A rotating disk technique was used to determine the dissolution rate and diffusivity of CaO and MgO in slags. The dissolution rate was deduced from the measured changes in concentration of oxides in slag with respect to reaction time. The experimental set- up was initially tested with dissolution of magnesia in the CaO ??? 55 wt% Al2O3 slag at 1430 ??C and a measured rate of 2.7 ??10 -5 g/cm2.s was obtained. The dissolution rate was increased by slag chemistry and ranged from 6.5??10-5 to 2.1??10-4 g/cm2.s. The dissolution rate of CaO was measured in CaO ??? 42 wt% Al2O3 ??? 8% SiO2 based slag. The measured dissolution rates were found to be strongly dependent on the slag chemistry and temperature and ranged from 5.03??10 -5 to 3.3??10 -4 g/cm2.s. The dissolution rates were strongly dependent on the rotation speed and results indicate mass transfer in the slag phase to be rate- limiting step. The diffusivity of MgO / CaO was calculated from the dissolution rate and solubility data, using known mass transfer correlations. The diffusivity of MgO in the calcium aluminate slag at 1430 ??C was found to be about 1.1??10-5 cm2/s. Additions of 5 and 10 wt% Fe2O3 increased the diffusivity by a factor ~ 1.5 to 3, respectively. However, with introduction of (CaF2 5 wt% + Fe2O3 5 wt%) and (CaF2 5 wt% + Fe2O3 10 wt%) in the slag, the diffusivity increased considerably by a factor of about 29 and 11, respectively. The diffusivity of CaO in calcium aluminosilicate was measured to be in the order of 10-6 to 10-5 over a temperature range of 1430 ??? 1600 ??C. CaF2 increased the diffusivity by a factor of 3 to 5 while MnOx and FeOx, ilmenite and TiO 2 increased the diffusivity substantially and SiO2 had an opposite effect. The measured diffusivities are in accord with published data on comparable systems and are discussed with reference to Eyring theory. It was concluded that MnOx, FeOx and ilmenite in the slag increase the dissolution rate and diffusivity of lime, showing comparable results with respect to CaF2.

A rotating disk technique was used to determine the dissolution rate and diffusivity of CaO and MgO in slags. The dissolution rate was deduced from the measured changes in concentration of oxides in slag with respect to reaction time. The experimental set- up was initially tested with dissolution of magnesia in the CaO ??? 55 wt% Al2O3 slag at 1430 ??C and a measured rate of 2.7 ??10 -5 g/cm2.s was obtained. The dissolution rate was increased by slag chemistry and ranged from 6.5??10-5 to 2.1??10-4 g/cm2.s. The dissolution rate of CaO was measured in CaO ??? 42 wt% Al2O3 ??? 8% SiO2 based slag. The measured dissolution rates were found to be strongly dependent on the slag chemistry and temperature and ranged from 5.03??10 -5 to 3.3??10 -4 g/cm2.s. The dissolution rates were strongly dependent on the rotation speed and results indicate mass transfer in the slag phase to be rate- limiting step. The diffusivity of MgO / CaO was calculated from the dissolution rate and solubility data, using known mass transfer correlations. The diffusivity of MgO in the calcium aluminate slag at 1430 ??C was found to be about 1.1??10-5 cm2/s. Additions of 5 and 10 wt% Fe2O3 increased the diffusivity by a factor ~ 1.5 to 3, respectively. However, with introduction of (CaF2 5 wt% + Fe2O3 5 wt%) and (CaF2 5 wt% + Fe2O3 10 wt%) in the slag, the diffusivity increased considerably by a factor of about 29 and 11, respectively. The diffusivity of CaO in calcium aluminosilicate was measured to be in the order of 10-6 to 10-5 over a temperature range of 1430 ??? 1600 ??C. CaF2 increased the diffusivity by a factor of 3 to 5 while MnOx and FeOx, ilmenite and TiO 2 increased the diffusivity substantially and SiO2 had an opposite effect. The measured diffusivities are in accord with published data on comparable systems and are discussed with reference to Eyring theory. It was concluded that MnOx, FeOx and ilmenite in the slag increase the dissolution rate and diffusivity of lime, showing comparable results with respect to CaF2.

A rotating disk technique was used to determine the dissolution rate and diffusivity of CaO and MgO in slags. The dissolution rate was deduced from the measured changes in concentration of oxides in slag with respect to reaction time. The experimental set- up was initially tested with dissolution of magnesia in the CaO ??? 55 wt% Al2O3 slag at 1430 ??C and a measured rate of 2.7 ??10 -5 g/cm2.s was obtained. The dissolution rate was increased by slag chemistry and ranged from 6.5??10-5 to 2.1??10-4 g/cm2.s. The dissolution rate of CaO was measured in CaO ??? 42 wt% Al2O3 ??? 8% SiO2 based slag. The measured dissolution rates were found to be strongly dependent on the slag chemistry and temperature and ranged from 5.03??10 -5 to 3.3??10 -4 g/cm2.s. The dissolution rates were strongly dependent on the rotation speed and results indicate mass transfer in the slag phase to be rate- limiting step. The diffusivity of MgO / CaO was calculated from the dissolution rate and solubility data, using known mass transfer correlations. The diffusivity of MgO in the calcium aluminate slag at 1430 ??C was found to be about 1.1??10-5 cm2/s. Additions of 5 and 10 wt% Fe2O3 increased the diffusivity by a factor ~ 1.5 to 3, respectively. However, with introduction of (CaF2 5 wt% + Fe2O3 5 wt%) and (CaF2 5 wt% + Fe2O3 10 wt%) in the slag, the diffusivity increased considerably by a factor of about 29 and 11, respectively. The diffusivity of CaO in calcium aluminosilicate was measured to be in the order of 10-6 to 10-5 over a temperature range of 1430 ??? 1600 ??C. CaF2 increased the diffusivity by a factor of 3 to 5 while MnOx and FeOx, ilmenite and TiO 2 increased the diffusivity substantially and SiO2 had an opposite effect. The measured diffusivities are in accord with published data on comparable systems and are discussed with reference to Eyring theory. It was concluded that MnOx, FeOx and ilmenite in the slag increase the dissolution rate and diffusivity of lime, showing comparable results with respect to CaF2.

A rotating disk technique was used to determine the dissolution rate and diffusivity of CaO and MgO in slags. The dissolution rate was deduced from the measured changes in concentration of oxides in slag with respect to reaction time. The experimental set- up was initially tested with dissolution of magnesia in the CaO ??? 55 wt% Al2O3 slag at 1430 ??C and a measured rate of 2.7 ??10 -5 g/cm2.s was obtained. The dissolution rate was increased by slag chemistry and ranged from 6.5??10-5 to 2.1??10-4 g/cm2.s. The dissolution rate of CaO was measured in CaO ??? 42 wt% Al2O3 ??? 8% SiO2 based slag. The measured dissolution rates were found to be strongly dependent on the slag chemistry and temperature and ranged from 5.03??10 -5 to 3.3??10 -4 g/cm2.s. The dissolution rates were strongly dependent on the rotation speed and results indicate mass transfer in the slag phase to be rate- limiting step. The diffusivity of MgO / CaO was calculated from the dissolution rate and solubility data, using known mass transfer correlations. The diffusivity of MgO in the calcium aluminate slag at 1430 ??C was found to be about 1.1??10-5 cm2/s. Additions of 5 and 10 wt% Fe2O3 increased the diffusivity by a factor ~ 1.5 to 3, respectively. However, with introduction of (CaF2 5 wt% + Fe2O3 5 wt%) and (CaF2 5 wt% + Fe2O3 10 wt%) in the slag, the diffusivity increased considerably by a factor of about 29 and 11, respectively. The diffusivity of CaO in calcium aluminosilicate was measured to be in the order of 10-6 to 10-5 over a temperature range of 1430 ??? 1600 ??C. CaF2 increased the diffusivity by a factor of 3 to 5 while MnOx and FeOx, ilmenite and TiO 2 increased the diffusivity substantially and SiO2 had an opposite effect. The measured diffusivities are in accord with published data on comparable systems and are discussed with reference to Eyring theory. It was concluded that MnOx, FeOx and ilmenite in the slag increase the dissolution rate and diffusivity of lime, showing comparable results with respect to CaF2.

Thesis (M.Sc.). / Written for the Dept. of Bioresource Engineering. Title from title page of PDF (viewed 2008/05/14). Includes bibliographical references.

Thesis (Ph.D.)--Drexel University, 2010. / Includes abstract and vita. Includes bibliographical references (leaves 159-171).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1928. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 76-80).

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

No description available.

<p> The dominant slag-metal reaction site in AC electro-slag remelting (ESR) has been directly determined by estimating the rate of sulphur transfer at the electrode tip/slag and metal pool/slag interfaces. In this investigation, negligible sulphur transfer has been assumed at the droplet/slag interface, and the basis for such assumption is discussed. Using a 5.825" diameter mould and CaF2-CaO slags, it has been established that the electrode tip/slag interface is the dominant reaction site. Calculations indicate that the pool sulphur is close to equilibrium with the slag. The importance of all six reaction sites in AC ESR are discussed. The results indicate the importance of the slag/atmosphere interface, especially when using slags of low lime content. Conventonal overall sulphur balances have been carried out and the results are in agreement with the rates obtained at the different interfaces, thus indicating internal consistency of the results. </p> / Thesis / Master of Engineering (MEngr)