Novel multi-stage aluminium production: part 2 – experimental investigation on carbosulphidation of Al2O3 using H2S and sodiothermic reduction of Al2S3. (2nd October 2017)

• Record Type: Journal Article
• Authors: Huda, N.; Khaliq, A.; Rhamdhani, M. A.; Sheppard, D.; Brooks, G.; Monaghan, B.; Prentice, L.
• Is Part Of: Transactions. Volume 126:Number 4(2017)
• Page Start: 245
• Page End: 258
• Publication Date: 2017-10-02
• Subjects: Carbosulphidation of alumina -- indirect carbothermal reduction -- thermodynamic modelling -- carbosulphidation of bauxite -- aluminium sulphide production -- Al2S3 -- sodiothermic reduction of Al2S3; Ore-dressing -- Periodicals; Metallurgy -- Periodicals; Mineral industries -- Periodicals; 622.7
• DOI: 10.1080/03719553.2016.1257411
• Languages: English
• ISSNs: 0371-9553

Abstract

ABSTRACT: In this paper, experimental investigation on the carbosulphidation of alumina (Al2 O3 ) for aluminium (Al) production and the sodiothermic reduction of aluminium sulphide (Al2 S3 ) are presented. Hydrogen sulphide (H2 S) was used as a reductant and source of sulphur. This work is the second of two-parts paper series. The experimental investigations of the Stage-1 process (Al2 O3 carbosulphidation) were carried out at 1100–1600°C using a laboratory scale horizontal tube resistance-furnace. H2 S gas, diluted with argon (5% H2 S and 95% Ar), was reacted with pellets of a mixture of γ-Al2 O3 and C powders (1:6 molar ratio) to produce Al2 S3 . The effects of gas injection rate, pelletizing pressure, temperature and reaction time on the conversion of Al2 O3 to Al2 S3 were investigated. The X-ray diffraction results confirmed the formation of Al2 S3 (s) in the reaction product above 1400°C. The conversion of Al2 O3 to Al2S3 was found to be 99.5% at 1600°C and 12 h. The kinetics analysis of alumina sulphidation using Ginstling-Brounshtein diffusion model suggested the overall reaction was controlled by the diffusion of H2 S gas through the reaction product (liquid Al2 S3 ). The activation energy of the alumina sulphidation reaction was calculated to be 148.5 kJ mol −1 . It has also been demonstrated in this study that Al can be extracted from Al2 S3 by sodiothermic reduction using Na or NaH. In the case of Na, a level of Al conversion of 75% has been observed for reaction at 290°C.