Characteristics and uses of calcium silicate
Silica-calcium alloy is made of silica, limestone (or lime) as raw materials, using carbonaceous reductants in the furnace through high temperature reduction and other methods.
Because calcium has strong affinity with oxygen, sulfur, hydrogen, nitrogen and carbon in molten steel, si-Ca alloy is mainly used for deoxidizing, degassing and fixing sulfur in molten steel. The addition of molten steel produces a strong exothermic effect, which turns into calcium vapor in molten steel, stirring the molten steel and making it favorable for non-metallic inclusion to float. After deoxidizing, si-Ca alloy produces non-metallic inclusion with large particles and easy to float, and also changes the shape and properties of non-metallic inclusion. Therefore, si-Ca alloy is used to produce clean steel, high-quality steel with low oxygen and sulfur content, and special steel with extremely low oxygen and sulfur content. The addition of silica-calcium alloy can eliminate the nodulation of aluminum final deoxidizing steel in ladle nozzle and the blockage of tundish nozzle in continuous casting.
