Notes on replacement and maintenance of converter steelmaking taphole

The measures to extend the life of the taphole are as follows:

(1) Reduce the amount of slag discharged at the beginning and end of tapping (Figure 5-2). At the same time, a slag blocking process should be used to block the slag during tapping.

(2) If necessary, the slag can be reversed from the tapping port after adjusting the slag to reduce the erosion of the tapping port by the slag.

(3) Reduce the damage to the tapping port caused by high-temperature steel, over-oxidized steel, etc.

(4) Repair the tapping port in time to maintain its normal shape and size.

1.Early slag discharge; 2.Late slag discharge

(5) Use high-quality materials. The material used for the tapping port is required to be resistant to high temperature, erosion, scouring, and rapid cooling and heating.

The principles for replacing the taphole are as follows:

(1) The tapping time is less than 3 minutes.

(2) The tapping hole is irregular in shape or has obvious pits inside, and the tapping steel is scattered.

(3) The tapping hole life is longer than the specified furnace life, which is pre-arranged according to the production plan.

The method of replacing the tapping hole is as follows:

(1) The plan for replacing the taphole should be issued at least 4 hours in advance to facilitate production organization.

(2) After the steel is tapped, the residual slag is emptied and the converter is moved to an appropriate position on the large surface to clean the residual steel in the taphole. After the slag splashing of this furnace is completed, the vaporization flue is purged with high-pressure nitrogen to remove the sticky slag.

(3) The converter is moved downward to an appropriate position and the taphole drilling machine is adjusted to the position to match the taphole angle. Ensure that the drilling angle is accurate, the hole wall is smooth, the hole is round, and the size is appropriate to avoid damaging the taphole base brick.

(4) After the taphole hole is drilled, the converter is moved to a position that is convenient for installing the taphole. While drilling the taphole, the new taphole, taphole material, and taphole material trough should be prepared.

(5) Use a forklift and special tools to place the new taphole into the drilled channel, adjust the position, and weld the new taphole guard plate to the taphole steel plate of the furnace shell with electric welding to position it (to facilitate positioning, an appropriate amount of taphole material can be filled into the taphole channel before placing the new taphole).

(6) After the taphole is positioned, the upper part of the taphole guard plate should be cut open to facilitate filling of the taphole material.

(7) Use a forklift and a taphole material trough to fill the taphole with an appropriate amount of adjusted taphole material.

Fill and compact the end of the gap between the new taphole and the channel, and ensure that the taphole is sintered for 3 to 5 minutes. While sintering the taphole, adjust the taphole material at the back of the furnace.

(8) Rock the converter to an appropriate position to facilitate filling the taphole, and pour the adjusted taphole material into the gap between the new taphole and the channel. Avoid filling the material incompletely during operation.

(9) During the filling process, timely observation should be made to ensure that there is no leakage. After the filling is completed, the sintering time should be ensured to be more than 15 minutes.

(10) After each change of the taphole, the slag stopper should be adjusted in time to ensure that the slag stopper is accurately positioned.

The requirements for taphole maintenance and replacement are as follows:

(1) The furnace master should pay attention to the condition of the tapping port for each batch of steel. After tapping, the inner and outer ports of the tapping port should be checked. If the inner port is not good, the master should pay attention to the condition of the rear large surface, and do a good job of final slag and post-slag pouring to maintain the rear large surface and the inner port of the tapping port. If the inner port is severely corroded, the furnace supervisor should be contacted in time to confirm on site, take measures, replace the tapping port, and maintain the rear large surface.

(2) If the outer port of the tapping port is severely corroded, it should be repaired in time. If the shaped steel plate is damaged, the converter foreman should be notified in time. If steel seepage is found at the tapping port, the furnace supervisor should be notified to confirm on site and arrange for replacement in time.

(3) As long as the tapping port is found to be broken or corroded, the furnace supervisor should be notified to confirm on site and arrange for replacement of the tapping port regardless of the number of times the tapping port is used.

(4) If the tapping time is less than 3 minutes, the furnace supervisor should be notified immediately to confirm on site, and the furnace supervisor should report to the dispatch room on site to coordinate the plan for replacing the tapping port.

(5) The furnace supervisor should always keep track of the taphole situation, determine the time to replace the taphole, and report to the planner. When replacing the taphole according to the plan, the foreman and the furnace master should arrange to replace the drill bit and clean the furnace mouth.

(6) When drilling the old taphole, the second assistant and the furnace master must confirm the correct angle of the drill rod and must not deviate.

(7) Before installing a new taphole, make sure there is no residual steel. If there is residual steel, use a coal oxygen gun to burn it clean to ensure that the inside of the inner mouth is uniform and smooth. When installing a new taphole and spraying the outer mouth, the furnace supervisor must ensure that the taphole is in the correct position before spraying the material. After spraying the outer mouth, use a coal oxygen gun to bake it for 3 to 5 minutes before shaking it to the back of the furnace.

(8) When spraying the back of the furnace, ensure that the material-water ratio is adjusted to the required level and the viscosity is appropriate before entering the furnace for spraying. Do not adjust the spray gun after inserting it into the furnace. If a dry self-flowing material is used at the tapping hole, the temperature must be appropriate and the self-flowing material must be fluid enough to fill the tapping hole completely.

(9) Before adding molten iron, make sure that the gunning material is completely dry before adding molten iron.

(10) Before production, make sure that the tapping hole is in good condition before adding molten iron. If flames are emitted from the tapping hole during blowing, it means that the tapping hole is unobstructed.