The raw materials used in the ramming material are of high purity, the material ratio is reasonable, and they have enhanced resistance to molten iron erosion, high softness, strong impact resistance, high load softening temperature, high high temperature compressive strength, erosion resistance, wear resistance, and thermal shock resistance. Good performance, high softening temperature under load.
The main component of alkaline ramming material is alkaline oxide. The currently widely used alkaline material is magnesium material, which has the advantages of excellent corrosion resistance, high melting point, high softening temperature under load, and does not react with alkaline slag or alkaline melt. However, the thermal shock stability of magnesia ramming materials is poor and the sintering temperature is relatively high. The thermal shock during operation will cause cracks and peeling of the furnace lining material, so it is only suitable for small-capacity induction furnaces.
The main component of acidic dry ramming material is SiO2. In the presence of other impurities, the crystalline transformation of SiO2 is complicated, and an excessively high heating rate during the oven will significantly reduce the melting temperature of the material. Silica dry ramming material can be used in a variety of induction furnace lining materials, but its refractoriness and purity limit its use.
The main components of neutral dry ramming materials are neutral oxides such as Al2O3 or their complexes. Corundum dry ramming material has the characteristics of high temperature resistance, good resistance to slag erosion, no impact on the quality of molten steel, short construction time and no need for baking during construction. It is widely used in the smelting of various alloy steels. Corundum dry ramming materials currently have shortcomings such as low service life, difficulty in sintering, and difficulty in controlling thermal expansion. Magnesium-aluminum spinel has good slag resistance. Adding fused magnesite to corundum material to generate magnesia-aluminum spinel in situ can reduce the penetration of molten iron or slag into refractory materials and improve the material's slag resistance. During the use of alumina-magnesite materials, the secondary spinelization reaction can effectively inhibit cracks in the furnace lining. The aluminum-magnesium ramming material used in the furnace lining can weaken the thermal cracking of the furnace lining material and reduce the generation of micro-cracks in the medium material.
In addition, according to the type of materials used, ramming materials can be divided into siliceous ramming materials, corundum ramming materials, magnesium ramming materials, magnesia-calcium ramming materials, magnesium-aluminum ramming materials, and aluminum-magnesium ramming materials. Ramping materials and Al2O3~SiC~C ramming materials, etc.; according to different parts of use, ramming materials can be divided into tundish working lining, electric furnace bottom and power frequency melting trench dry ramming materials.
