Gas-solid reactions towards new frontiers
2008 (English)In: Transactions of the Institution of Mining and Metallurgy Section C - Mineral Processing and Extractive Metallurgy, ISSN 0371-9553, E-ISSN 1743-2855, Vol. 117, no 2, 77-85 p.Article in journal (Refereed) Published
Reactions between solids and a gas phase have interesting theoretical aspects as well as technological applications. Studies of the decomposition of alkaline earth carbonates have been carried out over the past decade by thermogravimetric analyses, using thin powder beds and isostatically pressed compacts with embedded thermocouples. The investigations revealed the complexity of the reactions and the impact of heat and mass transfer on the reaction kinetics. In the case of BaCO3, the kinetics of decomposition is complicated by the formation of a liquid phase. For SrCO3, the reaction kinetics could be simulated by theoretical modelling. Gas-solid reactions were also employed as a versatile process tool towards the production of alloys and intermetallics involving transition elements by hydrogen reduction of complex oxides involving transition metals. Thin powder beds were employed to examine the microkinetics, whereas fluidised beds were utilised to produce bulk alloys. Preliminary correlations could be drawn between the thermodynamic stabilities of the oxides and the activation energies of chemical reduction. By adjusting the process parameters, nanoscale products could be produced, the structural, mechanical and thermal properties of which were investigated. The potentialities of this method as a green route to produce industrially important alloys and intermetallics with unique properties are demonstrated.
Place, publisher, year, edition, pages
2008. Vol. 117, no 2, 77-85 p.
Carbonate decomposition, Green processing, Hydrogen reduction, Nanocrystals, Solid-gas reactions, Alkaline earth metals, Chlorine compounds, Mass transfer, Powders, Alkaline earths, Embedded thermocouples, Gas-phase, Gas-solid reactions, Heat and mass transfer, Powder beds, Pressed compacts, Technological applications, Reaction kinetics
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-154454DOI: 10.1179/174328508X290858ScopusID: 2-s2.0-48849099609OAI: oai:DiVA.org:kth-154454DiVA: diva2:758325
QC 201410272014-10-272014-10-202015-06-17Bibliographically approved