Blast furnace full coke smelting method

Abstract

The invention discloses a blast furnace full coke smelting method. The blast furnace full-coke smelting method comprises the following steps: obtaining smelting data of a blast furnace in a normal production state, and determining a coke load and a coke supplementing amount of the blast furnace in a full-coke smelting state according to the smelting data; when the coal injection system of the blast furnace cannot inject coal, blast furnace oxygen-enriched blast of the blast furnace is stopped for oxygen enrichment, so that the blast furnace enters a full-coke smelting state; adding and supplementing coke into the blast furnace, and adding ore and coke into the blast furnace according to the coke load in the blast furnace full-coke smelting process; and according to a preset air volume control rule, adjusting the furnace inlet air volume of the blast furnace until one full-coke smelting period is completed. Smooth transition of the full-coke smelting process of the blast furnace can be achieved, impact on furnace temperature and furnace conditions due to unscientific adjustment in the full-coke smelting transition period is greatly relieved, and the smelting cost is reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of smelting technology, and in particular to a blast furnace full coke smelting method. Background Art

[0002] In the traditional blast furnace smelting system, most blast furnaces spray pulverized coal from the lower tuyere of the blast furnace. When the blast furnace's spraying system is abnormal, pulverized coal cannot be sprayed and the blast furnace needs to implement full coke load smelting, that is, all fuel is coke.

[0003] During the full coke smelting process of the blast furnace, due to the lack of coal powder injection at the bottom and the increase in the amount of coke entering the blast furnace at the top, the internal airflow of the blast furnace changes greatly, resulting in changes in the blast furnace smelting process parameters. Under the existing technical conditions, the full coke smelting of the blast furnace is obtained by technicians based on their own experience. The preliminary survey and statistics show that the domestic blast furnace full coke smelting load is in the range of 2.8t / t to 3.3t / t, and the coke ratio is in the range of 500-600kg / t. Within this range, the technicians determine the full coke load level based on their own experience. The existing full coke smelting preparation process, when the coke ratio is high, will cause the blast furnace temperature to rise sharply during the full coke smelting process, which is not conducive to the smooth operation of the furnace, wastes coke, and causes increased fuel costs; when the coke ratio is low, it is very easy to cause the blast furnace temperature to drop during the full coke smelting process, and even cause the blast furnace temperature to be low, causing process accidents such as furnace cooling, requiring subsequent remedial measures such as heat supplementation and blast furnace wind reduction, which will also increase production costs. Summary of the invention

[0004] The present invention provides a blast furnace full coke smelting method to achieve a smooth transition of the full coke smelting process of the blast furnace, greatly alleviate the impact of unscientific regulation on the furnace temperature and furnace conditions during the full coke smelting transition period, and minimize the smelting cost.

[0005] In a first aspect, an embodiment of the present invention provides a blast furnace full coke smelting method, comprising:

[0006] Acquire smelting data of a blast furnace under normal production conditions, and determine the coke load and the amount of additional coke of the blast furnace under full coke smelting conditions according to the smelting data;

[0007] When the coal injection system of the blast furnace is in a state where coal injection is unable to be performed, stopping the blast furnace oxygen-enriched blast of the blast furnace to perform oxygen enrichment, so that the blast furnace enters a full coke smelting state;

[0008] Adding the additional coke amount to the blast furnace, and adding ore and coke to the blast furnace according to the coke load during the blast furnace full coke smelting process;

[0009] The air volume entering the blast furnace is adjusted according to the preset air volume control rules until a full coke smelting cycle is completed.

[0010] Further, the air volume of the blast furnace is adjusted according to a preset air volume control rule until a full coke smelting cycle is completed, including:

[0011] In a first preset time period of the current full coke smelting cycle, the wind speed in the blast furnace is adjusted within a preset range, and a first air volume required for smelting a preset weight of ore in the first preset time period is calculated;

[0012] During a second preset time period in the current full coke smelting cycle, the real-time air volume entering the blast furnace is adjusted according to the first air volume.

[0013] Furthermore, in the first preset time period of the current full coke smelting cycle, adjusting the wind speed in the blast furnace within a preset range, and calculating the first air volume required for smelting a preset weight of ore in the first preset time period, comprises:

[0014] In the first preset time period of the current full coke smelting cycle, the wind speed in the blast furnace is adjusted to meet: V1≤V;

[0015] The total amount of ore smelted in the blast furnace and the amount of air entering the blast furnace within the first preset time period are obtained, and the first air volume required for smelting the preset weight of ore within the first preset time period is calculated according to the total amount of ore smelted in the blast furnace and the amount of air entering the blast furnace within the first preset time period, and the first air volume satisfies:

[0016] M1=M 总 ÷Q2;

[0017] Wherein, V1 is the wind speed in the blast furnace, V is the wind speed when the hot air of the blast furnace enters the tuyere of the blast furnace under normal production state; M1 is the first air volume, M 总 is the air volume entering the furnace, and Q2 is the total amount of ore smelted in the blast furnace within the first preset time period.

[0018] Furthermore, in the second preset time period of the current full coke smelting cycle, the real-time air volume of the blast furnace is adjusted according to the first air volume in real time, including:

[0019] In the second preset time period of the current full coke smelting cycle, the total air volume required for the blast furnace in the second preset time period is calculated according to the first air volume, and the total air volume required for the blast furnace in the second preset time period satisfies:

[0020]

[0021] The real-time air volume of the blast furnace is adjusted according to the total air volume required by the blast furnace, and the real-time air volume of the blast furnace satisfies:

[0022] M3=M2÷(t-t1)÷60;

[0023] Among them, M2 is the total air volume required for the blast furnace in the second preset time period, S1 is the number of ore batches entering the blast furnace per hour; M3 is the real-time air volume entering the blast furnace, t is the smelting cycle of the blast furnace under normal production conditions, and t1 is the time of the first preset time period.

[0024] Furthermore, the obtaining of smelting data of the blast furnace under normal production conditions includes:

[0025] Obtain the coal injection ratio of the blast furnace under normal production conditions, normal coke load, total amount of hot air entering the blast furnace per unit ore consumption, theoretical combustion temperature of the tuyere of the blast furnace, wind speed when hot air enters the tuyere of the blast furnace, theoretical combustion temperature, weight of each batch of ore entering the blast furnace, gas utilization rate, and smelting cycle.

[0026] Further, the determining of the coke load and the amount of additional coke of the blast furnace in the full coke smelting state according to the smelting data includes:

[0027] The coal injection ratio is replaced by the coke ratio to obtain the volume percentage of the increase in each batch of coke after the coal injection ratio is converted into the coke ratio;

[0028] Obtaining the coke load of the blast furnace in the full coke smelting state according to the volume ratio of each batch of coke increase;

[0029] The amount of additional coke for the blast furnace in the full coke smelting state is obtained according to the volume ratio of each batch of coke increase.

[0030] Furthermore, the coal injection ratio is replaced with the coke ratio to obtain the volume percentage of the increase in each batch of coke after the coal injection ratio is converted to the coke ratio, including:

[0031] The coal injection ratio is replaced by the coke ratio to obtain the volume percentage of each batch of coke increase after the coal injection ratio is converted to the coke ratio. The volume percentage of each batch of coke increase after the coke ratio satisfies:

[0032]

[0033] in, is the volume proportion of the increase in each batch of coke, R is the coal injection ratio of the blast furnace under normal production conditions, and K is the normal coke load of the blast furnace under normal production conditions.

[0034] Furthermore, the coke load of the blast furnace in the full coke smelting state is obtained according to the volume proportion of the increase in each batch of coke, including:

[0035] The coke load of the blast furnace in the full coke smelting state is obtained according to the volume proportion of each batch of coke increase, and the coke load of the blast furnace in the full coke smelting state satisfies:

[0036]

[0037] Wherein, K1 is the coke load of the blast furnace in the full coke smelting state, and Q is the weight of each batch of ore entering the blast furnace in the normal production state.

[0038] Furthermore, the amount of additional coke for the blast furnace in the full coke smelting state is obtained according to the volume ratio of the increased amount of each batch of coke, including:

[0039] The amount of additional coke for the blast furnace in the full coke smelting state is obtained according to the volume proportion of the additional amount of each batch of coke, and the amount of additional coke for the blast furnace in the full coke smelting state satisfies:

[0040]

[0041] Among them, M is the amount of additional coke in the blast furnace under full coke smelting state, Y is the gas utilization rate of the blast furnace under normal production state, t is the smelting cycle of the blast furnace under normal production state, and t1 is the blast furnace coal injection reaction time of the blast furnace under normal production state.

[0042] Furthermore, the step of adjusting the air volume of the blast furnace according to the preset air volume control rule until a full coke smelting cycle is completed further includes:

[0043] The air volume entering the blast furnace is adjusted to control the air volume entering the blast furnace to the total amount of hot air entering the blast furnace per unit ore consumption of the blast furnace under normal production conditions.

[0044] The present invention provides a blast furnace full-coke smelting method. The method comprises the following steps: firstly, smelting data of the blast furnace under a normal production state is obtained, and the coke load and the amount of additional coke of the blast furnace under the full-coke smelting state are calculated according to the smelting data; when the coal injection system of the blast furnace is in a state where coal injection cannot be performed, the blast furnace oxygen-enriched blast of the blast furnace is stopped for oxygen enrichment, so that the blast furnace enters the full-coke smelting state, the theoretical combustion temperature of the tuyere is reduced, and the rapid accumulation and expansion of heat in the lower part of the blast furnace is avoided to cause furnace condition fluctuation; coke is added into the blast furnace according to the amount of additional coke, and during the full-coke smelting process of the blast furnace, charge and coke are added into the blast furnace according to the coke load, so that the volume proportion of charge and coke in the blast furnace is normal; the inlet air volume of the blast furnace is adjusted according to a preset air volume control rule until a full-coke smelting cycle is completed, so as to realize a smooth transition of the full-coke smelting process of the blast furnace, greatly alleviate the impact of unscientific adjustment on the furnace temperature and furnace condition during the transition period of the full-coke smelting, and minimize the smelting cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A flow chart of a blast furnace full coke smelting method provided in an embodiment of the present invention.

[0046] Figure 2 A flow chart for determining coke load and additional coke amount provided in an embodiment of the present invention.

[0047] Figure 3 A flow chart for adjusting the air volume entering a blast furnace provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0049] In the prior art, the full coke load of a blast furnace refers to the ratio of the weight of ore to the weight of coke in the coal injection system of the blast furnace without injection (injection of pulverized coal, natural gas, etc.). The operation of a blast furnace in a full coke smelting state is the full coke smelting process, and the coke ratio of a blast furnace in a full coke smelting state is the fuel ratio. The charge placed in the blast furnace is placed in turn in a pattern of one can of coke and one can of ore. A complete batch of charge consists of one can of coke and one can of ore. In a complete batch of charge, the ratio of the weight of ore to the weight of coke is called the coke load.

[0050] When the blast furnace cannot be sprayed (most of the existing blast furnaces spray pulverized coal from the lower tuyere of the blast furnace), the blast furnace needs to implement full coke load smelting, that is, all fuel is coke. Under normal production conditions, the time from the charge entering the blast furnace to the complete reaction is usually called a smelting cycle (from the charge entering the blast furnace to the completion of all the charge reactions). A smelting cycle of a large blast furnace is generally 6-8 hours or even longer. The reaction effect of coke also takes a cycle to manifest, and the spraying of pulverized coal at the bottom of the blast furnace can generally take effect in 2-3 hours.

[0051] During the blast furnace full coke smelting process, as the amount of coke inside the blast furnace increases, the contact surface area between the coal gas flow inside the blast furnace and the ore is greatly reduced, the indirect reduction amount of the blast furnace decreases (coal gas reduces the ore), and the direct reduction increases (the carbon element in the coke reduces the ore). How to use the best process parameters to deal with coke to improve the utilization of coal gas, increase the indirect reduction ratio, and reduce the energy loss caused by the smelting process? There is currently no relevant technical standard, and all rely on operating technicians to adjust the process parameters of the full coke smelting process based on their own experience.

[0052] Under the existing technical conditions, in the full coke smelting process, the full coke load level is not adjusted dynamically according to the changes in the smelting state in the furnace, and it is difficult to achieve stable and smooth operation of the blast furnace under the full coke smelting state. In the full coke smelting process, it is very easy for the furnace temperature to deviate from the normal level, or the molten iron quality to deviate from the normal level. Therefore, the embodiment of the present invention provides a blast furnace full coke smelting method, which dynamically adjusts the full coke load level according to the changes in the smelting state in the furnace, so as to achieve a smooth transition of the full coke smelting process of the blast furnace.

[0053] Figure 1 A flow chart of a blast furnace full coke smelting method provided by an embodiment of the present invention, the blast furnace full coke smelting method should be used when the blast furnace coal injection system cannot inject coal, such as Figure 1 As shown, the blast furnace full coke smelting method specifically includes the following steps:

[0054] S110, obtaining smelting data of the blast furnace under normal production conditions, and determining the coke load and the amount of additional coke of the blast furnace under full coke smelting conditions according to the smelting data.

[0055] Among them, the coal injection system of the blast furnace is in normal production state of the blast furnace when the coal injection is normal. The smelting data of the blast furnace in normal production state may include the coal injection ratio of the blast furnace, the normal coke load, the total amount of hot air entering the blast furnace per unit ore consumption, etc. The amount of coke added is the amount of coke that should be added in one go when the blast furnace enters the full coke smelting state.

[0056] Specifically, coke load refers to the ratio of ore weight to coke weight when the coal injection system of the blast furnace is not injecting. When the coal injection system of the blast furnace cannot inject, the blast furnace needs to implement full coke load smelting, that is, all fuel is coke, while in the normal production state of the blast furnace, the fuel of the blast furnace is coke and coal powder. Therefore, in the process of full coke smelting of the blast furnace, since there is no coal powder injected in the lower part of the blast furnace, the amount of coke entering the blast furnace from the upper part of the blast furnace increases, and the air flow inside the blast furnace changes greatly, resulting in changes in the blast furnace smelting process parameters. It is necessary to calculate the coke load and the amount of additional coke in the full coke smelting state of the blast furnace through the smelting data of the blast furnace in normal production state, so that the blast furnace can operate stably in the full coke smelting state. The coke load of the blast furnace in normal production state can be used to determine the volume of coke that should be added to each batch of charge in the full coke smelting state of the blast furnace, thereby determining the coke load of the blast furnace in the full coke smelting state, so as to add charge and coke according to the coke load of the blast furnace in the full coke smelting state. In addition, since the blast furnace no longer sprays pulverized coal as fuel after entering the full coke smelting state, additional coke needs to be added to make the smelting process of the blast furnace stable and normal. The amount of additional coke after the blast furnace enters the full coke smelting state can be determined through the smelting data of the blast furnace in normal production state and the coke load of the blast furnace in the full coke smelting state.

[0057] S120. When the coal injection system of the blast furnace is in a state where coal injection is unable to be performed, the blast furnace oxygen-enriched blast of the blast furnace is stopped to perform oxygen enrichment, so that the blast furnace enters a full coke smelting state.

[0058] Specifically, when the blast furnace is in normal production, all the charges in the internal space of the blast furnace are in normal state. When the coal injection system of the blast furnace is in a state where coal injection cannot be performed, that is, when there is no pulverized coal as fuel in the blast furnace, the blast furnace enters the full coke smelting state. When entering the full coke smelting state, the blast furnace oxygen-enriched blast of the blast furnace is first stopped to enrich oxygen at the blast furnace tuyere. Regardless of the amount of oxygen enrichment in the blast furnace under normal conditions, oxygen enrichment is stopped in the absence of pulverized coal fuel injection, thereby reducing the theoretical combustion temperature at the tuyere and avoiding the rapid accumulation and expansion of heat in the lower part of the blast furnace, which causes fluctuations in furnace conditions.

[0059] S130, adding additional coke to the blast furnace, and during the blast furnace full coke smelting process, adding ore and coke to the blast furnace according to the coke load.

[0060] Specifically, after the coke load and the amount of additional coke in the blast furnace under the full coke smelting state are determined, and the blast furnace enters the full coke smelting state, the additional coke is added to the blast furnace to ensure that the charge in the blast furnace continues to react normally. The coke load is the coke load in the blast furnace full coke smelting process, that is, the ratio of the weight of ore to the weight of coke in a batch of charge in the blast furnace full coke smelting process. In the subsequent blast furnace full coke smelting process, ore and coke are added to the blast furnace according to the coke load, that is, the weight ratio of ore to coke in each batch of charge is the same as the coke load.

[0061] S140. Adjust the air volume of the blast furnace according to the preset air volume control rules until a full coke smelting cycle is completed.

[0062] Specifically, during the full coke smelting process in the blast furnace, ore and coke are added to the blast furnace according to the coke load. As the volume of coke inside the blast furnace gradually increases, the gas flow penetration ability inside the blast furnace is enhanced, the hot air volume of the blast furnace automatically increases, and the wind speed in the blast furnace will continue to increase. Therefore, it is necessary to adjust the air volume entering the blast furnace to avoid a substantial increase in the blast furnace temperature during the full coke smelting process, which is detrimental to the furnace condition, wastes coke, and increases fuel costs. In addition, due to the cessation of coal blowing and oxygen enrichment in the blast furnace, coupled with a substantial increase in the amount of coke inside the blast furnace, the furnace temperature in the blast furnace will drop, and even the furnace temperature will be low, which is easy to cause process accidents such as furnace cooling. Therefore, it is also necessary to adjust the air volume entering the blast furnace to avoid a series of remedial measures such as subsequent heat supplementation and blast furnace wind reduction, which will increase production costs. Therefore, the preset air volume control rules can be determined according to the real-time furnace temperature in the blast furnace, or according to the operation cycle of the blast furnace, and can be adjusted according to the actual operation conditions of the blast furnace to ensure a smooth transition of the blast furnace's full-coke smelting process, greatly alleviate the impact of unscientific adjustment on the furnace temperature and furnace conditions during the transition period of the blast furnace's full-coke smelting, and minimize the smelting cost.

[0063] The embodiment of the present invention provides a blast furnace full coke smelting method, firstly, smelting data of the blast furnace under a normal production state is obtained, and the coke load and the amount of additional coke of the blast furnace under the full coke smelting state are calculated and determined according to the smelting data; when the coal injection system of the blast furnace is in a state where coal injection cannot be performed, the blast furnace oxygen-enriched blast of the blast furnace is stopped for oxygen enrichment, and the blast furnace enters the full coke smelting state, and the theoretical combustion temperature of the tuyere is reduced, so as to avoid the rapid accumulation and expansion of heat in the lower part of the blast furnace causing fluctuations in furnace conditions; coke is added to the blast furnace according to the amount of additional coke, and during the full coke smelting process of the blast furnace, charge and coke are added to the blast furnace according to the coke load, so that the volume proportions of charge and coke in the blast furnace are normal; the inlet air volume of the blast furnace is adjusted according to a preset air volume control rule until a full coke smelting cycle is completed, so as to achieve a smooth transition of the full coke smelting process of the blast furnace, greatly alleviate the impact of unscientific adjustment on the furnace temperature and furnace conditions during the transition period of the full coke smelting, and minimize the smelting cost.

[0064] Another method for smelting full coke in a blast furnace is provided in an embodiment of the present invention. In the embodiment of the present invention, smelting data of a blast furnace in a normal production state is obtained, including:

[0065] Obtain the coal injection ratio of the blast furnace under normal production conditions, normal coke load, total amount of hot air entering the blast furnace per unit ore consumption, theoretical combustion temperature of the blast furnace tuyere, wind speed when hot air enters the blast furnace tuyere, theoretical combustion temperature, weight of each batch of ore entering the blast furnace, gas utilization rate, and smelting cycle.

[0066] Among them, the smelting data of the blast furnace under normal production conditions include the coal injection ratio of the blast furnace under normal production conditions, normal coke load, the total amount of hot air entering the blast furnace per unit ore consumption, the theoretical combustion temperature of the blast furnace tuyere, the wind speed when the hot air enters the blast furnace tuyere, the theoretical combustion temperature, the weight of each batch of ore entering the blast furnace, gas utilization rate, and smelting cycle.

[0067] Specifically, the coal injection ratio R (the amount of coal powder injected to smelt one ton of ore, unit: kg / t) of the blast furnace under normal production conditions is obtained, the coke load K (the ratio of ore weight to coke weight) of the blast furnace under normal production conditions is obtained, and the total amount of hot air entering the blast furnace M (the ratio of the air volume entering the blast furnace to the smelting ore in a certain period of normal production, unit: m) consumed to smelt one ton of ore under normal production conditions is obtained. 3 / t, the air volume is obtained by real-time instrument detection, and the ore is calculated by adding the internal charge of the blast furnace); obtain the theoretical combustion temperature T of the tuyere under the normal state of the blast furnace, in °C; obtain the wind speed V when the blast furnace hot air enters the tuyere of the blast furnace, in meters per second; obtain the weight of each batch of ore under the normal production state of the blast furnace as Q, and the batch weight of coke as Q / K; the gas utilization rate Y under the normal production state of the blast furnace, in %; obtain the smelting cycle t under the normal state of the blast furnace, in hours, and the average batch of materials per hour in the smelting cycle as S, in batches per hour.

[0068] Figure 2 A flow chart for determining the coke load and the amount of additional coke provided by an embodiment of the present invention is as follows: Figure 2 As shown, in an embodiment of the present invention, the coke load and the amount of additional coke in a blast furnace under full coke smelting state are determined according to smelting data, including the following steps:

[0069] S210, replacing the coal injection ratio with the coke ratio, and obtaining the volume percentage of the increase in each batch of coke after the coal injection ratio is converted into the coke ratio.

[0070] Among them, the coke ratio is the amount of coke converted from the coke, coal powder, heavy oil and other fuels consumed by the blast furnace to produce one ton of molten iron, and the unit is kg / t. The coal injection ratio refers to the amount of coal powder injected into coal to smelt one ton of pig iron. By replacing the coal injection ratio with the coke ratio, the volume percentage of the increase in each batch of coke after the coal injection ratio is converted into the coke ratio is obtained.

[0071] Specifically, after the blast furnace enters the full coke smelting state, the coal injection ratio of the blast furnace under normal production conditions is replaced with the coke ratio to obtain the volume percentage of each batch of coke increase after the coal injection ratio is converted to the coke ratio, which represents the percentage of coke in a complete batch of furnace charge compared with the volume increase under normal conditions.

[0072] Optionally, the coal injection ratio is replaced by the coke ratio to obtain the volume ratio of each batch of coke increase after the coal injection ratio is converted into the coke ratio. The volume ratio of each batch of coke increase after the coke ratio satisfies:

[0073]

[0074] in, is the volume percentage of each batch of coke increase, R is the coal injection ratio of the blast furnace under normal production conditions, and K is the normal coke load of the blast furnace under normal production conditions.

[0075] Specifically, the volume percentage of the increase in coke in each batch of charge after the coal injection ratio of the blast furnace under normal production conditions is converted into the coke ratio: Represents the volume increase of coke in a complete batch of charge under full coke smelting state compared with the volume increase of coke in each batch of charge under normal state of blast furnace, which is equivalent to the total amount of ore that needs to be reduced in a complete batch of charge. (The bulk density of coke is about 0.5 tons / m 3 , the ore volume density is about 2.0 tons / m 3 ).

[0076] S220. Obtain the coke load of the blast furnace in the full coke smelting state according to the volume proportion of each batch of coke increase.

[0077] Specifically, the blast furnace air volume will inevitably decrease during the full coke smelting process. When preparing the full coke smelting charge of the blast furnace, the coal needs to be converted into coke to avoid a substantial increase in the volume of coke in each batch of charge. Since the volume of the blast furnace charge tank is fixed, in order to avoid the charge volume exceeding the charge tank volume, the total volume of ore and coke in each batch of charge cannot be increased. The batching method of maintaining the coke weight and reducing the amount of ore can be adopted, that is, the coke load of the blast furnace in the full coke smelting state is different from the coke load of the blast furnace in the normal state. Therefore, it is necessary to calculate the coke load of the blast furnace in the full coke smelting state according to the volume ratio of each batch of coke increase, so as to add charge and coke according to the coke load of the blast furnace in the full coke smelting state, and then achieve a smooth transition of the full coke smelting process of the blast furnace.

[0078] Optionally, the coke load of the blast furnace in the full coke smelting state is obtained according to the volume ratio of each batch of coke increase, and the coke load of the blast furnace in the full coke smelting state satisfies:

[0079]

[0080] Among them, K1 is the coke load of the blast furnace under full coke smelting state, and Q is the weight of each batch of ore entering the blast furnace under normal production state.

[0081] Specifically, the weight of each batch of ore in the blast furnace under full coke smelting state is The coke weight of each batch of charge is kept at Q / K, so the coke load of the charge is

[0082] S230. According to the volume proportion of each batch of coke increase, the amount of coke added to the blast furnace in the full coke smelting state is obtained.

[0083] Specifically, since the blast furnace no longer sprays pulverized coal as fuel after entering the full coke smelting state, additional coke needs to be added to ensure a smooth and normal smelting process of the blast furnace. The amount of additional coke to be added after the blast furnace enters the full coke smelting state can be determined through the smelting data of the blast furnace under normal production conditions and the coke load of the blast furnace under the full coke smelting state.

[0084] Optionally, the amount of additional coke in the blast furnace under the full coke smelting state is obtained according to the volume ratio of each batch of coke increase, and the amount of additional coke in the blast furnace under the full coke smelting state satisfies:

[0085]

[0086] Among them, M is the amount of additional coke added to the blast furnace under full coke smelting conditions, Y is the gas utilization rate of the blast furnace under normal production conditions, t is the smelting cycle of the blast furnace under normal production conditions, and t1 is the blast furnace coal injection reaction time under normal production conditions.

[0087] Specifically, because the volume of ore in a batch of blast furnace charge is smaller than normal Therefore, it is predicted that the utilization rate of blast furnace gas will decrease during the corresponding charge reaction process. (The contact area between gas and ore becomes smaller), and the predicted value of gas utilization under full coke smelting condition is The reduction of gas utilization rate will lead to an increase in the blast furnace coke ratio (indirect reduction releases heat, direct reduction absorbs heat). Therefore, the amount of coke in the full coke smelting process will inevitably increase by This part of the added coke is the additional coke amount, which is not included in a single batch of charge. It is added in a centralized manner and is added as soon as possible after the coal injection system of the blast furnace is unable to inject coal. The addition period that needs to be calculated is: the length of a smelting cycle of the blast furnace t minus the reaction time of the coal injection in the blast furnace t1, that is, t-t1 (t1 is the effect time of the blast furnace coal injection combustion reaction, which can be 3 hours. It is empirical data. The general blast furnace coal injection reaction effect is between 2-3 hours. The value is taken according to the change in the theoretical combustion temperature of the blast furnace tuyere after the coal injection system of the blast furnace is unable to inject coal. The lower limit is when the theoretical combustion temperature increases by more than 50°C, and the upper limit is when the theoretical combustion temperature decreases by more than 50°C). The centralized additional coke amount M of the blast furnace is By adding additional coke M at the beginning stage of the blast furnace's full coke smelting, it can be ensured that there is sufficient fuel in the blast furnace during the full coke smelting process of the blast furnace, thereby avoiding the furnace temperature deviating from the normal level or the molten iron quality deviating from the normal level during the full coke smelting process of the blast furnace, and achieving smooth operation of the blast furnace under the full coke smelting state.

[0088] Figure 3A flow chart for adjusting the air volume of a blast furnace provided by an embodiment of the present invention is as follows: Figure 3 As shown, in an embodiment of the present invention, the air volume of the blast furnace is adjusted according to a preset air volume control rule until a full coke smelting cycle is completed, which specifically includes the following steps:

[0089] S310. In a first preset time period of the current full coke smelting cycle, adjust the wind speed in the blast furnace within a preset range, and calculate a first air volume required for smelting a preset weight of ore in the first preset time period.

[0090] Specifically, during the full coke smelting process in the blast furnace, ore and coke are added to the blast furnace according to the coke load. As the volume of coke inside the blast furnace gradually increases, the gas flow penetration ability inside the blast furnace is enhanced, the hot air volume of the blast furnace automatically increases, and the wind speed in the blast furnace will continue to increase. Therefore, it is necessary to adjust the air volume entering the blast furnace. By adjusting the wind speed in the blast furnace within a preset range during the first preset time period in the current full coke smelting cycle, it is possible to avoid a substantial increase in the blast furnace temperature during the full coke smelting process, which is detrimental to the smooth operation of the furnace, waste of coke, and increased fuel costs. At the same time, the first air volume required for smelting a preset weight of ore within the first preset time period is calculated, so that the total air volume required by the blast furnace in the current full coke smelting cycle and the air volume consumed in the remaining time of the cycle are calculated based on the first air volume required for smelting the preset weight of ore within the first preset time period, so that the air volume entering the blast furnace for the remaining time of this cycle is adjusted according to the air volume consumed in the remaining time of the cycle, thereby achieving a smooth transition of the full coke smelting process of the blast furnace, and greatly alleviating the impact of unscientific adjustment on the furnace temperature and furnace conditions during the transition period of full coke smelting.

[0091] Optionally, in the first preset time period of the current full coke smelting cycle, the wind speed in the blast furnace is adjusted to satisfy: V1≤V;

[0092] The total amount of ore smelted in the blast furnace and the air volume entering the furnace within the first preset time period are obtained, and the first air volume required for smelting the preset weight of ore within the first preset time period is calculated according to the total amount of ore smelted in the blast furnace and the air volume entering the furnace within the first preset time period. The first air volume satisfies:

[0093] M1=M 总 ÷Q2;

[0094] Among them, V1 is the wind speed in the blast furnace, V is the wind speed when the hot air enters the tuyere of the blast furnace under normal production conditions; M1 is the first air volume, M 总 is the air volume entering the furnace, and Q2 is the total amount of ore smelted in the blast furnace within the first preset time period.

[0095] Specifically, in the first preset time period t0, as the volume of coke inside the blast furnace gradually increases, the gas flow penetration capacity inside the blast furnace is enhanced, the hot air volume of the blast furnace is automatically increased, and the wind speed will continue to increase. The wind reduction operation mode must be adopted to maintain the wind speed V1 in the blast furnace not greater than the wind speed V when the hot air enters the tuyere of the blast furnace under normal production conditions. This is the standard for adjusting the air volume. When the full coke smelting time reaches the end of the first preset time period t0, the effects of stopping coal and stopping oxygen enrichment begin to manifest, and coupled with a substantial increase in the amount of coke inside the blast furnace, the blast furnace will show a downward trend in furnace temperature and a significant increase in air volume. In the first preset time period t0, the total amount of ore smelted in the blast furnace Q2 and the total air volume M entering the blast furnace are calculated. 总 , the first air volume M1=M required for smelting the preset weight of ore in the first preset time period t0 is obtained 总 ÷Q2. The total air volume required by the blast furnace in the current full coke smelting cycle and the air volume consumed in the remaining time of the cycle can be calculated through the first air volume M1, so as to adjust the air volume entering the blast furnace in the remaining time of this cycle according to the air volume consumed in the remaining time of the cycle.

[0096] S320. During a second preset time period in the current full coke smelting cycle, the real-time air volume entering the blast furnace is adjusted according to the first air volume.

[0097] Specifically, due to the cessation of coal blowing and oxygen enrichment in the blast furnace, and the substantial increase in the amount of coke inside the blast furnace, the furnace temperature in the blast furnace will drop, or even be low, which may easily cause process accidents such as furnace cooling. Therefore, it is also necessary to adjust the air volume entering the blast furnace to avoid a series of remedial measures such as subsequent heat supplementation and blast furnace wind reduction, which will increase production costs. That is, in the second preset time period of the current full coke smelting cycle, the total air volume required by the blast furnace in the current full coke smelting cycle and the total air volume required by the blast furnace in the second preset time period can be calculated according to the first air volume M1, so as to adjust the air volume entering the blast furnace in the second preset time period according to the total air volume required by the blast furnace in the second preset time period, thereby ensuring a smooth transition of the full coke smelting process of the blast furnace, greatly alleviating the impact of unscientific adjustment on the furnace temperature and furnace conditions during the transition period of the full coke smelting of the blast furnace, and minimizing the smelting cost.

[0098] Optionally, in a second preset time period in the current full coke smelting cycle, the total air volume required for the blast furnace in the second preset time period is calculated according to the first air volume, and the total air volume required for the blast furnace in the second preset time period satisfies:

[0099]

[0100] The real-time air volume of the blast furnace is adjusted according to the total air volume required by the blast furnace. The real-time air volume of the blast furnace meets the following requirements:

[0101] M3=M2÷(t-t0)÷60;

[0102] Among them, M2 is the total air volume required by the blast furnace in the second preset time period, S1 is the number of ore batches entering the blast furnace per hour; M3 is the real-time air volume entering the blast furnace, t is the smelting cycle of the blast furnace under normal production conditions, and t0 is the time of the first preset time period. The first preset time period t0 can also be the same as the effective duration t1 of the blast furnace coal injection combustion reaction, that is, the first preset time period t0 is the effective duration of the blast furnace coal injection combustion reaction, and the value can be 3 hours.

[0103] Specifically, during the smelting process of the full coke oven charge in the time period t0, the average batch of material per hour in a smelting cycle is S1. From the start time of the physical coal injection in the blast furnace to a smelting cycle t, the time required is the second preset time period t-t0. The batch of material that needs to be put into the blast furnace is: (t-t0)×S1, and the weight of the ore that needs to be put in is: Then the total air volume M2 required for the blast furnace in the second preset time period is At this time, due to the reduction of ore and the slowdown of smelting speed, the air volume of the blast furnace will decrease. The real-time air volume of the blast furnace is adjusted according to the total air volume required by the blast furnace. The real-time air volume of the blast furnace M3 is M2÷(t-t0)÷60, which is the real-time controlled air volume of the blast furnace, in m 3 / min. The air volume of the blast furnace is controlled by the real-time air volume M3, which can dynamically adjust the air volume of the blast furnace according to the changes in the smelting state in the furnace, so that the furnace temperature of the blast furnace during the full coke smelting process is stable, and the full coke smelting process of the blast furnace is smoothly transitioned, which greatly alleviates the impact of unscientific adjustment on the furnace temperature and furnace condition during the transition period of full coke smelting.

[0104] Further, the air volume of the blast furnace is adjusted according to the preset air volume control rule until a full coke smelting cycle is completed, and the method further includes:

[0105] Adjust the air volume entering the blast furnace and control the air volume entering the blast furnace to the total amount of hot air entering the blast furnace per unit ore consumption under normal production conditions.

[0106] Specifically, when the blast furnace completes a smelting cycle in the full coke smelting process, the air volume entering the blast furnace is adjusted, the blast furnace starts the air adding operation, and the air volume entering the blast furnace is controlled to the air volume value in the normal production state, so that the blast furnace starts a new blast furnace smelting cycle. In the next smelting cycle of the blast furnace, coke is still added to the blast furnace according to the amount of additional coke. In the blast furnace full coke smelting process, ore and coke are added to the blast furnace according to the coke load, and the air volume entering the blast furnace is adjusted according to the preset air volume control rules until a full coke smelting cycle is completed, thereby achieving a smooth transition of the blast furnace's full coke smelting process in each smelting cycle of the blast furnace full coke smelting process, greatly alleviating the impact of unscientific adjustment on furnace temperature and furnace conditions during the transition period of full coke smelting.

[0107] In addition, the prior art does not form relevant technical standards for the blast furnace full coke smelting process, and all rely on operating technicians to adjust the process parameters of the full coke smelting process based on their own experience. When the coke ratio is high, it is easy to cause the blast furnace temperature to rise significantly during the full coke smelting process, which is not conducive to the smooth operation of the furnace, wastes coke, and causes increased fuel costs; when the coke ratio is low, it is also very easy to cause the furnace temperature to drop during the full coke smelting process, or even the furnace temperature is low, causing process accidents such as furnace cooling, requiring subsequent remedial measures such as heat supplementation and blast furnace wind reduction, which will also cause production costs. Therefore, the blast furnace full coke smelting method provided by the embodiment of the present invention stabilizes the furnace temperature during the blast furnace full coke smelting process, realizes a smooth transition of the blast furnace full coke smelting process, and can greatly reduce the smelting cost of the blast furnace full coke smelting process.

[0108] The embodiment of the present invention provides a blast furnace full coke smelting method, thereby achieving a smooth transition of the full coke smelting process of the blast furnace, greatly alleviating the impact of unscientific adjustment on the furnace temperature and furnace conditions during the full coke smelting transition period, and minimizing the smelting cost.

[0109] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A blast furnace full coke smelting method, characterized in that: include: Acquire smelting data of a blast furnace under normal production conditions, and determine the coke load and the amount of additional coke of the blast furnace under full coke smelting conditions according to the smelting data; When the coal injection system of the blast furnace is in a state where coal injection is unable to be performed, stopping the blast furnace oxygen-enriched blast of the blast furnace to perform oxygen enrichment, so that the blast furnace enters a full coke smelting state; Adding the additional coke amount to the blast furnace, and adding ore and coke to the blast furnace according to the coke load during the blast furnace full coke smelting process; The air volume entering the blast furnace is adjusted according to the preset air volume control rules until a full coke smelting cycle is completed.

2. The blast furnace full coke smelting method according to claim 1, characterized in that: The step of adjusting the air volume of the blast furnace according to the preset air volume control rule until a full coke smelting cycle is completed includes: In a first preset time period of the current full coke smelting cycle, the wind speed in the blast furnace is adjusted within a preset range, and a first air volume required for smelting a preset weight of ore in the first preset time period is calculated; During a second preset time period in the current full coke smelting cycle, the real-time air volume entering the blast furnace is adjusted according to the first air volume.

3. The blast furnace full coke smelting method according to claim 2, characterized in that: The step of adjusting the wind speed in the blast furnace within a preset range within a first preset time period in the current full coke smelting cycle, and calculating a first air volume required for smelting a preset weight of ore within the first preset time period includes: In the first preset time period of the current full coke smelting cycle, the wind speed in the blast furnace is adjusted to meet: V1≤V; The total amount of ore smelted in the blast furnace and the amount of air entering the blast furnace within the first preset time period are obtained, and the first air volume required for smelting the preset weight of ore within the first preset time period is calculated according to the total amount of ore smelted in the blast furnace and the amount of air entering the blast furnace within the first preset time period, and the first air volume satisfies: M1=M 总 ÷Q2; Wherein, V1 is the wind speed in the blast furnace, V is the wind speed when the hot air of the blast furnace enters the tuyere of the blast furnace under normal production state; M1 is the first air volume, M 总 is the air volume entering the furnace, and Q2 is the total amount of ore smelted in the blast furnace within the first preset time period.

4. The blast furnace full coke smelting method according to claim 3, characterized in that: The method of adjusting the real-time air volume of the blast furnace according to the first air volume in real time during the second preset time period of the current full coke smelting cycle comprises: In the second preset time period of the current full coke smelting cycle, the total air volume required for the blast furnace in the second preset time period is calculated according to the first air volume, and the total air volume required for the blast furnace in the second preset time period satisfies: The real-time air volume of the blast furnace is adjusted according to the total air volume required by the blast furnace, and the real-time air volume of the blast furnace satisfies: M3=M2÷(t-t0)÷60; Among them, M2 is the total air volume required for the blast furnace in the second preset time period, S1 is the number of ore batches entering the blast furnace per hour; M3 is the real-time air volume entering the blast furnace, t is the smelting cycle of the blast furnace under normal production conditions, and t0 is the time of the first preset time period.

5. The blast furnace full coke smelting method according to claim 1, characterized in that: The obtaining of smelting data of the blast furnace under normal production state includes: Obtain the coal injection ratio of the blast furnace under normal production conditions, normal coke load, total amount of hot air entering the blast furnace per unit ore consumption, theoretical combustion temperature of the tuyere of the blast furnace, wind speed when hot air enters the tuyere of the blast furnace, theoretical combustion temperature, weight of each batch of ore entering the blast furnace, gas utilization rate, and smelting cycle.

6. The blast furnace full coke smelting method according to claim 5, characterized in that: The step of determining the coke load and the amount of additional coke of the blast furnace in a full coke smelting state according to the smelting data comprises: The coal injection ratio is replaced by the coke ratio to obtain the volume percentage of the increase in each batch of coke after the coal injection ratio is converted into the coke ratio; Obtaining the coke load of the blast furnace in the full coke smelting state according to the volume ratio of each batch of coke increase; The amount of additional coke for the blast furnace in the full coke smelting state is obtained according to the volume ratio of each batch of coke increase.

7. The blast furnace full coke smelting method according to claim 6, characterized in that: The method of replacing the coal injection ratio with the coke ratio to obtain the volume percentage of the increase in each batch of coke after the coal injection ratio is converted into the coke ratio includes: The coal injection ratio is replaced by the coke ratio to obtain the volume percentage of each batch of coke increase after the coal injection ratio is converted to the coke ratio. The volume percentage of each batch of coke increase after the coke ratio satisfies: in, is the volume proportion of the increase in each batch of coke, R is the coal injection ratio of the blast furnace under normal production conditions, and K is the normal coke load of the blast furnace under normal production conditions.

8. The blast furnace full coke smelting method according to claim 7, characterized in that: The coke load of the blast furnace in the full coke smelting state is obtained according to the volume proportion of each batch of coke increase, including: The coke load of the blast furnace in the full coke smelting state is obtained according to the volume proportion of each batch of coke increase, and the coke load of the blast furnace in the full coke smelting state satisfies: Wherein, K1 is the coke load of the blast furnace in the full coke smelting state, and Q is the weight of each batch of ore entering the blast furnace in the normal production state.

9. The blast furnace full coke smelting method according to claim 8, characterized in that: The method of obtaining the amount of additional coke for the blast furnace in the full coke smelting state according to the volume proportion of the increased amount of each batch of coke comprises: The amount of additional coke for the blast furnace in the full coke smelting state is obtained according to the volume proportion of the additional amount of each batch of coke, and the amount of additional coke for the blast furnace in the full coke smelting state satisfies: Among them, M is the amount of additional coke in the blast furnace under full coke smelting state, Y is the gas utilization rate of the blast furnace under normal production state, t is the smelting cycle of the blast furnace under normal production state, and t1 is the blast furnace coal injection reaction time of the blast furnace under normal production state.

10. The blast furnace full coke smelting method according to claim 1, characterized in that: The method of adjusting the air volume of the blast furnace according to the preset air volume control rule until a full coke smelting cycle is completed also includes: The air volume entering the blast furnace is adjusted to control the air volume entering the blast furnace to the total amount of hot air entering the blast furnace per unit ore consumption of the blast furnace under normal production conditions.

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