JPH0332610B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for charging sintering raw materials into a DL type sintering machine.

[Conventional technology]

As is well known, in a DL type sintering machine (hereinafter simply referred to as a sintering machine), bedding ore is charged onto pallets arranged in an endless chain, and sintering raw materials are placed on top of the pallets in a layered manner. entered. The upper layer of the charged sintering raw material is ignited in an ignition furnace, and as the pallet progresses, it is sequentially fired from the upper layer to the lower layer, and is discharged from the ore discharge section to subsequent equipment as sintered ore.

As disclosed in Japanese Patent Publication No. 53-34082, the charging of raw materials onto the pallet is usually carried out by storing bedding ore and other sintering raw materials in dedicated hoppers provided above the pallet. and was supplied to the pallet from this dedicated hopper. Furthermore, since it is necessary to widely control the amount of sintering raw material supplied, a drum feeder is provided between the hopper and the pallet to charge the raw material into the pallet.

By the way, in the above-mentioned sintering process, it is important to control the sintering in the layer height direction by promoting sintering in the upper layer and suppressing excessive melting in the lower layer in order to make the quality of the sintered ore uniform. be. Therefore, in the layer of sintered raw material charged to the pallet (hereinafter referred to as raw material layer), the blending ratio of coke powder and fine grains or fine grain raw material increases as the layer goes up, and conversely, the ratio of coke powder and fine grains increases as it goes to the bottom. It is known that it is necessary to reduce the blending ratio of powder and increase the proportion of coarse particles, which is called particle size segregation. In order to obtain this particle size segregation, many charging methods and means have been proposed and attempts have been made to put them into practical use. For example, Tokukai Akira
In JP 48-48303, high-pressure gas is blown from a gas injection header installed at the bottom of the drum feeder to deposit coke or powder ore with low specific gravity in the sintering raw material on the upper part of the raw material layer, and to deposit coke in the lower layer. A charging method has been proposed in which the amount of coarse ore is increased and the amount of coarse ore is increased. Furthermore, Japanese Utility Model Publication No. 52-21682 proposes a method in which a plow rod is arranged between the drum feeder and the pallet to adjust the charging density of the raw material layer.

Further, as mentioned above, the bottom layer of the pallet contains, for example, the aforementioned Japanese Patent Publication No. 53-34082 and 97 of the Iron Ore Handbook.
~ As disclosed on page 117, the palette contains
Bed ore of about 20 to 30 mm is formed. This bedding ore is formed to prevent sintering raw materials from falling through the gaps between the grade bars laid on the bottom of the pallet, and to protect the grade bars from the high heat of the firing process. It was common to return a portion of the produced sintered ore for use. As mentioned above, this bedding ore is formed by directly charging the sintered ore stored in a dedicated hopper separate from the sintering raw material onto a pallet, and the above-mentioned method is applied on top of this bedding ore. Alternatively, the sintering raw material was charged by other means.

[Problem that the invention seeks to solve]

By the way, in the conventional charging method of sintering raw materials,
In order to form the bedding layer, dedicated conveyance equipment, hoppers, cutting equipment, etc. are required, and the equipment and maintenance costs are high. In addition, the use of sintered ore as a raw material for bedding has led to a decline in the product yield of the manufactured sintered ore.

The present invention is an attempt to fundamentally solve the above-mentioned conventional problems, and provides a charging method that eliminates the need for equipment dedicated to bedding and that accurately produces the required particle size segregation.

[Means for solving problems]

To solve the above problems, the present invention provides a raw material charging method for a sintering machine in which the sintering raw material stored in a hopper is charged onto a pallet via a drum feeder. Coarse grain iron ore with a particle size of 8 to 30 mm is added and mixed in advance at a weight ratio of 2 to 10%, and a classification and feeding device is installed directly below the drum feeder, and this classification and feeding device performs sieving. The method is characterized in that the coarse-grained iron ore is charged into the lowest layer of the pallet.

Further, as the classification supply device, a group of inclined slit bars are arranged at predetermined intervals in the width direction of the pallet,
This apparatus is characterized in that the slit bars are attached to the rear end located in the pallet advancing direction at approximately the same level, and the tips of the slit bars are at a lower level than the rear end and are successively different in level.

Next, a specific configuration of the present invention will be explained based on FIG.

In the figure, 1 is a pallet, 2 is a hopper, and 3 is a sintering raw material. 4 is a drum feeder for cutting out the sintering raw material 3 stored in the hopper 2 and charging it into the pallet 1. A classification supply device 5 is disposed directly below the drum feeder 4.

Sintering raw material 3 is mixed raw materials such as powdered iron ore, auxiliary raw materials, coke, and return ore, and further has a particle size of 8 to 25 mm.
Coarse-grained iron ore such as pellets, iron ore, and sintered ore3
a is added and mixed in advance. This coarse iron ore 3
The means for adding and mixing a may be, for example, cutting out a predetermined amount of coarse iron ore 3a stored in a storage tank together with the raw materials and mixing it with a well-known drum mixer, or at the stockpiling stage in a raw material yard. This may be done by means of blending. The proportion of coarse iron ore 3a in the entire sintering raw material 3 is adjusted to 2 to 10% by weight for reasons described later.

As long as the classification and supply device 5 is capable of classifying the raw materials described later and smoothly charging the raw materials onto the pallet 1, for example, as shown in FIG. A multistage sieving machine arranged at predetermined intervals, or a vibrating sieving machine using a well-known woven mesh, although not shown, may be used as appropriate. 5b in FIG. 1 is the classification supply device 5.
This is a vibration device.

2 and 3 show another example based on the present invention, in which reference numeral 50 denotes a classifying and feeding device comprising a group of inclined slit bars in which a plurality of slit bars 51 are arranged in the width direction x of the pallet 1. The slit bar 51 is a rod-shaped body having a round or square cross section and is formed to have a predetermined length. This slit bar 51 has a predetermined interval in the width direction x of the pallet 1,
An appropriate number of them are arranged substantially parallel to the direction in which the pallet 1 travels. Rear end 51b of slit bar 51
(In the present invention, the end located in the traveling direction with respect to the traveling direction y of the pallet 1 is referred to as the rear end 51b,
The end located in the opposite direction of travel is referred to as the tip 51a)
are fixed at almost the same level in the width direction x, and the tip 5
1a is configured to be at a lower level than the rear end 51b, so that each slit bar 51 has a downward slope. Also, the tip 51a is the third
As shown in the figure, the slit bars 51 are arranged so as to be sequentially arranged at different levels from the adjacent slit bars 51, and the classification supply device 50 is
is configured. The rear end 51b of the slit bar 51 in FIGS. 2 and 3 is fixed to the lower end of the slopping chute 6, so that it is substantially level in the width direction x. Also, the tip 51a
is held via a fixture 54 to a holding member 53 which is stretched horizontally on a support member 52 suspended from the slopping chute 6.

Note that the rear end 51b of the slit bar 51 may be fixed, for example, to the midsection of the surface of the slopping chute 6 (on the sliding surface side of the raw material), or may be used to support the slit bar without providing the sloping chute 6. It is also possible to arrange a supporting metal fitting such that the raw material from the drum feeder 4 falls directly onto the group of slit bars 51. In this case, the slit bar 51
There is no problem even if a slight level difference occurs at the rear end 51b.

As described above, in the present invention, the classification supply devices 5 and 50 are arranged directly below the drum feeder 4, and the sintering raw material 3 falling from the drum feeder 4 and being supplied onto the pallet 1 is transported to the classification supply device 5, 50. This method is characterized in that coarse-grained iron ore 3a is charged into the lowest layer of pallet 1 through a sieving action of 500 ml. The classification supply devices 5 and 50 may be disposed directly below the drum feeder 4 as described above, or may be disposed via the slopping chute 6.

[Effect]

In the present invention, 2 to 10% by weight of coarse iron ore 3a having a particle size of 8 to 30 mm is added and mixed in advance to the normal sintering raw material 3. Since the coarse iron ore 3a functions as a bedding ore, its particle size must be in the range of 8 to 30 mm. That is, the spacing between the grate bars 10 attached to the bottom of the pallet 1 is usually around 5 mm, and when this reaches 8 mm, it is common to replace them to maintain the above-mentioned spacing. Therefore, unless the coarse iron ore 3a has a particle size of at least 8 mm or more, preferably 10 mm or more, it will fall from the above-mentioned interval and will not function as bedding ore. On the other hand, ore used in blast furnaces is sized to a particle size of 30 mm or less in order to stabilize operations. Since the coarse iron ore 3a in the present invention is supplied to the blast furnace together with the sintered ore, its particle size is
If it exceeds 30 mm, special crushing means will be required and production efficiency will decrease. Therefore, in order to effectively perform its function as bedding ore and not cause a decrease in production efficiency, the particle size of the coarse iron ore 3a must be within the range of 8 to 30 mm.

If the blending ratio of the coarse iron ore 3a is less than 2%, the layer thickness within the pallet 1 will become thinner, making it impossible to protect the above-mentioned great bars 10. On the other hand, if the blending ratio becomes too high, the amount of other sintering raw materials charged will decrease, resulting in a decrease in the production efficiency of sintered ore. In the experience of the present inventors, approximately 30% was possible from the balance of sintering production capacity, but 10% was almost the upper limit due to the overall economic efficiency of sintering and blast furnace. This is the reason why, in the present invention, the blending ratio of coarse iron ore 3a is limited to a range of 2 to 10%.

As described above, the coarse-grained iron ore 3a as bedding ore can be used as it is as a blast furnace raw material together with sintered ore, so it can be used as pellets, iron ore,
This also has the side effect of simplifying transportation routes. Of course, sintered ore is used as coarse iron ore 3a.
It is also possible to use it as a material, and it may be arbitrarily selected depending on the supply status and stockpiling status of various raw materials. The term "coarse iron ore" used in the present invention collectively refers to pellets, iron ore, and sintered ore, which are appropriately selected and used based on the above-mentioned circumstances.

The sintered raw material 3 containing the coarse iron ore 3a is cut out from the hopper 2 by the drum feeder 4, as shown in FIGS. 1.
Therefore, the coarse iron ore 3a passes through the sieve mesh 5 of the classification supply device 5.
Most of them are loaded onto the pallet 1 from the tip in the opposite direction of travel without falling from the pallet 5. For this purpose, the coarse iron ore 3a is deposited at the bottom layer of the pallet 1, forming a bedding layer 30. Fine or fine grain raw materials other than the coarse iron ore 3a fall sequentially through the sieve mesh 55 and are charged onto the bedding layer 30. By configuring the opening degree of the sieve mesh 30 to increase toward the tip, particle size segregation, in which the particle size of the raw material gradually increases from the upper layer to the lower layer of the raw material layer, can be effectively prevented. It becomes possible to cause this to occur.

In particular, in the classification and supply device 50 consisting of a group of slit bars shown in FIGS. 2 and 3, the tip 51a of the slit bar 51 is inclined and arranged at a lower position than the rear end 51b, and there is a step at the tip. Since it is provided, rolling of the raw material is promoted. At this time, most of the fine particles in the raw material fall downward from the gaps between the adjacent slit bars 51, that is, from the sieve mesh 55, but the coarser the particles, the more they roll between the slit bars 51 and the tip of the inclined slit bars 51, that is, the lower position. Since the raw material layer after charging has a low density and the upper layer is filled with fine particles and the lower layer is filled with coarse particles, a modern packed bed is obtained. .

〔Example〕

The present invention was carried out using a sintering machine with a daily production capacity of 5,500 tons.

In this embodiment, the classification supply device 50 consisting of the slit bar group shown in FIGS. 2 and 3 is used,
As shown in FIGS. 4a and 4b, the interval in the width direction of the slit bars 51 is 3 mm, the angle of the difference in level between the slit bars 51 is 0.85°, and the level difference in the tip portion 51 is 32 mm.
And so.

The sintering raw material has an average particle size of 12.5 mm, and 93% is over 10 mm.
Savage River pellets with a particle size distribution of 4
% added and mixed. This sintered raw material was dropped into the classification supply device 50 via the drum feeder 4 and the slopping chute 6, and was supplied onto the pallet 1 while being sieved by the classification supply device 50. FIG. 5 shows an example of the results of investigating the particle size distribution of the raw material layer on the pallet 1 after charging using the above charging method. FIG. 5b is a diagram showing the average grain size in the layer height direction of the raw material layers excluding the bottom layer. As can be seen from Figure 5, the bottom layer contains approximately 93% coarse grains larger than 10 mm, which fully functions as a bedding layer, and in the upper layer, the grain size increases from top to bottom. It was confirmed that grain size segregation occurred.

〔Effect of the invention〕

As explained above, in the present invention, coarse iron ore with a particle size of 8 to 30 mm is added to the sintering raw material at a weight ratio of 2 to 10 mm.
Coarse grained iron ore is charged into the bottom layer of the pallet to form a bedding layer by adding and mixing this mixed sintering raw material through the sieving action of a classification and feeding device. There is no need for dedicated conveyance equipment, hoppers, cut-out equipment, etc. for the bed layer, which simplifies the equipment and significantly reduces equipment costs and costs required for maintenance management. In addition, coarse-grained iron ore as bedding ore can be used as is as a blast furnace raw material together with sintered ore, making it possible to effectively utilize pellets, iron ore, etc. Furthermore, the product yield of sintered ore is greatly improved, and uneven You can get a good quality product without any problems.

[Brief explanation of the drawing]

1 to 5 show examples of the present invention, FIGS. 1 and 2 are longitudinal cross-sectional views showing the structure of the raw material charging section, FIG. 3 is a cross-sectional view of FIG. 2, FIG. 4 shows the arrangement of the slit bars in a specific example, in which FIG. 4a is a longitudinal sectional view, FIG. 4b is a horizontal sectional view, and FIG.
FIG. 5 shows an example of the results of investigating the effects of the charging method of the present invention.
FIG. 5b shows the average particle size in the layer height direction of the raw material layer excluding the bottom layer. 1...Pallet, 2...Hopper, 3...Sintering raw material, 4...Drum feeder, 5, 50...Classification supply device, 6...Slopping chute, 10
...Great bar, 51...Slit bar, 51
a... Tip of the slit bar, 51b... Rear end of the slit bar.

Claims (1)

[Claims] 1. Sintering raw material stored in a hopper is charged onto a pallet via a drum feeder.
In the raw material charging method for a DL type sintering machine, 2 to 10% by weight of coarse iron ore with a particle size of 8 to 30 mm is added and mixed into the sintering raw material in advance, and the iron ore is added directly below the drum feeder. A method for charging sintering raw materials, characterized in that a classification and supply device is disposed in the pallet, and the coarse iron ore is charged into the lowest layer of the pallet by the sieving action of the classification and supply device. 2 A group of inclined slit bars are arranged at predetermined intervals in the width direction of the pallet, and the slit bars at the rear end located in the pallet advancing direction are installed at almost the same level, and the tips of the slit bars are installed at a lower level than the rear end and sequentially at different levels. A method for charging a sintering raw material according to claim 1, using a classification and feeding device.