• Paul, Alexander
• Cheremisina, Elizaveta
• Schenk, Johannes
• Wimmer, Gerald
• Ludwig, Nocke

Abstract

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,<br/>directly in the hot process. The decrease in solubility of lime with the increasing content of magnesium<br/>oxide is due to the formation of high temperature solid chemical compounds (Ca2SiO4, (Mg,Fe)2SiO4) and<br/>solutions based on MgO like ((Mg,Fe) O) in the volume of lime samples. Formed slightly soluble phases<br/>hinder the process of CaO dissolution and slow down the rate of dissolution of lime samples. Based on<br/>differential equations of mass balance of the dissolving substance and taking into account its transition<br/>into 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 decrease<br/>in the concentration gradient, increase in the process of slag saturation with lime. Activation energy has<br/>been calculated under conditions of non-stationary linear and spatial semi-infinite diffusion. Based on the<br/>dependency of the logarithm of diffusion coefficients on the inverse temperature derived value of the<br/>activation energy of diffusion is 230.2±14.0 kJ/mol.

Topics

• impedance spectroscopy
• compound
• Magnesium
• Magnesium
• melt
• activation
• lime
• dissolving
• magnesium oxide