Method for inhibiting edge effect of sintering machine

Abstract

The invention discloses a method for inhibiting the edge effect of a sintering machine, which comprises the following steps of: arranging a lump ore storage bin above a machine head of the sintering machine, uniformly mixing high-burst lump ore and carbon-containing powder according to a certain proportion, and feeding the mixture into the lump ore storage bin through a belt; on the basis of sintering grate-layer material distribution, a common iron ore powder sintering mixture is distributed in the middle of a sintering machine, and a lump ore and carbon-containing powder mixture is distributed on the edge, close to a baffle of the sintering machine, of the sintering machine according to a certain width through special distribution equipment; after ignition and sintering, the lump ore and the sintered ore enter a circular cooler together for cooling, the cooled sintered ore and lump ore are fed into a screening device for screening, and the lump ore of more than + 5mm is fed into a blast furnace for smelting. The edge effect of a sintering machine is restrained through the high bursting performance of the lump ore, the lump ore is dried and screened through sintering heat, the lump ore proportion is effectively increased, and energy consumption and carbon emission of a blast furnace are reduced.

Description

Technical Field

[0001] The invention relates to the field of sintering machines, and in particular to a method for suppressing edge effects of sintering machines. Background Art

[0002] Iron ore sintering is one of the main methods of iron ore agglomeration. During the sintering process, high-quality and high-yield sintered ore can be achieved by controlling the operating speed, material layer thickness, air volume and other parameters of the sintering machine. Iron ore sintering is mainly produced by sintering machines, but the edge effect of the sintering machine will lead to an increase in the sintering return rate: since the sintering return rate at the edge of the sintering machine is significantly higher than that in the normal area, this leads to an increase in the return rate of the entire sintering process, thereby affecting the economic benefits of sintering. The edge effect also causes uneven airflow distribution on the material surface, unreasonable thermal system, and poor air permeability, which further leads to a lag in the vertical sintering speed in the middle. Different vertical sintering speeds aggravate the uneven airflow distribution, forming a vicious circle and increasing energy consumption and costs. In summary, the edge effect of the sintering machine has brought serious harm to production and affected the economic benefits and product quality of the enterprise. Therefore, it is necessary to take corresponding measures to prevent and reduce the occurrence of edge effects.

[0003] The main reasons for the edge effect of the sintering machine can be summarized as follows: At the edge of the sintering machine trolley, the material is usually loose and has a large porosity. This physical property makes the wind resistance in the edge area smaller and the wind speed significantly increased, thus forming the edge effect. During the sintering process, the material shrinks and separates from the trolley railing, forming a side seam. This side seam increases the air volume in the edge area, further exacerbating the edge effect. Part of the wind follows the channel with the lowest resistance and does not enter the sintering process, which leads to poor quality and low yield of sintered ore in the edge zone.

[0004] In order to reduce or eliminate the edge effect of the sintering machine, the main methods currently include thickening the edge cloth and edge pressing, such as patent numbers CN 101825395A, CN 202613974U, CN 202814080U, CN 202853373U, etc., increasing the edge ignition temperature and improving the baffle structure, such as patent numbers CN 201003906Y, CN 203224132U. These methods mainly increase the air intake resistance in the edge area of ​​the sintering trolley, which can reduce the edge effect to a certain extent. However, there is still a gap between the material surface and the trolley baffle, and the effect of suppressing the edge effect is limited.

[0005] In recent years, the steel industry has gradually developed towards refined materials in order to reduce pollutant emissions and reduce ironmaking costs. Reasonable charge structure is an important means to effectively improve the technical and economic performance of blast furnaces. Among blast furnace charges, natural lump ore is cheaper than pelletized ore. However, the high thermal burst index of lump ore and the crushing of lump ore caused by the decomposition of crystal water further limit the proportion of lump ore added to the blast furnace. Therefore, in general, lump ore needs to be dried before being added to the blast furnace. The current lump ore drying process mainly involves the construction of a new rotary kiln or drum dryer and screening system to dry and screen the lump ore, which has problems such as high investment, large floor space, and high energy consumption.

[0006] Therefore, it is necessary to develop a new method for suppressing the edge effect of the sintering machine in a targeted manner to overcome the problems of the existing technology. Summary of the invention

[0007] Purpose of the invention: In view of the shortcomings and defects of the prior art, the present invention provides a method for suppressing the edge effect of a sintering machine, utilizing the high bursting performance of lump ore to suppress the edge effect of a sintering machine, utilizing the sintering heat to dry and screen the lump ore, effectively improving the lump ore ratio, and reducing the energy consumption and carbon emissions of the blast furnace.

[0008] Technical solution: A method for suppressing the edge effect of a sintering machine of the present invention is characterized by comprising the following steps:

[0009] 1) Determine the thermal cracking index DI of different types of lump ore to be added to the blast furnace according to the national standard, i.e. -6.3mm, and classify the lump ore with a thermal cracking index ≥10% as high-cracking lump ore;

[0010] 2) A lump ore storage bin is set above the sintering machine head, and the high-explosive lump ore and carbon-containing powder are mixed in a certain proportion and then sent into the lump ore storage bin by a belt;

[0011] 3) On the basis of sintering base material distribution, the common iron ore powder sintering mixture is distributed in the middle of the sintering machine, and the lump ore and carbon-containing powder mixture is distributed in a certain width close to the edge of the sintering machine baffle through a special distribution equipment;

[0012] 4) After ignition and sintering, the lump ore and sintered ore enter the ring cooler for cooling. The cooled sintered ore and lump ore are sent to the screening device for screening, and those above +5mm are sent to the blast furnace for smelting.

[0013] Wherein, the carbon-containing powder in step 2) includes one or more of coke powder, coal powder, and blue coke sintering common fuels.

[0014] Wherein, the particle size of the carbon-containing powder in step 2) is greater than 60% of -3mm.

[0015] Wherein, in step 3), the mass ratio of lump ore to carbon-containing powder is 85-95:5-15.

[0016] Wherein, in the step 3), the width of the mixture of lump ore and carbonaceous powder is 5cm-20cm starting from the edge of the trolley baffle.

[0017] Among them, the high-explosive lump ore mixture is located at the edge of the sintering machine baffle outside the ordinary iron ore powder sintering mixture.

[0018] Wherein, the sintering machine baffle is connected to the sintering machine grate bars.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention solves the problem of edge effect during the sintering process. During the sintering process, the wet block ore is placed on the edge of the sintering machine, which eliminates the influence of the edge effect and reduces the air leakage rate at the sintering edge. It has the advantages of being economical, simple and easy to operate.

[0020] At the same time, the heat of the sintering machine is used to dry the lump ore. After the lump ore added to the blast furnace is dried and preheated, the crystal water and carbonate in the lump ore are decomposed and removed in advance before entering the blast furnace, which can effectively reduce the energy consumption of the blast furnace, increase the lump ore ratio in the blast furnace, achieve energy saving and consumption reduction, and reduce carbon emissions. At the same time, it solves the adverse effects of the sintering machine edge effect and lump ore burst on the blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] In the figure, 1 is a common iron ore powder sintering mixture; 2 is a sintering machine baffle; 3 is a high-explosion lump ore mixture; and 4 is a sintering machine grate. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0024] The present invention is a method for suppressing the edge effect of a sintering machine by utilizing the high bursting performance of lump ore, and at the same time solves the adverse effects of the edge effect of the sintering machine and the bursting of lump ore on the blast furnace. During the sintering process, the powder generated by the bursting of the lump ore fills the gaps at the edge of the sintering machine, eliminates the influence of the edge effect, and reduces the air leakage rate at the edge of the sintering machine, thereby saving sintering energy consumption, improving the quality of sintered ore, and increasing the productivity of sintered ore. At the same time, the sintering heat is used to dry and screen the lump ore, effectively improving the lump ore ratio, and reducing the energy consumption and carbon emissions of the blast furnace.

[0025] The method for suppressing the edge effect of a sintering machine of the present invention comprises the following steps:

[0026] 1) The different types of lump ores to be added to the blast furnace are measured for the thermal cracking index DI according to the national standard, i.e. -6.3 mm, and the lump ores with a thermal cracking index ≥ 10% are classified as high-cracking lump ores.

[0027] 2) A lump ore storage bin is arranged above the sintering machine head, and the above-mentioned high-explosion lump ore and carbon-containing powder are mixed in a certain proportion and then sent into the lump ore storage bin by a belt; the carbon-containing powder includes one or more of coke powder, coal powder, and semi-coke sintering common fuels; the particle size of the carbon-containing powder is greater than 60% of -3mm.

[0028] 3) On the basis of sintering base material distribution, the common iron ore powder sintering mixture is distributed in the middle of the sintering machine, and the lump ore and carbon-containing powder mixture is distributed in a certain width close to the edge of the sintering machine baffle through a special distribution equipment; the distribution width of the lump ore and carbon-containing powder mixture is 5cm-20cm starting from the edge of the trolley baffle.

[0029] 4) After ignition and sintering, the lump ore and sintered ore enter the ring cooler for cooling. The cooled sintered ore and lump ore are sent to the screening device for screening, and those above +5mm are sent to the blast furnace for smelting.

[0030] The high-explosion lump ore mixture 3 of the present invention is located at the edge of the sintering machine baffle 2 outside the ordinary iron ore powder sintering mixture 1. The sintering machine baffle 2 is connected to the sintering machine grate 4.

[0031] The invention solves the problem of edge effect in the sintering process. During the sintering process, the wet block ore is placed on the edge of the sintering machine, eliminating the influence of the edge effect and reducing the air leakage rate of the sintering edge. It has the advantages of being economical, simple and easy to operate.

[0032] At the same time, the heat of the sintering machine is used to dry the lump ore. After the lump ore added to the blast furnace is dried and preheated, the crystal water and carbonate in the lump ore are decomposed and removed in advance before entering the blast furnace, which can effectively reduce the energy consumption of the blast furnace, increase the lump ore ratio in the blast furnace, achieve energy saving and consumption reduction, and reduce carbon emissions. At the same time, it solves the adverse effects of the sintering machine edge effect and lump ore burst on the blast furnace.

Claims

1. A method for suppressing the edge effect of a sintering machine, characterized in that: The steps include: 1) Determine the thermal cracking index DI of different types of lump ore to be added to the blast furnace according to the national standard, i.e. -6.3mm, and classify the lump ore with a thermal cracking index ≥10% as high-cracking lump ore; 2) A lump ore storage bin is set above the sintering machine head, and the high-explosive lump ore and carbon-containing powder are mixed in a certain proportion and then sent into the lump ore storage bin by a belt; 3) On the basis of sintering base material distribution, the common iron ore powder sintering mixture is distributed in the middle of the sintering machine, and the lump ore and carbon-containing powder mixture is distributed in a certain width close to the edge of the sintering machine baffle through a special distribution equipment; 4) After ignition and sintering, the lump ore and sintered ore enter the ring cooler for cooling. The cooled sintered ore and lump ore are sent to the screening device for screening, and those above +5mm are sent to the blast furnace for smelting.

2. The method for suppressing the edge effect of a sintering machine according to claim 1, characterized in that: The carbon-containing powder in step 2) includes one or more of coke powder, coal powder, and blue coke sintering fuels.

3. The method for suppressing the edge effect of a sintering machine according to claim 1, characterized in that: In the step 2), the particle size of the carbon-containing powder is -3 mm and is greater than 60%.

4. The method for suppressing the edge effect of a sintering machine according to claim 1, characterized in that: In the step 3), the mass ratio of lump ore to carbon-containing powder is 85-95:5-15.

5. The method for suppressing the edge effect of a sintering machine according to claim 1, characterized in that: In the step 3), the width of the mixture of lump ore and carbonaceous powder is 5 cm to 20 cm starting from the edge of the trolley baffle.

6. The method for suppressing the edge effect of a sintering machine according to claim 1, characterized in that: The high-explosion lump ore mixture (3) is located at the edge of the sintering machine baffle (2) outside the ordinary iron ore powder sintering mixture (1).

7. The method for suppressing the edge effect of a sintering machine according to claim 6, characterized in that: The sintering machine baffle (2) is connected to the sintering machine grate (4).

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