JPH03240910A - Molten iron tapping hole in smelting reduction furnace - Google Patents

Abstract

PURPOSE:To prevent clogging of a molten iron tapping hole and to smoothen iron tapping and slag tapping works by arranging a brick body in inner part of a smelting reduction furnace, forming the molten iron tapping hole in there and extending inlet end of the molten iron tapping hole to furnace center direction. CONSTITUTION:In the smelting reduction furnace 1 for executing the smelting reduction to iron series metal oxide with carbonaceous material, the brick body 5 forming extended hole of the molten iron tapping hole 4 in there, is set at the molten iron tapping hole 4 part in the furnace. By this constitution, the inlet end 6 of the above molten iron tapping hole 4 is extended to the furnace center direction. Then, it is desirable to arrange the above brick body 5 so that the above inlet end 6 positions to 0.5-1.0R (wherein, R is radius at the furnace bottom) from the wall in the furnace. By this method, the slag tapping time is made to early and the clogging of the molten iron tapping hole 4 caused by solidification of the slag 11 is prevented and the iron tapping and the slag tapping work can be smoothened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tap hole of a smelting reduction furnace for controlling the amount of slag remaining in the furnace to an appropriate amount.

[Prior Art] FIG. 5 is a diagram showing the steps of the melt reduction method. Hot metal is put into the smelting reduction furnace 1 as a seed hot water, and 15 dragons of iron ore and 10 to 20 dragons of coal materials (coal,
Pour coke, etc.) from above. On the other hand, oxygen is blown in through a lance 3 inserted from above to burn the carbonaceous material and melt and reduce the fine iron ore. The combustion gas generated in the smelting reduction furnace is removed with dust by a cyclone and is blown into the preliminary reduction furnace 2 from the bottom of the furnace. The iron ore charged into the pre-reduction furnace 2 is preheated and pre-reduced by combustion gas at 300 to 600° C. in a fluidized state. Iron ore powder entrained in the combustion exhaust gas that has become low temperature in the pre-reduction furnace 2 is collected by a cyclone and introduced into the smelting reduction furnace 1. The combustion gas leaving the cyclone is released outside the system as exhaust gas. In the above-mentioned process, fine iron ore and carbonaceous material are continuously charged into the melting reduction furnace 1, and the iron ore is melted down and accumulated at the bottom of the furnace. When the molten metal accumulated at the bottom of the furnace reaches a predetermined level, the tap hole is opened to tap the iron and tap the slag. FIG. 3 shows the situation inside the furnace during tapping and slag tapping, and FIG. 3(A) shows the state at the start of tapping, with molten metal 10 flowing out from the tap hole 4. (B)
The figure shows a state in which the slag 11 is flowing out, and the figure (<C,) shows a state in which the slag 11 has finished flowing out and gas is gushing out.

[Problems to be Solved by the Invention] In a reduction melting furnace, it is necessary to leave a predetermined amount of molten metal at the bottom of the furnace in order to continue operation. For this reason, tapping and slag are carried out with the furnace in an upright position, but since the slag is highly viscous, a large amount remains in the furnace as shown in Figure 4, and it takes time to tap and slag (if it takes more than 7 minutes, this phenomenon will occur). ), the slag in the tap hole may solidify and block the tap hole, causing problems in the tap slag work.

[Means for Solving the Problems] The present invention aims to solve the above-mentioned problems. A tap hole for a smelting reduction furnace is characterized in that a brick body with a tap hole formed therein is provided, and the entrance end of the tap hole extends in the direction of the core. The entrance end of the tap hole is 0.5R to 1.5R from the inner wall of the furnace. It is more preferable to set it in the range of OR.

[Function] If the entrance end of the tap hole is located closer to the center of the furnace than the side wall, the slag will be tapped faster, the slag will not solidify and block the tap hole, and the tap slag work will be easier. Become smoother. The entrance end of the tap hole is set at 0.5R or more from the inner wall of the furnace.
This is because if it is less than 0.5, the slag tapping time will become long and the slag will block the tap hole. The reason for setting it below OR is that even if it is 1.0R or more, the slag tapping time will become long and the slag will block the tap hole.

[Embodiments] Examples of the present invention will be described below based on the drawings. 1st
In the figure and FIG. 2, 1 is a smelting reduction furnace, 4 is a tap hole (the slag is also tapped in the tap hole), and 5 is a brick body in which an extension hole of the tap hole according to the present invention is formed inside. . Numeral 10 is seed metal (hot metal) remaining at the bottom of the furnace, and 11 is slag remaining in the furnace, and because of its high viscosity, it has a mountain shape that slopes toward the entrance end 6 of the tap hole.

Next, the main dimensions of the brick body according to the present invention will be explained. The height h of the tap hole from the hearth bottom was a 5T furnace (test furnace, furnace height: 4 m, hearth diameter: 1.4 m).

Since 4.5T of seed water is required in the case of 501, a practical furnace of 400T furnace (furnace height: 10m, hearth diameter: 7m, furnace volume: 600) is 400T, so it is 150cm. For example, if the length ρ of the brick body is 0.7R, it will be 49 cm in a 5T furnace and 245 cm in a 400T furnace. In addition, the tap hole diameter is 3 in a 5T furnace.
60-70I1m is good for 0-40 dragon 400T furnace.

Table 1 shows the results of investigating changes in tapping time by changing the length of the brick body in a 5T furnace.

Table 1 there were.

As shown in Table 1, the ρ-20CIl slag tapping time was 7 minutes, and tap hole blockage occasionally occurred, but when the slag was 30C11 or higher, it took less than 6 minutes, and the slag solidified and clogged the tap hole. is gone.

[Effects of the Invention] Since the present invention is configured as described above, the slag tapping time is shortened, the slag does not solidify and clog the tap hole, and the tapping operation can be carried out smoothly. effective.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view of a smelting reduction furnace with a tap hole according to the present invention, Figure 2 is a cross-sectional view taken along the line ■-■ in Figure 1, and Figure 3 shows the situation inside the furnace from tapping to completion of slag tapping. FIG. 4 is a diagram showing the state of the seed hot water and residual slag after completion of tapping and slag tapping using a conventional tap hole, and FIG. 5 is a process diagram of the smelting reduction method. 1. Smelting reduction furnace, 4.. Tapping hole, 5.. Brick body, 10.
Seed bath, 11...Residual slag.

Claims (2)

[Claims] (1) In the tap hole of a smelting reduction furnace that melts and reduces iron-based metal oxides with carbonaceous material, a brick body with a tap hole formed inside is provided inside the furnace, and the entrance end of the tap hole is connected to the core. A tap hole of a smelting reduction furnace characterized by extending in the direction. (2) The entrance end of the tap hole is 0.5R to 1.0R from the furnace inner wall.
The tap hole of a smelting reduction furnace according to claim 1, wherein the brick body is provided so as to be located at R. However, R: radius of the hearth bottom.