JP2016089268A - Method for operating sintering machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for operating a sintering machine where, when sintering blending raw material containing magnetized fine powder raw material, the permeability of a sintering raw material charging layer is made satisfactory, and the improvement of sinterability can be attained.SOLUTION: In the method for operating a sintering machine where a sintering blending raw material is charged to the surface of the pallet of the sintering machine via a chute whose back side is provided with a magnet, and sintering is performed, when the magnetized fine powder raw material in the sintering blending raw material is charged to the surface of the pallet, in which the velocity upon zero of the velocity of the sintering blending raw material when magnetic force is not applied to the surface of the chute is defined as ν, in such a manner that the velocity ν of the magnetized fine powder raw material at the lower edge part of the chute is controlled to the one of 1/5ν1 to 4/5ν1, the magnetic force Fof the magnet is controlled.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a method for operating a sintering machine, which is characterized by a method for charging a sintering compound raw material. In particular, in the present invention, a sintered blending raw material containing magnetite fine iron ore, which is easier to magnetize than ordinary sintering raw materials, and a magnetic fine powder raw material, such as sintered ore, is mounted on a pallet of a sintering machine. We propose a method of operating a sintering machine that enters and sinters.

  As shown in Fig. 1, the sintered ore that is the main raw material of the blast furnace ironmaking method is iron ore powder, recovered powder in the steelworks such as mill scale and iron making dust, sinter ore sieving powder (sintered ore) Sintered blended raw materials such as CaO-containing raw materials such as limestone and dolomite, granulating aids such as quick lime, powdered coke, and charcoal (solid fuel) such as anthracite are placed on the pallet of the DL sintering machine. Manufactured by charging and sintering. As the sintered blending raw material, a mixture of a plurality of kinds of sintered raw material powders using a drum mixer or the like and subsequent granulation are used to obtain pseudo particles having an arithmetic average diameter of 6.0 mm or less. The raw material for sinter production obtained in this way, that is, the sintered blending raw material is charged on the pallet of the sintering machine to form a sintered raw material charging layer, also called a charging layer. It becomes the raw material of.

  In general, the thickness (height) of the sintered raw material charging layer is about 400 to 800 mm. The sintered raw material charging layer is then ignited by the carbonaceous material contained in the sintered raw material charging layer in an ignition furnace installed above the pallet, and disposed below the pallet. By sucking the air in the sintering raw material charging layer downward through the wind box, the carbonaceous material in the sintering raw material charging layer is sequentially burned, and the combustion is matched to the movement of the pallet. It gradually advances downward and forward, and the sintering blended raw material is melted and converted into a sintered cake by the combustion heat generated at this time. Thereafter, the obtained sintered cake is cooled by a cooler after crushing, and sized, and becomes a product sintered ore made of agglomerates having a predetermined particle size (for example, 5.0 mm or more).

The production amount of sintered ore is generally determined by the sintering production rate (t / hr · m ² ) × sintering machine area (m ² ). However, the production amount of sintered ore is the width and length of the sintering machine, the thickness of the raw material deposition layer (thickness of the sintering raw material layer), the bulk density of the sintering compound raw material, the sintering (combustion) time, It changes depending on the yield. And in order to increase the production amount of this sintered ore, the air permeability (pressure loss) of the sintering raw material charging layer is improved to shorten the sintering time, or the coldness of the sintered cake before crushing is reduced. It is effective to improve the yield by increasing the strength.

In recent years, as for iron ore powder blended in the sintered blending raw material, gangue components such as A1 ₂ O ₃ and SiO ₂ increase, while the Fe content tends to decrease. For this reason, the amount of slag generated in the blast furnace and converter is increased, and this slag treatment is a heavy burden. On the other hand, so-called attachment such as magnetite-type fine iron ore, mill scale, and iron-making dust, which has been conventionally used as a raw material for sintering, has a high iron content (FeO) and a large amount of fine powder (-250 μm). The use of what is called a magnetic fine powder raw material is attracting attention.

  Table 1 shows the chemical composition and average particle diameter of general iron ores A and B and magnetized fine powder raw materials such as magnetite fine iron ore, sintered ore, mill scale, and iron dust (blast furnace dust, steel dust, etc.). An example is shown. The feature of these magnetized fine powder materials is that they usually contain more iron (FeO) than fine iron ore. However, as shown in FIG. 2, the particle size of the magnetized fine powder raw material such as magnetite-based fine iron ore and iron dust is not as large as that of the pellet feed, but is finer than that of ordinary powdered iron ore for sintering, The air permeability in the sintering process is likely to deteriorate, which may reduce the productivity of the sintered ore.

  When using a fine powder raw material as a sintering raw material, conventionally, efforts have been made to effectively use a general fine iron ore. For example, in Patent Document 1, by adjusting the ratio of the fine iron ore and the core fine iron ore as described above at the blending stage, it is possible to obtain pseudo particles in which the fine ore is efficiently attached around the core. Have proposed a method of improving the granulation properties of the raw materials and suppressing the deterioration of air permeability.

  Furthermore, Patent Document 2 proposes a technique for producing a sintered blending raw material in which, when fine ore is used, it is pulverized and stirred in a separate line, and a granulated property is improved by mixing a binder. Has been.

JP 2008-101263 A JP 2007-77512 A

  As described above, in the prior art, when finely divided iron ore or the like is used as a constituent component of a sintered blending raw material, it has been studied to improve granulation properties first. For example, in the method of Patent Document 1, when the content of the gangue component of fine ore or the amount of fine ore used increases further in the future, it becomes impossible to match the ratio of core particles to fine powder to form pseudo particles, There is a risk that the ratio of the core ore becomes the rate-limiting factor for productivity. Moreover, in patent document 2, since magnetite type | system | group fine iron ore is not so small as a pellet feed, it becomes necessary to grind this newly, and the subject that the use of a binder etc. is needed, and cost becomes high. Is left.

  Accordingly, an object of the present invention is to improve the sinterability by improving the air permeability of the sintered raw material charging layer when sintering the sintered blend raw material containing the magnetic fine powder raw material. It is to propose a method of operating the machine.

The present invention has been developed in order to solve the above-mentioned problems when using a sintered blending raw material containing a large amount of magnetic fine powder raw materials that cause deterioration of the air permeability of the sintered raw material charging layer. That is, the present invention relates to a sintering machine operating method in which a sintering compound raw material is charged and sintered on a pallet of a sintering machine through a chute having a magnet disposed on the back surface. The blended raw material has 5 to 30 mass% of the raw material, the FeO content is 4.5 mass% or more, and the particle size has an arithmetic average diameter of 0.2 to 2.5 mm. Is a magnetized fine powder material in which the amount of fine powder of 250 μm or less is 60 mass% or less by weight, and when this magnetized fine powder material is charged onto a pallet, a magnetic force (F _M ) is applied to the chute. When the speed of the sintered blending raw material at the lower end of the chute when no (F _M = 0) is v ₁ , the speed v _{m of the} magnetic fine powder raw material at the lower end of the chute is 1/5 v ₁ to 4 / 5ν and so that the speed of _1, adjust the magnetic force F _M of the magnet A operation method of sintering machine, wherein Rukoto.

In the operation method of the sintering machine according to the present invention,
(1) The amount of fine powder of 250 μm or less is 5 mass% or more by weight,
(2) The velocity ν _m of the magnetized fine powder raw material at the lower end of the chute is 2 / 5ν _{1 to} 3 / 5ν ₁ ,
(3) speed [nu _m of the deposition magnetic fine material in the chute lower end, be adjusted by the magnetic force _{F M} of the magnet within the 0.0004～0.01N,
(4) the magnetic force F _M of the magnet, it is a numerical value determined by the following equation,
(5) At least 5 to 15 mass% of the raw material for magnetized fine powder is sintered ore, and the remainder is one or more of magnetite fine iron ore, mill scale, and iron-making dust. Consist of,
Is a more preferable configuration.

  According to the method of operating a sintering machine according to the present invention, when a sintered blending raw material containing a magnetized fine powder raw material is charged onto a pallet of a sintering machine using a chute having magnets arranged on the back, the sintering is performed. Since the magnetic fine powder raw material of the blended raw material can be selectively deposited (segregation charged) on the upper portion of the sintering raw material charging layer, the air permeability of the sintering raw material charging layer It becomes possible to suppress the deterioration of. As a result, it is possible to improve quality such as production rate, yield, and cold strength in the production of sintered ore.

It is a schematic diagram explaining DL sintering process. It is a figure which shows particle size distribution, such as a magnetic fine powder raw material. It is a figure which shows distribution of the temperature and pressure in a sintering raw material charge layer. It is a figure of the temperature distribution and yield distribution in the sintering raw material charge layer in a sintering machine. It is a schematic diagram which shows the state by which a magnetic fine powder raw material is partly charged by the upper layer part of a sintering raw material charging layer. It is a schematic diagram explaining the movement of the particle | grains on a chute | shoot. It is a figure which shows the deposition condition when changing the magnetic force (F _M : 0.01N) and charging the magnetic fine powder raw material. It is a figure which shows the deposition condition when changing the magnetic force (F _M : more than 0.01N) and charging the magnetic fine powder raw material. It is a figure which shows the deposition condition when changing magnetic force (F _M : 0.004N) and charging a magnetic fine powder raw material. It is a figure which shows the deposition condition when changing a magnetic force (F _M : 0N) and charging a magnetic fine powder raw material. It is a basic diagram of the charging machine used with the test apparatus. It is a figure which shows the deposition result of the magnetic fine powder raw material when it inserts using a test apparatus. It is a figure which shows the relationship between the compounding rate of a magnetic fine powder raw material, and a production rate.

  As shown in FIG. 3, the pressure loss in the sintered raw material charging layer deposited on the pallet is burned in the region where the loaded wet raw material is deposited (wet zone) and carbonaceous materials such as powdered coke. It occurs in the region where the sintering reaction of the sintering compound raw material is proceeding (reaction / melting zone), and in the region where the sintered ore exists after the sintering reaction is completed (sintering zone) It is known that there is not much loss. In order to improve the sinterability, it is important to reduce the pressure loss as a whole and improve the air permeability in the entire raw material charging layer.

  Therefore, in the present invention, when the sintered blending raw material includes a magnetic fine powder raw material such as magnetite-based fine iron ore that deteriorates air permeability due to a large amount of fine powder component, the magnetic fine powder raw material is intentionally In addition, the sintering reaction can be completed early by depositing it on the upper part of the sintering raw material charging layer (segregation charging), and the deterioration of air permeability when a large amount of magnetic fine powder raw material is blended is minimized. Thus, the above problems were solved.

  Such an idea of the present invention can be understood from FIG. That is, FIG. 4 (a) shows the sintering process of the sintered blending raw material in the sintering raw material charging layer (hereinafter also simply referred to as “charging layer”) on the sintering machine pallet. b) shows the temperature distribution (heat pattern) in the sintering process in the charging layer, and FIG. 4 (c) shows the yield distribution of the sintered cake. As can be seen from FIG. 4 (b), the temperature of the upper layer portion of the charge layer of the sintered blending raw material is less likely to rise than the lower layer portion, and the high temperature region holding time tends to be relatively short. Therefore, in the upper layer portion of this charging layer, the combustion and melting reaction (sintering reaction) becomes insufficient, and the strength of the sintered cake is lowered. Therefore, as shown in FIG. This is a factor causing a decrease in productivity.

  According to the research of the inventors, for this problem, a raw material (magnetized fine powder raw material) containing a larger amount of easily magnetized components such as FeO and fine powder in the sintered mixed raw material is blended. It has been found that this can be solved by performing so-called segregation charging, in which this raw material is selectively deposited on the upper layer of the charging layer when charging it onto the pallet. In general (Trans. AIME 218 (1960), 116), in the phase diagram showing the influence of components in the sintering reaction, the melting point (liquidus temperature) that generates a melt necessary for the sintering reaction as the FeO content increases. ) Is known to decrease. Therefore, if the upper part of the sintered raw material charging layer is segregated and charged with a magnetic fine powder material such as magnetite fine iron ore containing a large amount of FeO, the upper layer part is in a situation where the temperature is difficult to rise. Sintering reaction is promoted, and yield and strength can be improved.

  In addition, the charging layer, which is a deposited layer of the sintered compounding material formed by charging the sintered compounding material on the pallet, is generally accompanied by particle size segregation due to percolation when sliding down on the chute. In the upper layer and middle layer of the sintering raw material charging layer, a large amount of fine sintered compounding material having a small particle size is distributed, while a coarse sintering compound material having a large particle size is deposited in the lower layer. Thus, segregation of the charging layer occurs. However, when more fine (more -260 μm) fine powder is contained, the segregation state becomes insufficient, and in the present invention, a sintered blending raw material containing more of such a magnetic fine powder raw material is charged. Solve the problem when you do.

  That is, the present invention has a magnetite fine iron ore as shown in FIG. 2, that is, a high content of FeO (4.5 to 60 mass%), and the particle size is 0.2 to 2. The premise is that a magnetically fine powder raw material having a size of 5 mm and a size of 250 μm or less is 60 mass% or less in cumulative weight ratio is used as a part of the sintered blending raw material. And it is the method of solving the problem mentioned above when charging the sintering mixing | blending raw material which contains this magnetic fine powder raw material 5-30 mass% on a pallet using a chute | shoot as shown in FIG.

  In carrying out such a charging method, it is effective to dispose a permanent magnet or an electromagnet on the back surface of the chute so that a magnetic force acts on the flow of the sintered blended raw material on the chute. As a result, with respect to the magnetized fine powder raw material such as ferromagnetic magnetite fine iron ore and sintered ore, mill scale, iron making dust (blast furnace dust, steel making dust, etc.) contained in the sintered blending raw material, Since the speed under the action of the magnetic force is reduced (suppressed), it is guided and deposited on the upper layer side of the sintered raw material charging layer (B) when it slides (slides down) on the surface of the chute. In this case, a normal sintering compound material having a large particle size is deposited in the lower layer.

  The above-mentioned deposition structure is because when the sintered compounding raw material containing a large amount of magnetic fine powder raw material is charged onto the pallet by the chute, these raw materials are arranged on the back side of the chute. This is due to receiving the action of magnetic force by the permanent magnet or electromagnet. That is, for magnetic fine powder materials that are susceptible to magnetic force due to their high iron content and small particle size, the speed when sliding down on the chute is reduced, and as a result, non-magnetization that has low iron content and large particle size. The raw material (usually the sintering raw material) forms the lower layer first, while the magnetized fine powder raw material is delayed by the amount that the speed is reduced by the action of magnetic force. It is deposited on the upper layer of the charging layer.

  When the content of FeO is less than 4.5 mass%, the magnetized fine powder material is hardly affected by the magnetic force of the magnet disposed on the back surface of the sloping chute, and the speed adjusting (reducing) effect is hardly obtained. On the other hand, the upper limit of the FeO content can be changed by adjusting the magnetic force and is not particularly required, but the FeO content of the magnetically fine powder material is about 60 mass% at the maximum.

  Regarding the raw material particle size, when the arithmetic average particle size of the magnetic fine powder material is 2.5 mm or more, the particle size difference from the non-magnetic material becomes small, and the magnetic fine powder material is placed on the upper layer of the charging layer. It is difficult to segregate well in the part. On the other hand, when the arithmetic average diameter of the magnetized fine powder material is less than 0.2 mm, or when the ratio of particles having a particle size of 250 μm or less includes an integrated weight ratio of more than 60 mass%, the air permeability in the sintered bed is improved. Even if the magnetic fine powder raw material is deposited on the upper layer portion of the sintered raw material charging layer, the productivity of the sintering machine may be lowered. Further, when the amount of fine powder having a particle size of 250 μm or less is less than 5 mass%, the effect of the present invention is weakened. A preferable lower limit of the fine powder having a particle size of 250 μm or less is about 15 mass%.

  FIG. 6 is a diagram for explaining the movement of particles when a sintered blending raw material containing a large amount of magnetic fine powder raw material is charged through a chute having a magnet on the back surface. As shown in this figure, when the sintered blended raw material containing the magnetized fine powder raw material slides down on the chute, the force acting on the raw material particles has the particle motion direction component of gravity as (1), When the frictional resistance due to magnetic force is (2) and the air resistance accompanying the motion of particles is (3), the equation of motion in the particle motion direction (chute horizontal plane direction) can be expressed as follows.

In general formula of the magnetic force F _M in the above-mentioned equation (1) are as follows (2).

Therefore, when the deposition magnetic fine material sliding down on the chute, wherein the magnetic force F _M by the magnet of the formula (1) and (2) can be organized more in the following manner.
That is, in charging the sintered blended raw material containing the magnetic fine powder raw material, the content and particle size of the magnetic fine powder raw material, the blending ratio of the magnetic fine powder raw material are given, and the magnet and chute surface Distance (χ), chute angle (θ), chute length (L) are given, and as constants, gravitational acceleration (g), coefficient of friction between material and chute (μ), resistance coefficient (Cp), air When the density (ρ) and the relative velocity (v) of the particles to the air are given, the equations of motion of the above formulas (1) and (2) can be arranged like the energy conservation formula of the following formula (3). .

Furthermore, in the present invention, the magnetic force F _M in the above (3) acting on the adhesive magnetic fine material on the chute surface, the speed [nu ₁ in the chute bottom zero (0) to be larger than, i.e. , it is necessary to be lower than the speed of the non-magnetizable material when no given force F _M in the chute, therefore, be summarized as (3) still (4) it can.

  In short, in the present invention, adjusting the resistance when the magnetized fine powder material that is easily magnetized slides down on the chute (that is, suppressing the speed of the magnetized fine powder material in the sintered blended material, This is a method of operating so as to be segregated into the upper layer portion of the sintering material charging layer.

Incidentally, increasing indefinitely the force F _M, i.e., to ensure that not to adhere easily magnetizability fines material magnetized on the chute is not preferable. Table 2 shows the relationship between the speed [nu _m of magnetic force _{F M} and magnetizability chute lower end of the fine material in the chute bottom by DEM in the case of the _{F M} and 0 to 10.5 × ^{10 -3} N It is the simulation result investigated. As shown in this table, in the example where the magnetic force (F _M ) is too large and the frictional resistance is too large (S1: 0 / 5ν ₁ ), the magnetized fine powder material adheres on the chute. Thus, you and possibly become uneven charging in the width direction, in the worst case, the deposits by closing the chute F _M is, there are a possibility that the charging itself becomes impossible. On the other hand, in the example in which no magnetic force is given (S6: 5 / 5ν ₁ ), the segregation charging is not performed at all. On the other hand, S2 has a large braking effect due to magnetic force (F _M = 10.0 × 10 ⁻³ N), so that the density of the raw material charging layer is excessively decreased (the porosity is increased), and the air permeability is good and the production rate is high. However, the yield decreases. Further, S5 showed a result that the magnetic force (F _M = 0.4 × 10 ⁻³ N) was weak, the charging speed ν _m was large, and the effect of segregation charging was weak. Therefore, the magnetic force F _M, it is seen that the adjustment in connection with velocity [nu _m in the chute the lower end of the magnetizability pulverized raw material is effective. S3 and S4 are cases where segregation is good, and since the density of the raw material charging layer does not excessively decrease (the porosity increases), the air permeability is good, and the yield and production rate are also good. It is.

From the above, adjustment of the magnetic force F _M is performed based on the following criteria. In other words, preferable range of the magnetic force F _M, based on the speed difference between the magnetizable fine material and a non-magnetizable coarse-fine material in the chute bottom (speed ratio), magnetizable fine material on sintering pallet sintering It is preferable to adjust so as to segregate and deposit on the upper part of the raw material charging layer.

Therefore, in the present invention, in equation (4), which is the energy conservation equation, the velocity (initial velocity) at the position of dropping onto the chute is ν ₀ , and the velocity when no magnetic force is applied at the lower end of the chute. when was the _(same as the non-magnetizable material velocity) [nu _1, the speed [nu _m of the deposition magnetic fine material in the chute lower end so as to be in the range of below to adjust the magnetic force F _M.

Relationship between the velocity [nu _m of magnetic force _{F M} and the chute lower end, speed 0,1 / 5ν ₁ in the chute the lower end of the magnetizability pulverized raw _{material, 2 / 5ν 1, 3 /} 5ν 1, 4 / 5ν 1 From the results shown in Table 2 in the tests (S1 to S6) set to ν ₁ . That is, as shown in Table 2, when the velocity ν _m at the lower end of the chute of the magnetic fine powder material is in the range of 1 / 5ν ₁ to 4 / 5ν ₁ , the state of the segregation charging becomes good, In particular, the yield is further improved in the range of 2 / 5ν _{1 to} 3 / 5ν ₁ .

Therefore, in the present invention, when charging the sintered blending raw material containing the above-mentioned predetermined amount (5 to 30 mass%) of the magnetized fine powder material onto the sintering pallet, the FeO content of the magnetized fine powder material, When the mass m and the magnetic susceptibility X change in consideration of the particle size and blending amount, the magnetic flux density (H) of the magnet to be used, the distance χ between the chute surface and the magnet, and the chute angle are adjusted in advance, and then the chute (when shoots lower rate of non-magnetizable material is _{ν 1, 1 / 5ν 1 ~4} / 5ν 1) within該着magnetic fine material of slide off speed [nu _m is constant in the lower portion so as to, wherein by adjusting the magnetic force F _M by the magnet, it is possible to selectively deposit only the magnetizable fine raw material for sintering blended in the raw material at the top of the sintering raw material sintering bed on the pallet.

Eventually, certain conditions given (content of FeO of magnetizability pulverized raw material, the average particle size, the raw material mixing ratio, etc.) under the desired range of the magnetic force F _M, i.e., always magnetizability pulverized material The condition for depositing only on the upper layer portion of the sintering raw material charging layer so that the sintering machine can be operated stably is that the speed of the magnetic fine powder raw material at the lower end of the chute is 1/5 ν ₁ to 4 described above. / 5ν ₁ so as to, in the range of 0.0004 to 0.01 the magnetic force _{F M} by the magnet, it desirably make adjustments to loading of sintering mixed material in the range of 0.004 to 0.009 However, this leads to stable operation of the sintering machine.

FIG. 7 shows that the magnetic fine powder raw material in the sintered blending raw material contains FeO: 7.0 mass% sintered remineralization: 15 mass%, FeO: 4.7 mass% magnetite fine iron ore: 5 mass% , Shows a simulation result of charging with setting the magnetic force F _M in formula (4) to 0.01 N, the speed of the magnetically fine powder material on the chute decreases, and most of it is burned. It is clear that it is deposited on the upper layer of the binder layer.

Next, FIG. 8 shows the magnetic fine powder raw material in the sintered blending raw material containing FeO: 7.0 mass% sintered reversion: 15 mass%, FeO: 4.7 mass% magnetite fine iron ore: 5 mass% those that, was simulated by setting the magnetic force F _M in 0.01N than like, can not charging a sintering mixed material at a constant speed, an obstacle to operation of sintering machines.

Next, FIG. 9 shows the magnetic fine powder raw material in the sintered blending raw material containing FeO: 7.0 mass% sintered reversion: 15 mass%, FeO: 4.7 mass% magnetite fine iron ore: 5 mass% those that, it was simulated by setting the same way the magnetic force F _M to 0.004 N, it is understood to be a desired polarization析装input.

Next, FIG. 10 shows the magnetic fine powder raw material in the sintered blending raw material containing FeO: 7.0 mass% sintered reversion: 15 mass%, FeO: 4.7 mass% magnetite fine iron ore: 5 mass% those that illustrates an example of normal loading, the magnetic force F _M: 0 was simulated by setting the it can be seen that polarization析装input of magnetizability fines material can not be expected at all.

In the examples described below, an experiment of simulating the actual machine charging apparatus shown in FIG. In this experiment, a sintered blending raw material including a magnetite fine powder ore and a sintered fine powder raw material such as sintered reverse sinter was used with the blending shown in Table 3. And the said sintering compounding material was filled in the hopper installed above the said simulator, and it loaded on the simulation pallet using the chute | shoot on the conditions shown in Table 4. Sintered raw materials were collected from the upper layer portion, middle layer portion, and lower layer portion of the charging layer obtained by charging on the simulated pallet, and the segregation status of the magnetite component (FeO) by chemical analysis was investigated. Furthermore, after that, the sintered blending material after charging was transferred to a sintering pot test apparatus, and a sintering experiment was conducted to investigate the influence on productivity and the like.
As shown in Table 3, the magnetic force (F _M ) and the velocity (ν _m ) at the lower layer of the chute in this example are 6.0 × 10 ⁻³ N under the conditions (T1 to T6) suitable for the present invention. The speed ν _{m at} this time was 3 / 5ν ₁ .

  According to the result of the charging experiment by the sintering pot test apparatus, as shown in FIG. 12, the magnetite fine iron ore is 10 mass%, the sintered return 20 mass%, and the remainder is powdered by a chute having a magnet arranged on the back surface. Magnetization of a sintered blending raw material blended with iron ore and limestone in a charging example (T6) suitable for the present invention and a comparative example (T8) that is a charging example using a chute in which no magnet is arranged When the segregation status of the component (FeO) was compared, in the invention example (T6) charged using a chute provided with a magnet, the sintered blending material containing the magnetized component was segregated in the upper layer of the charged layer. I was able to confirm.

  Furthermore, about the invention example and comparative example in this experiment, the change of the production rate by the mixture ratio of a magnetite type | system | group fine iron ore is shown in FIG. As is apparent from the results shown in this figure, compared with the case where no magnetic fine powder raw material is included (T1), the condition (T2) in which the magnetic fine powder raw material is blended by 5 mass% has less magnetization components and the charging speed. Is not sufficiently obtained, and productivity in the sintering machine does not change much. On the other hand, in the examples (T3 to T6) adapted to the present invention, the effect of reducing the charging speed by the magnetic fine powder material is sufficiently obtained, and the productivity is improved as compared with the case where the magnetic fine powder material is not included (T1). To do. On the other hand, under the condition (T7) in which 40 mass% of the magnetic fine powder raw material is blended, the fine powder ratio increases and the fine powder is mixed not only in the upper layer part but also in the middle layer part and lower, so that the productivity is maintained high. Is no longer possible. Therefore, in the present invention, it has been found that the effect appears remarkably when the blending amount of the magnetic fine powder material in the sintered blending material is 5 mass% to 30 mass% or less, preferably 20 mass% or more to 30 mass% or less.

  Although the technology according to the present invention has a larger particle size than that specified in the present invention, and there is a difference in effect even when charging a sintered blend raw material with a small amount or a large amount of magnetic fine powder raw material, Application is possible.

Claims (6)

In the operation method of the sintering machine, the sintered blending raw material is charged and sintered on the pallet of the sintering machine through a chute having a magnet disposed on the back surface.
The sintered blending raw material has a size of 5 to 30 mass% of the raw material, FeO content is 4.5 mass% or more, and the particle diameter is 0.2 to 2.5 mm in terms of arithmetic average diameter. And a magnetically fine powder raw material in which the amount of fine powder of 250 μm or less is 60 mass% or less by weight,
When this magnetized fine powder raw material is charged onto a pallet, the velocity of the sintered blended raw material at the lower end of the chute when no magnetic force (F _M ) is applied to the chute (F _M = 0) is represented by ν ₁ to time, the speed [nu _m of the deposition magnetic fine material in the chute lower end, so that the speed of _{1 / 5ν 1 ~4 / 5ν 1} , and characterized in adjusting the magnetic force F _M of the magnet and How to operate the sintering machine.   The method for operating a sintering machine according to claim 1, wherein the amount of the fine powder of 250 µm or less is 5 mass% or more by weight. The method of operating a sintering machine according to claim 1 or 2, wherein the velocity ν _m of the magnetic fine powder material at the lower end of the chute is 2 / 5ν _{1 to} 3 / 5ν _1. . Speed [nu _m of the deposition magnetic fine material in the chute lower end, one of the claims 1 to 3, characterized in that to adjust the magnetic force _{F M} of the magnet within the 0.0004~0.01N A method for operating the sintering machine according to claim 1. The magnetic force F _M of the magnet, operating method of the sintering machine according to any one of claims 1 to 4, characterized in that a numerical value determined by the following equation.
The magnetized fine powder raw material is at least 5 to 15 mass% of the raw material, which is sintered ore, and the remainder consists of any one or more of magnetite fine iron ore, mill scale, and iron dust. The method for operating a sintering machine according to any one of claims 1 to 5, wherein the operation method is as follows.