Development of a novel process for energy and materials recovery in steelmaking slags

Abstract

. (2017) Development of a novel process for energy and materials recovery in steelmaking slags. Mineral Processing and Extractive Metallurgy , 126 (1-2). pp. 94-105. Permanent WRAP URL:http://wrap.warwick.ac.uk/83697 Copyright and reuse: The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-for profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP URL' above for details on accessing the published version and note that access may require a subscription. Development of a novel process for energy and materials recovery in steelmaking slagsThis work aims at gathering fundamental knowledge for the development of a novel process for energy (H2 gas) and materials (magnetite Fe3O4) recovery in hotsteelmaking slags by reacting molten steelmaking slag with steam.Thermodynamic simulation was carried out to calculate the accumulated amount of produced H2 gas as a function of the volume of H2O-Ar gas introduced and the precipitated phases of the molten slags during controlled cooling. Laboratory experiments of crystallisation behaviours of molten slags during cooling were visualized in situ through a confocal laser scanning microscope (CSLM), and the cooled slags obtained were characterised by using SEM-EDS and XRD. CCT diagrams for different slags were created showing the slag crystallisation/phase transformation at different cooling rates. The recovery ratio of H2 gas and the maximum potential recovery ratio of iron oxide in the oxidised slags were calculated, which concludes that with increasing the slag basicity from 1.0 to 1.5 and 2.0, the recovery ratio of H2 was found to increase from 12.6% to 23.7% and 22.6%, and the maximum potential recovery ratio of iron oxide was found to increase from 18.3% to 34.4% and 32.8% under the investigated conditions.Keywords: steelmaking slag; H2 gas; spinel; CCT diagram; recovery IntroductionThe steel industry produces large volumes of waste slag with huge sensible heat (at extremely high temperature >1500°C) and considerable amount of metals (Fe, Mn, V, Cr, Semykina et al. (2010aSemykina et al. ( , 2010bSemykina et al. ( , 2011b. This promising method may enable efficient selective recovery of transitional metal oxide from steel...

Basic Oxygen Steelmaking Slag: Formation, Reaction, and Energy and Material Recovery

“…Recently a novel process was developed by the present authors [140][141][142] to recover thermal energy from molten BOS slag as syngas and hot gas, and recover valuable metals (Fe, Mn) in the form of magnetite by controlling the crystallization of the BOS slag after reacting the molten BOS slag with moisture. This process is based on the reaction of the molten steelmaking slag with the moist atmosphere (Figure 9).…”

“…This novel process has been extensively studied in terms of the fundamental understanding of the reaction mechanisms, effects of processing parameters on hydrogen harvesting, and optimal conditions for controlled crystallization of targeted phases. [140][141][142]…”