Seeing slag form on top of molten steel during ladle metallurgy is a beautiful sight that signals progress. It means the synthetic refining layer has formed, and steel cleaning has already begun. However, the thick layer that absorbs impurities and prevents contact between steel and oxygen also acts as a physical barrier, preventing the desulfurizer (Calcium Carbide) from reaching the molten steel below. That is where the particle size of calcium carbide becomes essential!
Removing sulfur from steel is a critical secondary refining step. It ensures that the formed steel is machinable and has minimal impurities. Adding CaC2 is a reasonably mature technique going back to the 1970s. However, the use of small particle size remains mainstream for control.
In this article, we will explore how the calcium carbide size (2-10mm) affects the desulfurization process. Also, analyze its effectiveness, safety, and cost-related aspects. By the end, the reader will have a clear idea of the ideal particle size for their steel desulfurization process. Let us begin with the basics: why sulfur is removed from steel.
