Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Modelling of slag foaming
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.ORCID iD: 0000-0002-3548-8638
2010 (English)In: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 37, no 8, 612-619 p.Article in journal (Refereed) Published
Abstract [en]

In this work, silicone oils of different viscosities were used to simulate slag foaming. The experimental results showed that the variations of foaming height with superficial gas velocity and liquid viscosity do not show simple increasing trends. At a constant viscosity, foaming height increased first and then started decreasing with increasing superficial velocity. Similarly, a maximum foaming height was observed at an optimum viscosity when a constant gas flowrate was applied. The foaming height started decreasing with further increasing viscosity. Based on the experimental data, a semiempirical equation of foaming height was developed. The predictions of the model agreed well with experimental data. The model could also reasonably well explain the industrial pilot trial experiments. The experimental results with paraffin particle additions indicated that a small amount of particle addition moved the onset of foaming to lower superficial velocity. However, the increase in viscosity due to the presence of solid particles was found not the main reason for the increase in foaming height.

Place, publisher, year, edition, pages
2010. Vol. 37, no 8, 612-619 p.
Keyword [en]
Slag foaming, Mathematical modelling, Physical modelling
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:kth:diva-27973DOI: 10.1179/030192310X12690127076550ISI: 000285043500010Scopus ID: 2-s2.0-78649600385OAI: oai:DiVA.org:kth-27973DiVA: diva2:382848
Note
QC 20110103 Available from: 2011-01-03 Created: 2011-01-03 Last updated: 2017-12-11Bibliographically approved
In thesis
1. Study on some phenomena of slag in steelmaking process
Open this publication in new window or tab >>Study on some phenomena of slag in steelmaking process
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The present work is to study slag phenomena in steelmaking process. In order to attain thegoal, a number of high temperature experiments and simulation experiments were carried out.

Four master slags were used to study the effect of CaF2 on slag viscosity. Experimentalresults indicated the effect of CaF2 on slag viscosity depended strongly on the composition ofmaster slag. For high basicity slags, CaF2 mainly suppressed the precipitation of solid phasesat lower temperatures, leading to a lower viscosity compared to CaF2-free slags. For slagswith higher SiO2 contents, CaF2 both lowered the viscosity of the liquid phase and suppressedthe precipitation of solid phases.

The viscosities of solid-liquid mixtures were experimentally determined for silicon oilparaffinsystem at room temperature and solid-liquid oxide mixture at steelmakingtemperature. The results of both measurements indicated that the increasing trend of mixturesviscosity with particle fraction can be described by Einstein-Roscoe equation.Silicone oils of different viscosities were used to simulate slag foaming. The experimentalresults showed, at a constant viscosity, the foaming height increased first with superficialvelocity before reaching a maximum value. Thereafter, the foaming height decreased with thefurther increase of the superficial velocity. Similar, a maximum foaming height was observedat an optimum viscosity when a constant superficial gas velocity was applied. Based on theexperimental data, a semi-empirical equation of foaming height was developed. Thepredictions of the model agreed well with experiment data. The model could also reasonablywell explain the industrial pilot trial experiments.

Water-silicon oils model and liquid alloy (Ga-In-Sn)- 12% HCl acid model were employed tosimulate the formation of open-eyes in a gas stirred ladle. The experimental results indicatedthat the viscosity of the top liquid and the interfacial tension between the two liquids had onlylittle effect on the open-eye size. A semi-empirical model was developed to describe the sizeof open-eye as functions of the gas flow rate, bath height and slag height. The two sets ofparameters obtained for the water and Ga-In-Sn models were very different. Industrial trialswere also conducted to examine the applicability of the models. Liquid alloy model couldwell predict the formation of an open-eye during ladle treatment.

Two cold models, sodium tungstate-oil model and water-oil model, were carried out tosimulate the formation of droplets in a gas stirred ladle. The experimental results showed thatthe gas flow rate and interfacial tension had strong impact on the size of droplets. A semiempiricalmodel was developed to describe the size of droplets for water model. Meanwhile,the parameter obtained for water model can be used for sodium tungstate-silicone oil system.The results indicate the model has strong compatibility.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2011. 46 p.
Keyword
Slag viscosity, calcium fluoride, fluid viscosity with particles, mixture viscosity
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-32740 (URN)978-91-7415-955-4 (ISBN)
Public defence
2011-05-12, F3, Lindstedtsvägen 26, Stockholm, 10:00 (English)
Opponent
Supervisors
Note
QC 20110419Available from: 2011-04-19 Created: 2011-04-19 Last updated: 2011-04-19Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Sichen, Du

Search in DiVA

By author/editor
Wu, LiushunAlbertsson, Galina JelkinaSichen, Du
By organisation
Materials Science and Engineering
In the same journal
Ironmaking & steelmaking
Materials Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 156 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf