Calcium carbide


Conventional medium for desulfurization and deoxidation of cast iron melts.

Technical calcium carbide is a colorless, crystalline to gray, amorphous mass that is obtained electrothermically by melting lime and coke. It must be stored in dry conditions, since under the influence of humidity it breaks down to calcium hydroxided and acethylene.

Due to its high melting point (around 1800 to 1850 °C) it is present as solid particles during desulfurization of cast iron melts.
In low-oxygen melts, the calcium carbide will directly react with sulfur according to the reaction equations specified below:

Eq. 1:


Eq. 2:

The calcium sulfide (CaS) slag formed has a solid, crumbly consistency, can be easily removed and is hardly aggressive to acidic ladle or furnace charges.

Additional references: