An investigation on the formation of molten salt containing chromium oxide during roasting of chromite ore with sodium and postassium hydroxides

Escudero Castejon, L orcid.org/0000-0003-1525-0435, Sanchez Segado, S, Parirenyatwa, S et al. (1 more author) (2016) An investigation on the formation of molten salt containing chromium oxide during roasting of chromite ore with sodium and postassium hydroxides. In: Reddy, RG, Chaubal, P, Pistorius, PC and Pal, U, (eds.) Advances in Molten Slags, Fluxes, and Salts: Proceedings of the 10th International Conference on Molten Slags, Fluxes and Salts. 10th International Conference on Molten Slags, Fluxes and Salts, 22-25 May 2016, Seattle, Washington, USA. Springer International Publishing , Cham, Switzerland , pp. 71-78. ISBN 978-3-319-48625-3

Abstract

The extraction of chromium from chromite ore is based on the oxidative alkali roasting of the mineral forming water-soluble alkali chromates. Previous investigations reported the formation of a molten Na2CO3-Na2CrO4 binary mixture during roasting of chromite with sodium carbonate. The physical properties of the Na2CO3-Na2CrO4 liquid phase, which are dependent on temperature, charge and gangue composition, play an important role in the oxidation reaction and may limit the chromium 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, and subsequent water leaching. The influence of the alkali ratio on the chromium extraction yield is analysed, and the results obtained with both hydroxides are compared. The formation of molten salt phase under different roasting conditions and its effect on chromium recovery is studied by means of sample characterization and phase diagram analysis.

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Authors/Creators:

Escudero Castejon, L https://orcid.org/0000-0003-1525-0435
Sanchez Segado, S
Parirenyatwa, S
Jha, A https://orcid.org/0000-0003-3150-5645

Keywords:

chromite ore; oxidative roasting; molten salt phase; NaOH; KOH; chromium recovery

Dates:

Published (online): 7 September 2016
Published: 7 September 2016

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
Millennium Inorganic Chemicals Ltd	NO REF GIVEN
London & Scandinavian Metallurgical Co Ltd	9416064
NERC	NE/M01147X/1

Depositing User:

Symplectic Publications

Date Deposited:

01 Aug 2017 10:12

Last Modified:

01 Aug 2017 10:12

Status:

Published

Publisher:

Springer International Publishing

Identification Number:

https://doi.org/10.1007/978-3-319-48769-4_7

CORE (COnnecting REpositories)

An investigation on the formation of molten salt containing chromium oxide during roasting of chromite ore with sodium and postassium hydroxides

Abstract

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