Mold flux is one kind of auxiliary material for steel-making and it could divided into three parts:

(1) the mainly slagging material such as SiO2,Al2O3,CaO,

(2) the special material like Na2O,Li2O, F,MgO and these could use to viscosity of slags and regulating melting point. 

(3) Carbonaceous materials and these could with the ability to control the melting rate 

The mold flux choosing process could based on the different type of steel.