Escudero Castejon, L orcid.org/0000-0003-1525-0435, Sanchez Segado, S orcid.org/0000-0002-3511-0723, Parirenyatwa, S et al. (1 more author) (2016) Formation of Chromium-Containing Molten Salt Phase during Roasting of Chromite Ore with Sodium and Potassium Hydroxides. Journal for Manufacturing Science and Production, 16 (4). ISSN 0793-6648
Abstract
Chromium has a wide range of applications including metals and alloys manufacturing, pigments, corrosion resistance coatings and leather tanning. The production of chromium chemicals is based on the oxidative alkali roasting of chromite ores, which leads to the formation of water-soluble alkali chromates. Previous investigations reported that when chromite is roasted with soda-ash, a molten salt containing chromium, which is mainly composed of sodium carbonate and sodium chromate (Na2CO3-Na2CrO4 binary mixture), forms under typical roasting conditions. The physical properties of the liquid phase, which are dependent on the temperature, charge and gangue compositions, play an important role on the oxidation reaction and may limit the chromate recovery by hindering the oxygen transport to the reaction interface. This investigation focuses on the alkali roasting of chromite ore at 1000oC using NaOH and KOH, followed by water leaching. The influence of the alkali ratio on the chromium extraction yield is analysed, and the results obtained with both hydroxides are compared. Sample characterisation and thermodynamic analysis, including phase diagrams, equilibrium calculations and computation of liquidus curves, are combined with the purpose of studying the formation of the molten salt phase under different roasting conditions and its effect on the final chromium recovery.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016, De Gruyter. This is an author produced version of a paper published in Journal for Manufacturing Science and Production. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | chromite ore; oxidative roasting; molten salt phase; NaOH; KOH; chromium recovery |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Funding Information: | Funder Grant number NERC NE/L002280/1 EU - European Union 331385 EPSRC GR/T08074/01 London & Scandinavian Metallurgical Co Ltd 9416064 |
Depositing User: | Symplectic Publications |
Date Deposited: | 10 Oct 2016 10:01 |
Last Modified: | 08 Dec 2017 01:38 |
Published Version: | https://doi.org/10.1515/jmsp-2016-0023 |
Status: | Published |
Publisher: | De Gruyter |
Identification Number: | 10.1515/jmsp-2016-0023 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:105716 |