JPH01152207A - Method for controlling iron tapping in blast furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 3. Detailed description of the invention [Industrial application field] The present invention relates to a method for managing tap iron in a blast furnace.

[Prior Art] Although the blast furnace itself operates continuously, the tapping operation for discharging the hot metal slag accumulated in the furnace is a batch operation.

Large blast furnaces of 2000 m' or more usually have two or more tap holes, and the tap holes are used alternately or cyclically to tap the iron about 10 times a day. . In order to ensure stable production in the blast furnace and to reduce fluctuations in hot metal composition, it is essential to tap the iron slag in accordance with the operating rate of the blast furnace so that the level of hot metal slag in the furnace does not rise too much. To this end, the current situation is to tap the next round of iron as early as possible. Unexamined Japanese Patent Publication No. 57-1983 for blast furnace tapping management
134504 ``Method for determining the end of tapping time in a blast furnace'' and JP-A-59-197511 ``Device for determining taping blockage time''
etc., but there is no literature regarding a method for predicting the start time of the next pig iron tapping.

[Problems to be Solved by the Invention] Currently, there is no way to accurately predict when the next taping will start, so the current situation is that the next taping is done early. For this reason, there is a problem that the number of times of tapping increases, and a large amount of work materials (opening trill, tap hole closing material, etc.) and labor are required, resulting in high costs. For example, in the example shown in Figure 3, gas blowing suddenly started after 240 minutes and the A taphole was blocked, but it was determined that there was a large amount of residual pig iron in the furnace, so the next B
The taphole was started at 180 minutes. In this example, about 6
This means that 0 minutes was wasted. The reason for starting tapping early is that as shown in Figure 1, the molten pig iron slag level A in the furnace at the beginning of tapping reaches the final stage, and the molten metal slag level B reaches the level B. This is because a large amount of gas 2 is blown out and a large amount of dust is generated, which causes environmental trouble and is dangerous to operators in front of the furnace.

[Means for Solving the Problems] The present invention attempts to solve the above-mentioned problems. The method is characterized in that the time distribution from the time until gas blowing starts from the taphole is determined, and the next taping start time is determined by adding a certain period of time determined by the tapping ratio, etc. to the time when the appearance rate is maximum. This is a method of managing tap iron in a blast furnace.

[Examples] Examples of the present invention will be described below. The inventors investigated in detail the time from when the slag flow rate reaches its maximum until gas blowing starts from the taphole. As a result, it was found that, as shown in FIG. 1, the maximum appearance rate occurs during the period from when the slag flow rate reaches its maximum until gas blowing begins. It was also found that the appearance rate differed slightly depending on the taphole.

In other words, by knowing the point in time when the slag flow rate reaches its maximum, it is possible to almost predict the time at which tapping is completed. The method of the present invention determines the next tapping start time for each taphole in the blast furnace by determining the time distribution from the time when the slag flow rate reaches its maximum until gas blowing starts from the taphole. The prediction is made by adding a certain time determined by the pig iron tap ratio etc. to the time when the rate reaches its maximum.

Table 1 shows a comparison of operating specifications before and after application of the method of the present invention. From this table, it can be seen that when the method of the present invention is applied, compared to before application, under a substantially constant tapping amount, the frequency of tapping is lower, and the variation in blow pressure and Six of hot metal is reduced. I can see that it is being done.

Table 1 [Effects of the Invention] Since the present invention is configured as described above, it is possible to predict the next time of tapping more accurately than before, and the frequency of tapping can be reduced than before. Since the number of work and man-hours can be reduced, costs can be reduced. It also has the effect of reducing environmental problems and danger to operators due to gas blow-outs.

[Brief explanation of the drawing]

FIG. 1 is a relationship between the appearance rate and the time from when the slag flow rate reaches its maximum until gas blowing, which was investigated in order to carry out the present invention,
FIG. 2 is a conventional diagram illustrating gas blowout due to a change in the level of hot metal slag in a furnace, and FIG. 3 is a conventional diagram showing the relationship between the elapsed time after the start of tapping and the tapping speed. 1...Taphole, 2...Blowout gas, a...Initial level, b...Late level.

Claims (1)

[Claims] For each taphole of the blast furnace, calculate the time distribution from the time when the flow rate of slag during tapping reaches its maximum until gas blowing starts from the taphole, and determine the time when the appearance rate is maximum. A blast furnace tapping management method characterized by determining the next tapping start time by adding a certain time determined by etc.