With magnesia,MgO-CaO sand and MgO-SIO as the main raw materials,the dry material has the characterstics of good construction performance,corrosion resistance and durabiliy,and the residual lining is easy to disintegrate and unpack,In particular,the dry material with specially treated magnesium-calcium sand as raw material can effectively control the disadvantage of easy hydration of magnesium-calium sand and ensure the product has good construction and service performance ina long period of time.The magnesium calcium dry material has obvious purifying effect on steel.