PMET_02: Desulphurization in a Ladle Furnace (LF)

The example, which is also available on our website, uses the Process Metallurgy Calculator to demonstrate the use of a Ladle Furnace (LF) with the Process Metallurgy Module.

The ladle furnace (LF) fulfils many purposes in the steelmaking process. Desulphurization, which we will focus on in this example, is merely one of them.

Desulphurization is usually performed by transferring S that is dissolved in the liquid metal to a CaO-rich slag phase. For this process to be successful, two conditions need to be fulfilled:

  1. The slag must be fully liquid (liquid fraction > 0.9). This is required for kinetic reasons. The slag phase must be fluid so that it can emulsify with the liquid steel and form a large surface area where the reaction between steel and slag can take place.
  2. The slag must take up a large amount of S from the liquid steel (have a “high sulphur capacity”) so that a significant amount of sulphur will move from the liquid steel to the slag phase.

The example demonstrates how the Process Metallurgy Module in Thermo-Calc can be used to explore these two conditions for an equilibrium between liquid steel and slag in a ladle furnace, trying to find good slag compositions. We also investigate why excessive slag carry-over from the BOF or EAF is detrimental for desulphurization in the LF and who how slag conditioning with CaC2 as fluxing agent can recover the desulphurizing ability of the slag.

  • Folder: Process Metallurgy
  • File names: PMET_02a_Ladle_Furnace.tcu or PMET_02b_Desulphurization_in_Ladle_Furnace.tcu.

Choose a or b versions of the example based on your license

  • PMET_02a_Ladle_Furnace.tcu can be run with OXDEMO database but requires the full license for Thermo-Calc 2021b and newer.
  • PMET_02b_Desulphurization_in_Ladle_Furnace.tcu requires the TCOX11 database and a full license for Thermo-Calc 2021b and newer.

Visualizations

This example is included as a Process Metallurgy tutorial on our website and as part of the playlist our YouTube channel.

One way to learn how to work with the Process Metallurgy Calculator is to use the project files as templates to help you set up your own simulation. For example, you can examine the settings available on the Configuration window and that are described in Process Simulation: Conditions Tab and the Process Metallurgy Calculator: Options Tab.

The resulting plots and details related to setting up this example are available to download via the dedicated web page.