(1) It is necessary to open an iron tunnel. When tapping, the slag and iron in the furnace converge to the taphole from all sides, and the holes near the inner wall are rapidly eroded. Therefore, when opening a hole, it should be slightly larger outside and smaller inside, and it should be prevented from bending. The pore size depends on the size of the blast furnace, and the flow rate of molten iron should be controlled, generally 4 ~ 8t minutes. Too fast or too slow is not conducive to taphole maintenance.
(2) The taphole must be dry, and the taphole cannot be tapped with wet mud. Because the wet mud on the channel wall comes into contact with high-temperature molten iron, the water quickly evaporates and produces explosive splash, which makes the runner channel rupture, which is very unfavorable for the maintenance of the taphole.
(3) Choose good gun-resistant mud. Maintenance of taphole mainly depends on refractory mud to form a mud bag in the furnace. Therefore, it is required that the refractory mud should have sufficient fire resistance and the ability to resist slag iron erosion and erosion. It should have good thermal conductivity and air permeability, be completely dry in the interval of tapping, and have certain plasticity so as to form a mud bag.
(4) In the blast furnace with slag port equipment, the upper slag should be discharged as far as possible to reduce the amount of slag discharged from the taphole.
(5) Slag and iron should be removed every time. Generally, it is required that the difference between the actual taphole quantity and the theoretical calculation quantity should not exceed 15%, and it is not allowed to blow the taphole excessively, which is harmful to taphole maintenance, especially when operating under high pressure, it is forbidden to blow the taphole greatly.
(6) The taphole angle should be reasonable. The angle of taphole refers to the angle between the opened taphole and the horizontal center line of taphole. Keeping a proper taphole angle can make the furnace contain proper residual iron, protect the bottom of the furnace and make the taphole mud bag stable and firm. With the increase of blast furnace life, the hearth and bottom of blast furnace are constantly eroded and expanded, the residual iron is reduced, and the molten iron gradually moves down. Therefore, the angle of taphole should be appropriately increased. However, under certain operating conditions, the taphole angle should be relatively fixed and should not be changed frequently. According to the experience of Angang, the tapping angles suitable for different furnace life are as follows:
When the furnace is turned on: 0 ~ 2; After one year: 5 ~ 7; Midterm:10 ~12; Late stage: 15 ~ 17.
After the dead iron layer of modern blast furnace deepens, the angle of taphole changes little, sometimes even the first generation blast furnace.
Angle.
(7) Maintain the mud jacket. The taphole mud sleeve is pressed by the gun pressing device for hanging the special mud sleeve, which is convenient for mud gun. Only when the mud sleeve is complete, the mud gun head and the mud sleeve can cooperate closely, and the refractory mud can be successfully driven into the taphole, so as to avoid the phenomenon that the gun mud emerges from the side and the taphole can't get into the mud.