TW200404898A - Method for charging material into blast furnace with distributing chute instead of bells - Google Patents

Abstract

A method for charging material into a blast furnace with a distributing chute instead of bells comprises the steps of: storing cokes in at least one top bunker; storing ores in the at least one top bunker; charging the stored cokes into the blast furnace while rotating the chute and changing an inclined angle of the chute; and charging the stored ores into the blast furnace while rotating the chute and changing the inclined angle of the chute. Discharging of the ores stored in the at least one top bunker commences when the discharging amount of the cokes stored in the at least one top bunker is 5 to 50 mass% relative to a coke amount of one batch. A mixed material of ores and cokes is stored in the one top bunker and the mixed material is charged into the blast furnace while rotating the chute and changing the inclined angle of the chute.

Description

200404898 (1) Description of the invention: [Technical field to which the invention belongs] The present invention relates to a method for using more than a hood-type loading device. [Prior technology] Generally, the amount of ore and coke that are melted and cast pig iron is charged in the upper part of the furnace (to form one layer of the filled carbon layer with these layered structures, which is called one-time loading of ore and coke). It is also carried out in the furnace to load the ore and coke in one batch. The oxygen-enriched air is blown into the furnace, and the high-temperature reducing stones (hereinafter (Referred to as ore only) because of the productivity of the blast furnace, it is important to reduce the aeration resistance system. To reduce the aeration in the furnace neck, it is known that mixed ore and coke are accumulated and deposited in the No. 2 8 2 0 7 7 bulletin series: During the cutting period and quantity of stone and coke in the ore, the raw material charging method of the coke oven is evenly mixed; in particular, iron ore and coke are loaded into the blast furnace blast furnace, and the iron is alternately charged below the iron from the top of the furnace. , Called the furnace neck (shaf 〇), shaped layer. The iron ore layer, coke charge ore, and coke. These 1 are not necessarily loaded in one time, the ore and coke are charged. Split into splits Ore and coke are referred to as the reduction and melting of iron ore in the furnace neck by using air or burning coke existing in the furnace from the lower part of the blast furnace. Therefore, in order to improve the ore or coke in the furnace neck, An effective device for resisting the filling layer of coke has always been in the furnace. For example, the Japanese patent No. 1 from the ore funnel and the coke funnel is studied in a hoodless blast furnace. 6 200404898 In addition, as a way to prevent the It is also known to increase the ventilation resistance of the device to stably maintain the gas flow in the furnace. The coke is charged into the center of the blast furnace so that the distribution of the gas flow rate rising in the furnace is greater than the center (referred to as this The intention of the center flow) becomes effective. For example, Japanese Patent Laid-Open No. 60-60 5 0 3 discloses that 1.5 to 8% by weight of coke charged in a single charge will be concentrated. The technology of charging into the center of the furnace. The center loading of the coke not only has the effect of reducing the ventilation resistance in the furnace, but also there is no ore in the center of the furnace. This has the effect of avoiding and reducing the deterioration of coke caused by the so-called "solution loss reaction" of oxidizing coke due to the carbon dioxide generated during ore reduction. In addition, the strength management of coke itself can be reduced Value, it is possible to reduce the cost of raw coke for making coke by using cheap, low-grade coal, and it can also prevent the so-called "core (also called deadma η)" particle size of coke formed at the bottom of the furnace Reduction is more than necessary, so it is also effective for improving the liquid permeability of the bottom of the furnace. Therefore, if the above-mentioned mixed charging of ore and coke (hereinafter, simply referred to as mixed charging) and the center charging of coke, it is possible Compared with the past, the ventilation resistance of the furnace neck is further reduced, and the so-called multiplication effect of improving productivity can be expected. However, in order to combine mixing and charging into the center of the coke in the same charge, specifically, it is necessary to cut out from the raw material hopper to become the normal charging batch of coke and the center of the coke. It is performed in batches and mixed loading 3 times. In order to load the coke into the furnace once, the coke furnace roof is rolled up three times. Also 7 312 / Explanation of the Invention_ Supplement) / 92-11 / 92123713 200404898 In other words, the time required to fill the coke for one charge is increased. Therefore, even if it is necessary to increase the productivity of the blast furnace, the rolling capacity of the raw material on the top of the furnace is insufficient for the amount of the raw material to be loaded, and the raw material is too late to be loaded. In this state, the central charging and mixing charging of coke must be interrupted at the same time, and the advantages of using cheap raw material charcoal caused by the implementation of the foregoing two cannot be enjoyed. In addition, it is not easy to keep the properties such as the particle size distribution of ore or coke used in the blast furnace, the content ratio of water or the type of ore, and the like. For example, when the mixing ratio of the adhesive ore in the ore is changed, the technology disclosed in Japanese Patent No. 2 8 0 478, the stacking behavior system put into the furnace top hopper is changed, and the furnace top hopper is changed. The mixing ratio of ore and coke in the raw materials discharged from the lower discharge port changes. However, as a device for increasing the particle size of the coke at the bottom of the furnace and improving the liquid permeability in the bottom part, it is also considered that it is installed in the center part in addition to the coke center. The particle size of coke becomes larger. In other words, in order to replace the prevention of charging in the center of the coke, the ore is accumulated in the center of the furnace, and the consumption of coke caused by the melting loss reaction in the center of the furnace is prevented, so the particle size of the coke in the center of the furnace can be made more The particle diameter of the coke larger than the periphery of the furnace can prevent the reduction of the particle diameter of the coke at the bottom of the furnace and the core even in a state where a melting loss reaction is caused. In addition, if the above-mentioned dedicated coke charging device for loading coke into the center is used, the particle size of the coke at the center of such a furnace can be increased by making the diameter of the coke loaded through the loading device larger in advance. The path has expanded. However, 8 200404898 is that setting up a special loading device for loading coke into the center, which is different from the general raw material loading device, requires huge equipment costs. In addition, even when coke with a large particle size is loaded into the center of the furnace through a hoodless charging device, coke with a large particle size is now prepared in advance, so that this is different from ordinary particle size coke. The other batches are rolled up into the furnace after being rolled up to the hopper set on the furnace top. Therefore, the number of batches of coke or ore charged in one charge increases. Increasing the number of batches of the raw materials charged into the furnace at a time to increase the number of batches is to determine the reaction speed in the state of increasing the throughput, and therefore, it becomes a major problem. SUMMARY OF THE INVENTION A first object of the present invention is to provide a raw material charging method of a hoodless blast furnace which can smoothly perform center charging of coke and mixed charging of ore and coke. A second object of the present invention is to provide a method for suppressing changes in molten pig iron temperature and molten pig iron quality by distributing ore and coke at a certain mixing ratio at the top of the blast furnace even when the properties of various raw materials used in the blast furnace are changed. Method for loading raw materials of hoodless blast furnace. A third object of the present invention is to provide a method for enabling a coke particle size to be maximized at the center of the furnace and forming a gas flow in the furnace at the center of the furnace when the center coke is charged into the chute using a hoodless blast furnace. In this way, the raw material charging method of the hoodless blast furnace for stable operation is carried out. A fourth object of the present invention is to provide a large-size coke having a larger particle size than those charged to the periphery without selectively adding a special charging device for coke and without increasing the number of raw materials. Raw material loading method of hoodless blast furnace to 200404898 parts of blast furnace center. In order to achieve the foregoing object, therefore, in the first aspect: the present invention provides a raw material charging method for a hoodless blast furnace having a hoodless charging device having the following steps: (a) storing coke in at least one furnace top hopper Steps: (b) Store the ore in at least 1 furnace top hopper; (c) For the chute of the aforementioned hoodless loading device, rotate it while changing its tilting angle and follow the inside of the furnace The step of loading the stored coke in the radial direction from the center of the furnace toward the wall of the furnace; (d) For the chute of the aforementioned hoodless loading device, it is rotated while changing its tilting angle, and along the furnace The step of loading the stored ore from the center of the furnace toward the wall of the furnace in the inner radius direction; and (e) controlling the discharge amount of coke stored in the at least one furnace top hopper, Between 5 and 50 mass%, the step of discharging the ore stored in the aforementioned at least one furnace hopper begins. In the second aspect, the present invention provides a raw material charging method for a hoodless blast furnace having a hoodless charging device having the following steps: (a) storing the mixed raw materials of mixed ore and coke in a furnace top hopper In the step (b), the loading chute is rotated around the central axis of the blast furnace, and the tilting angle of the loading chute is sequentially changed while the mixed raw materials stored in the furnace hopper are loaded to Steps in the blast furnace; and (c) controlling the total amount of the aforementioned mixed raw materials stored in the aforementioned furnace top hopper between the aforementioned loading chute at least once and back along the radius of the blast furnace, 10 312 / Invention Specification (Supplementary Document) ) / 92-11 / 92123713 200404898 to load into the aforementioned blast furnace. In the third aspect, the present invention provides a raw material charging method for a hoodless blast furnace having a hoodless charging device having the following steps: (a) The central portion of the blast furnace is set to 0 and The furnace wall portion is set to a dimensionless radius of 1, leaving a position corresponding to a radius of 0.1 to 0.4, and the coke charging step is started using the loading chute of the aforementioned hoodless loading device; and (b) The step of charging the coke by sequentially rotating the tilting angle of the charging chute to the center of the furnace in each rotation of the charging chute. In the fourth aspect, the present invention provides a coke sieving step including: cutting out coke stored in at least two storage tanks, and screening the cut coke through a sieve provided at the lower part of the tank; The coke on the weighing sieve is used to store the weighing and storage steps in the hopper set on the furnace top; and through the chute of the hoodless loading device, from the furnace center to the furnace wall side, the chute is rotated while A raw material charging method of a hoodless blast furnace equipped with a hoodless charging device in the step of loading stored coke into a blast furnace. The aforementioned coke sieving step is performed by a first sieving step of sieving coke cut out by a sieve having a larger sieve opening (A) and by a sieve having a smaller sieve opening (B). The second sieving step of the cut coke. The foregoing weighing and storage steps are performed by firstly transferring only a certain amount of coke from the first sieving step to the aforementioned weighing funnel, then transferring the coke from the second sieving step and performing 1 batch of coke weighing, and stored in In the hopper provided on the top of the furnace. In the 5th: the present invention provides a method for loading the raw material 11 200404898 in the 4th hoodless blast furnace, so that it is screened by a sieve having a larger sieve (A). The amount of coke in the first sieving step of the cut coke becomes a raw material charging method of a hoodless blast furnace in which the coke amount in the batch is 5 to 50% by mass. In the sixth aspect, the present invention provides a raw material charging method of a hoodless blast furnace having a hoodless charging device having the following steps: (a) a step of storing coke in at least one furnace top hopper; (b) in Steps for storing ore in at least one furnace top hopper; (c) Steps for storing mixed raw materials of mixed ore and coke in one furnace top hopper; (d) For the chute of the aforementioned hoodless loading device, changing its tilting Step of turning it at an angle, and loading the stored $ coke from the center of the furnace toward the wall of the furnace along the radius of the furnace; (e) For the chute of the aforementioned uncovered loading device, change its Tilt the angle while rotating it, and load the stored ore from the furnace center to the furnace wall along the radius of the furnace; (f) Control the amount of coke stored in the at least one furnace top hopper Start the process of discharging the ore stored in the at least 1 furnace-top hopper between 5 ~ 50 mass% of 1 batch of coke loading; (g) rotate the loading chute and sequentially change one side The tilt angle of the aforementioned loading chute, and one side will store The step of loading the mixed raw materials into the blast furnace at the aforementioned furnace top hopper; and (h) controlling the mixing of the raw materials stored in the aforementioned furnace hopper while the loading chute reciprocates at least once along the radius of the blast furnace. The total amount is charged into the aforementioned blast furnace. 12 200404898 [Embodiment] In order to achieve each of the aforementioned objects, the inventor conducted research with repeated efforts to make the results of the present invention concrete. That is, the raw material charging method of the hoodless blast furnace of the present invention (referred to as Embodiment 1) is characterized in that the tilt angle of the chuteless blast furnace charging device is changed and rotated, and along the When the coke or ore stored in a plurality of furnace-top hoppers is loaded from the furnace center toward the furnace wall in the radial direction of the furnace, the coke discharged from the above-mentioned storage in one furnace-top hopper becomes 1 batch of coke. Beginning at a predetermined time between 5 and 50 mass% of the input, the ore stored in other furnace top hoppers will be discharged, and coke and ore will be loaded at the same time. In the first embodiment, the tilting angle of the blast furnace is gradually increased in stages from zero in the vertical state. At the same time, if the chute of the hood-less charging device of the rotary blast furnace is stored in a furnace top hopper, If the amount of coke discharged becomes 5 to 50 mass% of the coke loading amount of 1 batch, the ore stored in other furnace top hoppers will be discharged. At the same time, coke and ore will be loaded at the same time, and only filled near the center of the furnace. Coke is filled with a mixture of coke and ore on the side of the furnace wall surrounding it. As a result, the coke and ore mixed loading is not stopped due to the condition of the capacity of the raw material on the top of the furnace, and the coke and ore mixed loading can be smoothly performed all the time. The raw material charging method of the hoodless blast furnace of the present invention (hereinafter, referred to as Embodiment 2) is to use the hoodless charging device to load raw ore and coke into the hoodless blast furnace. For the loading method, the mixed raw materials of mixed ore and coke are stored in a furnace top hopper, and the blast furnace 13 200404898 mandrel is used as the center to rotate the chute, and the chute is sequentially changed. The tilting angle is to load the total amount of the mixed raw materials stored in the furnace top hopper into the blast furnace while the chute is reciprocated at least once along the radial direction of the blast furnace. In the aforementioned second embodiment, it is preferable that the charging chute is loaded from the blast furnace wall side to load mixed raw materials, or the blast furnace center side is used to load mixed raw materials. The raw material charging method (hereinafter, referred to as Embodiment 3) of the hoodless blast furnace of the present invention is a hoodless blast furnace that uses the hoodless charging device to load raw materials of ore and / or coke into the blast furnace. The raw material charging method is characterized in that when using a charging chute to load coke into the center of the hoodless blast furnace, the central portion of the furnace for the hoodless blast furnace is set to 0 and the furnace wall portion is set to 1 has no dimensional radius and corresponds to a radius position of 0.1 to 0.4, and coke loading is started. At each rotation of the aforementioned loading chute, its tilting angle is sequentially transferred to the center of the furnace. Mount. The raw material charging method (hereinafter referred to as Embodiment 4) of the hoodless blast furnace of the present invention is characterized in that coke stored in a plurality of storage tanks is cut out and screened by a sieve provided at the lower part of the tank. In order to make the coke on the sieve pass through the weighing funnel and the hopper set on the furnace top sequentially, through the chute of the hoodless loading device from the furnace center to the furnace wall side, the chute is simultaneously loaded into the blast furnace. In order to make the coke from the lower part of the tank above the mesh of other storage tanks larger than the meshes of other storage tanks and start to transport coke from the storage tanks to the weighing funnel, the coke from the storage tank of the large mesh was initially only After a certain amount is conveyed to the weighing hopper, 14 200404898, the coke from the other storage tank is conveyed, and 1 batch of the coke is weighed, and then loaded into the blast furnace through the hopper. In this state, it is preferable that the amount of coke from the large-mesh storage tank is 5 to 50 mass% of the total amount of coke in the batch (hereinafter, referred to as embodiment 5). According to Embodiments 4 and 5, it is not necessary to install a special charging device for coke, and the existing uncovered charging device can be used, without increasing the number of batches of raw materials. At the same time, the particle size can be selectively increased. Large-size coke larger than those charged into the periphery is charged into the center of the blast furnace. Preferably, in the first to fifth embodiments, a raw material charging method of a hoodless blast furnace in which at least three furnace top hoppers are provided in parallel (hereinafter, referred to as embodiment 6) is adopted. (Embodiment 1) Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, Fig. 1 shows a longitudinal section of the top of a blast furnace equipped with a hoodless charging device. The raw material 2 (ore or coke) stored in the furnace top hopper 1 is dropped through a gate called a flow adjustment gate 3 and the discharge amount is adjusted by its opening degree, and is supplied to the freely rotatable through a vertical chute 4 Chute (commonly referred to as the loading chute 5). The loading chute 5 can be rotated in the horizontal direction with the central axis 7 of the blast furnace 6 as the center. At the same time, the tilt angle (0) of the central axis 7 can be changed. During the rotation, the chute 5 is loaded, and at the same time, the tilting angle Θ is changed stepwise in order. In the furnace, a wide stacking surface is formed, and raw materials are charged. Generally, as the tilting angle 0, a number of angles are set in advance. At each angle, the number 15 200404898 is assigned. When the chute 5 is loaded into the chute 5 and the raw material 2 is loaded at the same time, the number of rotations can be determined by starting the loading. Gradually load the same raw material to a certain position. In addition, the furnace top hopper 1 is shown in Fig. 1 as shown in Figs. 1 and 2 b. However, it also has a state of 3 or more. It can be rolled up and stored in batches of raw materials 2 in each. Embodiment 1 is a method for loading blast furnace raw materials using such a hoodless charging device. The tilt angle is sequentially changed from the furnace center side toward the furnace wall side. At the same time, coke is charged, and the coke is charged. At the same time, ore is also loaded. Specifically, the loading period of coke and ore is as shown in the conceptual diagram of Fig. 2 (a). That is, the coke is discharged from the top hopper (for example, 1 a) storing coke, and if the discharge amount from the top hopper of the coke becomes 5 to 5 of the coke loading amount stored in one batch at the top hopper. If it is 50% by mass, the ore is started to be discharged from other furnace top hoppers (for example, 1 b) storing the ore. This can be used to make the center loading of coke at the beginning, and from the way, the coking and ore mixing loading. In Fig. 3, an example of the raw material accumulation in the furnace formed by performing such charging is shown. Here, the symbols C and 0 in FIG. 3 indicate coke and ore, and the attached words below indicate the number of batches. This FIG. 3 is a state in which coke and ore are mixed and charged after the coke is charged in three rotations. After coke charging is started, coke is only charged to the center of the furnace. Therefore, In the central part of the furnace, only a coke deposit layer C 2 is formed, and then coke and ore are charged together. As a result, a coke and ore mixed layer C 2 + 0! Is formed. In this state, the coke that was loaded first is in the center of the furnace to form a mountain. Then, the mixture of coke and ore is loaded into the wall side of the furnace 16 200404898 more than this. Therefore, the mixture that is loaded later is It did not flow into the coke hill in the center of the furnace. As a result, a central coke layer in which only coke is deposited is formed at the center of the furnace. In addition, the ore loaded later is outside the center coke layer (side of the furnace wall), and coke is accumulated at the same time. Therefore, a mixed layer C 2 + 0 of a predetermined layer thickness is formed at a predetermined position in the furnace radial direction. Further, in the first embodiment, it is preferable that the opening degree of the flow regulating gate 3 is adjusted so that the coke and ore discharge are completed simultaneously. However, the discharge time from the top hopper 1 of the coke or ore varies depending on the particle size, the amount of water contained, and the like. Therefore, the opening degree of the flow regulating gate 3 can be appropriately adjusted. The example in FIG. 3 is to discharge the second batch of coke and the first batch of ore which are divided into two batches at the same time to form a central coke and a mixed layer. However, in the present invention, it is not Limited to this, each time charging is performed without loading the coke and ore into the furnace in batches, a so-called charging method in which a separate layer of coke is formed in the center of the furnace and a mixed layer is formed around the furnace can also be used. In addition, after the coke is divided into two batches and the coke is separately batched C! After the coke is charged in the whole furnace, the so-called second batch of coke can be used to mix and load the ore once. How to load the ingredients. Further, in Embodiment 1, the discharge start time from the furnace top hopper of the ore mixed to coke is set to start the separate discharge of coke from other furnace top hoppers and the equivalent of 5 to 5 of the amount of coke charged in the batch is discharged. 0 mass% of coke. The reason is as follows. When the amount of coke alone is less than 5 mass%, the amount of coke accumulated in the center of the furnace 17 200404898 becomes too small, and the mixture of coke and ore loaded later is mixed into the coke layer of the center of the furnace, which cannot be The effect of filling the coke center is obtained. In addition, after coke loading of more than 50niass% is performed separately, when coke and ore mixed loading is started, the amount of coke in the mixture cannot be sufficiently increased, and it is not easy to obtain the effect of mixed loading. In addition, in this state, a wide range of the center of the furnace produces a portion where no ore is present, and the furnace cannot be effectively used. On the contrary, the throughput cannot be increased. (Embodiment 2) FIG. 4 is a cross-sectional view schematically showing a furnace top of a blast furnace (hereinafter, referred to as a hoodless blast furnace) having a hoodless charging device. In FIG. 4, the angle (hereinafter, referred to as the tilt angle) formed between the central axis of the blast furnace and the rotary chute is made zero. Two or more furnace-top hoppers 1 are provided in the two hoodless furnaces 5 ^ but ’one of the furnace-top hoppers 1 stores a mixed raw material 20 of mixed ore and coke. The mixed raw material 20 is discharged from the lower part of the top hopper 1 and is adjusted to a predetermined flow rate by the flow adjustment gate 3, and then supplied to the loading chute 5 through the vertical chute 4. The charging chute 5 is rotated around the central axis of the blast furnace, and at the same time, the tilting angle 0 is changed, and the mixed raw material 20 is charged into the blast furnace 6. The arrow a in FIG. 4 indicates the rotation of the chute 5, and the arrow b indicates the fall of the mixed raw material 20. In this way, when mixed raw materials 20 are loaded in the blast furnace 6, the chute 5 can be loaded by rotation, and the tilt angle 0 can be sequentially changed to cover a wide range on the raw material stacking surface 8 on the top of the blast furnace 7. , To load mixed raw materials 20. 18 312 / Invention Manual (Supplement) / 92-11 / 92123713 200404898 In addition, in Figure 4, it is shown that there are no hood-type heights provided with two furnace-top hoppers 1. However, it is also possible to install three or more furnace-top hoppers 1. No cover type ί is applied to the second embodiment. In the present invention 2, the method for storing the mixed raw material 20 of the mixed ore and coke in the top hopper 1 is not limited to a specific method. For example, it can be used: from the ore blasting funnel (not shown) and coke weighing leaks ^ not shown) cut out the ore and coke simultaneously at a predetermined ratio and load them into the conveying device (not shown) ) And transfer it to the furnace hopper 1 and so on. However, due to the different characteristics of ore and coke, it is unavoidable to mix the raw materials 20 in the furnace 1 to locally change the mixing ratio. That is, the average diameter of the small-sized carbon particles is about 15 mm relative to the ore particle size. The diameter becomes a large diameter of about 50 mm on average. Therefore, at the time point when mixing 20 is put into the furnace top hopper 1, the coke with a relatively large particle size moves on the wall side of the furnace top hopper 1, and the particle size is relatively small. Ore is easy to pile into place. In addition, when the mixed raw materials are discharged from the lower portion of the furnace top hopper 1, the mixed raw materials 20 stored in the furnace hopper 1 are distributed vertically from the lower layer portion to the surface layer portion to the surface layer portion. The above-mentioned mixed raw material 20 is discharged preferentially. When the accumulation level is lowered directly above the discharge port, it is discharged from the surrounding area and flows into the mixed raw material (so-called funnel flow) for discharge. As a result, when the mixed raw materials 20 are fed into the furnace top hopper 1, the ore and coke are mixed in advance regardless of the negative ratio, and the furnace hopper 1 comes to the furnace, the furnace, and the furnace (and penetrates to the top material: also. The coke raw materials are accumulated in the direction of 20 ^ 2 0 in the discharge direction to discharge 19 200404898. When the raw materials 20 are mixed, the mixing ratio of ore and coke changes. That is, in the initial stage of discharge, the ore ratio increases In the later period of discharge, the ratio of coke increases. As such, when the mixed raw material 20 is discharged from the furnace top hopper 1, fluctuations in the mixing ratio cannot be avoided.

As described above, since the mixed raw material 20 is discharged from the furnace top hopper 1, the mixing ratio varies. Therefore, when the mixed raw material 20 is charged into the blast furnace 6 through the charging chute 5, the raw material is mixed. The ore or coke system in 20 cannot be uniformly distributed on the raw material stacking surface 6, which is a cause of segregation in a specific area. Therefore, in the second aspect of the present invention, in order to prevent segregation on the raw material stacking surface 8, after starting the charging of the mixed raw materials 20 stored in the one furnace top hopper 1, it is continued until the total loading is completed. The chute 5 is inserted into the chute 5 with the blast furnace central axis as the center, and the tilting angle 0 is sequentially changed, and the chute 5 is reciprocated at least once along the radius of the blast furnace. However, when the tilt angle 0 is changed, the chute 5 is incorporated in each tilt angle.

In other words, after a predetermined tilt angle 0 and the blast furnace center axis as the center are rotated once to load the chute 5 to load the mixed material 20, the tilt angle 0 is changed, and the mixing of the raw material 20 is continued. At the same time, until the loading of the total amount of mixed raw materials 20 in the furnace top hopper 1 is completed, the loading chute 5 is reciprocated at least once along the radial direction of the blast furnace. Therefore, between the total amount of mixed raw materials 20 stored in a furnace top hopper 1 and at any position on the raw material stacking surface 8, the mixed raw materials 20 or more are loaded twice. In the operation of the blast furnace, the tilt angle 0 of the chute 5 is usually set to several stages, and each number is assigned (hereinafter, referred to as a scale number). Therefore, after loading the chute 5 once with the predetermined scale number and loading the mixed raw material 20, the mixed raw material 20 can be loaded by changing to the next scale number, and The hoodless blast furnace is suitable for the second embodiment. Fig. 5 is a cross-sectional view schematically showing an example in which a mixed raw material is applied in accordance with the second embodiment. In FIG. 5, it is shown that the loading of the mixed raw materials 20 is started from the blast furnace wall side, and the tilting angle 0 is sequentially reduced, the mixed raw materials 20 are loaded, and the mixed raw materials 20 are loaded in the center of the blast furnace. Example of tilting angle 0 and loading mixed raw material 20. Therefore, in FIG. 5, the mixed raw material charged in the first rotation (hereinafter, referred to as the first rotation) of the chute 5 loaded with the mixed raw material 20 stored in the furnace top hopper 1 is started. The 2 0 a system is located on the wall side of the blast furnace on the raw material stacking surface 6, and the mixed raw material 2 0 b system is loaded in the 12th rotation of the chute 5 (hereinafter, referred to as the 12th rotation). It is located on the mixed raw material 20a loaded in the first rotation. Fig. 5 shows a state in which the total amount of mixed raw materials 20 has been charged at the 12th rotation. However, the loading chute 5 is rotated every time with the predetermined tilt angle 0 and the blast furnace center axis as the center. Therefore, in the cross-sectional view of FIG. 5, the mixed raw material 20 is loaded into two of the blast furnace center axis. Side, however, in FIG. 5, only one side is illustrated. In addition, FIG. 5 shows an example of charging into the chute 5 which is rotated once or twice between the total amount of the mixed raw materials 20 stored in the furnace-top hopper 1. However, in the second embodiment, the charging The number of rotations of the chute 5 is not limited to the value set in JP 21 200404898. In addition, FIG. 5 shows an example in which the charging chute 5 is reciprocated once along the radius of the blast furnace between the total amount of the mixed raw materials 20 stored in the top hopper 1 and stored therein. In the second embodiment, the chute 5 can be installed and reciprocated at least once along the radial direction of the blast furnace. Therefore, after loading the mixed raw materials 20 stored in the furnace top hopper 1, the loading chute 5 can be reciprocated once along the radius of the blast furnace, and then can be rotated several times, or It is repeated two or more times. In other words, between the total amount of the mixed raw materials 20 stored in the furnace top hopper 1, the number of times that the charging chute 5 is rotated with the blast furnace center axis as the center and the charging chute can be appropriately set. 5 times of reciprocating in the radial direction of the blast furnace, and the flow rate of the mixed raw material 20 discharged from the furnace top hopper 1 is adjusted by the flow adjustment gate 3. In Fig. 5, an example is shown in which the mixed raw material 20 is loaded from the blast furnace wall side. However, the mixed raw material 20 may be loaded from the blast furnace center side, and the tilt angle 0 is sequentially increased while The mixed raw material 20 is charged, and the mixed raw material 20 is charged into the blast furnace wall portion, and then the mixed raw material 20 is charged while sequentially reducing the tilt angle 0. In this way, when the mixed raw material 20 stored in the furnace top hopper 1 is loaded, and the mixed raw material 20 is loaded at any position on the raw material stacking surface 6 twice, Once loaded, the mixing ratio of the mixed raw material 20 changed (for example, the ore ratio increased), and after the second loading, the mixing ratio showed the opposite behavior (for example, the ratio of coke 22 200404898 increased) ). Therefore, ore and coke can be distributed on the raw material stacking surface 8 at a certain mixing ratio. As a result, it is possible to improve the air permeability of the dazzling zone, suppress the fluctuation of the molten pig iron temperature, and obtain molten pig iron of uniform quality. In addition, when the actual loading is performed once with a predetermined scale number, the mixed raw materials 20 are diffused and stacked on the raw material stacking surface 8 in a radial direction. Therefore, the loading chute 5 is arranged along the radial direction. When reciprocating, loading does not need to be performed at the same scale. The chute 5 can be reciprocated at least once with a predetermined width in the radial direction. (Embodiment 3) As shown in FIG. 6, in a hoodless blast furnace 6 having a chute 5, starting from the furnace roof, raw materials such as ore, coke, etc. are charged through the chute 5 to form a stack in the furnace. Layers 1 to 4. The loading chute 5 is adjusted so that the furnace central axis of the furnace central portion 6a becomes an inclination angle 0, and the periphery of the furnace central axis is rotated, and at the same time, the raw material is loaded. Next, a point-symmetrical raw material stacking surface with the furnace center portion 6a as the center is formed. In addition, the loaded raw materials can be put into any place on the top surface of the furnace by changing the angle of loading into the chute. The adjustment of the loading position with respect to the furnace radial direction is performed by adjusting the tilting angle 0 of the loading chute 5. Usually, a predetermined scale number is assigned to a predetermined tilting angle in advance, and when the furnace is rotated (rotated) with the central axis of the furnace as the center at the same time, starting from the loading of the raw material, each rotation of the chute, The scale number is determined, and the loading control of the raw material loading form in the furnace is controlled by controlling the form of the scale number. When investigating the filling of the raw materials in the furnace before the start of the blast furnace operation, investigate in advance the position of falling of the raw materials corresponding to the tilt angle of the chute. Alternatively, the centrifugal force and gravity when the raw material flows down into the rotating chute and the upward flow of the gas in the furnace can be considered, and the falling track of the raw material can be calculated mechanically to determine the loading position of the raw material. However, when considering the loading of the central coke, as shown in FIG. 7, when the coke is loaded from the start of loading and the tilt angle is reduced with each rotation, as shown in FIG. 7, compared with the first rotating coke The loading position, the coke loading position for the second rotation is relatively close to the furnace center side. In this way, when the central coke is charged, the coke of the second rotation falls into the furnace center side after falling to the furnace center side than the coke of the first rotation. At this time, the relatively coarse particles in the second-time rotating coke flowed more to the center of the furnace. That is, as the rotation progresses, the falling position of the coke is moved to the center of the furnace, so that the falling coke will flow from the falling position toward the center of the furnace and flow into the inclined surface. The coarsest particles in the coke are deposited in the center of the furnace. In addition, at this time, when the dropping positions of the first rotation and the second rotation are the same, the coke system of the second rotation is divided into the furnace center side and the furnace wall side and flows in, so the coke of the second rotation Part of the coarse-grained coke flowing into the furnace wall becomes a problem. However, as in Embodiment 3, the coarse-grained coke can be made close to the center of the furnace by rotating the coke as the rotation progresses. The entire flow into the furnace center side is effective in terms of strengthening coarse coke segregation in the furnace center portion. In addition, it is suitable that in Embodiment 3, the starting position of the charging of the central coke is equivalent to 0.1 to 0, with respect to making the central portion 24 of the blast furnace 24 200404898 0 and the non-dimensional radius of the furnace wall portion 1. Radius of 4. When the loading start position is more than 0.4, even if the loading of the central coke is started, the amount of coke loaded in one revolution will be reduced, so that the coke does not flow into the vicinity of the center of the furnace. The effect of charging coarse-grained coke into the center of the furnace becomes insufficient. In addition, when the loading start position is less than 0.1, the distance in which the coke loaded flows becomes shorter, and the effect of causing particle size segregation becomes insufficient.

The appropriate range of the starting position of the loading of the central coke was tested. Therefore, a model experiment of the scale of the 1/5 scale of the blast furnace top loading device of the internal volume of 50000 m3 was performed to investigate the difference in starting position The resulting ratio of coarse coke particles in the radial direction. The results are shown in FIG. 9. Here, the so-called coarse coke particle ratio refers to a predetermined amount of sampling at each non-dimensional radius position after the end of the loading experiment, and the particle size distribution of the coke is measured. Boil

Coarse grains show the proportion of coarse grains in each sample. In each experiment, coke was charged in 5 rotations. Here, the state in which the loading start position becomes 0.05 and 0.1 is adjusted at each revolution with a dimensionless radius of 0.1 each time, so that the loading position is moved to the center of the furnace for loading. . In addition, the state where the loading start position is 0.4 and 0.45 is adjusted by 0.5 with each dimensionless radius every rotation so that the loading position is moved to the center of the furnace for loading. In the state where the loading start position is at a non-dimensional radius of 0.5, the coke system after the second rotation starts from the center of the furnace, and on the contrary is filled with 25 200404898 in the direction of the wall of the furnace. There is not much difference from the state of being directly installed in the center of the furnace. Even in particle size measurement, it is the result of increasing the coarse particle ratio from the center of the furnace toward the wall of the furnace. In addition, in the state where the loading start position is a non-dimensional radius of 0.45, the coke coarse particle ratio in the range of the non-dimensional radius of 0 to 0.3 hardly changes, which results in the so-called segregation not increasing. . On the other hand, it was found that in a state where the loading start position is within a range of 0.1 to 0.4, within a range of a non-dimensional radius of 0 to 0.2, more than 70% of the coke becomes coarse particles, and the center portion Nearby coarse grain segregation was strengthened. Next, Embodiments 4 and 5 will be described. When the inventor used the hoodless charging device to load the raw materials into the blast furnace, he found that, as shown in FIG. , Change the angle (0) formed by the loading chute and the central axis of the furnace, and load the raw materials discharged from the furnace top hopper 1 into the arbitrary position in the direction around the furnace, uniformly and along the radial direction. That is to say, the coke loading can be started by making the tilt angle (0) almost 0 degrees and the loading chute almost vertical, and in each rotation, the 0 is changed stepwise. It is large enough to be charged, so that when the coke deposited in the furnace is initially loaded, it is deposited in the center of the furnace and is deposited on the furnace wall side as time passes. When this charging method is used, if the large-size coke discharged from the original batch of coke discharged from the furnace top hopper into the furnace can be selectively discharged, it can be in the center of the blast furnace. , Coke with large particle size is selectively loaded. In order to make the particle size of the coke initially loaded in one batch larger than 26 200404898, the particle size of the coke loaded later will be described below. In the lower part of a plurality of storage tanks storing blast furnace coke, a sieve 2 1 is usually provided, and the mesh is set at 35 mm. Therefore, the meshes of some storage tanks, for example, become larger than the meshes of other storage tanks. At this time, as shown in FIG. 10, when coke is started to be transferred from the storage tanks 22 to the weighing funnel 23, if the coke 24a from the large-mesh storage tank 22a is initially transported only by a certain amount, If the coke 2 4 b from the other storage tank is transported to the aforementioned weighing funnel 23, coke 2 4 a with a particle size of 5 5 mm or more can be deposited on the lower side of the weighing funnel 3 and the particle size can be deposited on the coke 2 4 a. One batch of coke 24b over 35mm. Then, after weighing the coke in one batch, even if it is cut out from the lower part of the hopper 3 and transferred to the hopper 1 on the top of the furnace, the pellets are also accumulated in the hopper 1 on the lower side. Coke 2 4 a having a diameter of 5 5 in m or more and 1 batch of coke 2 4 b having a particle size of 3 5 mm or more were deposited thereon. Therefore, as shown in Fig. 1, when the above-mentioned reverse tilt loading of the coke is started through the chute 5 through the hopper 1, the diameter of the coke particles accumulated in the blast furnace is larger on the average than on the periphery. In Embodiments 4 and 5, the amount of coke 2 4 a having a particle size of 5 5 mm or more was estimated empirically based on the accumulation height of the weighing funnel 23. In addition, it is preferable that the amount of coke in one batch is 5 to 50% by mass. At less than 5% by mass, the amount of coke with a large particle size at the center of the furnace is reduced. Therefore, coke with a normal particle size flows into the center of the furnace to form a strong central flow, which becomes insufficient; at more than 50% by mass Although Yu became a strong central flow, it became sufficient, but the increase in the amount of coke that could not be used for the blast furnace as a coke sieve 27 200404898 also caused unsuitability. As described above, Embodiments 1 to 5 are effective even in each case, but the combination can be used to more effectively optimize the distribution of blast furnace contents. For example, in FIG. 3, Embodiment 4 can be applied to the C1 layer, Embodiment 3 can be applied to the C2 layer, Embodiment 1 can be applied to the C 2 + 0! Layer, and Embodiment 2 can be applied to the 02 layer. (Example) (Example 1) A blast furnace equipped with a hoodless charging device with a furnace internal volume of 5,000 m3 was used to conduct a test operation to increase its throughput. In this blast furnace, as shown in Table 3, the tilting angle of the chute is corresponding to the scale number. In addition, the larger the number of scales, the smaller the tilting angle becomes. Therefore, immediately after the loading is started, at the 20th scale, the loading chute system is almost vertical, and then the tilting angle is gradually increased. At the same time, loading is performed. In addition, the test operation was performed in such a blast furnace, so that the target milling ratio was set as three levels of 1.8, 2 · 0 and 2 · 1 (cases 1 to 3). However, the output was increased in order. The operations of the milling ratios of 1.8 and 2.0 are conventional methods of loading materials, and the operations of the milling ratio of 2.1 are performed by the method of loading materials of the present invention. Here, the so-called milling ratio refers to the value of the blast furnace's milling output (t / d) divided by the furnace inner volume (m3). The larger the milling ratio, the more it is aimed at high-volume operations. In addition, the coke and ore loading conditions (types of batches, batches of batches, number of scales installed in the chute, and furnace top hopper used) in this test operation are shown in Table 1. First, case 1 is the operation of milling ratio 1.8. Here, only 28 312 / Invention Specification (Supplement) / 92-11 / 92123713 200404898 coke is loaded as C i and then loaded as C 2 The center is filled with coke, and then mixed in advance. At the same time, it is charged with coke c3 and 0 ore mixed and stored in the furnace top hopper to form a mixed layer. Then, only the ore as 0 2 is charged on the side of the furnace wall to form a separate layer of the ore. The O2 ore is a material having a small particle diameter, and is particularly charged in the furnace wall even if it is in ore. With this series of loading, one charging is performed, and the repeated loading operation is performed. In addition, this operation is the prior art, and is equivalent to performing the center charging and mixing charging of the coke separately. In the operation of this case 1, in order to increase the production of molten pig iron, to increase the milling ratio to 2.0, as the purpose, increase the air supply to the blast furnace and increase the ore reduction per unit time. operating. However, in this operation, in order to divide one charge of coke and ore into five batches and roll it up to the furnace top hopper, it takes considerable time and it is not easy to keep the stacking surface in the furnace almost at The accurate supply of raw materials has led to the need to shorten the roll-up time. Therefore, the formation of the mixed layer formed by the instant mixing of pre-mixed coke and ore was abandoned, and as a case 2 it was an operation caused by rolling up 4 batches of each charge. In addition, at this time, as a countermeasure for the increase in the milling ratio, it is necessary to increase the processing ore ratio (the proportion of the sintered ore in the ore) to 82% by mass to improve the reduction in the furnace. The operation status of Case 2 is shown in Table 2. However, when the milling ratio is increased, the mixed loading of Case 1 is abandoned. Although the processing ore ratio has been increased, the ventilation resistance index in the furnace is still 1.0. 5 increased to 1. 17 and the air permeability was worsened than that in case 1. 29 200404898 Therefore, the method of charging the raw materials to which the present invention is applied starts from the center of the furnace to the middle of the furnace, and rotates into the chute 13 times to load the sixth rotation of the coke chamber as C 2 at the same time. Load the ore. At this point, about 40% by mass of the total amount of coke charged in C2, coke * and ore mixed loading were started. The operation results of the case 3 and the cases 1 and 2 are shown in the above table 2 together. The coke ratio and fine powder charcoal ratio in Table 2 are the amounts of coke and fine powder charcoal (k g) used when producing 1 t of molten pig iron. The so-called processing ore ratio is a numerical value of ® representing the mass ratio of sintered ore within the ore etc. loaded from the furnace roof in%. The so-called coke strength T I is a rotation strength index. The ventilation resistance index is expressed by the following formula. [{(BP / 9 8. 0 6 6 5 + 1. 0 3 3) x 10000} 2-{(TP / 98. 0665 + 1. 033) χ 10000} 2] / (1.033χ 10000 X LSLOT) / (BGV / SAVE) 丨. 7 x 2 7 3 / {(SGT + 2 7 3) / 2 + 2 7 3} BP: supply air pressure [kPa] TP: furnace top pressure [kPa]

LSLOT: the distance between the material line and the air outlet [m] BGV: the gas amount in the furnace belly [Nm3 / min] SAVE: the average cross-sectional area in the blast furnace [m2]

S G T: The furnace neck represents the gas temperature: 1 0 0 0 ° C It is obvious from Table 2 that if the present invention is adopted, the milling ratio rises to 2.1. In addition, in this state, it is possible to perform coke center charging and mixing charging without stopping mixing charging halfway, and the ventilation resistance index system can be reduced to the same range as in Example 1, 30 200404898 degrees. 200404898 (Ne lifted. ^ Ή 嗦 哲 ^ V 〇 ¥ C3 趔 vg -fi- 3. is 0 nl ff 4 田 mr ί The number of ticks in the chute for one rotation 〇rH cn > oo CD CO LO LO Inch CO CO oo 16 17 18 19 20 ◦ t—H t—H t—H (XI CO i—H LTD rH LO T—H CO T—i oo CO LO 〇CD OO CD CO LO LO CO CO 16 17 18 19 20 05 〇rH i—H csi t—H CO T—H LO t— (CO rH oo 卜 co LO ◦ rH ① oo CD CD CO LO LO inch OO CO CO CD r—H rH CS3 rH oo inch t—H LO rH CO BU i—H 05 o < M CD rH r—H 1—H OJ t—H CO r—H Ye 1—H LO CO t—1 05 oo CD LO 1 Loading capacity (t / ch) CN1 LO ss —T " H inch LO CO CO CO s rH inch CNI LO CO or— ^ inch LO Content of hopper * G (coke) c2 (center coke) Gb (coke) Ch ( Ore) Ck C ore) G (coke) G (central coke) Oi (ore) Ck (ore) G (coke) c2 (coke) 〇l (ore) 〇2 (ore) Utilization project hopper 1-< CQ PQ pq OQ PO PO-< _1 _2 Paste 3 j 丨 bismuth ^^^ 处 ^ 疟 ^ 4 «^^^ 迗 ^ 4« ^ ¥ 二 冬 蛉 举 4 ^ 关 e US 1CN6 / ιι-(Ν6 / (φ) ®). ^^ κκ / (NI e 200404898

Table 2 Case 1 Case 2 Case 3 Sharp ratio t / d / m3 from the South Furnace 1.8. 2.1 2.1 The coke center is filled with mixed loading with or without coke ratio kg / t-p 403 400 402 fine powder carbon ratio kg / t — p 10 1 99 97 mass ratio of treated ore 74 82 74 coke strength (TI)% 84.5 85 84.5 out of milling S i mass% 0.27 0.31 0.25 ventilation resistance index — 1.05 1.17 1.03 312 / Instruction of the Invention (Supplement) / 92 -11 / 92123713 33 200404898 Table 3 Scale No. Tilt Angle 1 58 0 2 57 0 3 56 0 4 55 0 5 54 0 6 53 0 7 52 ° 8 51 ° 9 50 ° 10 49 ° 11 48 0 12 46 ° 13 44 ° 14 42 ° 15 40 0 16 38 ° 17 32 0 18 26 ° 19 21 0 20 15 ° (Example 2)

In the hoodless blast furnace (with an internal volume of 5000m3), the ore layer and the coke layer are alternately formed. When the ore layer is formed, as shown in FIG. 5, the mixed raw material 20 in which coke is mixed in the ore is stored in 1 stove top hopper 1. The amount of coke in the mixed raw material 20 is 16% by mass relative to the total amount of coke in one cycle of the ore layer and the coke layer. When the mixed raw material 20 is loaded through the loading chute 5, the flow rate 34 200404898 is used to adjust the gate 3 to adjust the flow rate of the mixed raw material 20 discharged from the furnace top hopper 1, and between 12 rotations, so that The chute 5 is charged to the total amount of mixed raw materials 20 in the furnace top hopper 1. That is, as shown in FIG. 5, the charging is started from the side of the blast furnace wall (that is, the mixed raw material 2 0 a loaded in the first rotation), and the tilting angle 0 is sequentially reduced. At the same time, the mixing is started. The raw material 20 is charged with the mixed raw material 20 to a predetermined tilting angle in the direction of the center of the blast furnace, and then the tilting angle 0 is sequentially increased, and at the same time, the mixed raw material 20 is charged. In this way, the charging is started from the blast furnace wall side, and the loading chute 5 is reciprocated once along the radius of the blast furnace, and then reinstalled on the blast furnace wall side (that is, it is installed on the 12th rotation). The mixed raw materials 20 b) are completed and the total amount of the mixed raw materials 20 in the furnace top hopper 1 is charged. Take this as an example of invention. On the other hand, as a comparative example, it is the same as the invention example. When the mixed raw material 20 is charged, it is adjusted by the flow adjustment gate 3, and it is inserted into the chute 5 between 1 and 2 rotations. The total amount of mixed raw materials 20 in the furnace hopper 1. Next, the charging is started from the blast furnace wall side, and the tilt angle β is sequentially reduced. At the same time, the mixed raw material 20 is loaded. At the blast furnace center side, the total loading of the mixed raw material 20 in the top hopper 1 is finished. The hoodless blast furnace used here is operated by setting the tilt angle 0 of the chute 5 into the scale number. The correspondence between the scale number and tilt angle (9 is the same as that shown in Table 3. In addition, the setting of the scale number when the mixed raw material is 20 is shown in Table 4. In addition, the scale number setting in Table 4 It is displayed that each scale number is inserted into the chute 5 each time. For example, in the comparative example, the two consecutive records of the scale number "5" indicate that the scale number "5" 35 200404898 is rotated 2 Next, after the chute 5 is installed, the chute 5 is rotated and installed in the next scale number "6". In addition, when the coke layer is formed, the invention examples and comparative examples are based on the total coke amount in one cycle. An amount equivalent to 10% by mass is charged into the center of the blast furnace (so-called central coke), and the remaining coke is uniformly charged along the radial direction of the blast furnace. That is, the chute system is coke-coke-ore (mixed) The raw materials 20) were loaded in three batches. For the invention example and the comparative example, operations were performed for 5 days to measure the coke ratio, fine powder carbon ratio, air supply temperature, molten pig iron temperature, and Si concentration in molten pig iron. The results are combined in Table 4. The coke ratio and fine powder carbon ratio in Table 4 are the ratios of the total coke use amount and the total fine powder char amount to the total amount of milling. In addition, the supply air temperature, the molten pig iron temperature, and the Si concentration in the molten pig iron are The average value of the values measured at regular intervals (6 to 7 times / day). In terms of the molten pig iron temperature and the Si concentration in the molten pig iron, the measured values are also uneven. From Table 4, it is clear that: In the invention example, the difference between the molten pig iron temperature and the Si concentration in the molten pig iron is further reduced compared to the comparative example. Therefore, in the invention example, even if the supply air temperature is lowered to 30 ° C in the comparative example, Operate stably while maintaining the same molten pig iron temperature.

200404898 (Example 3) In a large blast furnace with an internal volume of 50000 m3, the operation under the operating conditions shown in Table 5 was carried out. Here, in the comparative example, when the central coke was loaded, the chute was loaded at a tilt angle of 0 °, and the load was concentrated in the center of the furnace. On the other hand, in the example of the present invention, the loading start position is set to a dimensionless radius of 0.3, and with each rotation, the dimensionless radius of each of the movements is moved to the center of the furnace, and the central coke is loaded. In each operation, starting from the stacking surface of the furnace top of the neck of the blast furnace, the probe (sonde) set at a level below 5m is sent to the furnace radius direction, and the sampling starts from the furnace wall to the center of the furnace. The gas in the furnace at various locations up to the end was analyzed for CO gas and CO gas, and the gas utilization rate was calculated from these volume percentages. In addition, it can be considered that the so-called gas utilization rate is calculated by the gas utilization rate (%) two {C〇2 (vol%)} / {C0 (vol%) + C〇2 (vol%)} x 1 0.00. As a result, the proportion of ore is relatively increased in the part where the gas utilization rate in the blast furnace is large. The calculation result of the gas utilization rate is shown in FIG. 8. As shown in Fig. 8, in the comparative example, the gas utilization rate at the central portion of the furnace rises higher than the surrounding portion (up to a position with a dimensionless radius of about 0.2). It is thought that this is because the central coke is packed into the central part of the furnace. As a result, the coarse particles in the coke flow into the peripheral part of the furnace center to strengthen the gas flow in the furnace. Therefore, the charged ore is blown to the In some cases, the ore layer disintegrated and flowed into the center of the furnace. As a result, in the operation of the comparative example, the gas flow at the center of the furnace became unstable, and the fuel ratio became approximately 50.7 kg / t (melted pig iron). On the other hand, it is known that in the example of the present invention, the rate at the center of the furnace is reduced to about 15%, and a strong gas is formed at the center of the furnace. Since the distribution of the contents in the furnace becomes stable, That is, until the ratio drops to about 498 kg / t (melted pig iron), it is also the same as or more than the production of the comparative example. In addition, it is clear from Table 5 that in the present invention example, more low-cost fine powder carbon can be used, and in addition, the fuel ratio can be partially. (Example 4) A raw material loading test was performed using a furnace having an internal volume of about 10 m3 provided with a hoodless loading device. The raw materials charged were used as iron ore (symbol 0), and blast furnace coke (symbol C) which was generally used was used. At this time, the mass ratio of ore / coke is 3.2, and the ore system is such that one batch is charged into one batch, and the coke batch is loaded into one batch. In addition, the application of coke is performed by the raw material charging method in the state caused by the aforementioned raw material charging method of the present invention (two types of states are caused by the screen of all storage tanks. Then, when the coke is loaded, The coke dropped by the chute is captured at a certain time each time, and the horizontal axis of the obtained sample 1 1 is measured by the amount of coke discharged from the hopper (the total amount is taken as%, and the vertical axis becomes 5 of the sample coke). A ratio of 5 or more is apparent from Figure 11: if the present invention is used, the gas is used for mass flow. Then the fuel can be used as a comparative example to reduce the full test high sinter ore to carbon as 0. The / C system makes the 1-packed system solid and the sample size by a 35 mm). Figure 100%) ^ (%). In the initial stage, 39 200404898, that is, the particle size of the coke deposited in the center of the furnace, became larger than the state caused by the usual installation method. (Industrial Applicability) According to the first embodiment, when a high-throughput operation is performed by using a hoodless blast furnace, coke and ore mixing charging and coke center charging can be performed simultaneously all the time. This can effectively prevent the increase of pressure loss in the furnace which is easy to occur during high-volume operations, and can increase the production of melting products without increasing the use of high-grade raw materials such as sinter or reduced iron. According to the second embodiment, even when the particle size distribution of the raw materials used in the blast furnace and the properties including the moisture content are changed, the raw material stacking surface on the top of the blast furnace can be mixed at a certain mixing ratio. The distribution of ore and coke suppresses changes in the temperature and quality of molten pig iron. By applying the third embodiment, the center coke of the uncovered blast furnace equipped with a chute can be used, so that the particle size of the coke in the center of the furnace is maximized and stable operation can be realized. Then, it is possible to carry out the same or higher production with a lower fuel and to achieve a better blast furnace operation. In the fourth and fifth embodiments, the existing uncovered loading device can be used even if a special coke loading device is not provided, and the particle size can be larger than the surrounding size without increasing the number of raw materials. The large-size carbon is selectively loaded into the center of the blast furnace. This department indicates that if the present invention is used in a practical blast furnace, the furnace gas can be stabilized and ensured. 312 / Invention Manual (Supplement) / 92-11 / 92123713 The birth of the combination of iron and iron is better The central stream of the coking mining body 40 200404898 can be used to dazzle pig iron with high productivity and economy. Table 5 ^ —————— A Comparative Example Milling ratio (t / d / m1) 2.03 2.05 Coke ratio (kg / t) 405 378 Fine powder carbon ratio (kg / t) 102 120 Fuel ratio (kg / t) 507 498 ore processing ratio (%) 78 78 [Simplified illustration of the drawing] Fig. 1 is a sectional view illustrating the top of a furnace without a hood. Fig. 2 is a conceptual diagram illustrating a method for loading raw materials according to the first embodiment; Fig. 2 (a) shows a period of loading ore, and Fig. 2 (b) shows a loading position in a blast furnace. Fig. 3 is a sectional view showing a state of accumulation of raw materials in a furnace in a state where the raw material charging method of the first embodiment is applied. Fig. 4 is a cross-sectional view illustrating the furnace top of the hoodless blast furnace according to the second embodiment. Fig. 5 is a cross-sectional view schematically showing an example in which a mixed raw material is charged by applying the raw material charging method of the second embodiment. Fig. 6 is a schematic view showing a chute arrangement of a hoodless blast furnace according to the third embodiment. Fig. 7 is a schematic cross-sectional view of a build-up layer in a furnace incorporated in a charging chute according to the third embodiment. Fig. 8 is a graph showing a gas utilization distribution in the blast furnace of Example 3. 41 1] 2 / Invention Specification (Supplement) / 92-11 / 92123713 200404898 Fig. 9 is a graph showing the distribution of the coarse granulation rate of the central coke caused by the difference in the loading start position of Embodiment 4. FIG. 10 is a diagram illustrating a raw material charging method according to the fourth embodiment. Fig. 11 is a graph showing the relationship between the amount of coke discharged (%) from the hopper of Example 4 and the ratio (%) of 55 or more in the sample coke. (Description of component symbols) Θ Tilt angle

a Spin b Drop Cl Coke C 2 Stacked layer C 2 + 0 1 Mixing layer 0 2 Ore 1 Furnace hopper la Furnace hopper lb Furnace hopper 2 Raw material 3 Flow adjustment gate 4 Vertical chute 5 Loading chute 6 Furnace 6 a Furnace center 7 Central shaft 8 Raw material stacking surface 42 200404898

14 Stacked layers in the furnace 20 Mixed raw materials 20a Mixed raw materials 20b Mixed raw materials 21 Sieve 22 Storage tank 22a Storage tank 23 Weighing funnel 24a Coke 24b Jiaoshangan 312 / Invention Manual (Supplement) / 92-11 / 92123713 43

Claims (1)

200404898 Scope of patent application: 1. A raw material charging method for a hoodless blast furnace equipped with a hoodless charging device, comprising the following steps: (a) the step of storing coke in at least 1 furnace top hopper; ( b) the step of storing ore in at least one furnace top hopper; (c) the chute of the aforementioned unloaded loading device is rotated while changing its tilt angle, and is moved from the center of the furnace along the radius of the furnace Step of charging the stored coke with the part facing the furnace wall part; (d) The step of loading the stored ore for the chute of the aforementioned hoodless loading device while rotating it while changing its tilt angle, and from the center of the furnace toward the wall of the furnace along the radius of the furnace ; And (e) controlling the discharge of coke stored in the at least one furnace-top hopper, and starting to discharge between 5 to 50 mass% of the coke loading amount in one batch, Steps of ore. 2. —A raw material charging method for a hoodless blast furnace equipped with a hoodless charging device, comprising the following steps: (a) the step of storing the mixed raw materials of mixed ore and coke in a furnace top hopper; ( b) The step of rotating the loading chute around the central axis of the blast furnace and sequentially changing the tilt angle of the loading chute, and loading the mixed raw materials stored in the furnace hopper into the blast furnace And (c) a step of loading into the blast furnace the total amount of the mixed raw materials stored in the furnace hopper while the loading chute reciprocates at least once along the radius of the blast furnace. 44 200404898 3. —A raw material charging method for a hoodless blast furnace provided with a hoodless charging device, which includes the following steps: (a) Set the furnace center to 0 and the furnace to the hoodless blast furnace The wall portion is set to a dimensionless radius of 1, leaving a radius position corresponding to 0.1 to 0.4, and the coke charging step is started using the loading chute of the aforementioned hoodless loading device; and (b) the The step of loading the chute in order to move the tilting angle of the chute to the center side of the furnace in order to load coke. 4. A raw material charging method for a hoodless blast furnace, comprising a raw material charging method for a hoodless blast furnace having a hoodless charging device including the following steps: Cutting out and storing in at least 2 storage tanks Coke, a coke screening step of screening the cut coke through a sieve set at the lower part of the tank; a coke on the sieve being weighed by a weighing funnel, stored in a weighing storage step in a hopper set on the top of the furnace; Step; and the step of loading the stored coke into the blast furnace by rotating the chute while rotating the chute from the furnace center to the furnace wall side through the chute of the hoodless charging device; It is the first screening step of screening the cut coke by a sieve having a larger sieve (A), and the first screening step of screening the coke that is cut by a sieve having a smaller sieve (B). It consists of 2 sieving steps. The aforementioned weighing and storage step is to initially transfer a certain amount of coke from the first sieving step to the aforementioned weighing funnel, and then to convey from No. 2 45 312 / Invention Specification (Supplement) / 92-11 / 92123713 20040489 8 Screen the coke in the step and weigh it in 1 batch, and store it in a hopper set on the top of the furnace. 5. The raw material charging method of the hoodless blast furnace according to item 4 of the patent application, wherein the coke from the first screening step of screening the cut coke through a sieve having a larger sieve opening (A) The amount is 5 to 50% by mass of the coke amount in the batch. 6. —A raw material charging method for a hoodless blast furnace equipped with a hoodless charging device, comprising the following steps: (a) the step of storing coke in at least 1 furnace top hopper; (b) in at least 1 Steps for storing ore on the furnace top hopper; (c) Steps for storing mixed raw materials of mixed ore and coke in a furnace hopper; (d) For the chute of the aforementioned hoodless loading device, changing its tilting angle while Rotating it, and loading the stored coke from the center of the furnace toward the wall of the furnace along the radial direction of the furnace; (e) for the chute of the aforementioned hoodless loading device, changing its tilting angle while One side is rotated, and the stored ore is loaded from the center of the furnace toward the wall of the furnace along the radius of the furnace; (f) controlling the amount of coke discharged stored in the at least one furnace top hopper at 1 Between 5 and 50 mass% of coke loading in batches, the step of discharging the ore stored in the aforementioned at least one furnace top hopper is started; (g) rotating the loading chute and sequentially changing the loading on the one side Tilt angle of chute, while one side will be stored in front The step of loading the mixed raw materials of the furnace top hopper into the blast furnace; and 46 200404898 (h) during the aforementioned loading chute reciprocating at least once along the radius of the blast furnace, controlling the mixing of the raw materials stored in the foregoing furnace hopper The total amount is charged into the aforementioned blast furnace. 47