Dolomite is the second largest alkaline refractory after magnesite, which is mainly used to prepare dolomite refractory. Chemical composition of dolomite used in refractory industry in China. Firstly, dolomite ore is calcined (or melted) to obtain magnesia calcium raw materials (such as dolomite sand / magnesia dolomite sand, magnesia calcium sand, magnesia calcium iron sand), and then various dolomite refractories are made. Cao not only has the advantages of high fire resistance, slag corrosion resistance and thermal shock resistance, but also can absorb s, P, Al2O3, SiO2 and other non-metallic inclusions in molten steel, and has the function of purifying molten steel. Therefore, it is widely used in stainless steel refining furnace. In addition, dolomite sand (snowflake white) contains a lot of free CaO in 10-20 mesh, so it is easy for them to react with C2S in cement kiln material to form C3S and form stable kiln shell.