Lime In Slag Research Articles

Evolution behaviour of interfacial structure between quicklime and converter slag: slag-forming route based on FetO component

ABSTRACT In order to enable the steel companies to achieve carbon peaks and carbon neutrality, the f-CaO content in steel slag should be reduced. For this reason, this study investigates the interface reaction evolution of the quicklime and different slag in the ‘iron’ slagging route of the CaO-FetO-SiO2-MgO system at the converter steelmaking temperature. The microstructure of the reaction interface was observed by an electron microscope. The results showed that the interface reaction formed CaO-FeO solid solution, (Ca, Mg) olivine phase, and 2CaO·SiO2. The change in thickness of CaO-FeO and (Ca, Mg) olivine shows a clear trend with the change in slag components.Therefore, the dissolution mechanism of quicklime in the slag was discussed, and the liquid phase mass transfer coefficients in different slags were obtained. The results will provide a theoretical basis for the faster dissolution of lime in slag and reduction of f-CaO content in slag.

A Dynamic Flux Dissolution Model for Oxygen Steelmaking

A modified model for prediction of flux dissolution in oxygen steelmaking process is presented in this study. The aim of this paper is to introduce a procedure for simulating the amount of dissolved lime with respect to the saturation concentration of CaO by coupling the existing thermodynamic and kinetic models simultaneously. The procedure is developed to calculate the saturation concentrations/solubility of CaO in slag using thermodynamic models namely FactSage™, Cell Model, and Thermo-Calc™. Total amount of dissolved lime is evaluated by integrating solubility values in the rate equation of lime dissolution over time taking into account the effects of physical properties and temperature of slag and particle size of flux additions and validated against industrial data available in literature. Comparison between measured and calculated undissolved lime shows a good agreement between them using any thermodynamic models even though there are some differences in the predictions of saturation concentration of CaO in slag. It has been shown that two distinct control mechanisms for lime dissolution in BOF slags exist and consideration of the free lime-controlled mechanism is essential for accurate prediction of dissolution rate of lime in slag.

Dissolution of lime in BOS slag: from laboratory experiment to industrial converter

In the basic oxygen steelmaking (BOS) process, fast dissolution of lime in slag would promote quick formation of a suitable slag, which could increase the process productivity and improve the steel quality at reduced cost. Many studies have been carried out to investigate the dissolution of lime in slag in terms of the mechanism, dissolution rate and influencing factors under well controlled experimental conditions. In this study, the dissolution of lime in BOS slag was studied by characterising the lime particle and its surrounding area in the slag samples taken from a laboratory induction furnace during hot metal dephosphorisation experiment, a 6 t pilot plant converter and a 320 t industrial converter. The mechanism of lime dissolution in BOS slag is discussed under varying dynamic conditions from laboratory experiment to industrial converter.

スラグ中の遊離ライムの定量法

スラグ中の遊離ライムの定量法