Material input method for large-scale hydrogen-rich carbon circulation oxygen blast furnace

Abstract

The invention belongs to the technical field of blast furnace metallurgy, and particularly discloses a large-scale hydrogen-rich carbon circulation oxygen blast furnace material input method, which comprises the following steps of: loading a plurality of raw materials and fuels into a blast furnace through a charging device and a material distributing device in a matched charging sequence; cold-state oxygen is introduced to assist combustion to generate reducing gas; furnace top gas generated by a blast furnace is decarbonized and recycled; and the other part of furnace top gas enters a gas system user and a gas heating furnace for combustion and heat storage after being dedusted. In order to solve the problems that blowing coal gas of a hydrogen-carbon-rich circulating oxygen blast furnace is rich in reducing components, the coke ratio of solid fuel is reduced, the basicity of slag is influenced, and low-temperature reduction degradation of sintered ore is caused, the negative influence caused by reduction degradation is relieved by improving the FeO content and the basicity of the sintered ore.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace metallurgy, and in particular to a method for inputting materials into a large-scale hydrogen-rich carbon circulating oxygen blast furnace. Background Art

[0002] The consumption of blast furnace ironmaking is mainly concentrated in the metallurgical coke used in it. Metallurgical coke requires coking coal to be produced through the coking process, and the coking process has serious pollution emissions. With the substantial increase in blast furnace productivity, the demand for metallurgical coke will surge. In addition, blast furnaces are the main reactors for iron ore reduction and will dominate for a long time. As the most energy-consuming link in the steel industry, the steel industry accounts for 16% of the energy consumption and 72% of CO2 emissions in the entire industry, while blast furnaces account for 70% of the energy consumption and 52% of CO2 emissions in the steel industry. In order to reduce energy consumption and CO2 emissions, it is necessary to study a modification of the blast furnace process to improve the process method of traditional blast furnaces and achieve the purpose of reducing energy consumption and CO2 emissions.

[0003] The hydrogen-rich carbon circulating oxygen blast furnace process is a new type of ironmaking process modified from blast furnace ironmaking. It has the advantages of greatly reducing fuel ratio, reducing CO2 emissions and improving molten iron production efficiency. The coal gas injected into the hydrogen-rich carbon circulating oxygen blast furnace is rich in reducing components. After injection, it can promote the development of indirect reduction, reduce direct reduction, reduce the solid fuel ratio, and especially reduce the solid fuel coke ratio. Due to the reduction of the coke ratio, the ash content in the coke entering the furnace is reduced, affecting the slag basicity. At the same time, with the development of indirect reduction, the position, shape and thickness of the soft melting zone of the charge have a significant impact on its operation, affecting the distribution of heat in the large hydrogen-rich carbon circulating oxygen blast furnace. In addition, with the significant increase in the reduction degree and reduction rate of the sintered ore, the low-temperature reduction pulverization of the charge is aggravated. Summary of the invention

[0004] The object of the present invention is to provide a method for inputting materials into a large hydrogen-rich carbon circulating oxygen blast furnace to solve the changes in slag basicity and soft melting zone caused by the reduction of coke ratio, and to address the problem of low-temperature reduction and pulverization of sintered ore.

[0005] To achieve the above object, the basic scheme provided by the present invention is: a method for inputting materials into a large-scale hydrogen-rich carbon circulating oxygen blast furnace, comprising the following steps:

[0006] S1, the furnace top input end includes the first main raw material, the second main raw material, the first auxiliary raw material, the second auxiliary raw material, the first main fuel and the second main fuel, which are loaded into the furnace in the order of loading by the charging equipment and the material distribution device;

[0007] S2, cold oxygen is input from the composite tuyere of a large or medium-sized hydrogen-rich carbon cycle oxygen blast furnace, and the first main fuel and the second main fuel after combustion and ignition produce reducing gas CO+H2. At the same time, the powdered auxiliary fuel injection device inputs auxiliary raw materials from the composite tuyere, and after combustion by cold oxygen, it also produces reducing gas CO+H2. The generated reducing gas CO+H2 reduces the iron oxides in the first main raw material, the second main raw material, the first auxiliary raw material and the second auxiliary raw material at the furnace top input end into qualified elemental iron, heats the elemental iron into liquid, and melts other components of the iron oxides to become slag, and the qualified liquid iron and slag are discharged from the iron mouth;

[0008] S3, partial reduction gas CO+H2 takes away oxygen from iron oxides, generating a calorific value of 6000-7000 kJ / Nm 3 The mixed top gas is discharged from the top of the furnace, and a part of it enters the decarbonization system after dust removal and cooling. After the CO2 in the top gas is removed, it is heated by the gas heating furnace and then sprayed into the furnace through the composite tuyere device as the first gas fuel;

[0009] S4. Another part of the furnace top gas enters the gas system users and gas heating furnaces for combustion and heat storage after dust removal.

[0010] The principle and beneficial effect of the present invention are as follows: oxygen assists combustion of the first main fuel and the second main fuel to generate reducing gas, which reduces the iron oxides in the first main raw material, the second main raw material, the first auxiliary raw material and the second auxiliary raw material at the furnace top input end into qualified elemental iron. The top gas is decarbonized and recycled through the decarbonization system, which reduces energy consumption and can provide the heat required for ore reduction in the upper part of the hydrogen-rich carbon circulating oxygen blast furnace, while increasing the belly gas flux.

[0011] Scheme 2 is the preferred basic scheme. The fuel and raw material input in S1 includes the following specific contents:

[0012] First main raw material: TFe = 55%, basicity R2 = CaO / SiO2 = 1.85-1.9, FeO = 8-10%, MgO 2.0-2.5%, drum index above 81%;

[0013] The second main raw material: TFe = 63%, compressive strength is 2000-2500N / ball, basicity R2 = 0.1-0.5;

[0014] First auxiliary raw material: TFe = 45-57%;

[0015] Second auxiliary raw material: TFe = 95-99%;

[0016] First main fuel: cold crushing strength M40: 86%-92%, wear resistance M10: ≥6.8%, hot strength CSR ≥50%, CRI ≥30%, average particle size 50-55mm;

[0017] The first gas fuel: it is a reducing gas fuel after CO2 is removed from the furnace top, with a volume fraction of CO+H2 of about 65-75%;

[0018] Second main fuel: similar to the first main fuel strength index, particle size 10-25mm;

[0019] Auxiliary fuel: pulverized coal made from bituminous coal, with volatile matter controlled to ≯25%, and pulverized coal with a mesh size of minus 200 and less than 0.071mm reaching 60%-65%;

[0020] Raw material and fuel ratio: (first main raw material: second main raw material: first auxiliary raw material = 43-47%: 45-52%: 2-5%); second auxiliary raw material 20-80kg / t iron, first main fuel 280-350kg / t iron, second main fuel 20-30kg / t iron, first gas fuel 550-750Nm 3 / t iron, secondary fuel 20-100kg / t iron;

[0021] Increasing the FeO content and basicity in the first main raw material and the second main raw material to improve the strength of the raw materials can reduce reduction pulverization, increase the raw material particle size, make the material column have good air permeability, and facilitate the contact between the reducing gas and the raw materials.

[0022] Scheme 3, which is the preferred basic scheme, is that in S1, 50-65t / batch of the first main raw material and the second main raw material ore batch and 13-17t / batch of the first main fuel and the second main fuel are loaded into the furnace by using the charging equipment and the distribution device, and the chute of the distribution device rotates β angle in the furnace and moves radially at an angle α based on the center of the furnace to continuously distribute the materials;

[0023] The first gear of the normal material line is controlled at 1.2-1.9m, which also includes the second gear of the abnormal material line 1.9-2.4m, the third gear 2.4-3.1m, and the fourth gear >3.1m;

[0024] The first main fuel and the second main fuel are adjusted in 4 gears. The first gear: the α angle reference angle is 39.5, 37.5, 35.5, 33, and 30.5 degrees; the second gear: the α angle reference angle is 38.5, 36.5, 34.5, 32, and 29.5 degrees; the third gear: the α angle reference angle is 37.5, 35.5, 33.5, 31, and 28.5 degrees; the fourth gear: the α angle reference angle is 36, 34, 32, 29.5, and 27 degrees; the first, second, third, and fourth gears correspond to the same number of β angle rotations: 3 turns, 3 turns, 3 turns, 2 turns, and 2 turns respectively;

[0025] The first main raw material, the second main raw material, the first auxiliary raw material and the second auxiliary raw material are adjusted in 4 levels. The first level: the α angle reference angle is 39.5, 37.5, 35.5 and 33 degrees; the second level: the α angle reference angle is 38.5, 36.5, 34.5 and 32 degrees; the third level: the α angle reference angle is 37.5, 35.5, 33.5 and 31 degrees; the fourth level: the α angle reference angle is 36, 34, 32 and 29.5 degrees; the first, second, third and fourth levels correspond to the same number of β angle rotations: 3, 3, 3 and 2 respectively.

[0026] According to the needs of the central airflow, the α angle of the raw material can be adjusted to be 0.5-1 degree larger than the α angle of the fuel. According to the needs of the edge airflow, the α angle of the raw material can be adjusted to be 0.5-1 degree smaller than the α angle of the fuel. The charging system is based on a matrix, with the stabilization of the central airflow as the main focus and the appropriate development of the edge airflow as the auxiliary. By adjusting the α angle reference angle, the raw materials and fuel are distributed in alternating layers in the blast furnace, forming a funnel + platform-shaped material surface.

[0027] By controlling the angle and number of distribution circles of the distribution device, the raw materials and fuel are evenly distributed on the circumference of the furnace, so that the fuel burns fully and the generated reducing gas fully contacts the raw materials.

[0028] Scheme 4, which is the preferred basic scheme, after the furnace top gas in S3 is dusted and cooled, the decarbonization system will be sprayed to the large and medium-sized hydrogen-rich carbon circulating oxygen blast furnace to reduce the CO2 of the reducing gas in the furnace to less than 3%, and then heated to 910-1250℃ by the gas heating furnace and sprayed from the composite tuyere, and the second gas fuel is also sprayed from the composite tuyere;

[0029] Second gas fuel: hydrogen-rich gas, which can be coke oven gas, natural gas, or pure hydrogen;

[0030] After the first gas fuel is heated in the gas heating furnace and mixed with the second gas fuel to 910-1250℃ and then sprayed from the composite tuyere, the partial pressure of CO and H2 in the gas increases, the reduction potential of the gas increases, and the reduction reaction and interaction of the iron-containing charge under the high reduction potential gas condition lower the initial reduction temperature of the iron-containing charge entering the large and medium-sized hydrogen-rich carbon cycle oxygen blast furnace, accelerate the reduction speed, and improve the indirect reduction degree. At the same time, the furnace gas significantly improves the reduction degree of the furnace body charge. While spraying to remove CO2 in the furnace top gas, it also has the technical capability to add cold coke oven gas, natural gas, and pure hydrogen to the mixing device and pipeline after heating.

[0031] Scheme 5 is the preferred basic scheme. In S2, the oxygen is cold oxygen, the temperature is 10-30°C, the purity is ≥90%, and the composite tuyere (8) and the first gas fuel, the auxiliary fuel, and the second gas fuel are sprayed into the furnace through different channels. The injection amount of cold oxygen is related to the control of the input amount of the first main fuel, the second main fuel, and the auxiliary fuel, and is controlled at 180-260Nm 3 / t;

[0032] The use of full oxygen reduces the N2 content in the furnace belly and increases the reaction rate of the reducing gas in the furnace kinetics. Under the conditions of the first and second gas fuels and strong reducing atmosphere, the soft melting zone will become thinner under the conditions of large and medium-sized hydrogen-rich carbon circulating oxygen blast furnaces, the ore soft melting temperature will increase significantly, the soft melting temperature range will decrease, and the air flow resistance coefficient of the soft melting zone will decrease, and the permeability of the material column will be significantly improved. Under a strong reducing atmosphere, the softening zone in the large hydrogen-rich carbon circulating oxygen blast furnace becomes wider, while the melting zone becomes narrower, the permeability of the raw materials is improved, and the permeability of the charge is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a method for inputting materials into a large-scale hydrogen-rich carbon circulating oxygen blast furnace according to the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below through specific embodiments:

[0035] The figure marks in the drawings of the specification include: hydrogen-rich carbon circulating oxygen blast furnace-1; charging equipment-2; distribution device-3; cold oxygen-4; auxiliary fuel injection device-5; decarbonization system-6; gas heating furnace-7; composite air inlet-8; gas system user-9; mixing device and pipeline-10.

[0036] Example

[0037] like Figure 1 As shown: A method for inputting materials into a large hydrogen-rich carbon circulating oxygen blast furnace comprises the following steps:

[0038] S1, the furnace top input end includes the first main raw material, the second main raw material, the first auxiliary raw material, the second auxiliary raw material, the first main fuel and the second main fuel, the raw material and fuel ratio structure ratio: the first main raw material: the second main raw material: the first auxiliary raw material = 43-47%: 45-52%: 2-5%; the second auxiliary raw material 20-80kg / t iron, the first main fuel 280-350kg / t iron, the second main fuel 20-30kg / t iron; the charging device 2 and the distribution device 3 cooperate to load the raw materials and fuels into the furnace in the charging order of alternating layer distribution in the blast furnace; The first main fuel and the second main fuel are adjusted in 4 gears, the first gear: α angle reference angle 39.5, 37.5, 35.5, 33, 30.5 degrees; the second gear: α angle reference angle 38.5, 36.5, 34.5, 32, 29.5 degrees; the third gear: α angle reference angle 37.5, 35.5, 33.5, 31, 28.5 degrees; the fourth gear: α angle reference angle 36, 34, 32, 29.5, 27 degrees; the first, second, third, and fourth gears correspond to the same β angle rotation number: 3 turns, 3 turns, 3 turns, 2 turns, and 2 turns respectively;

[0039] The first main raw material, the second main raw material, the first auxiliary raw material and the second auxiliary raw material are adjusted in 4 levels. The first level: the α angle reference angle is 39.5, 37.5, 35.5 and 33 degrees; the second level: the α angle reference angle is 38.5, 36.5, 34.5 and 32 degrees; the third level: the α angle reference angle is 37.5, 35.5, 33.5 and 31 degrees; the fourth level: the α angle reference angle is 36, 34, 32 and 29.5 degrees; the first, second, third and fourth levels correspond to the same β angle rotation number: 3 circles, 3 circles, 3 circles and 2 circles respectively

[0040] S2, the above cold oxygen 4 with a temperature of 10-30℃ and a purity of ≥90% is input from the composite tuyere 5 of large and medium-sized hydrogen-rich carbon cycle oxygen blast furnace. The injection amount of cold oxygen is related to the control of the input amount of the first main fuel, the second main fuel, and the auxiliary fuel, and is controlled at 180-260Nm 3 / tThe main fuel after combustion-supporting ignition generates reducing gas CO+H2. At the same time, the powdered auxiliary fuel injection device 5 inputs the auxiliary raw material through the composite tuyere 8, and the auxiliary raw material is also generated by the cold oxygen after combustion. The generated reducing gas CO+H2 reduces the iron oxide in the first main raw material, the second main raw material, the first auxiliary raw material and the second auxiliary raw material at the furnace top input end into qualified elemental iron, heats the elemental iron into liquid, and the other components of the iron oxide are melted to become slag. The qualified liquid iron and slag are discharged from the iron mouth;

[0041] S3, partial reduction gas CO+H2 takes away oxygen from iron oxides, generating a calorific value of 6000-7000 kJ / Nm 3The mixed top gas is discharged from the top of the furnace, and a part of it enters the decarbonization system 6 after dust removal and cooling. After the CO2 in the top gas is removed, it is heated to 910-1250℃ by the gas heating furnace 7 and then sprayed into the furnace through the composite tuyere 8 device as the first gas fuel;

[0042] S4. Another part of the furnace top gas enters the gas system user 9 and the gas heating furnace for combustion and heat storage after dust removal.

[0043] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for inputting materials into a large hydrogen-rich carbon cycle oxygen blast furnace, characterized in that: The steps include: S1, the furnace top input end includes the first main raw material, the second main raw material, the first auxiliary raw material, the second auxiliary raw material, the first main fuel and the second main fuel, which are loaded into the furnace in a loading sequence by the charging device (2) and the material distribution device (3); S2, cold oxygen (4) is input from the composite tuyere (8) of a large or medium-sized hydrogen-rich carbon cycle oxygen blast furnace, and the main fuel after combustion and ignition produces reducing gas CO+H2. At the same time, the powdered auxiliary fuel injection device (5) inputs the auxiliary raw material from the composite tuyere (8), and the auxiliary raw material is also produced after combustion by the cold oxygen. The produced reducing gas CO+H2 reduces the iron oxide in the first main raw material, the second main raw material, the first auxiliary raw material and the second auxiliary raw material at the furnace top input end into qualified elemental iron, heats the elemental iron into liquid, and the other components of the iron oxide are melted to become slag, and the qualified liquid iron and slag are discharged from the iron mouth; S3, partial reduction gas CO+H2 takes away oxygen from iron oxides, generating a calorific value of 6000-7000 kJ / Nm 3 The mixed top gas is discharged from the top of the furnace, a part of which enters the decarbonization system (6) after dust removal and temperature reduction, and the top gas is heated by the gas heating furnace (7) as the first gas fuel and then sprayed into the furnace through the composite tuyere (8) device after CO2 in the top gas is removed; S4. Another part of the furnace top gas enters the gas system user (9) and the gas heating furnace for combustion and heat storage after dust removal.

2. A method for inputting materials into a large hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: The fuel and raw material input in S1 includes the following specific contents: First main raw material: TFe = 55%, basicity R2 = CaO / SiO2 = 1.85-1.9, FeO = 8-10%, MgO 2.0-2.5%, drum index above 81%; The second main raw material: TFe = 63%, compressive strength is 2000-2500N / ball, basicity R2 = 0.1-0.5; First auxiliary raw material: TFe = 45-57%; Second auxiliary raw material: TFe = 95-99%; First main fuel: cold crushing strength M40: 86%-92%, wear resistance M10: ≥6.8%, hot strength CSR ≥50%, CRI ≥30%, average particle size 50-55mm; Second main fuel: similar to the first main fuel strength index, particle size 10-25mm; The first gas fuel: it is a reducing gas fuel after CO2 is removed from the furnace top, with a volume fraction of CO+H2 of about 65-75%; Auxiliary fuel: pulverized coal made from bituminous coal, with volatile matter controlled to ≯25%, and pulverized coal with a mesh size of minus 200 and less than 0.071mm reaching 60%-65%; Raw material and fuel ratio: (first main raw material: second main raw material: first auxiliary raw material = 43-47%: 45-52%: 2-5%); second auxiliary raw material 20-80kg / t iron, first main fuel 280-350kg / t iron, second main fuel 20-30kg / t iron, first gas fuel 550-750Nm 3 / t iron, secondary fuel 20-100kg / t iron, second gas fuel 20-150Nm 3 / t.

3. A method for inputting materials into a large hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: In S1, 50-65 t / batch of main raw material ore and 13-17 t / batch of first main fuel are loaded into the furnace by using a charging device (2) and a distribution device (3), and the chute of the distribution device (3) rotates in the furnace at an angle β and moves radially at an angle α based on the center of the furnace to continuously distribute the materials; The first gear of the normal material line is controlled at 1.2-1.9m, which also includes the second gear of the abnormal material line 1.9-2.4m, the third gear 2.4-3.1m, and the fourth gear >3.1m; The first main fuel and the second main fuel are adjusted in 4 gears. The first gear: the α angle reference angle is 39.5, 37.5, 35.5, 33, and 30.5 degrees; the second gear: the α angle reference angle is 38.5, 36.5, 34.5, 32, and 29.5 degrees; the third gear: the α angle reference angle is 37.5, 35.5, 33.5, 31, and 28.5 degrees; the fourth gear: the α angle reference angle is 36, 34, 32, 29.5, and 27 degrees; the first, second, third, and fourth gears correspond to the same number of β angle rotations: 3 turns, 3 turns, 3 turns, 2 turns, and 2 turns respectively; The first main raw material, the second main raw material, the first auxiliary raw material and the second auxiliary raw material are adjusted in 4 levels. The first level: the α angle reference angle is 39.5, 37.5, 35.5 and 33 degrees; the second level: the α angle reference angle is 38.5, 36.5, 34.5 and 32 degrees; the third level: the α angle reference angle is 37.5, 35.5, 33.5 and 31 degrees; the fourth level: the α angle reference angle is 36, 34, 32 and 29.5 degrees; the first, second, third and fourth levels correspond to the same number of β angle rotations: 3, 3, 3 and 2 respectively. According to the demand of central airflow, the α angle of raw material can be adjusted to be 0.5-1 degree larger than that of fuel; according to the demand of edge airflow, the α angle of raw material can be adjusted to be 0.5-1 degree smaller than that of fuel; the charging system is in accordance with the matrix, focusing on stabilizing central airflow and appropriately developing edge airflow as a supplement; by adjusting the α angle reference angle, the raw materials and fuel are distributed in alternating layers in the blast furnace, forming a funnel + platform-shaped material surface.

4. A method for inputting materials into a large hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: After the top gas is dusted and cooled, the decarbonization system (6) reduces the CO2 content of the reducing gas injected into the large and medium-sized hydrogen-rich carbon circulating oxygen blast furnace to less than 3%, and is heated to 910-1250°C by the gas heating furnace (7) and then injected through the composite tuyere (8); The second gas fuel is also injected through the composite air port (8). The second gas fuel: hydrogen-rich gas, which can be coke oven gas, natural gas, or pure hydrogen.

5. A method for inputting materials into a large hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that In S2, the oxygen is cold oxygen, the temperature is 10-30℃, the purity is ≥90%, and it is sprayed into the furnace through different channels with the first gas fuel, the auxiliary fuel, and the second gas fuel through the composite tuyere (8). The injection amount of cold oxygen is related to the control of the input amount of the first main fuel, the second main fuel, and the auxiliary fuel, and is controlled at 180-260Nm 3 / t.

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