JP2018178166A - Manufacturing method of blending raw material for sinter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a blending raw material for sinter which can prevent burying of granulated charcoal wood without largely raising cost.SOLUTION: A manufacturing method of a blending raw material for sinter manufacturing the blending raw material for sinter by blending and granulating raw materials including iron-ore, auxiliary materials, charcoal wood and return fines includes a main raw material granulation step (S1) making a main raw material by blending and granulating a part of the return fines, iron-ore and auxiliary materials in the raw materials, and a rear addition step (S2) adding the remains of the return fines and all of the charcoal wood in the raw materials at the same time to the main raw material. Mass ratio of the return fines used in the rear addition step (S2) for the gross weight of the return fines contained in the blending raw material for sinter is 1/15-7/15.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method of producing a compounding material for sintering.

Raw materials for sintering include multiple types of iron ore, auxiliary materials such as limestone (CaO source) and vermiculite (SiO ₂ , MgO source), carbonaceous materials such as powdered coke, returned ore, and the like.
The raw materials for sintering are stored in the raw material tank for each grade, and are cut out quantitatively according to the composition. The cut out raw materials are joined together on a belt conveyor for raw material transfer, and are transferred to a granulator such as a drum mixer. In the granulator, water is added to the raw material for sintering to be granulated.

The raw material for sintering after granulation (hereinafter also referred to as "compounding material for sintering") is supplied from the surge hopper of the raw material charging device to the sintering machine, and is charged into the pallet to form a sintered packed bed. Do.
The sintered packed bed is transferred horizontally with the pallet and ignited at the top of the packed bed. Furthermore, the coke breeze burns by the air in the atmosphere being drawn downward through the layer from the top to the bottom of the sintered packed bed. The particles of the compounding raw material for sintering are heated and heated by the high temperature gas generated by the combustion.

  Sintering progresses from the upper layer portion to the lower layer portion of the sintered packed bed by heating and suction. The mass (hereinafter also referred to as “sinter cake”) which has been sintered to the lowermost layer is roughly crushed in a displacement portion of a sintering machine, cooled by a cooler, and sized by a sieve. The sieve is sintered ore, and the sieve is used as a return material for sintering materials.

The raw materials for sintering do not necessarily have to mix and granulate all the raw materials at the same time.
For example, in Patent Document 1, after granulating a sintering material, the water content of the granulated material is obtained by adding a return ore at a ratio of 5 to 25% by mass with respect to the sintering compound material. Techniques to reduce are described.

  Patent Document 2 describes a technology for increasing the particle diameter of granulated material by post-adding a solid fuel-based powder raw material such as powdered coke on the downstream side of a drum mixer.

  According to Patent Document 3, after the raw material for sintering is granulated, the solid carbon material particles are completely buried in the granulated product to prevent the burning rate from being reduced by adding the whole amount of the solid carbon material particles and the return ore. The technology is described.

Unexamined-Japanese-Patent No. 2009-097027 Japanese Patent Application Publication No. 2003-160815 JP, 2015-193930, A

However, the techniques described in Patent Documents 1 to 3 have the following problems.
Patent Document 1 has a problem that the carbon material is buried in the granulated material because the carbon material is added first.
When the carbon material is buried, the carbon material is difficult to contact with the air in the packed bed at the time of sintering, and there is a problem that the burning rate is reduced.

  Patent document 2 is more difficult to immerse the carbon material in the granulated material than the patent document 1 because the carbon material is post-added, but since there is no other means to prevent the burial, the combustion rate is sufficiently prevented from decreasing. There was a problem that I could not do it.

Patent Document 3 is useful in that the carbon material can be prevented from being buried by post-addition of the carbon material and the return ore.
However, in Patent Document 3, since the entire amount of the carbon material and the return ore is post-added, there is a problem that the facility for the post-addition becomes large and the cost becomes high.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method for producing a compounding material for sintering, which can prevent the carbon material from being buried during granulation without significantly increasing the cost. To aim.

  The method for producing a compounding material for sintering according to the present invention is a compounding material for sintering, which mixes and granulates materials including iron ore, auxiliary material, carbon material and return ore to produce a compounding material for sintering. In the production method, a main raw material granulating step of mixing and granulating some of the raw materials among the raw materials, iron ore, and secondary raw materials as the main raw materials; And post-addition step of simultaneously adding the whole amount of the carbonaceous material to the main raw material, and the mass of the return ore used in the post-addition step with respect to the total amount of return ore contained in the sintering compounding raw material The ratio is 1/15 to 7/15, which is a method for producing a compounding material for sintering.

According to the present invention, by simultaneously post-adding the carbon material and the return metal, the return metal prevents the contact of the carbon material with the main material at the time of dispersing the carbon material into the main material by mixing. Therefore, it is possible to prevent the carbon material from being buried in the granulated material at the time of granulation to deteriorate the burning rate.
According to the present invention, since only a part of the returned ore is post-added, the upsizing of the post-addition equipment can be prevented, and an increase in cost due to the implementation of the post-addition step can be prevented.
According to the present invention, the mass ratio of the returned ore used in the post-addition step is 1/15 to 7/15 with respect to the total amount of returned ore contained in the compounding raw material for sintering, and the returned ore comprises the carbonaceous material and the raw material Post addition of return metal in the range where the effect of preventing contact with is high.
Therefore, it is possible to prevent the burying of the carbon material during granulation without adding the entire amount of return ore.

The post-addition step is preferably a step of adding the return ore in a range of 1% by mass or more and 7% by mass or less with respect to 100% by mass of the compounding raw material for sintering.
According to the present invention, since the return metal is post-added within a range in which the return metal has a high effect of preventing the contact between the carbon material and the compounding raw material for sintering, the granulation during granulation is performed without significantly increasing the cost. It is possible to prevent the burial of the carbon material.

The graph which shows the mass ratio of the returned addition ore to add to the total amount of the returned ore contained in a raw material, and the relationship of productivity. The figure which shows the manufacturing apparatus of the mixing | blending raw material for sintering which concerns on the 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The flowchart which shows the manufacturing method of the compounding raw material for sintering which concerns on the 1st Embodiment of this invention. The figure which shows the manufacturing apparatus of the compounding raw material for sintering which concerns on the 2nd Embodiment of this invention. Graph showing the relationship between the mass ratio of the post-added return ore, the increase in productivity a, and the increase in productivity b assuming that the relationship between the post-addition amount of the ore and the productivity is linear .

(History of invention)
First, the process of creating the present invention will be briefly described.
As described in Patent Document 3, preventing the carbon material from being buried in the granulated material by post-adding the carbon material and the return ore after granulation of the other raw materials (after granulation of the main raw material) It is known that it is possible.

  On the other hand, in Patent Document 3, since the entire amount of returned ore is post-added, there is a possibility that the enlargement of equipment required for the post-addition step and cost increase may be caused. In addition, it was also unclear how much the effect of preventing the carbon material from being buried in the granulated product could be obtained by setting the post-addition amount of the return ore.

  Therefore, contrary to Patent Document 3, the present inventors perform granulation by gradually increasing the mass ratio of the post-added return metal from 0 to the total amount of return metal in the compounding raw material for sintering. The influence on sex was investigated.

  As a result, as shown in FIG. 1, it was found that the effect of improving the productivity by the addition may be greater as the proportion of the returned ore to be added is smaller.

Specifically, in FIG. 1, when the mass ratio of the post-added return ore to the total amount of ore included in the compounding raw material for sintering is 10/15 or more, as indicated by the reference line indicated by the dotted line. , The proportion of returned ore added and productivity were in a linear relationship.
On the other hand, when the mass ratio is in the range of 1/15 to 7/15, the productivity is higher than that of the reference line. This result indicates that in the range of 1/15 to 7/15 of the mass ratio, the effect of the reversion preventing the carbon material from being buried in the granulated material is higher than that in the other range.

From this result, it is possible to prevent the burial of the carbon material in the granulated material without increasing the size of the equipment required for the post-addition step if the return ore is post-added in the mass ratio range of 1/15 to 7/15. The inventors have found that it is possible to make the present invention high.
The above is the background of the invention.

  Next, a first embodiment of the present invention will be described with reference to FIGS. 2 and 3 with reference to the drawings.

  First, with reference to FIG. 2, the structure of the compounding raw material manufacturing apparatus 1 for sintering used for the manufacturing method of the compounding raw material for sintering which concerns on 1st Embodiment is demonstrated.

  As shown in FIG. 2, the sintering compound raw material manufacturing apparatus 1 includes a main granulation line 3, a post-addition line 5, and a granulated material conveyance conveyer 13.

The main granulation line 3 is a line which mixes and granulates a part of return ore, iron ore, and auxiliary materials, and is used as a main material, and is provided with a raw material tank 7, a main raw material conveyance conveyor 9, and a granulator 11.
The raw material tank 7 is a tank in which a part of returned ore, iron ore, and auxiliary materials are stored. One of the raw material tanks 7 is a raw material tank 7B in which return ore is stored.
The main raw material conveyance conveyor 9 is an apparatus for conveying the raw material cut out from the raw material tank 7 to the granulator 11, and for example, a belt conveyor is used. The main raw material transport conveyor 9 is provided below the raw material tank 7.

  The granulator 11 is an apparatus which manufactures the main raw material by adding water to the raw material cut out from the raw material tank 7, and granulating, and a drum mixer is used, for example.

The post addition line 5 is a line for mixing and granulating the remaining portion of the return ore (return ore not granulated in the main granulation line 3) and the carbonaceous material and post-adding them to the main raw material. An additive material transport conveyor 19 is provided.
The raw material tank 15 is a tank in which a carbon material is stored. The raw material tank 17 is a tank in which return ore is stored.
The post-addition raw material conveyance conveyor 19 is a device for conveying the carbon material and return metal cut out from the raw material tanks 15 and 17 to the granulated material conveyance conveyor 13, and for example, a belt conveyor is used. The post-addition raw material transfer conveyor 19 is provided above the granulated material transfer conveyor 13.

The granulated material transport conveyor 13 is a device for transporting the main raw material granulated by the granulator 11 and the post-added compounded raw material to the sintering machine, and for example, a belt conveyor is used. The granulated material transfer conveyor 13 is provided at the downstream end of the granulator 11 such that the upstream end is disposed in the granulator 11.
The above is description of a structure of the compounding raw material manufacturing apparatus 1 for sintering.

  Next, a method of producing the compounded raw material for sintering using the compounded raw material manufacturing apparatus 1 for sintering will be described with reference to FIGS. 2 and 3.

First, the main granulation line 3 is used to mix and granulate iron ore, auxiliary materials, and raw materials including a part of returned ore to produce a main raw material (S1 in FIG. 3, main raw material granulation step).
Specifically, first, a raw material including iron ore, a secondary raw material, and a part of return ore is cut out from the raw material tank 7 and conveyed to the granulator 11 by the main raw material conveyance conveyor 9.

  Next, water is added to the raw material in the granulator 11 to mix and granulate. The granulated material (main raw material) is mounted on a granulated material conveying conveyor 13.

Next, the post-addition line 5 is used to simultaneously add the remainder of the return and the entire amount of carbonaceous material to the main raw material (S2, post-addition step in FIG. 3).
Specifically, first, the carbon material and the return ore are cut out from the raw material tanks 15 and 17 and mounted on the post-added raw material conveyance conveyor 19.
The post addition line 5 does not necessarily have to be provided with a mixer or the like for mixing the carbon material and the return ore. Charcoal material and return ore are naturally mixed on the granulated material conveyance conveyer 13 at the time of conveyance, in the surge hopper (not shown) of the sintering machine (not shown) and on the sloping shoot (not shown). It is enough.

Next, the carbon material and the returned ore are conveyed to the granulated material conveying conveyor 13 by the post-addition raw material conveying conveyor 19 and simultaneously post-added to the main raw material on the granulated material conveying conveyor 13.
At this time, since the returning ore prevents the contact between the carbon material and the main raw material, the carbon material is prevented from being buried in the main raw material.

  The position of the post-addition on the post-addition raw material transport conveyor 19 is not particularly limited. As shown by the symbol A in FIG. 2, the upstream end of the post-addition raw material transport conveyor 19 (inside the granulator 11) may be used. As indicated by the symbol B, it may be downstream.

  The addition on the upstream side is advantageous in that the carbonaceous material can be mixed more uniformly. The addition to the downstream side is advantageous in that the carbon material is less likely to be buried in the granulated material.

  The amount of carbon material to be added is preferably the total amount of carbon material in the compounding raw material for sintering. This is because the larger the post-addition ratio of the carbonaceous material, the more difficult it is to be buried in the granulated material, and the productivity is improved.

The mass ratio of the post-added return ore to the total amount of return ore contained in the sintering compounding raw material is in the range of 1/15 to 7/15. For example, when the proportion of returned ore in the compounding raw material for sintering is 15% by mass, the proportion of returned ore to be added is 1% by mass or more and 7% by mass or less with respect to 100% by mass of the compounding raw material for sintering Become.
This is because the effect of the return is high for preventing the carbon material from being buried in the granulated material, as compared to other ranges. If the post-addition return falls outside the lower limit of this range, the post-addition effect may not be sufficiently obtained. When the post-added return metal is out of the upper limit of this range, the anti-burring effect is saturated.

The compounding raw material for sintering to which the carbon material and the return ore have been added is sent to a sintering machine using the granulated material conveying conveyor 13 and subjected to sintering.
The above is description of the manufacturing method of the compounding raw material for sintering using the compounding raw material manufacturing apparatus 1 for sintering.

As described above, according to the first embodiment, the main raw material is manufactured by mixing and granulating the raw material including iron ore, auxiliary raw material, and return ore, and the remaining portion of the return or main carbon material is simultaneously mainly Add to raw materials.
Therefore, the effect of preventing the carbon material from being buried in the granulated material can be enhanced.

Further, according to the first embodiment, the mass ratio of the post-added returned ore to the total amount of returned ore contained in the compounding raw material for sintering is in the range of 1/15 to 7/15, and Returning ore is post-added within a range where the returning ore is highly effective in preventing contact with the main raw material.
Therefore, even if it does not add the whole amount of return ore, a burial prevention effect is obtained and it is possible to prevent burial of the carbon material during granulation without significantly increasing the cost.

Next, a second embodiment will be described with reference to FIG.
In the second embodiment, the raw material tanks 15 and 17 are not provided in the post-addition line 5 in the first embodiment.
In the second embodiment, elements having the same functions as in the first embodiment are given the same reference numerals, and portions different from the first embodiment will be mainly described.

As shown in FIG. 4, the raw material tank 15, 17 is provided in the main granulation line 3 as a part of the raw material tank 7, as the sintering compound raw material production apparatus 1 </ b> A according to the second embodiment.
A removal device 23 is provided in the raw material tank 15, and the cut-out carbon material is conveyed to the post-addition raw material conveyance conveyor 19 without being mounted on the main raw material conveyance conveyor 9.
A distributor 21 is provided in the raw material tank 17, and a part of the returned ore is distributed to the main raw material conveyance conveyor 9, and the remaining is distributed to the post-addition raw material conveyance conveyor 19.

As described above, it is not necessary to provide the raw material tanks 15 and 17 in the post addition line 5, and a part of the return metal and the carbonaceous material are extracted from the raw material tank 7 of the main granulation line 3 and supplied to the post addition line 5. May be
With such a structure, even if the existing raw material tank 7 is used as it is, it is possible to post-add a part of the return metal and the carbon material.
In addition, since the manufacturing method of the compounding raw material for sintering using the compounding raw material manufacturing apparatus 1A for sintering is the same as that of 1st Embodiment, description is abbreviate | omitted.

As described above, according to the second embodiment, the main raw material is manufactured by mixing and granulating the raw materials including iron ore, auxiliary raw material, and return ore, and the balance of the return or mineral and the entire amount of carbon material are simultaneously main Add to raw materials.
Therefore, the same effect as that of the first embodiment can be obtained.

Hereinafter, the present invention will be specifically described based on examples.
The proportion of post-added returned ore was changed to produce and sinter a mixed material for sintering, and the influence on productivity was evaluated. The specific procedure is as follows.

First, a pot test apparatus was prepared as a sintering machine.
Next, about 1.5 kg of bedbed was placed in a test pot (inner diameter 300 mm, height 660 mm) of the pot test apparatus. Next, about 70 kg of compounding materials for sintering having the compounding ratio shown in Table 1 were prepared.

Next, the remaining raw materials from which the post-addition planned raw materials have been removed are mixed and granulated for 285 seconds using a drum-like mixer to obtain a main raw material. Thereafter, the whole amount of coke breeze and a part of returned ore are added to the main raw material as a post-addition raw material, and mixed for 15 seconds to obtain a compounding raw material for sintering.
Next, the compounding raw material for sintering is put into a test pan, and after igniting the surface of the packed bed with a burner by heating for 90 seconds, air in the test pan under a suction negative pressure of 14.7 kPa (1500 mmAq is converted to kPa) Was aspirated. Thereby, sintering was advanced from the upper layer to the lower layer of the compounding raw material for sintering to produce a sintered cake.

Next, the sintered cake was dropped 5 times from a height of 2 m, and then sintered ore having a particle size of 5 mm or more was sieved and weighed as a product. Furthermore, based on the mass of the product, the sintering time, and the sintering area (area of the ignition surface of the packed bed), the unit sintering time, the tonnage of the product per unit sintering area can be produced (t / d / Calculated as m ² ).
The above tests were carried out by changing the proportion of post-added returned ore in the range of 0 to 15% by mass. The results are shown in FIG.

As shown in FIG. 1, the productivity was improved as the proportion of the post-added return metal increased.
However, when the addition amount is 10% by mass or more, as shown by the dotted line in FIG. 1, the relationship between the ratio of returned ore to be added and productivity is linear, but 1% by mass or more and 7% by mass In the following cases, no linear relationship was found. Moreover, in the case of 1 mass% or more and 7 mass% or less, it turned out that productivity is higher than a dotted line, and the effect by addition of return ore is high.

Therefore, in order to examine the effect of the addition of the return metal in more detail, the relationship between the mass ratio of the return metal to be added and the increase amount of productivity a, and the effect of improving the productivity by adding the return metal , And the relationship with the increase amount b when assuming linear.
Here, the amount of increase a is the difference between the obtained productivity and the productivity when the post-addition return ore is 0%. The amount of increase b is assumed that the relationship between the mass ratio of the post-added return ore and the production can be represented by a straight line passing through the measurement point (linear) at 0% and 15% return ore. It is the difference between the productivity in the case of having been done and the productivity in the case of 0% of the return added to be added. If the increase amount a is larger than the increase amount b, it means that the effect of the addition of the return metal is high. Conversely, when the increase amount a is less than the increase amount b, it means that the effect of the addition of return ore is low.
The results are shown in Table 2. The relationship between the mass ratio of returned ore to be added and the increase amounts a and b is shown in FIG.

As shown in Table 1 and FIG. 5, when the addition amount of return ore was 1 mass% or more and 7 mass% or less, the increase amount a was larger than the increase amount b.
From this result, when the addition amount of return ore is 1 mass% or more and 7 mass% or less, the improvement effect of the productivity by the addition of the return ore compared with the case of 10 mass% or more (a-b in Table 2) ") Was found to be high.

  DESCRIPTION OF SYMBOLS 1, 1A ... Compounding raw material manufacturing apparatus for sintering, 3 ... Main granulation line, 5 ... Post addition line, 7, 7B ... Raw material tank, 9 ... Main raw material conveyance conveyor, 11 ... Granulating machine, 13 ... Granulation thing Conveying conveyor, 15, 17 ... Raw material tank, 19 ... Post-added raw material conveying conveyor.

Claims (2)

A method for producing a compounding material for sintering, which comprises mixing and granulating materials including iron ore, auxiliary material, carbon material and return ore to produce a compounding material for sintering,
Main raw material granulation process which mixes and granulates a part of returned ore among said raw materials, iron ore, and auxiliary materials as main raw materials,
A post-addition step of simultaneously adding the remainder of the return from the raw material and the entire amount of the carbonaceous material to the main raw material;
To carry out
The mass ratio of the returned ore used in the post-addition step is 1/15 to 7/15 with respect to the total amount of the returned ore contained in the sinter compounded material Method. It is a manufacturing method of the compounding materials for sintering according to claim 1,
The post-addition step is a step of adding the return ore in a range of 1% by mass or more and 7% by mass or less based on 100% by mass of the compounding raw material for sintering Manufacturing method.

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