A method for charging a blast furnace

Abstract

The present invention relates to the technical field of blast furnace smelting, and in particular to a blast furnace charging method, comprising the following steps: coke diced and ore material are alternately put into a furnace top material tank through a feeding main belt, and then the coke diced and ore material are alternately distributed in the blast furnace through a rotating chute; the coke diced and ore material are alternately distributed in a radial annular manner in the blast furnace, and the coke diced is evenly distributed in the center and edge of the blast furnace; wherein the total batches of coke diced are n times, and the total batches of ore material are (n-1) times, and n is selected from an integer of 3-8. In the blast furnace charging method of the present invention, coke diced and ore material are alternately distributed in a radial annular manner in the blast furnace, and the coke diced is evenly distributed in the center and edge of the blast furnace. When the ore layer mixed with the coke diced reaches the soft melting zone, the ore is soft-melted and liquefied, and the permeability of the blast furnace is deteriorated, but the coke diced in the ore layer in the soft melting zone can form a small coke window, which greatly improves the permeability of the blast furnace.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace smelting, and in particular to a blast furnace charging method. Background Art

[0002] Blast furnace is an important equipment for steel smelting. The use of blast furnace for ironmaking has the advantages of good economic indicators, simple process, large production volume, high labor productivity and low energy consumption. The blast furnace body is divided into five parts from top to bottom: center, furnace body, furnace waist, furnace belly and furnace hearth. When the blast furnace is in production, iron ore, coke and slag-making flux are loaded from the top of the furnace, and preheated air is blown into the tuyere located at the bottom of the furnace along the furnace periphery. The carbon in the coke burns with the oxygen in the blown air at high temperature to generate carbon monoxide and hydrogen. The oxygen in the iron ore is removed during the rising process in the furnace, thereby reducing iron; the smelted molten iron is released from the iron mouth; the unreduced impurities in the iron ore combine with fluxes such as limestone to form slag, which is discharged from the slag mouth; the generated coal gas is discharged from the top of the furnace, and after dust removal, it is used as fuel for hot blast stoves, heating furnaces, coke ovens, boilers, etc.; the main product of blast furnace smelting is pig iron, and there are also by-products of blast furnace slag and blast furnace gas.

[0003] The permeability of the soft melting zone in the blast furnace is an important factor affecting the stable and smooth operation of the blast furnace, and is determined by the softening and melting characteristics of the charge. When the charge softens and melts inside, the viscous resistance coefficient and the internal inertial resistance coefficient of the charge to the gas change greatly, resulting in poor permeability and increased internal maximum pressure difference. Studies have found that the permeability of the blast furnace can be effectively improved by adjusting the distribution method of the blast furnace. For example, Chinese patent application 201010197018.7 discloses a new central coking method for multi-ring matrix distribution of the bell-free furnace top of a blast furnace. This method is based on the multi-ring matrix distribution method, and more than 50% of the coke is distributed in the central area, so that the thickness of the central coke layer is greater than the thickness of the edge coke layer, and the central charge surface is realized. The shape of the bun. The advantage is that the distribution method can adapt to coke fluctuations and is conducive to the use of small-particle ore, keeping the furnace condition stable and smooth, and opening the center. However, the central coking technology is prone to low gas utilization and high fuel ratio under the condition that the raw fuel is generally stable, which is not conducive to reducing production costs. Therefore, it is necessary to provide a charging method that can improve the permeability of the blast furnace and has low cost. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a blast furnace charging method, which adopts alternating feeding of coke and ore materials, and the coke is distributed in multiple rings from the center to the edge of the blast furnace, which effectively improves the permeability of the blast furnace.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A blast furnace charging method comprises the following steps:

[0007] The coke diced and the ore material are alternately fed into the top material tank through the main feeding belt, and then the coke diced and the ore material are alternately distributed into the blast furnace through the rotating chute; the coke diced and the ore material are alternately distributed in a radial annular manner in the blast furnace, and the coke diced is evenly distributed in the center and the edge of the blast furnace;

[0008] The total number of batches of chopped coke is n, the total number of batches of ore is (n-1), and n is an integer selected from 3-8.

[0009] In some of the embodiments, the ore material includes 60%-70% sintered ore, 20%-30% pelletized ore, and 5%-15% lump ore, calculated by mass percentage, and the iron content of the ore material is 50%-60%.

[0010] In some of the embodiments, the particle size of the chopped coke is 8mm-18mm, and the chopped coke ratio is 20kg / t·Fe-35kg / t·Fe.

[0011] In some of the embodiments, before the coke and ore are charged, the steps of testing the blast furnace permeability index k and determining the total number of coke batches n and the coke ratio q according to the blast furnace permeability index k are also included.

[0012] In some embodiments, the total batches n of the coke diced and the blast furnace permeability index k satisfy:

[0013] n=(15.5-k) / 0.3+3

[0014] Among them, 14≤k≤15.5, the total batch n of diced coke is an integer.

[0015] In some embodiments, the coke ratio q and blast furnace permeability index k of the coke satisfy:

[0016] q=(15.5-k)×10+20

[0017] Among them, 14≤k≤15.5, the unit of coke ratio q is kg / t·Fe.

[0018] In some of the embodiments, the feeding amount of the nth batch of diced coke is greater than or equal to the feeding amount of the (n+1)th batch of diced coke.

[0019] In some preferred embodiments, the feeding amount of the nth batch of diced coke is greater than the feeding amount of the (n+1)th batch of diced coke.

[0020] In some of the embodiments, the feed amount of the nth batch of chopped coke accounts for 10%-30% of the total feed amount of chopped coke.

[0021] In some embodiments, the blast furnace is 1080m 3 -1380m 3 blast furnace.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) In the blast furnace charging method of the present invention, coke diced and ore materials are alternately distributed in a radial annular manner in the blast furnace, and coke diced is evenly distributed in the center and edge of the blast furnace. When the ore layer mixed with coke diced reaches the soft melting zone, the ore is soft-melted and liquefied, and the permeability of the blast furnace deteriorates. However, the coke diced in the ore layer in the soft melting zone can form a small coke window, which greatly improves the permeability of the blast furnace. The charging method of the present invention can effectively avoid the phenomenon of suspended materials in the blast furnace caused by the deterioration of the blast furnace raw material conditions and the deterioration of the blast furnace permeability, ensure the normal operation of the blast furnace production order, and reduce the economic losses caused by handling the blast furnace conditions.

[0024] (2) The inventors of this application have found through long-term practice that for 1080m 3 -1380m 3 When the permeability of blast furnace is between 14 and 15.5, the total number of coke batches, the coke ratio and the permeability of blast furnace are roughly linearly correlated, and the calculation relationship between the total number of coke batches, the coke ratio and the permeability of blast furnace is further given, that is, according to 1080m 3 -1380m 3 The permeability value of the blast furnace determines the total number of coke batches and the coke ratio of the charge, which greatly simplifies the production process and maximizes the thermal effect of the coke, thereby maximizing the economic value of blast furnace production. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0026] Example 1

[0027] This embodiment adopts an effective furnace capacity of 1080m 3 The blast furnace has a permeability index of 15.5 and adopts the following charging method:

[0028] Three batches of diced coke and two batches of ore are alternately fed into a charging tank on the furnace top through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring shape in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 60% of sintered ore, 25% of pelletized ore, and 15% of lump ore, and the iron content of the ore is 50%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 20kg / t·Fe, and the ratio of the feeding amount of the first batch to the third batch of diced coke is 1:0.8:0.5.

[0029] Example 2

[0030] The difference between this embodiment and embodiment 1 is that the total batch of coke diced materials is different, and the present embodiment specifically comprises the following steps:

[0031] Use effective furnace capacity 1080m 3 The blast furnace has a permeability index of 15.5 and adopts the following charging method:

[0032] Four batches of diced coke and three batches of ore are alternately fed into a charging tank on the furnace top through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 60% of sintered ore, 25% of pelletized ore, and 15% of lump ore, and the iron content of the ore is 50%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 20kg / t·Fe, and the ratio of the feeding amount of the first batch to the fourth batch of diced coke is 1:0.8:0.7:0.5.

[0033] Example 3

[0034] The difference between this embodiment and embodiment 1 is that the total batch of coke diced materials is different, and the present embodiment specifically comprises the following steps:

[0035] Use effective furnace capacity 1080m 3 The blast furnace has a permeability index of 15.5 and adopts the following charging method:

[0036] Seven batches of diced coke and six batches of ore are alternately fed into a charging tank on the top of a furnace through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring shape in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 60% of sintered ore, 25% of pelletized ore, and 15% of lump ore, and the iron content of the ore is 50%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 20kg / t·Fe, and the ratio of the feeding amount of the first batch to the seventh batch of diced coke is 1:0.6:0.6:0.6:0.6:0.6:0.6.

[0037] Example 4

[0038] The difference between this embodiment and embodiment 1 is that the coke-to-dining ratio is different, and the present embodiment specifically comprises the following steps:

[0039] Use effective furnace capacity 1080m 3 The blast furnace has a permeability index of 15.5 and adopts the following charging method:

[0040] Three batches of diced coke and two batches of ore are alternately fed into a charging tank on the furnace top through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 60% of sintered ore, 25% of pelletized ore, and 15% of lump ore, and the iron content of the ore is 50%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 25kg / t·Fe, and the feeding ratio of the first batch to the third batch of diced coke is 1:0.8:1.5.

[0041] Comparative Example 1

[0042] This comparative example uses an effective furnace capacity of 1080m 3 The blast furnace has a permeability index of 15.5 and adopts the following charging method:

[0043] The diced coke and the ore are mixed evenly to obtain a mixture, the mixture is put into a material tank on the top of the furnace through a main feeding belt, and then the mixture is distributed into a blast furnace through a rotating chute; the diced coke and the ore are evenly distributed in the blast furnace; wherein, calculated by mass percentage, the ore includes 60% of sintered ore, 25% of pelletized ore, and 15% of lump ore, and the iron content of the ore is 50%; the particle size of the diced coke is 8mm-18mm, and the diced coke ratio is 20kg / t·Fe.

[0044] The blast furnace application effects of Examples 1-4 and Comparative Example 1 are shown in Table 1:

[0045] Table 1

[0046] Gas utilization rate (%) Improved air permeability (increased value) Daily output (tons) Cost per ton of iron (yuan / ton) Example 1 44 0.1 4110 2849 Example 2 43.8 0.1 4120 2848 Example 3 43.8 0.1 4120 2848 Example 4 43.5 0.2 4130 2847 Comparative Example 1 44.3 0 4100 2850

[0047] By comparing Example 1 and Example 2-3, it can be seen that when the coke and ore materials are alternately distributed in a radial ring in the blast furnace, an increase in the total batch number of coke is beneficial to improving the permeability of the blast furnace, which will make the forward running state of the blast furnace smoother and increase the output of the blast furnace; this is because when the ore layer reaches the soft melting zone and is heated and liquefied, the coke layer in the ore forms a coke window to play a role, thereby improving the permeability of the blast furnace; however, when the blast furnace permeability index is relatively high, the effect of improving the permeability of the blast furnace brought about by the increase in the total batch number of coke is not obvious, because in this state, the raw material conditions entering the furnace are relatively good, the powder entering the furnace is relatively small, and the metallurgical properties of the ore can meet the smelting needs of the blast furnace. The blast furnace permeability index of Examples 1-3 is relatively high, reaching 15.5. Compared with Example 1, Example 2-3 increases the total number of batches of diced coke, but the blast furnace output is only increased by 10 tons, and the cost per ton of iron is only reduced by 1 yuan. On the contrary, the increase in the number of batches of diced coke will increase the complexity of blast furnace operation. That is, when the blast furnace permeability index is relatively high, the overall benefit of Example 2-3 after increasing the total number of batches of diced coke is slightly lower than that of Example 1.

[0048] Comparing Example 1 and Example 4, it can be seen that the increase in the coke-butadiene ratio is conducive to the improvement of the blast furnace permeability, because the increase in the coke-butadiene ratio makes the coke window volume in the soft melting zone relatively increase; however, when the blast furnace permeability index is relatively high, the effect of improving the blast furnace permeability brought about by the increase in the coke-butadiene ratio is not obvious, because at this time, the raw material conditions entering the furnace are relatively good, the powder entering the furnace is relatively small, and the metallurgical properties of the ore can meet the smelting needs of the blast furnace. The blast furnace permeability index of Example 1 and Example 4 is relatively high, reaching 15.5. Example 4 increases the coke-butadiene ratio relative to Example 1, but the blast furnace output is only increased by 20 tons, and the cost per ton of iron is only reduced by 2 yuan; and the increase in the coke-butadiene ratio will lead to an increase in cost, that is, when the blast furnace permeability index is relatively high, increasing the coke-butadiene ratio will not significantly improve the blast furnace production effect.

[0049] By comparing Example 1 and Comparative Example 1, it can be seen that the charging method of alternatingly distributing diced coke and ore along the radial annular direction in the blast furnace can significantly improve the permeability of the blast furnace. This is because when the ore reaches the soft melting zone, the diced coke is relatively concentrated compared to the dispersed addition, and a coke window of a certain size can be formed in the soft melting zone, which has a positive effect on the permeability of the blast furnace; while in Comparative Example 1, the diced coke and ore are mixed and directly charged, and the diced coke is directly mixed and dispersed in the ore layer. When the ore reaches the soft melting zone, the diced coke is too dispersed in this method to form a coke window of a certain size, and thus the permeability of the blast furnace cannot be improved, and the cost-effectiveness of the blast furnace cannot be achieved.

[0050] A comprehensive comparison of Examples 1-4 and Comparative Example 1 shows that the provision of butane during blast furnace charging is beneficial to improving the air permeability of the blast furnace. However, the determination of the number of butane rings, i.e., the total number of butane batches, is closely related to the air permeability of the blast furnace. Only when the two are matched can the thermal improvement effect of butane be maximized, thereby maximizing the production efficiency of the blast furnace.

[0051] Example 5

[0052] This embodiment adopts an effective furnace capacity of 1080m 3 The blast furnace has a permeability index of 15 and adopts the following charging method:

[0053] Five batches of diced coke and four batches of ore are alternately fed into a furnace top material tank through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 25kg / t·Fe, and the ratio of the feeding amount of the first batch to the fifth batch of diced coke is 1:0.8:0.7:0.6:0.5.

[0054] Example 6

[0055] The difference between this embodiment and embodiment 5 is that the total batch of coke diced materials is different, and specifically comprises the following steps:

[0056] Four batches of diced coke and three batches of ore are alternately fed into a charging tank on a furnace top through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 25kg / t·Fe, and the ratio of the feeding amount of the first batch to the fourth batch of diced coke is 1:0.8:0.7:0.5.

[0057] Example 7

[0058] The difference between this embodiment and embodiment 5 is that the total batch of coke diced materials is different, and specifically comprises the following steps:

[0059] Seven batches of diced coke and six batches of ore are alternately fed into a charging tank on the top of a furnace through a main feeding belt, and then the diced coke and the ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and the ore are alternately distributed in a radial ring shape in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 25kg / t·Fe, and the ratio of the feeding amount of the first to seventh batches of diced coke is 1:0.6:0.6:0.6:0.6:0.6:0.6.

[0060] Example 8

[0061] The difference between this embodiment and embodiment 5 is that the coke-to-dining ratio is different, and the present embodiment specifically comprises the following steps:

[0062] Five batches of diced coke and four batches of ore are alternately fed into a charging tank on a furnace top through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 20kg / t·Fe, and the ratio of the feeding amount of the first batch to the fifth batch of diced coke is 1:0.8:0.7:0.6:0.5.

[0063] Example 9

[0064] The difference between this embodiment and embodiment 5 is that the coke-to-dining ratio is different, and the present embodiment specifically comprises the following steps:

[0065] Five batches of diced coke and four batches of ore are alternately fed into a charging tank on a furnace top through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring shape in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 30kg / t·Fe, and the ratio of the feeding amount of the first batch to the fifth batch of diced coke is 1:0.8:0.7:0.6:0.5.

[0066] Example 10

[0067] The difference between this embodiment and embodiment 5 is that the ratio of the feeding amount of chopped coke is different, and specifically comprises the following steps:

[0068] Five batches of diced coke and four batches of ore are alternately fed into a charging tank on a furnace top through a main feeding belt, and then the diced coke and the ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and the ore are alternately distributed in a radial ring shape in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 25kg / t·Fe, and the ratio of the feeding amount of the first batch to the fifth batch of diced coke is 1:1:1:1:1:1.

[0069] Embodiment 11

[0070] The difference between this embodiment and embodiment 5 is that the ratio of the feeding amount of chopped coke is different, and specifically comprises the following steps:

[0071] Five batches of diced coke and four batches of ore are alternately fed into a charging tank on a furnace top through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 25kg / t·Fe, and the ratio of the feeding amount of the first batch to the fifth batch of diced coke is 1:0.8:0.7:0.6:0.2.

[0072] Comparative Example 2

[0073] Five batches of ore materials and four batches of diced coke are alternately fed into a furnace top material tank through a main feeding belt, and then the ore materials and diced coke are alternately distributed into a blast furnace through a rotating chute; the ore materials and diced coke are alternately distributed in a radial ring shape in the blast furnace, and the ore materials are evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore materials include 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore materials is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 25kg / t·Fe, and the ratio of the feeding amount of the first batch to the fourth batch of diced coke is 1:0.8:0.7:0.5.

[0074] Comparative Example 3

[0075] Four batches of ore and four batches of diced coke are alternately fed into a furnace top material tank through a main feeding belt, and then the ore and diced coke are alternately distributed into a blast furnace through a rotating chute; the ore and diced coke are alternately distributed in a radial ring in the blast furnace, with the diced coke distributed in the center of the blast furnace and the ore distributed at the edge; wherein, calculated by mass percentage, the ore comprises 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 25kg / t·Fe, and the ratio of the feeding amount of the first batch to the fourth batch of diced coke is 1:0.8:0.7:0.5.

[0076] Comparative Example 4

[0077] Four batches of diced coke and four batches of ore are alternately fed into a charging tank on the top of a furnace through a main feeding belt, and then the diced coke and the ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and the ore are alternately distributed in a radial ring in the blast furnace, and the ore is distributed in the center of the blast furnace and the diced coke is distributed at the edge; wherein, calculated by mass percentage, the ore comprises 65% of sintered ore, 30% of pelletized ore, and 5% of lump ore, and the iron content of the ore is 60%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 25kg / t·Fe, and the ratio of the feeding amount of the first batch to the fourth batch of diced coke is 1:0.8:0.7:0.5.

[0078] The blast furnace application effects of Examples 5-11 and Comparative Examples 2-4 are shown in Table 2:

[0079] Table 2

[0080] Gas utilization rate (%) Improved air permeability (increased value) Daily output (tons) Cost per ton of iron (yuan / ton) Example 5 43.5 0.5 4150 2845 Example 6 43.8 0.2 4120 2848 Example 7 43.8 0.2 4120 2848 Example 8 43.9 0.1 4100 2850 Example 9 43.8 0.2 4120 2848 Example 10 43.5 0.3 4130 2850 Embodiment 11 43.8 0.2 4120 2848 Comparative Example 2 44.1 0 4100 2850 Comparative Example 3 43.9 0.1 4100 2850 Comparative Example 4 43.9 0.1 4100 2850

[0081] By comparing Example 5 with Examples 6-7, it can be seen that when the diced coke and the ore materials are alternately distributed in a radial ring shape in the blast furnace, the total number of batches of diced coke will affect the effect of improving the air permeability of the blast furnace within a certain range. The blast furnace permeability index in Examples 5-7 is 15. The total batches of coke bits in Example 5 are increased from 4 batches to 5 batches relative to Example 6, the blast furnace permeability is significantly improved, the blast furnace runs better, and the output is increased. This is because when the quality of the blast furnace charge deteriorates, the permeability of the soft melting zone gradually deteriorates due to the deterioration of the metallurgical properties of the ore or the excessive powder entering the furnace. If no relevant measures are taken to alleviate this, it is very likely to affect the smooth running of the blast furnace and cause a suspended material accident. Although Example 6 alleviates the blast furnace permeability, the coke bits in the ore are too concentrated and the ore ring belt is relatively wide, so the improvement effect is limited; Example 7 further improves the total batches of coke bits relative to Example 5, and the number of coke bits rings increases, resulting in a narrowing of the width of each coke bit ring belt, and the size of the coke window formed is limited. At this time, the effect of improving the blast furnace permeability is not obvious. Compared with Example 5, Examples 6 and 7 are not ideal, and the permeability index is only increased by 0.2, and the blast furnace forward trend is still in a poor state.

[0082] By comparing Example 5 with Examples 8-9, it can be seen that a proper increase in the coke-butadiene ratio is beneficial to improving the air permeability of the blast furnace. The coke-butadiene ratio of Example 8 is relatively low, and the coke-butadiene ring zone formed is narrow, which has limited effect on improving the air permeability of the blast furnace and cannot reverse the passive situation of the deterioration of the forward trend of the blast furnace; the coke-butadiene ratio of Example 9 is relatively high, and although the air permeability improvement effect of the blast furnace is good at this time; the coke-butadiene ratio of Example 9 is significantly higher than that of Example 5, but the effect of improving the air permeability of Example 9 is equivalent to or even slightly worse than that of Example 5. It can be seen that the extra coke-butadiene in Example 9 is excess performance, resulting in a waste of coke-butadiene, leading to a further increase in cost.

[0083] Comparing Example 5 with Comparative Examples 2-4, it can be seen that the distribution of coke and ore in the blast furnace will affect the effect of coke on improving the air permeability of the blast furnace. The blast furnace operation rules must ensure the edge and center airflows, so that the blast furnace can run smoothly. Comparative Example 2 evenly distributes ore at the center and edge. This distribution method does not implement coke distribution at the edge and center. Although coke is also used, the thermal improvement effect of coke cannot be exerted, so that the air permeability of the blast furnace is still poor; Comparative Example 3 distributes ore at the edge of the blast furnace and coke in the center. Comparative Example 4 distributes ore at the center of the blast furnace and coke at the edge. Compared with Comparative Example 2, it has a certain effect of improving air permeability; however, the edge airflow is suppressed in Comparative Example 3, and the center airflow is suppressed in Comparative Example 4. Compared with the solution of simultaneously ensuring the edge and center airflows in Example 5, the two still have poor effects on improving the air permeability of the blast furnace.

[0084] By comparing Example 5 with Examples 10-11, it can be seen that the amount of coke cut into the center and edge of the blast furnace will also affect the effect of coke cut into improving the air permeability of the blast furnace. In Example 10, the amount of coke cut into each batch is the same, and the improvement of the air permeability of the blast furnace is not obvious. This is because for the coke cut into the ring belt, the coke cut into the outermost ring generally occupies the largest volume, and the volume of the central coke cut into the smallest volume. The equal distribution in Example 10 is equivalent to greatly reducing the burden of the central airflow, but it will cause the thickness of the coke cut into the edge to decrease, thereby increasing the burden on the edge, making the overall airflow distribution improvement effect not obvious; Example 11 is just the opposite. The amount of coke cut into the last batch accounts for less than 10%, the coke cut into the edge is too much, but the center is limited, and the effect of improving the air permeability of the blast furnace is not obvious.

[0085] Example 12

[0086] This embodiment adopts an effective furnace capacity of 1080m 3 The blast furnace has a permeability index of 14.6 and adopts the following charging method:

[0087] Six batches of diced coke and five batches of ore are alternately fed into a charging tank on a furnace top through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 70% of sintered ore, 20% of pelletized ore, and 10% of lump ore, and the iron content of the ore is 55%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 29kg / t·Fe, and the ratio of the feeding amount of the first batch to the sixth batch of diced coke is 1:0.9:0.8:0.7:0.6:0.5.

[0088] Example 13

[0089] This example uses an effective furnace capacity of 1380m 3The blast furnace has a permeability index of 14 and adopts the following charging method:

[0090] Eight batches of diced coke and seven batches of ore are alternately fed into a charging tank on a furnace top through a main feeding belt, and then the diced coke and ore are alternately distributed into a blast furnace through a rotating chute; the diced coke and ore are alternately distributed in a radial ring shape in the blast furnace, and the diced coke is evenly distributed in the center and edge of the blast furnace; wherein, calculated by mass percentage, the ore comprises 70% of sintered ore, 20% of pelletized ore, and 10% of lump ore, and the iron content of the ore is 55%; the particle size of the diced coke is 8mm-18mm, the diced coke ratio is 35kg / t·Fe, and the ratio of the feeding amount of the diced coke from the first batch to the eighth batch is 1:0.8:0.8:0.8:0.8:0.7:0.7:0.7.

[0091] The blast furnace application effects of Examples 12-13 are shown in Table 3:

[0092] Table 3

[0093] Gas utilization rate (%) Improved air permeability (increased value) Daily output (tons) Cost per ton of iron (yuan / ton) Example 12 43.5 1.5 4150 2845 Example 13 43.5 1.5 4150 2845

[0094] By comparing Examples 1, 5, 12, 13, 2, 6, 3, and 7, it can be seen that the total number of coke batches is highly correlated with the blast furnace permeability value. When the blast furnace permeability value is high, the coke ratio can be appropriately reduced while reducing the total number of coke batches. When the blast furnace permeability value is low, the coke ratio needs to be increased and the total number of coke batches needs to be increased. The inventors of this application have found through practice that for 1080m 3 -1380m 3 Blast furnace, when the blast furnace permeability value is 14-15.5, the total number of coke batches, coke ratio and blast furnace permeability value are roughly linearly correlated, that is, according to 1080m 3 -1380m 3 The permeability value of the blast furnace determines the total number of coke batches and coke ratio of the charge, thereby maximizing the economic value of the blast furnace production.

[0095] In summary, the blast furnace charging method of the present invention adopts alternating feeding of coke and ore, and makes the coke and ore alternately distributed in a radial ring shape in the blast furnace, and the coke is evenly distributed in the center and edge of the blast furnace, which successfully improves the permeability of the blast furnace and is suitable for industrial promotion.

[0096] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description here should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in the field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A blast furnace charging method, characterized in that: The following steps are involved: The coke diced and the ore material are alternately fed into the top material tank through the main feeding belt, and then the coke diced and the ore material are alternately distributed into the blast furnace through the rotating chute; the coke diced and the ore material are alternately distributed in a radial annular manner in the blast furnace, and the coke diced is evenly distributed in the center and the edge of the blast furnace; The total number of batches of coke diced is n, the total number of batches of ore ore is (n-1), and n is an integer selected from 3 to 8; The particle size of the coke diced is 8mm-18mm, and the coke diced ratio is 20kg / t•Fe-35kg / t•Fe; Before the coke and ore are charged, the method further includes testing the blast furnace permeability index k, and determining the total number of coke batches n and the coke ratio q according to the blast furnace permeability index k; The total batches n of the coke diced and the blast furnace permeability index k satisfy: ； Wherein, 14≤k≤15.5, the total batches of coke diced are integers; The coke ratio q of the coke and the blast furnace permeability index k of the coke satisfy: ； Among them, 14≤k≤15.5, the unit of coke ratio q is kg / t•Fe.

2. The blast furnace charging method according to claim 1, characterized in that: Calculated by mass percentage, the ore material includes 60%-70% sintered ore, 20%-30% pelletized ore, and 5%-15% lump ore, and the iron content of the ore material is 50%-60%.

3. The blast furnace charging method according to claim 1, characterized in that: The amount of coke fed to the nth batch is greater than or equal to the amount of coke fed to the (n+1)th batch.

4. The blast furnace charging method according to claim 3, characterized in that: The amount of coke fed to the nth batch is greater than the amount of coke fed to the (n+1)th batch.

5. The blast furnace charging method according to claim 4, characterized in that: The feeding amount of the nth batch of coke diced accounts for 10%-30% of the total feeding amount of coke diced.

6. The blast furnace charging method according to any one of claims 1 to 5, characterized in that: The blast furnace is 1080m 3 -1380m 3 blast furnace.

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