and kinetics of the fuming process. The carbon presence led to formation of CO (g) and a corresponding oxygen deficit in the atmosphere above the liquid metal which seem to have prevented full oxidation to Mn3O4. In these experiments, the Mn vapour formed MnO fume as a first oxidation step, which was then stabilized (quenched) in the off-gas cooler. The flux (molar amount/time unit) of fume produced was one order of magnitude greater than for other ferroalloys, such as Si and SiMn. This may, according to previous studies and theories, be attributed to the formation of an oxide (MnO) mist in the boundary layer.
Keywords:
Dust; Manganese; Metallurgy; Oxidation;References:
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