JPH044378B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for producing sintered ore to be used as a raw material for blast furnace charging, so that grain size segregation changes continuously from the bottom to the top. The present invention relates to a method for charging sintering raw materials into pallets of a sintering machine.

[Conventional technology]

In the method of manufacturing sintered ore from ironmaking raw materials such as fine ore, iron ore powder of approximately 10 mm or less is mixed with coke of an appropriate particle size and limestone powder as necessary, and this mixture is supplied to a sintering pallet. was.
Then, the coke on the surface of the supplied sintering raw material is ignited, and the coke is combusted while sucking air downward, and the combustion heat generated at this time sinteres the fine ore. Here, when the sintering raw material is distributed with a uniform particle size distribution along the height direction of the raw material layer, due to heat movement inside the raw material layer, the lower part of the raw material layer becomes higher in temperature and the ventilation resistance increases. do. In addition, the surface layer portion is cooled by the drawn outside air, resulting in insufficient temperature rise and incomplete sintering. As a result, the strength of the sintered ore decreases, and a large proportion of the sintered ore is pulverized during post-processing such as crushing and sieving and is not used as a raw material for blast furnace charging.

In order to avoid such drawbacks, various methods have been proposed in which a raw material layer is formed on a pallet in which the particle size of the surface layer is fine and the particle size of the lower layer is large.
As a means for forming a raw material layer having such grain size segregation, a chute such as an inclined plate is most commonly employed. However, in such a shoot method, the sintering raw material is not sufficiently distributed according to the particle size, and it is difficult to obtain the particle size segregation necessary for uniform sintering.

Therefore, in Japanese Patent Application Laid-open No. 61-73841,
It is shown that two frit bars stacked in a staggered manner are arranged at an angle, and the sintering raw material is fed onto the pallet through a chute formed of the slit bars. As a result, the fine particles of the charged sintering raw material pass between the slit bars and form the upper layer on the pallet, while the coarse particles that do not pass between the slit bars fall down the slope of the chute and are sent. to form the lower layer.

[Problem that the invention seeks to solve]

When feeding the sintering raw material according to the description in JP-A-61-73841, the sintering raw material is divided into the upper part of the sieve and the lower part of the sieve, and each part is divided into a raw material layer, an upper layer part, and a lower part on the pallet. Become. For this reason, a boundary is created between the upper layer and the lower layer where the particle size change is discontinuous, resulting in an insufficient state to perform stable ventilation and uniform sintering throughout the raw material layer.
Furthermore, since the classification is performed in two stages, above the sieve and below the sieve, although carbonaceous materials such as coke with small particle size are collected in the upper layer, the classification ability is small.
As a result, the ventilation resistance still did not meet the desired setting, localized overheating and low temperature areas occurred, which inevitably resulted in uneven sintering of the raw material and resulted in a low sintering yield. . Furthermore, since the chute is made up of stacked staggered slit bars, clogging is likely to occur, and the work to remove clogging once it has occurred is troublesome.

Therefore, the present invention aims to distribute the sintering raw material with continuous grain size segregation and send it to the sintering pallet under stable conditions without causing any discontinuity in grain size between the upper layer and the lower layer. , with the aim of enabling a uniform sintering reaction.

[Means for solving problems]

In order to achieve the object, the charging method of the present invention has a plurality of rods with one or more chevrons on the lower side, and the distance between the bars on the upper part of each chevron is on the lower side. The bars and strips are arranged at different angles of inclination so as to be larger than each other, and the sintering raw material is supplied onto the sintering pallet through the sieve surface formed by these bars and strips. do.

〔Example〕

Hereinafter, the features of the present invention will be specifically explained using examples with reference to the drawings.

FIG. 1 shows the process of conveying the sintering raw material from the hopper to the pallet of the sintering machine in this embodiment.

The charged sintering raw material 1 is stored in a hopper 2, and is sequentially conveyed to a particle size segregation imparting device 5 by a conveying means such as a drum feeder 3 via a chute 4 such as an inclined plate. This particle size segregation imparting device 5 is one in which a plurality of bars and strips 6 are provided along the conveyance direction of the sintering raw material 1.

In the illustrated example, one end of each of these bars and strips 6 is attached to the lower part 4a of the chute 4, and the other end is attached to the lower end attachment plate 7. On the lower end mounting plate 7 side, a hole 8 is formed into which the lower end side of each bar 6 is inserted, as shown in FIG. 2, for example. The vertical distances l ₁ to _{l 4} between the holes 8 are set smaller toward the bottom. In addition, it is also possible to arrange the bars 6 in the same way by making the lower end of the bars 6 a free end and adjusting the attachment angle of the upper side.

In this way, by holding the upper end of the bar 6 at the bar mounting position 4a at approximately the same height and inserting the lower end into each hole 8,
The positional relationship of the respective bars and strips 6 is as shown in FIG. That is, the inclination angle α ₁ of the first bar 6a with respect to the horizontal plane is the same as that of the second bar 6.
The difference ( _{α 2 -} α ₁ ) between the inclination angle α ₂ of the second bar 6b and the inclination angle α ₃ of the third bar 6c (α ₃ - α ₂ ), the difference between the inclination angle α ₃ of the third bar 6c and the inclination angle α ₄ of the fourth bar 6d (α ₄
−α ₃ ), and the difference (α 5 −α 4 ) between the inclination angle α ₄ of the fourth bar 6d and the inclination angle α ₅ of the fifth bar 6e (α ₅ −α ₄ ).

As a result, particles of the same particle size are transferred to the first bar 6 at the position P1 closest to the bar attachment position _4a .
The material passes through the space between the material 6a and the second bar 6b and falls onto the pallet 9 of the sintering machine. Also, position P ₁
At a slightly lower position _P2 , it passes through the gap between the second bar 6b and the third bar 6c and falls onto the pallet 9. Similarly, from between the third bar 6c and the fourth bar 6d, at position _P3 ,
Particles having the same particle size fall onto the pallet 9 at position _P4 from between the fourth bar 6d and the fifth bar 6e. As a result, the bar installation position 4
In the range L ₁ from a, particles of the same particle size are sintered raw material 1
It is classified and sent to pallet 9. By performing this classification over the range _L1 , for example, small particles accompanying large-diameter particles can be reliably sorted, and the classification accuracy is improved.

Further, for example, at position P ₄ , the fourth bar 6
At the same time, particles with a relatively large diameter fall from between the first bar 6a and the second bar 6b.
The ratio of large-diameter particles to small-diameter particles increases continuously toward the lower side of the bar 6. Therefore, there is no discontinuity in the particle size distribution of the raw material layer 10 formed on the pallet 9, and the lower layer is filled with coarse particles and the upper layer is filled with fine particles.

In addition, in the above example, the bar 6 is held at substantially the same height at the bar attachment position 4a. However, on the bar and strip mounting position 4a side, the bar and strip 6
It is also possible to mutually change the height of the . For example, the upper side of the bars and strips 6 may be formed into a ridge shape in correspondence with the ridge shape on the lower side, or may be formed into a ridge shape in which the peaks and valleys are reversed. By changing the height of the upper end of the bar 6, the distance between the bars 6a to 6e can be reduced.
Greater freedom for adjustment.

In addition to the usual round shape, the bars and strips 6 can be
It is possible to use a material having an appropriate cross-sectional shape such as a horizontally long or vertically long rectangle or a diamond shape as shown in FIGS. 4a to 4c. Furthermore, as shown in FIG. 4d, the bar 6 can be made into a hollow member and high-pressure air can be fed into the interior to provide the effect of removing fine ore etc. adhering to the surface of the bar 6. It is. Since the sieve is made up of the bars 6,
To remove the raw materials etc. attached to the bars and strips 6, use a brush.
This can be easily done by blowing compressed air or the like.

Furthermore, the sieves made of bars and strips 6 may be arranged in multiple stages. When adopting this multi-tiered arrangement, the top of the next tier is placed at the bottom of the first tier.
It is preferable to arrange the bars 6. As a result, the flow of the sintering raw material 1 that has passed through the lowermost stage has a uniform flow rate distribution along the width direction. Further, the number of rods 6 constituting each stage can be three or more per one mountain-shaped slope.

These rods 6 can also be arranged in an inclined state as shown in FIG. 3 by having the lower side thereof as a free end without being supported by the lower end mounting plate 7. . In this case, the angle of inclination is regulated by the attachment angle of each bar 6 with respect to the bar attachment position 4a.

FIG. 5 is a graph specifically representing the particle size distribution of the raw material layer on the pallet obtained when the sintering raw material is supplied to the pallet of the sintering machine using such a particle size segregation imparting device 5. be.

In this example, the vertical distance between the bar mounting position 4a and the lower end mounting plate 7 is 100 mm, and the first
Each bar 6a has an inclination angle of approximately 41 degrees for the fifth bar 6a to 45 degrees for the fifth bar 6e.
The angle of ~6e was set appropriately. As a result, the longitudinal distance between the bars 6a to 6e is l ₁ =50 mm, l ₂
= 40mm, l ₃ = 30mm, l ₄ = 20mm. Moreover, a steel wire with a diameter of 9 mm was used as the bar 6.

With these specifications, raw materials with a particle size of 10 mm or more are supplied to pallet 9 of the sintering machine, and a thickness of 500 mm is supplied.
A raw material layer 10 having a thickness of mm was formed. This raw material layer 10 is
Corresponding to the gaps between the bars and strips 6, the lower the layer, the greater the proportion of raw materials with larger particle sizes. That is, in FIG. 5, compared to the conventional chute method, the inclination angle of the particle size distribution in the thickness direction of the raw material layer in this example is smaller, and the raw material is distributed with excellent particle size segregation. I know that there is.

Therefore, the air permeability increases as the layer becomes lower in the raw material layer 10, and the coke ratio decreases in the lower layer due to particle size segregation. The raw material layer 10 having such particle size segregation was sintered while being sucked downward by the wind box 11. Due to the particle size segregation, the heat level in the lower layer was lowered, and the entire raw material layer 10 underwent a uniform sintering reaction, making it possible to manufacture sintered ore with a high product yield.

〔Effect of the invention〕

As explained above, in the charging method of the present invention, by supplying the sintering raw material to the pallet of the sintering machine through the bars and strips whose distance from each other increases downward, It is possible to form a raw material layer in which the particle size gradually decreases towards the end of the process.
Moreover, the upper layer is rich in carbonaceous materials such as coke. Therefore, local overheating in the lower part is avoided, the reaction during sintering is made uniform along the height direction of the raw material layer, and it becomes possible to produce sintered ore with a high yield.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the flow of the supplied sintering raw material in an embodiment of the present invention, Fig. 2 shows a lower end mounting plate indicating the lower side of the bar forming the sieve, and Fig. 3 is a diagram explaining the inclined state of the bars and the particles falling between the bars in relation to the particle size. Figure 4 shows several examples of bars and strips, and Figure 5 shows the pallet. It is a graph which shows the particle size distribution of the raw material layer formed on top.

Claims (1)

[Claims] 1. A plurality of bars and strips have one or more chevrons on the lower side, and the distance between the bars at the top of each of the chevrons is greater than the distance between the bars at the bottom. A method for charging sintering raw materials, characterized in that the sintering raw materials are supplied onto a sintering pallet through sieve surfaces formed by bars and strips arranged at different angles of inclination.