6 precautions to prevent blast furnace burn-through accidents（1）

The prevention of hearth burn-through accidents and the longevity project of the entire blast furnace are a complex system project. As long as there is a problem in one link, it will have an adverse impact on the entire longevity system, and ultimately the longevity goal of the blast furnace hearth cannot be achieved.

From the first day after the blast furnace production, longevity must be placed in the most important position at work, and there must be no luck. Although the erosion of carbon bricks in the hearth is inevitable, burn-through accidents can be avoided.

Practice has shown that blast furnaces in production do not have flashover accidents in an instant, and daily monitoring data will have abnormal performance before the accident. It must be found as soon as possible and handled as soon as possible to eliminate the accident in the bud stage.

1.Choose carbon brick with high thermal conductivity or carbon brick with microporous structure

Thermal conductivity and microporous structure are two important characteristics when choosing a carbon brick. It is necessary to ensure that the cooling system has sufficient cooling capacity. The material of the carbon layer that is close to the thermal conductivity of the carbon brick is selected to avoid the formation of a "thermal resistance layer". It is suggested that in the selection of carbon bricks at the bottom of the blast furnace, carbon bricks with microporous structure and strong resistance to molten iron corrosion should be selected. It is ensured that the heat transfer capacity of each part of the material in the direction of heat transfer from the hot surface of the carbon brick (contact surface with the molten iron) to the cooling wall is sequentially increased, and the heat can be transferred in time. Practice shows that the furnace life of the blast furnace with carbon bricks with microporous structure and good resistance to molten iron corrosion can meet the standard. After 4.5 ~ 9 years of damage investigation on two 3200m3 blast furnaces in the western district of Anshan Iron and Steel Group, we confirmed that 300 ~ 400mm Manchuria carbon bricks are still reserved at the bottom of the ceramic cup.

2. Improve online monitoring program

During the design or overhaul of a blast furnace, an online longevity detection scheme should be designed so that the online temperature field status of the blast furnace can be grasped in real time to protect the longevity of the blast furnace. Don't just look at the immediate interests and be fortunate. Once an accident occurs, the loss will be several times the investment. Ansteel has suffered in this regard. After the blast furnace was burned through, the company installed monitoring equipment in all blast furnaces, eliminating monitoring blind spots.