What kind of refractories are mainly used in steelmaking?

Semi-acidic raw materials (mainly refractory clay) are mainly used for steelmaking: in the past classification, clay was classified as acidic raw materials, which is actually inappropriate. The acidity of refractory raw materials is mainly based on free silica (SiO2) for the following reasons:

1. Because according to the chemical composition of refractory clay and siliceous raw materials, the free silica in refractory clay is much less than that in siliceous raw materials.

2. Because there is 30% to 45% alumina in general refractory clay, and alumina rarely exists in a free state, it must be combined with silica to form kaolinite. Even if there is excessive silica, the amount is very small and the effect is very small.

3. So the acidity of refractory clay is much weaker than that of siliceous raw materials. Refractory clay decomposes into free silicic acid and free alumina at high temperature, but they are different. When heating is continued, free silicic acid and free alumina will combine to form quartz. Yingshi has good acid resistance to alkaline slag. Due to the increase of alumina content in refractory clay, its acidic substances gradually weaken. When alumina reaches 50%, it will have alkaline or neutral properties, especially.

4. The ability of resisting alkaline slag at high temperature is stronger than that of silica. As far as its corrosiveness is concerned, Shi Ying is also very slow, so it is more appropriate to list refractory clay as semi-acidic raw material. Refractory clay is a widely used raw material in refractory industry.

Refractory clay: