Thermal conductivity of CaO–SiO2–Al2O3glassy slags: Its dependence on molar ratios of Al2O3/CaO and SiO2/Al2O3

Susa, Masahiro; Watanabe, Minoru; Ozawa, Sumito; Endo, Rie

doi:10.1179/174328107x165672

Cited by 27 publications

(24 citation statements)

References 12 publications

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“…This knowledge can be used to improve the reproducibility of the slag yard practice, and it provides a decision tool to determine when the yard is cold enough to be emptied. Considering the fact that large volumes of slag may remain hot or even liquid for very long times, 7) as a consequence of the low thermal conductivity and the associated large thermal gradients, 8) this would represent a leap forward in overall safety during slag pit handling.…”

Section: Introductionmentioning

confidence: 99%

A Quantitative Model for Slag Yard Cooling

Pandelaers

D’alfonso²,

Jones

et al. 2013

ISIJ Int.

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In order to get a safer and more reproducible slag yard practice, the cooling of slags from stainless steel production in a slag yard was studied. A numerical 1D model was used to predict the spatial and temporal evolution of the temperature in the yard. This model has been validated based on temperature measurements at the surface and in the bulk of an industrial yard consisting of 22 layers. Each new layer initially cools down, but is heated again as additional layers are poured on top. In the bulk of the yard, temperatures of over 1 273 K can be maintained throughout the filling of the yard. This temperature is a function of the process parameters. The validated model was used to quantify the influence of the layer thickness and the interval between subsequent layers on the temperature evolution within the yard.

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Section: Introductionmentioning

confidence: 99%

A Quantitative Model for Slag Yard Cooling

Pandelaers

D’alfonso²,

Jones

et al. 2013

ISIJ Int.

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“…3,10,[24][25][26] Kang and Morita 23) measured the thermal conductivity in the CaO-SiO2-Al2O3 conventional iron-making slag system using the hot-wire method, reporting that the movement of phonons through covalent bonds is more effective than through ionic bonds in silicate melts; thus resulting in a higher thermal conductivity in more polymerized slag systems.…”

Section: Introductionmentioning

confidence: 99%

Relationship between Molten Oxide Structure and Thermal Conductivity in the CaO–SiO2–B2O3 System

Kim

Morita

2014

ISIJ Int.

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Using a transient hot-wire method, the thermal conductivity of the CaO-SiO2-B2O3 mold flux system was measured. The effects of temperature, BO1.5 concentration and basicity on the thermal conductivity were considered, along with structural investigation by Raman spectroscopy. It was found that the addition of boron oxide caused both a decrement and increment of thermal conductivity, depending on the basicity. These conflicting effects on thermal conductivity were considered to be caused by the following two different behaviors in the oxide melts. Boron oxide is incorporated into silicate networks at a lower basicity, while it tends to form borate networks at higher CaO/SiO2 ratios. In the case of basicity dependency, thermal conductivity initially decreases or remains constant with increasing CaO/SiO2 ratio in regions of low basicity, but increases when the CaO/SiO2 ratio is higher than 1.15. Due to the incorporated state of boron oxide in silicate networks at low basicity, the thermal conductivity is likely to be predominantly affected by the silicate networks. However, at a relatively high CaO/SiO2 ratio, an increase in chain-type metaborate was observed through Raman spectroscopy; this structural change in borate being responsible for the increment in thermal conductivity with higher basicity. Finally, the apparent activation energy of thermal conductivity was calculated, and was found to be reduced by the addition of boron oxide.

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“…The chemical composition of the steel likely changes the thermal conductivity and heat capacity of the melts, which have been documented elsewhere. [16][17][18] The in-coming hot metal temperatures are between 1 554-1 637 K, as shown in Table 2. In addition, unexpected process issues such as breakouts at the continuous caster, cold ladles, or prolonged LMF (ladle metallurgical furnace) processing can result in extended power-on-times that can exacerbate plant data scatter.…”

Section: )mentioning

confidence: 99%

Effect of Hot Metal on Decarburization in the EAF and Dissolved Sulfur, Phosphorous, and Nitrogen Content in the Steel

Lee

Sohn

2015

ISIJ International

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The effect of hot metal additions on the decarburization and dissolved sulfur, phosphorous, and nitrogen content in the steel of a DC EAF was investigated. The addition of hot metal of maximum 36% provided heat into the EAF allowing faster melting and reduced power on times of the furnace. The increased melting rate lowered the FeO in the slag and seems to allow faster kinetics for CaO dissolution into the slag. Hot metal utilization into the slag resulted in higher phosphorous distribution ratios compared to hot metal free heats achieving comparable phosphorous levels at the ladle metallurgical furnace even though the initial input phosphorous was much higher than hot metal free heats. The effect of hot metal on the desulfurization was not pronounced and no apparent difference could be ascertained compared with the 100% scrap charge. With the addition of carbon saturated iron units in the EAF, the evolution of CO and foaming was promoted, which inhibited the infiltration of nitrogen and lowered the overall partial pressure of nitrogen resulting in lower nitrogen levels in the steel. In addition, the dilution effect of the tramp elements Cu and Sn with hot metal ensured the critical defect index to be less than 10% resulting in a 50% reduction of the quality defect index.

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Thermal conductivity of CaO–SiO₂–Al₂O₃glassy slags: Its dependence on molar ratios of Al₂O₃/CaO and SiO₂/Al₂O₃

Cited by 27 publications

References 12 publications

A Quantitative Model for Slag Yard Cooling

A Quantitative Model for Slag Yard Cooling

Relationship between Molten Oxide Structure and Thermal Conductivity in the CaO–SiO2–B2O3 System

Effect of Hot Metal on Decarburization in the EAF and Dissolved Sulfur, Phosphorous, and Nitrogen Content in the Steel

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