Blast furnace smelting process for high-proportion vanadium-titanium pellets

Abstract

The invention relates to the technical field of iron and steel smelting, in particular to a high-proportion vanadium-titanium pellet blast furnace smelting process which comprises the following steps: mixing vanadium-titanium pellets, sintered ore, raw ore, coke, pulverized coal and slag to obtain furnace burden, and putting the furnace burden into a blast furnace for smelting; wherein the vanadium-titanium pellet ore comprises a vanadium-titanium pellet 1 and a vanadium-titanium pellet 2; the grade of the vanadium-titanium pellets 1 is 55%-60%, the content of FeO is 1%-1.5%, the content of V2O5 is 0.66%-0.7%, and the content of TiO2 is 9.0%-9.5%; the grade of the vanadium-titanium pellets 2 is 53.5%-55%, the content of FeO is 1.5%-2%, the content of V2O5 is 0.7%-0.8%, and the content of TiO2 is 9.5%-10.0%. When blast furnace smelting is carried out, appropriate furnace charge is selected, smelting parameters are cooperatively regulated and controlled for smelting, the quality of a sintering furnace is improved, sintering components are reduced, and the requirement of blast furnace smelting is completely met.

Description

Technical Field

[0001] The invention relates to the technical field of steel smelting, in particular to a blast furnace smelting process for high-proportion vanadium-titanium pellets. Background Art

[0002] Due to the iron-titanium symbiotic mineral structure in vanadium-titanium magnetite, the iron content in vanadium-titanium magnetite is low and the titanium content is high. During the sintering process, TiO2 reacts with CaO in the flux to form perovskite. The hard and brittle characteristics of perovskite reduce the strength of the sintered ore, deteriorate the quality of the sintered ore, and lead to a high total return rate of the sintered ore, which increases the sintering processing cost. At the same time, due to the low iron content in vanadium-titanium magnetite, after entering the blast furnace, the blast furnace grade is reduced, which is not conducive to increasing the pig iron output of the blast furnace. In order to improve this situation, pellets are often used to replace sintered ore.

[0003] Vanadium-titanium magnetite is a complex magnetite that is difficult to select and smelt. Its spheroidization index is 0.2-0.3, which means it has no spheroidization or weak spheroidization and poor spheroidization. Therefore, it is of great significance to develop a blast furnace smelting process for high-proportion vanadium-titanium pellets. Summary of the invention

[0004] In order to solve the defects in the prior art, the present invention provides a blast furnace smelting process for high-proportion vanadium-titanium pellets, which can realize blast furnace smelting of vanadium-titanium pellets with a proportion of up to 50%.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a blast furnace smelting process for high-proportion vanadium-titanium pellets, comprising the following steps:

[0007] Mixing vanadium-titanium pellets, sintered ore, raw ore, coke, coal powder and slag to obtain a charge, and putting the charge into a blast furnace for smelting;

[0008] Among them, the vanadium-titanium pellet ore includes vanadium-titanium pellet 1 and vanadium-titanium pellet 2; the grade of the vanadium-titanium pellet 1 is 55-60%, the FeO content is 1-1.5%, the V2O5 content is 0.66-0.7%, and the TiO2 content is 9.0-9.5%; the grade of the vanadium-titanium pellet 2 is 53.5-55%, the FeO content is 1.5-2%, the V2O5 content is 0.7-0.8%, and the TiO2 content is 9.5-10.0%.

[0009] Preferably, the mass ratio of the vanadium-titanium pellets 1 to the vanadium-titanium pellets 2 is 35:(10-15).

[0010] Preferably, the grade of the sintered ore is ≥48%, the mass content of TiO2 is 3.8-4.8%, the mass content of FeO is 8.0-9.0%, the mass content of V2O5 is ≥0.35%, the low-temperature reduction pulverization rate +3.15≥55%, and the binary basicity of the sintered ore is 2.45-2.65.

[0011] Preferably, the coke requires fixed carbon ≥ 85.5%, strength after reaction ≥ 60%, reactivity ≤ 28%, and moisture ≤ 3%.

[0012] Preferably, the pulverized coal requires fixed carbon ≥ 78%, S ≤ 0.7%, and lower calorific value ≥ 7000 kcal.

[0013] Preferably, the slag composition is controlled to have a titanium dioxide content of 21.5-23%.

[0014] Preferably, the mass ratio of vanadium-titanium pellets, sintered ore and raw ore in the charge is (45-50):47:3.

[0015] Preferably, the blast furnace air volume in the smelting process is controlled at 3300m 3 / min, oxygen enrichment 12000m 3 / h, wind temperature is controlled at 1200~1210℃.

[0016] Preferably, the coke load in the smelting process is between 4.7 and 4.85, the theoretical combustion temperature of the tuyere is controlled at 2280°C, and the actual wind speed is controlled at 270m / s.

[0017] The beneficial effects of the present invention are:

[0018] During blast furnace smelting, the present invention selectively selects two vanadium-titanium pellets with different chemical compositions to mix as vanadium-titanium pellet ore, and adaptively selects the chemical composition and proportion of sintered ore, raw ore, coke, pulverized coal, slag and other components to form suitable charge, and coordinately regulates smelting parameters for smelting to improve the quality of the sintering furnace and reduce the sintering components, which fully meets the requirements of blast furnace smelting. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solution of the invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0020] Example 1

[0021] (1) Raw material preparation:

[0022] The chemical composition selection of vanadium-titanium pellets includes: vanadium-titanium pellets 1 and vanadium-titanium pellets 2, wherein the grade of vanadium-titanium pellets 1 is 55%, the FeO content is 1%, the V2O5 content is 0.66%, and the TiO2 content is 9.0%; the grade of vanadium-titanium pellets 2 is 53.5%, the FeO content is 1.5%, the V2O5 content is 0.7%, and the TiO2 content is 9.5%.

[0023] Sintered ore selection: grade ≥48%, TiO2 mass content of 3.8%, FeO mass content of 8.0%, V2O5 mass content ≥0.35%, low-temperature reduction pulverization rate +3.15≥55%, sintered ore binary basicity 2.45.

[0024] Coke quality requirements: fixed carbon ≥ 85.5%, strength after reaction ≥ 60%, reactivity ≤ 28%, moisture ≤ 3%;

[0025] Coal powder quality requirements: fixed carbon ≥ 78%, S ≤ 0.7%, lower calorific value ≥ 7000 kcal;

[0026] Slag composition control: 21.5% titanium dioxide in the slag.

[0027] (3) Forming charge:

[0028] Mix vanadium-titanium pellets, sintered ore, raw ore, coke, coal powder and slag to form a furnace charge, wherein the mass ratio of vanadium-titanium pellets, sintered ore and raw ore in the furnace charge structure is 50:47:3. The total proportion of pellets entering the furnace is 50% (including vanadium-titanium pellets 1: vanadium-titanium pellets 2 = 35:15, and the compressive strength is ≥ 2200N).

[0029] (3) Blast furnace smelting:

[0030] The charge obtained in (2) is put into a blast furnace for smelting, and the blast furnace air volume is controlled at 3300m 3 / min, oxygen enrichment 12000m 3 / h, wind temperature is controlled at 1200℃; ore batch is controlled at 37t / batch, coke load is 4.70, coal ratio is controlled at 160kg / ton iron, theoretical combustion temperature of tuyere is controlled at 2280℃, and actual wind speed is controlled at 270m / s.

[0031] Example 2

[0032] (1) Raw material preparation:

[0033] The chemical composition selection of vanadium-titanium pellets includes: vanadium-titanium pellets 1 and vanadium-titanium pellets 2, wherein the grade of vanadium-titanium pellets 1 is 60%, the FeO content is 1.5%, the V2O5 content is 0.7%, and the TiO2 content is 9.5%, and the grade of vanadium-titanium pellets 2 is 55%, the FeO content is 2%, the V2O5 content is 0.8%, and the TiO2 content is 10%.

[0034] Sintered ore selection: grade ≥48%, TiO2 mass content of 4.8%, FeO mass content of 9.0%, V2O5 mass content ≥0.35%, low-temperature reduction pulverization rate +3.15≥55%, sintered ore binary basicity 2.65.

[0035] Coke quality requirements: fixed carbon ≥ 85.5%, strength after reaction ≥ 60%, reactivity ≤ 28%, moisture ≤ 3%;

[0036] Coal powder quality requirements: fixed carbon ≥ 78%, S ≤ 0.7%, lower calorific value ≥ 7000 kcal;

[0037] Slag composition control: 23% titanium dioxide in the slag.

[0038] (3) Forming charge:

[0039] Mix vanadium-titanium pellets, sintered ore, raw ore, coke, coal powder and slag to form a furnace charge, wherein the mass ratio of vanadium-titanium pellets, sintered ore and raw ore in the furnace charge structure is 45:47:3. The total proportion of pellets entering the furnace is 45% (including vanadium-titanium pellets 1: vanadium-titanium pellets 2 = 35:10, and the compressive strength is ≥ 2200N).

[0040] (3) Blast furnace smelting:

[0041] The charge obtained in (2) is put into a blast furnace for smelting, and the blast furnace air volume is controlled at 3300m 3 / min, oxygen enrichment 12000m 3 / h, wind temperature is controlled at 1210℃; ore batch is controlled at 38t / batch, coke load is 4.85, coal ratio is controlled at 170kg / ton iron, theoretical combustion temperature of tuyere is controlled at 2280℃, and actual wind speed is controlled at 270m / s.

[0042] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A high proportion of vanadium titanium pellet blast furnace smelting process, characterized in that: The following steps are involved: Mixing vanadium-titanium pellets, sintered ore, raw ore, coke, coal powder and slag to obtain a charge, and putting the charge into a blast furnace for smelting; Among them, the vanadium-titanium pellet ore includes vanadium-titanium pellet 1 and vanadium-titanium pellet 2; the grade of the vanadium-titanium pellet 1 is 55-60%, the FeO content is 1-1.5%, the V2O5 content is 0.66-0.7%, and the TiO2 content is 9.0-9.5%; the grade of the vanadium-titanium pellet 2 is 53.5-55%, the FeO content is 1.5-2%, the V2O5 content is 0.7-0.8%, and the TiO2 content is 9.5-10.0%.

2. The blast furnace smelting process according to claim 1, characterized in that: The mass ratio of the vanadium-titanium pellets 1 to the vanadium-titanium pellets 2 is 35:(10-15).

3. The blast furnace smelting process according to claim 2, characterized in that: The mass ratio of vanadium-titanium pellets, sintered ore and raw ore in the furnace charge is (45-50):47:

3.

4. The blast furnace smelting process according to any one of claims 1 to 3, characterized in that: The grade of the sintered ore is ≥48%, the mass content of TiO2 is 3.8-4.8%, the mass content of FeO is 8.0-9.0%, the mass content of V2O5 is ≥0.35%, the low-temperature reduction pulverization rate is +3.15≥55%, and the binary basicity of the sintered ore is 2.45-2.

65.

5. The blast furnace smelting process according to any one of claims 1 to 3, characterized in that: The coke is required to have fixed carbon ≥85.5%, strength after reaction ≥60%, reactivity ≤28%, and moisture ≤3%.

6. The blast furnace smelting process according to any one of claims 1 to 3, characterized in that: The coal powder is required to have fixed carbon ≥78%, S≤0.7%, and a lower calorific value ≥7000 kcal.

7. The blast furnace smelting process according to any one of claims 1 to 3, characterized in that: The slag composition is controlled to contain 21.5-23% titanium dioxide in the slag.

8. The blast furnace smelting process according to any one of claims 1 to 3, characterized in that: The blast furnace air volume during the smelting process is controlled at 3300m 3 / min, oxygen enrichment 12000m 3 / h, wind temperature is controlled at 1200~1210℃.

9. The blast furnace smelting process according to any one of claims 1 to 3, characterized in that: The coke load in the smelting process is between 4.7 and 4.85, the theoretical combustion temperature of the tuyere is controlled at 2280°C, and the actual wind speed is controlled at 270m / s.