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Kinetics of desulphurisation of molten pig iron
Author(s) -
Deo Brahma,
Grieveson Paul
Publication year - 1986
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.198600815
Subject(s) - aluminium , silicon , chemistry , mass transfer , metal , sulfur , pig iron , phase (matter) , flux (metallurgy) , metallurgy , slag (welding) , kinetics , layer (electronics) , flue gas desulfurization , reaction rate , thermodynamics , chemical engineering , materials science , chromatography , catalysis , organic chemistry , physics , quantum mechanics , engineering
The analysis of the experimental data obtained in the present work and also of some classical data reported in literature on the basis of simple rate theory, surface renewal theory and the multicomponent mixed transport control theory has shown that in molten pig iron containing silicon the sulphur transfer to slags is controlled by mass transport in the metal phase. In the initial stages the desulphurisation rate is fast but after a few minutes it slows down. In the case of silicon containing iron this second slow stage, as also observed by other workers in the past, is due perhaps to the formation of a micro layer of silica enriched reaction product at the slag‐metal interface. On addition of aluminium the silica layer gets reduced and sulphur transfer is enhanced; once again the rate controlling step becomes mass transport in the metal phase. An important conclusion regarding the timing of aluminium is that maximum benefit of aluminium addition can be realised after about 4–5 min of adding the desulphurisation flux.