Safety elements of ladle breathable bricks

Breathable brick is an indispensable functional refractory material for ladle refining, and it is also one of the main refractory materials for ladle leakage. The stable production and laying of breathable bricks or seat bricks should be strengthened, the brick type should be optimized, and the operation should be standardized to enhance the safety of breathable bricks , to achieve the purpose of leak-proof steel.

1. Permeable brick materials and stable production

Breathable bricks should have good high temperature performance and normal temperature performance to achieve good air permeability and reliability. Ladle breathable bricks usually use tabular corundum as the main raw material, add aluminum magnesium spinel, activated alumina powder, binder and appropriate amount Additives, and a small amount of additives that can form solid solutions with the main crystalline phase. With proper configuration of its components, it has good service performance.

In order to stabilize the production of permeable bricks and avoid some uncertain factors in the production process, many domestic permeable brick manufacturers have successively purchased a series of advanced equipment. At present, there are computer-controlled automatic batching systems, computer-controlled automatic shaking tables, and computer-controlled constant temperature and humidity. Maintenance kiln, computer-controlled drying kiln and computer-controlled high-temperature firing kiln, etc. Through the implementation of advanced equipment, many human factors are avoided.

2. Brick masonry for breathable seat

The samples were kept at 1100 degrees Celsius for 20 minutes, and then air-cooled for 15 minutes. After repeating 3 times, the residual flexural strength was measured to obtain the residual strength retention rate after thermal shock. The samples were kept at 1550 degrees Celsius for 3 hours. The 3-point bending method was used. Determination of its high-temperature flexural strength produces cracks under the action of high thermal stress, which affects the normal operation of ladle breathable bricks or increases the risk of steel breakout; at the same time, to ensure the construction quality of corundum self-flowing materials, the amount of water added should be appropriate and within a certain range. Long-term use, the bottom of the spoon will be deformed. In order to prevent the bottom of the block from hanging in the air, it is necessary to lay dry material or use corundum self-flow material at the bottom of the block to ensure that the bottom of the block is as dense and flat as possible.

3. Oxygen burning curing of breathable bricks

In the process of ladle hot repair, it is necessary to burn oxygen on the permeable brick to clean the residual steel and residue on the surface of the permeable brick to ensure the permeability of the permeable brick. When burning oxygen, try to ensure the smoothness of the working surface of the ladle permeable brick to avoid partial permeable bricks Excessive burning will lead to misjudgment of the remaining height of the permeable brick. It will not only reduce the service life of the permeable brick, but also lead to the risk of steel leakage during use.