Rapid repair technology of blast furnace iron mouth



When the blast furnace is running to the middle and late stage of the furnace operation, local high temperature, gas blow-by, broken iron hole, etc. will occur in the hearth, furnace bottom or tuyere area. In order to maintain production, the ironworks will take measures such as hot gunning, grouting on the cold surface or hot surface of the cooling wall, increasing the cooling intensity, and repairing the hot state of the iron hole, and then shut down the furnace for maintenance after the maintenance node. These rapid maintenance methods can not only effectively prolong the operating life of blast furnaces, but also are widely used due to the continuous progress of their materials and repair processes. Among them, the blast furnace taphole quick repair technology adopts the hot pouring method to quickly repair the working lining of the taphole area in a very short maintenance time, and has achieved good application results.

If the blast furnace taphole area has sputtering, blowing gas, fire, broken taphole, etc., it indicates that there are gaps in the composite brick or casting layer in the taphole area and gas blowing, or the taphole channel has a fault. These conditions will affect the tapping volume, tapping cycle, tapping efficiency, and mud maintenance effect, etc., while the traditional mud maintenance efficiency is low and cannot be used for a long time. Therefore, the main ideas and measures for casting repair of blast furnace taphole are as follows:

First, after the molten iron is discharged, the blast furnace is briefly suspended, usually 6h~12h.

Second, the blast furnace was temporarily closed, and the sealing plate at the iron mouth was cut open, and the brick lining or castable in the iron mouth area was removed, and red slag iron was exposed inside.

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

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

Fifth, after the pouring is completed, the equipment can be removed, and the materials can be put into use after curing and hardening.

For the above-mentioned quick repair method of blast furnace iron mouth, in actual operation, the control of cleaning process, material selection and pouring process is more critical.