TY - JOUR

T1 - Influence of Magnesium Oxide content on kinetics of lime dissolution in steelmaking slags

AU - Cheremisina, Elizaveta

AU - Schenk, Johannes

AU - Ludwig, Nocke

AU - Paul, Alexander

AU - Wimmer, Gerald

PY - 2017/1/17

Y1 - 2017/1/17

N2 - The kinetics of lime dissolution containing different amounts of magnesium oxide (4.3–7.6%) in steelmaking slags has been studied in a non-stationary diffusion, at temperatures ranging from 1 300–1 600°C,directly in the hot process. The decrease in solubility of lime with the increasing content of magnesiumoxide is due to the formation of high temperature solid chemical compounds (Ca2SiO4, (Mg,Fe)2SiO4) andsolutions based on MgO like ((Mg,Fe) O) in the volume of lime samples. Formed slightly soluble phaseshinder the process of CaO dissolution and slow down the rate of dissolution of lime samples. Based ondifferential equations of mass balance of the dissolving substance and taking into account its transitioninto the melt phase, and accumulation in the consistently dissolving layers of solid, values of mass transfer coefficients and diffusion coefficients were calculated. Mass transfer coefficients, despite a decreasein the concentration gradient, increase in the process of slag saturation with lime. Activation energy hasbeen calculated under conditions of non-stationary linear and spatial semi-infinite diffusion. Based on thedependency of the logarithm of diffusion coefficients on the inverse temperature derived value of theactivation energy of diffusion is 230.2±14.0 kJ/mol.

AB - The kinetics of lime dissolution containing different amounts of magnesium oxide (4.3–7.6%) in steelmaking slags has been studied in a non-stationary diffusion, at temperatures ranging from 1 300–1 600°C,directly in the hot process. The decrease in solubility of lime with the increasing content of magnesiumoxide is due to the formation of high temperature solid chemical compounds (Ca2SiO4, (Mg,Fe)2SiO4) andsolutions based on MgO like ((Mg,Fe) O) in the volume of lime samples. Formed slightly soluble phaseshinder the process of CaO dissolution and slow down the rate of dissolution of lime samples. Based ondifferential equations of mass balance of the dissolving substance and taking into account its transitioninto the melt phase, and accumulation in the consistently dissolving layers of solid, values of mass transfer coefficients and diffusion coefficients were calculated. Mass transfer coefficients, despite a decreasein the concentration gradient, increase in the process of slag saturation with lime. Activation energy hasbeen calculated under conditions of non-stationary linear and spatial semi-infinite diffusion. Based on thedependency of the logarithm of diffusion coefficients on the inverse temperature derived value of theactivation energy of diffusion is 230.2±14.0 kJ/mol.

U2 - 10.2355/isijinternational.ISIJINT-2016-341

DO - 10.2355/isijinternational.ISIJINT-2016-341

M3 - Article

VL - 57.2017

SP - 304

EP - 313

JO - ISIJ international

JF - ISIJ international

SN - 0915-1559

IS - 2

ER -