Seat well block is made of corundum, chrome corundum and corundum spinel. It is the supporting product of separate and integral breathable brick, which has high thermal strength, good thermal stability, scour resistance and slag resistance. The breathable brick can effectively protect the breathable core brick, and it is the key supporting product to ensure the smooth implementation of bottom blowing argon function. Porous plug is a kind of new product with high life, energy saving and consumption reduction. The structure design is reasonable, and it has good thermal stability, anti-erosion, anti-erosion, and anti-permeability. It has the characteristics of high blowing rate, reliable operation and long service life.