Novel method for efficiently utilizing sintering return mine

Abstract

The invention belongs to the technical field of sintering processes in the metallurgical industry, and relates to a novel method for efficiently utilizing sintered return mine, which comprises a sintering process, an iron-making process and a steel-making process, and specifically comprises the following steps: conveying sintered ore generated in the sintering process to the iron-making process for primary screening, and enabling the obtained large-granularity sintered ore to enter a blast furnace for iron-making; and carrying out secondary screening on the residual sinter, feeding the obtained medium-particle-size sinter into a converter for steelmaking, and returning the residual small-particle-size sinter to the sintering process for re-sintering. The method has the beneficial effects that the proportion of the small particle size of the sintered ore entering the blast furnace is flexibly adjusted according to production requirements, when the sintering yield is larger than the ironmaking yield and the ironmaking yield is larger than the steelmaking yield, efficient use of the sintered ore with the three particle sizes in the sintering process, the ironmaking process and the steelmaking process is achieved, the return ore amount of the sintered ore can be reduced, and the production cost is reduced. And the air permeability index of the blast furnace can be improved, and energy conservation and emission reduction of the whole production process are facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of sintering process in metallurgical industry, and in particular relates to a new method for efficiently utilizing sintered return ore. Background Art

[0002] At present, the finished sintered ore (generally with a particle size greater than 5mm) produced in the sintering process will be sent to the blast furnace for ironmaking. However, the finished sintered ore will be bumped and damaged during transportation, resulting in a smaller particle size. It needs to be screened again before entering the furnace to re-screen the sintered ore with a particle size greater than 5mm for ironmaking to ensure the air permeability of the blast furnace. The particle size of the remaining sintered ore should be less than 5mm, and it cannot be used as cold material to enter the converter because it is easily sucked away by the converter dust removal. It can only be used as return ore for re-sintering, resulting in a huge waste of resources.

[0003] With the company's No. 3 sintering machine and No. 7 blast furnace put into operation, sintered ore and molten iron have become abundant. The company's production mode has been adjusted to a high iron consumption mode. Faced with the high iron consumption mode of steelmaking, sintered ore needs to be added as cold material for temperature adjustment. The efficient utilization of sintered ore is more urgent. Therefore, a new method for efficient utilization of sintered return ore is needed to solve the above technical problems. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the present invention provides a new method for efficient utilization of sintered return ore. When the sintering output is greater than the ironmaking output and the ironmaking output is greater than the steelmaking output, the sintered ore is recycled in the sintering process, the ironmaking process and the steelmaking process, and the proportion of small-particle sintered ore entering the furnace is reduced. The amount of return ore returned to the sintering process is reduced, the efficient utilization of the sintered ore is achieved, and the permeability of the blast furnace is improved.

[0005] The technical solution adopted in the embodiment of the present invention is: a new method for efficient utilization of sintered return ore, characterized in that it includes a sintering process, an ironmaking process and a steelmaking process, and the specific method is as follows:

[0006] The finished sintered ore produced in the sintering process is transported to the ironmaking process for the first screening, and the large-particle sintered ore obtained enters the blast furnace for ironmaking. The remaining sintered ore is screened for the second time, and the medium-particle sintered ore obtained enters the converter for steelmaking. The remaining small-particle sintered ore returns to the sintering process for sintering again.

[0007] Furthermore, the iron-making process is provided with an iron-making ore trough, and a first screen is provided at the lower part of the iron-making ore trough. The sintered ore produced in the sintering process is screened for the first time through the first screen to obtain the large-particle-size sintered ore.

[0008] Furthermore, the particle size of the large-grained sintered ore is greater than 8 mm.

[0009] Furthermore, the remaining sintered ore after the first screening is transported to a closed material yard, and the closed material yard is provided with a second screen for a second screening to obtain the medium-sized sintered ore and the small-sized sintered ore.

[0010] Furthermore, the particle size of the medium-sized sintered ore is 4 to 8 mm.

[0011] Furthermore, the particle size of the small-grained sintered ore is less than 4 mm.

[0012] Furthermore, the medium-sized sintered ore is sent as cold material to the high-level silo of the steelmaking process for addition and use.

[0013] Furthermore, the particle size of the finished sintered ore is greater than 8 mm.

[0014] The advantages and positive effects of the present invention are: when the sintering output is greater than the ironmaking output and the ironmaking output is greater than the steelmaking output, efficient use of sintered ore in the sintering process, the ironmaking process and the steelmaking process is achieved, which can not only reduce the amount of returned ore returning to the sintering process, but also improve the permeability index of the blast furnace, which is more conducive to energy conservation and emission reduction in the entire production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of an embodiment provided by the present invention. DETAILED DESCRIPTION

[0016] The embodiment of the present invention provides a new method for efficient utilization of sintered return ore, which is described below in conjunction with the accompanying drawings. In the existing process flow, the finished sintered ore produced by the sintering process is transported to the ironmaking process by a belt, and is screened before being sent to the blast furnace for ironmaking. Because it will be damaged during transportation and the particle size will become smaller, it is necessary to screen the sintered ore with a particle size of more than 5 mm into and out of the furnace. The sintered ore with a particle size of less than 5 mm can only be re-sintered, resulting in a huge waste of resources, and this part of the remaining sintered ore cannot be added to the steelmaking process as a cold material, because the particle size is mostly less than 5 mm, and it is easy to be sucked away by the converter dust removal during the addition of the converter, and cannot be efficiently utilized. Especially when the sintering output is greater than the ironmaking output and the ironmaking output is greater than the steelmaking output, this waste is more obvious, which is not conducive to the efficient utilization of resources, nor to energy conservation and emission reduction.

[0017] In order to solve the above technical problems, the technical solution of the present application redefines the return ore, and adjusts the particle size of the finished sintered ore from the original greater than 5mm to greater than 8mm, thereby reducing the sintered ore with a particle size of 5mm to 8mm entering the blast furnace, which is beneficial to improving the air permeability of the blast furnace. The remaining sintered ore can also be screened again into two types of sintered ores with a particle size of less than 4mm and 4-8mm. The sintered ore with a particle size of 4-8mm is used as cold material in the high-level silo of the steelmaking process, and only the sintered ore with a particle size less than 4mm is returned to the sintering process, realizing the efficient utilization of the sintered return ore.

[0018] Reference Figure 1 As shown, a new method for efficient utilization of sintered return ore is characterized by comprising a sintering process, an ironmaking process and a steelmaking process, and the specific method is as follows:

[0019] The sintered ore produced in the sintering process is transported to the ironmaking process for the first screening, and the large-particle sintered ore obtained enters the blast furnace for ironmaking. The remaining sintered ore is screened for the second time, and the medium-particle sintered ore obtained enters the converter for steelmaking. The remaining small-particle sintered ore returns to the sintering process for sintering again.

[0020] Steelmaking requires more molten iron, and then the heat is abundant, so cold materials need to be added to cool it down. Cold materials are generally sintered ore and iron ore. For the same blast furnace, if sintered ore with larger particle size is added in the ironmaking process (which means reducing the proportion of sintered ore with small particle size), the air permeability of the blast furnace can be improved. If sintered ore with smaller particle size (i.e. sintered return ore with a particle size of less than 5mm) is directly added in the steelmaking process, it will be sucked away by the converter dust removal, which will cause waste. Because sintered ore must meet the three processes of sintering, ironmaking and steelmaking at the same time in order to achieve efficient utilization, reasonable configuration will achieve efficient utilization of raw materials and be more conducive to energy conservation and emission reduction.

[0021] Since the sintering output is greater than the ironmaking output and the ironmaking output is greater than the steelmaking output, the sintering ore is sufficient. Therefore, the small-sized sintering ore added to the blast furnace is reduced to improve the permeability of the blast furnace. A part of it is sent to the converter for steelmaking, and only a small part is returned to the sintering process as return ore. Taking into account the production needs of the three processes, the sintering ore of different particle sizes can be used efficiently in the three processes, which can not only reduce the amount of sintering ore return, but also improve the permeability index of the blast furnace, which is more conducive to energy conservation and emission reduction in production.

[0022] Preferably, the ironmaking process is provided with an ironmaking ore trough, a first screen is provided at the lower part of the ironmaking ore trough, and the sintered ore produced in the sintering process is screened for the first time through the first screen to obtain the large-particle-size sintered ore.

[0023] Preferably, the particle size of the large-size sintered ore is greater than 8 mm. In this embodiment, the aperture of the first screen in the ore trough of the blast furnace is adjusted from 5 mm to 8 mm, so that the particle size of the large-size sintered ore entering the blast furnace increases by 3 mm, thereby improving the blast furnace permeability index. Correspondingly, the proportion of particle size in the sintered ore entering the furnace is increased, thereby improving the permeability.

[0024] The blast furnace permeability index refers to the ratio of the air volume to the total pressure difference (i.e. the difference between the hot air pressure and the furnace top pressure) during the blast furnace smelting process. When the air volume remains unchanged, the particle size of the sintered ore entering the furnace increases, which will cause the pressure difference of the blast furnace to decrease, thereby increasing the permeability index and improving the permeability of the blast furnace.

[0025] Preferably, the sintered ore remaining after the first screening is transported to a closed material yard, which is provided with a second screen for a second screening to obtain medium-sized sintered ore and small-sized sintered ore.

[0026] Preferably, the particle size of the medium-sized sintered ore is 4 to 8 mm.

[0027] Preferably, the particle size of the small-size sintered ore is less than 4 mm.

[0028] Preferably, the medium-sized sintered ore is sent as cold material to the high-level silo of the steelmaking process for addition and use.

[0029] Preferably, the particle size of the finished sintered ore is greater than 8 mm.

[0030] When in use, the finished sintered ore with a particle size greater than 8 mm is transported by belt to the first screen of the ironmaking process for screening, the sintered ore with a particle size greater than 8 mm is sent to the blast furnace, and the remaining sintered ore is sent to the closed material yard for a second screening. The sintered ore with a particle size of 4 to 8 mm is used as cold material for addition, and only a small part of the sintered ore with a particle size less than 4 mm is returned to the sintering process as return ore.

[0031] The advantages and positive effects of the present invention are: the particle size of the finished sintered ore can be flexibly adjusted according to production needs. When the sintering output is greater than the ironmaking output and the ironmaking output is greater than the steelmaking output, the sintered ore of three particle sizes can be efficiently used in the sintering process, the ironmaking process and the steelmaking process, which can not only reduce the amount of sintered ore returned, but also improve the permeability index of the blast furnace, which is more conducive to energy conservation and emission reduction in the entire production process.

[0032] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A new method for efficient utilization of sintered ore, characterized in that: It includes sintering process, ironmaking process and steelmaking process. The specific methods are as follows: The finished sintered ore produced in the sintering process is transported to the ironmaking process for the first screening, and the large-particle sintered ore obtained enters the blast furnace for ironmaking. The remaining sintered ore is screened for the second time, and the medium-particle sintered ore obtained enters the converter for steelmaking. The remaining small-particle sintered ore returns to the sintering process for sintering again.

2. The new method for efficient utilization of sintered ore according to claim 1, characterized in that: The iron-making process is provided with an iron-making ore trough, and a first screen is provided at the lower part of the iron-making ore trough. The sintered ore produced in the sintering process is screened for the first time through the first screen to obtain the large-particle-size sintered ore.

3. The new method for efficient utilization of sintered ore according to claim 2, characterized in that: The particle size of the large-size sintered ore is greater than 8 mm.

4. The new method for efficient utilization of sintered ore according to any one of claims 1 to 3, characterized in that: The remaining sintered ore after the first screening is transported to a closed material yard, which is provided with a second screen for a second screening to obtain the medium-sized sintered ore and the small-sized sintered ore.

5. The new method for efficient utilization of sintered ore according to claim 4, characterized in that: The particle size of the medium-sized sintered ore is 4 to 8 mm.

6. The new method for efficient utilization of sintered ore according to claim 5, characterized in that: The particle size of the small-size sintered ore is less than 4 mm.

7. The new method for efficient utilization of sintered ore according to claim 5, characterized in that: The medium-sized sintered ore is sent to the high-level silo of the steelmaking process as cold material for addition and use.

8. The new method for efficient utilization of sintered ore according to any one of claims 1 to 3 and 5 to 7, characterized in that: The particle size of the finished sintered ore is greater than 8 mm.

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