Rapid repair technology of blast furnace iron opening



Blast furnace operation to the middle and late stage of service, hearth, hearth or tuyere area, there will be local temperature, gas channeling, broken iron and so on. In order to maintain production, the iron factory will take measures such as hot spraying, grouting on cold or hot surface of cooling wall, improving cooling intensity, hot repair of iron mouth, etc., and then stop the furnace for maintenance of the nodes to be repaired. These rapid maintenance methods not only can effectively prolong the operation life of blast furnace, but also are widely used because of the continuous progress of its materials and repair technology. Among them, the fast repair technology of blast furnace iron mouth, in a very short maintenance time, using hot pouring way, fast repair of iron mouth area lining, has obtained a good application effect.

If the blast furnace iron mouth area spatter, gas channeling fire, broken iron mouth and other conditions, characterizes the iron mouth area combination brick or pouring layer gap and gas channeling, or iron mouth channel fault. These conditions will affect the amount of iron output, iron output period, iron output efficiency, blast mud maintenance effect, etc., while the traditional mud maintenance efficiency is low and can not be used for a long time. Therefore, the main ideas and measures for the repair of BF iron mouth pouring are as follows:

First, after the hot metal is released, the blast furnace is temporarily suspended, generally 6h~12h.

Second, the blast furnace temporarily shut down, cut the sealing plate at the iron mouth, remove the brick lining or castable in the iron mouth area, and expose red slag iron inside.

The third is to clean up all the debris and dust within the cleaning range, apply special interface agent on the material interface of the ring, install the sealing plate, open the pouring port and vent hole along the sealing plate, and install the iron pipe.

Fourth, the special stirred iron repair material is injected from the pouring hole, which can be assisted by small vibration.

Fifth, after the completion of pouring, the equipment is removed, and the material can be put into use after curing and hardening.

In the actual operation, the control of cleaning process, material selection and pouring process is more critical. For more than 10 years, the repair technology of blast furnace iron orifice has been applied in practice, helping many iron mills to solve the problem of iron orifice. Some of our cooperative iron mills have been able to repair the iron orifice independently, and have long been equipped with special iron orifice repair materials to timely repair the iron orifice, reduce the use of blast mud, and achieve high efficiency and energy saving. (Expert Group of Beijing United Rongda Engineering Materials Co., LTD.)