A study of the dissolution of Al2O3, MgO and MgAl2O4 particles in a CaO‐Al2O3‐SiO2 slag

Valdez, Martin; Prapakorn, Kritsada; Cramb, A. W.; Sridhar, Seetharaman

doi:10.1002/srin.200100120

Cited by 61 publications

(64 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3,[8][9][10]13 This model assumes first order kinetics. Full details of the derivation and the applicability of this model can be found in Levinspiel.…”

Section: Discussionmentioning

confidence: 99%

Effect of changing slag composition on spinel inclusion dissolution

Monaghan¹,

Chen²

2006

Ironmaking & Steelmaking

View full text Add to dashboard Cite

The rate of MgAl 2 O 4 spinel inclusion dissolution in CaO-SiO 2 -Al 2 O 3 slags at 1504uC has been measured using a laser scanning confocal microscope. It was found that the mechanism of spinel inclusion dissolution was at least in part controlled by mass transfer in the slag phase for the slag compositions used. Evidence in support of this finding was that the calculated diffusion coefficient was inversely proportional to the slag viscosity and that the diffusion coefficients were in reasonable agreement with those obtained in a separate study on alumina dissolution. The diffusion coefficients obtained were in the range of 0 . 76-2 . 2610 210 m 2 s 21 .

show abstract

“…3,[8][9][10]13 This model assumes first order kinetics. Full details of the derivation and the applicability of this model can be found in Levinspiel.…”

Section: Discussionmentioning

confidence: 99%

Effect of changing slag composition on spinel inclusion dissolution

Monaghan¹,

Chen²

2006

Ironmaking & Steelmaking

View full text Add to dashboard Cite

show abstract

“…In the past few years this has become a well accepted technique for studying inclusion behaviour, 2,9,12,13) capturing dissolution times and rates. A full description of the technique and the microscope has been described previously [9][10][11] with only the key details listed here.…”

Section: Confocal Scanning Laser Microscopementioning

confidence: 99%

Dissolution of ZrO2, Al2O3, MgO and MgAl2O4 Particles in a B2O3 Containing Commercial Fluoride-free Mould Slag

et al. 2004

View full text Add to dashboard Cite

Non-metallic inclusions composed of ZrO 2 , Al 2 O 3 , MgO and MgAl 2 O 4 are associated with problems during the continuous casting of steels and so it is desirable that such particles dissolve completely if they appear in the slag. The dissolution behaviour of particles of these oxides in a fluorine-free slag containing 1.5 wt% B 2 O 3 , was studied in situ using Confocal Scanning Laser Microscopy (CSLM). The effects of particle type, initial size, and slag temperature were investigated. Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS) was performed to chemically analyze quenched samples, in order to identify any surface reaction or diffusion layers formed. Analytical prediction models were compared to the experimental data to relate the kinetics to possible rate-limiting steps. Thermodynamic solubility limits for use in the model were determined using commercial CALPHAD based software. The dissolution rates of Al 2 O 3 , MgO and MgAl 2 O 4 were found to be comparable to one another whereas the dissolution rate of ZrO 2 , is four times slower. The surface reaction appears to be controlling the rate of dissolution, with the activation energy for ZrO 2 being 128.8 kJ/mol and for MgAl 2 O 4 being 77.8 kJ/mol. This implies that the removal of ZrO 2 particles by dissolution in this type of slag is not feasible for the typical residence times expected, and strategies that prevent the incorporation of these particles should be used.

show abstract

“…Sridhar and co-workers [9,10] used confocal scanning laser microscopy to directly observe the dissolution of small MgO particles in calcium silica aluminate [9] and calcium aluminate [10] slags at temperatures ranging from 1450 °C to 1600°C. Convection effects were ignored.…”

Section: Introductionmentioning

confidence: 99%

“…In these two studies, they reported conflicting rate controlling mechanisms for the MgO dissolution process. In the calcium silica aluminate [9] slag, it was concluded that boundary layer diffusion may be rate controlling, whereas in the calcium aluminate [10] slag, it was found that chemical reaction is rate limiting. Sridhar et al [9,10] make no comment on the different rate controlling mechanisms.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Degradation of MgO refractory in CaO-SiO2-MgO-FeO x and CaO-SiO2-Al2O3-MgO-FeO x slags under forced convection

Nightingale

Monaghan

Brooks

2005

Metall Mater Trans B

View full text Add to dashboard Cite

Experiments based on exposure of MgO to slags under forced convection flow conditions allowed the identification of different degradation mechanisms and the assessment of the role of Al 2 O 3 in the degradation process. Slag with no alumina present resulted in direct dissolution. Samples immersed in alumina containing slag underwent indirect dissolution, with a spinel forming at the MgO-slag interface. At 1530 °C, the spinel was not effective in reducing the corrosion rate, as the scattered spinel grains were easily removed from the MgO surface. At 1500 °C, the loss of MgO was reduced due to the formation of a more cohesive spinel layer. Mechanical erosion then appears to play a greater role. Strength of the bond between the spinel and underlying MgO needs to be considered in strategies to reduce degradation of MgO refractories.

show abstract

A study of the dissolution of Al₂O₃, MgO and MgAl₂O₄ particles in a CaO‐Al₂O₃‐SiO₂ slag

Cited by 61 publications

References 4 publications

Effect of changing slag composition on spinel inclusion dissolution

Effect of changing slag composition on spinel inclusion dissolution

Dissolution of ZrO2, Al2O3, MgO and MgAl2O4 Particles in a B2O3 Containing Commercial Fluoride-free Mould Slag

Degradation of MgO refractory in CaO-SiO2-MgO-FeO x and CaO-SiO2-Al2O3-MgO-FeO x slags under forced convection

Contact Info

Product

Resources

About