KR20010002169A - A selectoinable segment charging method solving unbalance hot metal tempreture using in bf - Google Patents

Abstract

PURPOSE: A partial charging method of cokes is for eliminating unstable factors to derive partial out of balance within blast furnace and poor discharge of melt by additionally charging cokes as raw material in a low temperature area to increase heat source. CONSTITUTION: A partial charging method of cokes is performed to reduce temperature deviation of melt in blast furnace by alternately charging coarse ores, cokes and fine ores to form laminate and to produce molten iron through reduction and melting processes. The method comprises to maintain uniform ores/cokes("O/C") ratio in furnace to eliminate temperature deviation of gas stream by additionally charging ores and cokes having a specific O/C ratio of 60-80 in a low temperature area. The method effects to extend life of furnace and improve productivity by continuously operating stable high-dust coal working process.

Description

Partially loaded method for resolving blast furnace melt temperature deviations {A SELECTOINABLE SEGMENT CHARGING METHOD SOLVING UNBALANCE HOT METAL TEMPRETURE USING IN BF}

The present invention relates to a method for charging coke in a furnace, and in particular, in order to minimize the deviation of the melt temperature discharged from the furnace (hereinafter referred to as "blast furnace") by the outlet, the coke which is a fuel in a direction in which the melt temperature is low. By adding additional heat source, it is possible to prevent the molten iron temperature deviation of each outlet, which is intensified during the operation of high pulverized coal, and to prevent the fluctuation of slag emissions and the fluctuation of the molten iron quality due to the temperature deviation. The present invention relates to a partial light loading method for resolving blast furnace melt temperature deviation, which performs partial light loading in the radial direction of the blast furnace to continuously feed the post process.

In recent years, the global trend is to gradually increase the use of pulverized coal, which is relatively inexpensive, instead of expensive coke as a reducing agent for iron ore. Therefore, how much can increase the pulverized coal injection cost and how to manage the silicon (Si), which is an impurity in the blast furnace, without any change, stably and supply it to the steelmaking, which is a post process, is the key. It is not an exaggeration to say that it is an indicator.

Increasing the pulverized coal injection ratio of the blast furnace means an increase in the ore ratio to the coke ratio (hereinafter referred to as "O / C") among the contents of the blast furnace in the relatively radial manner. It is easy to cause the imbalance of the softening fusion zone and the partial deflection phenomenon of the softening fusion zone, and the temperature difference of the melting point by the exit port frequently occurs due to the difference in the direction of the loading amount.

Therefore, instability of the blast furnace furnace (hereinafter referred to as “yellowing”), such as partial melt discharge in the blast furnace operation, fluctuations in the charter quality, and the like, a decrease in production and various instability of the operation may lead to a large-scale accident. Enhancement is implicated.

The present invention is to solve the partial imbalance of the blast furnace internal situation and the instability of the melt discharge failure by the exit port during the operation of the high O / C operation, and to add the coke which is a fuel relatively in the direction of low melt temperature By adding heat source by charging, it is possible to prevent the variation of molten iron temperature by the discharge port which is intensified during the operation of high pulverized coal, and to prevent the fluctuation of slag discharge and the quality of molten iron according to the temperature deviation, thus maintaining the quality of molten iron in a stable blast furnace. The technical gist of the present invention is to provide a method for solving the above-mentioned problems by performing partial light loading in the radial direction of the blast furnace to continuously supply the post process.

In general, the ore and the sintered ore cut out from the raw material bins 6-4 and 6-5 are transferred to the top of the blast furnace 1 through the charging belt conveyor 6, as shown in FIG. -4) and each notch set through a rotation chute (2-2; Rotation Chute) which can be charged by sintered ore particle size after being stored in the hopper (2; Hopper) through the upper seal valve (2-3) and hopper. Coke (particle size: 35 to 55 mm) is charged ↓, and opposing sintered light (particle size: 12 to 50 mm) is loaded so that it can be uniformly charged and distributed inside the blast furnace 1 by controlling the tilting angle. In the order of charging sintered ore (particle size: 5-12mm) ↓, coke is charged evenly in the radial direction, maximizing breathability and gas utilization rate by stable gas flow at the top of the blast furnace (1). The softening fusion zone 1-1 is made high and the gas flow of the middle part and the wall part is kept uniform.

On the other hand, a small sintered ore with excellent reducibility and breathability is installed on the side of the furnace to prevent the formation of inert zones of the furnace wall and induce the protection of the furnace wall. The high temperature hot air sent is blown through the blast furnace (1-2) to the inside of the blast furnace (1) to produce a molten iron (1-3) by reducing and melting the iron ore.

Such blast furnace operation requires stable profile within the blast furnace (1), so that the flow of gas, that is, the air permeability, becomes good overall, and thus the furnace situation is stabilized, and economic operation can be performed only when iron ore is reduced and melted. It is high and the lifetime of the blast furnace 1 is also extended. In order to stabilize the profile in the blast furnace 1 when O / C is 4.70 or more, it is most important to keep the O / C distribution uniformly in the whole direction in the blast furnace 1 in order to smooth gas flow and breathability. .

In particular, the higher the O / C of the whole blast furnace (1), the more difficult it is to maintain a uniform O / C in the direction of the blast furnace (1), and even if a slight difference occurs, partial imbalance of the furnace situation occurs, resulting in the melt of each exit port. This leads to temperature differences and maintains unstable aging.

In order to keep the O / C of the middle part of the blast furnace 1 uniform, the current charging method, that is, charged at the charging position of each site showing the fall trajectories 5-1 to 5-10 shown in FIG. Only if the amount is properly adjusted, it is possible to maintain the internal condition of the blast furnace (1) where the gas flow is smooth and breathable. However, with the current blast furnace charging method, it is difficult to maintain a uniform O / C distribution in the entire direction of the furnace during high O / C operation.

In recent years, as the cost of coking coal has been gradually increased for the economic operation of the blast furnace (1), the coke content has been replaced by pulverized coal. Due to this, it is very difficult to maintain uniformity of the overall load distribution inside the blast furnace 1.

As a conventional technique for improving this, there is a method of resolving the molten iron temperature deviation by performing a photosensitive operation that significantly lowers O / C when the molten iron temperature deviation occurs at each outlet to equalize the distribution of the blast furnace. . However, this conventional method requires a huge amount of coke amount due to the extensive photosensitive operation, and it takes a long time to reach normal operation by lowering the O / C. It is not only a fundamental solution to keeping the aging stable, but also being placed in the blast furnace's economic operations such as a change in the charter quality.

In view of the above circumstances, the inventors of the present invention carry out coking and charging of this charge to maintain a uniform distribution in all directions of the blast furnace while performing high pulverized coal operation, which is essentially an essential condition of economic operation in the blast furnace. In addition to ore loading, the molten iron temperature is provided by carrying out the function of carrying out two or three charges of low O / C (8-4a and 8-4b in Fig. 4) during normal operation. In case of deviation, the coke is charged at the lower side of the molten iron temperature to supply heat source, thereby maintaining the uniformity of the overall load distribution inside the blast furnace, and fundamentally eliminating the variation in the molten iron temperature at each exit port, thus maintaining stability in the furnace. The invention was completed.

The present invention has been invented to solve the problems caused in the conventional bone industry in view of the above situation, uniform in O / C distribution in the whole direction of the furnace during the high O / C operation in the operation of the blast furnace operation, especially high coal dust injection operation In order to provide a method for forming a uniform gas flow and relieving the deviation of the molten iron temperature, the molten iron temperature is lowered depending on the normal operation and the high O / C operation when the molten iron temperature deviation occurs at each exit. To add additional coke, which is the heat source of the blast furnace, it is equipped with the function of charging 2 or 3 times more of ore and coke with O / C of 60 ~ 80 level in normal operation, so that the whole blast furnace can be operated even in high O / C operation. The purpose is to provide a partial light loading method for resolving the blast furnace melt temperature deviation, which maintains stable aging due to the uniform O / C distribution in the direction and the elimination of the temperature difference of the molten iron by the exit port.

1 is a flow chart of the charging (ore and coke) of a typical blast furnace,

2 is a schematic diagram of the blast furnace load drop trajectory,

3 is a view showing an internal furnace situation when a molten iron temperature deviation occurs according to a conventional tapping port,

Figure 4 shows the charging mode and the set speed and the load distribution in accordance with the present invention

drawing,

Figure 5 shows the phenomenon of the temperature difference and the temperature distribution of the molten iron according to the conventional and the present invention

The graph shown.

<Description of reference numerals for the main parts of the drawings>

1: blast furnace 1-1: softening fusion zone

1-2: blowhole 1-3: molten iron

1-4: Charging baseline 1-5: Block

1-6: Charging position tracking device 1-7: Chain

1-8: Weight 2: Hopper Hopper

2-1: Light control valve 2-2: Charge turning chute

2-3: Hopper upper sealing valve 2-4: Flap gate (moving chute)

3-1: softening fusion zone of molten iron temperature

3-1a: softening fusion zone at the lower molten iron temperature

3-2: Outlet

3-3: Melt up temperature of molten iron 3-3a: Melt up temperature of molten iron

6: belt conveyor 6a: raw material movement position sensor

6-1: Coke storage hopper 6-2: Opposite sintered light storage hopper

6-3: small sintered ore storage hopper 6-4: coke storage tank

6-5: Ore Reservoir 6-1a: Coke Charged in Blast Furnace 6-2a: Opposite Ore Charged in Blast Furnace 6-3a: Small Ore Charged in Blast Furnace 7-1: Core Charged Coke 7-2: Heavy Coke

7-3: Thickness after intermediate ore layer 7-4,7-5,7-6: Furnace wall part load 5-1 ~ 5-10: High safety load base line drop of each notch at 1.0m Trajectory

5: charge baseline '0' meter point

8: Center charge coke molten iron temperature 8-1a: Main load coke

8-3a: small ore 8-4a: partial light coke 8-4b: partial light ore

8-5: Partial light load range (0 ~ 90 °) when melting temperature of # 2 exit port

8-6: Partial Light Load Range (90 ~ 180 °) at # 2 Outlet Melting Temperature Decrease

8-7: Partial Light Load Range (180 ~ 270 °) at # 2 Outlet Melting Temperature Decrease

8-8: Partial Light Load Range (270 ~ 0 °) at # 2 Outlet Melting Temperature Decrease

9-1: loaded opposing ore

Partial light charging method for solving the blast furnace melt temperature deviation of the present invention for achieving the above object is to alternately charge the ore (9-1) and coke (8-1a) and small ore (8-3a) from the top of the furnace. In the blast furnace operation in which a layer is formed and the molten iron is produced through reduction and melting, a charge set in advance by the charge position tracking device (1-6) after completion of charging of the charge of the blast furnace (1) when a temperature deviation occurs at each blast furnace outlet. After tracking the position level and reaching the tilt angle for each notch of the molten iron temperature drop, 60 ~ 80% of the ore (8-4b) and coke (8-4a) of normal operation O / C level are 5-10 times. It is characterized by resolving the temperature deviation of each blast furnace outlet by additional heat source by partially loading it once or twice a time.

Hereinafter, the operation of the present invention will be described in detail with reference to the accompanying drawings.

In general, in the blast furnace operation, as shown in FIGS. 1, 2, and 3, the coke and sintered ore discharged from the top hopper 2 is charged to the charging baseline 1.0 m (5-1a) during normal operation. Rotation of -2) alternately charges to form a layer.

When the coke is combusted by blowing hot hot air through the tuyere (1-2), a heat source and a reducing gas are generated, and the iron ore is reduced and melted by the heat source and the reducing gas, and finally a soft fusion zone (1--1). 1) The melt is present below.

In order for such melt reduction to occur effectively, the flow of reducing gas must be smooth, and in particular, when the initial charging is performed at the top of the blast furnace (1), uniform distribution of the blast furnace (1) charge in all directions should be achieved. However, in the blast furnace operation, in particular during the O O / C operation, as shown in Figure 3, the charging baseline (1-4), (1-4a) is different from each other in the direction, thereby softening fusion zone (3-1) ), (3-1a) position difference occurs, and heat loss increases due to sudden fluctuations and sudden rises of the underbody temperature at the part where the softening zones (3-1) and (3-1a) are hit. Fluctuation of molten metal on the melt side (3-3a) of molten melt (3-3) and lower (3-3a) due to variation in molten iron temperature caused by variation in molten iron temperature. Etc. are causing problems.

Therefore, the present invention, if the above-mentioned problems occur in the blast furnace operation, after filling the charge, the charge position tracking device (1-6; Sounding) after tracking the charge position level preset by the charging charter before charging is started Each notch of the charge of the temperature drop part

When the tilt angle is reached for each notch, O / C is charged 2 ~ 3 times more with ore (8-4b) and coke (8-4a), which is 60 ~ 80% of normal operation, and the whole direction of blast furnace (1) It will solve the uniform load distribution and melt temperature deviation of.

In recent years, the operation of high pulverized coal blowing operation for economic operation continues, and the present invention is applied in the event of rapid rise of O / C distribution in all directions due to high O / C operation and unevenness of distribution shown in FIG. 3. The example which aims at maintaining a yellowing condition and equalizing the internal condition of a blast furnace by eliminating a temperature deviation is shown in FIG.

As shown in Fig. 4, the molten iron temperature is charged with the ore (8-4b) and the coke (8-4a) of 60% to 80% of the normal operation O / C level, which is 5 to 10 charges. (

Each charge) is charged once, charging a total of two to three times, and the additional charge is determined based on the charter temperature deviation level. And the setting of the charging direction is performed by specifying a specific direction by dividing the direction (8-5, 8-6, 8-7, 8-8) of the blast furnace 1 into a total of four, as shown in FIG. The charging mode is carried out in a range of 2 to 4 notches in total with 2 to 6 notches depending on the amount of charge.

Here, when 60 ~ 80% of the ore (8-4b) and coke (8-4a) of normal operation O / C level is charged at 60% or less, the molten iron temperature of the part rises excessively, and the deviation occurs on the contrary. This is because when 80% or more of the heat source is insufficient, the effects of the present invention cannot be sufficiently obtained. The reason for charging once every 5 to 10 charges is that if the charge is too frequent, the instantaneous heat rises and the quality of the charterer is increased. If the charge is more than 10 charges, the supply is insufficient. This is because it does not help to resolve the temperature deviation.

In addition, the charging mode is carried out in the range of 2 to 4 notches, respectively, in the range of 2 to 6 notches depending on the amount of charge.The setting of the charging region to the 2 to 6 notch range is charged in the middle part, and the maximum zero supply is possible to the relevant part. In order to achieve the effect, the total rotational speed of 2 to 4 rotations to prevent the phenomenon of intensive charging in one place in one rotation, the amount of charge is insufficient when more than 4 rotations can not achieve the effect of the present invention to the maximum. Because.

According to the present invention, a partial light insertion was performed at the portion where the molten iron temperature was lowered, and the molten iron temperature was measured. As shown in FIG. 5, the molten iron temperature deviation was significantly reduced.

As described above, according to the present invention, compared to the conventional method, the difference in the load distribution according to the overall direction of the blast furnace generated during normal operation and high pulverized coal operation, the deflection phenomenon of the softening welding zone, the variation of the molten iron temperature and the molten iron quality fluctuation It is effective in improving productivity and securing blast furnace life by maintaining a stable yellowing and continuously performing high pulverized coal operation.

In addition, it is possible to solve the unstable instability by maintaining the uniform gas flow in all directions of the furnace by eliminating the uneven phenomenon of the furnace situation caused by the relatively low coke amount due to the level of O / C level of the high pulverized coal injection operation. Therefore, more stable and extremely high pulverized coal injection operation is possible. Due to this effect, it was possible to prevent the occurrence of deviation of the molten iron temperature.

Claims (1)

In the blast furnace operation in which allele ore (9-1), coke (8-1a), and small ore (8-3a) are alternately charged from the top of the furnace to form a layer and produce molten iron through reduction and melting. When the temperature deviation occurs, after the charging of the blast furnace (1) is completed, the loading position tracking device (1-6) tracks the preset loading position level and reaches the tilt angle for each notch of the charging temperature dropping portion. Ore (8-4b) and coke (8-4a) of 60 to 80% of the operating ore ratio vs. coke ratio are partially charged two to three times, once every 5 to 10 charges. Partial light loading method for solving the blast furnace melt temperature deviation, characterized in that to solve the temperature deviation.