Improve the age of DC electric arc furnace

According to the development trend of electric furnace steelmaking and the trend of general contracting of refractory materials, we should pay attention to refractories for electric furnaces as general contracting of refractory materials.

The life of electric smelting furnace is not only closely related to the design and material of the refractory material itself, but also related to quality and enhanced maintenance.

The maintenance of the furnace body not only includes the normal maintenance of the oven, repairing the furnace, and the furnace body, but also involves the continuity of production, equipment conditions, refractory materials, raw material selection, smelting process formulation, and scientific management and operation level.

Let's talk about specific methods to improve furnace age from the operational aspect:

1.1 Steel tapping temperature control

Adjust the tapping temperature of the electric furnace from the original greater than 1630°C to 1620°C±10°C. High-temperature tapping is strictly prohibited, especially for heats exceeding 1650°C. At present, the average tapping temperature of electric furnaces has dropped from 1636°C at the beginning of the year to 1630°C, and the proportion of high-temperature steel (tapping temperature ≥ 1650°C) is also controlled within 10%.

1.2 Control of tapping

It is required that the tapping must be ≥0.06%, and the number of peroxide furnaces is strictly controlled.

Once a peroxidation furnace occurs, remedial measures must be taken in the furnace in time (deoxidation in the furnace). A new process for post-furnace decarburization was developed for low-carbon steel grades (finished products ≤0.06%). At present, the average tapping rate of electric furnaces has increased from 0.05% at the beginning of the year to 0.071%, and the rate of tapping times has reached more than 60%.

1.3 Slagging control

Through the tracking analysis of the slag composition, the input method and timing of auxiliary materials such as lime and slag regulator are adjusted to find the relationship between the two. At the same time, it effectively combines the whole process of foaming slag to ensure the formation and maintenance of the protective layer of the furnace wall. The amount of slag regulator added increased from 4Kg/t.s at the beginning of the year to 5.8Kg/t.s.

1.4 Bottom electrode temperature monitoring

Monitor the temperature and flow rate of the cooling water of the bottom electrode throughout the smelting process

One is to ensure that the back pressure of the 04 system must be less than 4.2Kg, and the water treatment must be notified to flush if it exceeds this value.

The second is to ensure that the cooling water flow rate of the bottom electrode is ≥90NM3/h, and the filter must be flushed below this value. In addition, once the bottom electrode temperature alarms, the cause must be found out, otherwise the furnace body shall be exhausted to inspect the furnace bottom.

The third is to track and analyze the bottom electrode temperature (18 points).

The fourth is to monitor the temperature of the cooling water in the system, and the water treatment must be notified for air cooling if it exceeds 38°C.