خط مشی دسترسیدرباره ماپشتیبانی آنلاین
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Document Type:Latin Dissertation
Language of Document:English
Record Number:54097
Doc. No:TL24051
Call number:‭NR07928‬
Main Entry:Muhammad Akbar Rhamdhani
Title & Author:Reaction kinetics and dynamic interfacial phenomena in liquid metal-slag systemsMuhammad Akbar Rhamdhani
College:McMaster University (Canada)
Date:2005
Degree:Ph.D.
student score:2005
Page No:216
Abstract:Dynamic interfacial phenomena during reactions between liquid iron alloy droplets and liquid slags are well documented. However, they are only partially understood. Dynamic interfacial phenomena were investigated by studying high temperature reactions between Fe-Al alloy droplets and a CaO-SiO2-Al2 O3 slag. Interfacial area changes, changes in the number of droplets, and chemical changes of the metal droplets during reaction were tracked. The reacting interface was investigated by using scanning electron microscopy and energy dispersive x-ray analysis techniques. It was found that the increase of interfacial area is significant, i.e. 300% to 500% of original value. An approach for accommodating the interfacial area changes in kinetic equations for heterogeneous reactions in the presence of spontaneous emulsification was developed. This involved an incorporation of time-averaged interfacial area in the rate equations. The approach provided an excellent description of the reaction when tested against kinetic data obtained from reactions between Fe-Al alloy droplets and CaO-SiO2-Al2O3 slag. The kinetics were found to follow a first order relationship with respect to aluminum in the metal, and were controlled by mass transport in the metal phase. Solute oxygen distribution in the metal droplets was investigated by using dynamic SIMS technique. The results suggested the presence of pockets of fluid of the scale 1 to 2 μm with different oxygen contents moving about within the bulk during the reaction. The relative importance of the thermocapillary, solutocapillary and electrocapillary effects during the reaction was evaluated. The magnitude of these effects was determined using local equilibrium model and utilizing kinetic data to determine local composition, temperature and electrical potential. The electrocapillary effect was found to be dominant. The thermocapillary effect was found to be negligible. Local gradient of interfacial tension along the interface due to solutocapillary effect was estimated, i.e. Δγ = 274--440 mN/m over a 1 to 2 μm distance.
Subject:Applied sciences; Interfacial; Liquid metal-slag; Reaction kinetics; Slag; Metallurgy; 0743:Metallurgy
Added Entry:McMaster University (Canada)