Method for smelting high-titanium vanadium-titanium magnetite by means of hydrogen-enriched carbon-recycling oxygen blast furnace

Abstract

A method for smelting high-titanium vanadium-titanium magnetite by means of a hydrogen-enriched carbon-recycling oxygen blast furnace. The method comprises: S1, determining a furnace charge structure; S2, determining a furnace charge distribution regime; S3, determining a blast regime; S4, determining a thermal regime; S5, determining a slagging regime; and S6, smelting high-titanium vanadium-titanium magnetite on the basis of the relevant parameters in steps S1 to S5, wherein the furnace charge structure comprises ores, the ores comprise vanadium-titanium sinter and vanadium-titanium pellets, the vanadium-titanium sinter accounts for 10-70% by mass, the vanadium-titanium pellets account for 90-30% by mass, and the in-furnace mass percentage of vanadium-titanium magnetite contained in the vanadium-titanium sinter and the vanadium-titanium pellets is greater than 65%. The present invention can further improve the smelting intensity on the basis of reducing carbon emissions, thereby achieving efficient comprehensive utilization of the high-titanium vanadium-titanium magnetite, and further achieving efficient smelting of schreyerite.

Description

A method for smelting high-titanium vanadium-titanium magnetite in a hydrogen-rich carbon-cycle oxygen blast furnace

[0001] This application claims priority to Chinese Patent Application No. 202410978303.4, filed on July 19, 2024, entitled "A Method for Smelting High-Titanium Vanadium-Titanium Magnetite in a Hydrogen-Rich Carbon-Circulating Oxygen Blast Furnace", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention belongs to the technical field of smelting high-titanium vanadium-titanium magnetite, specifically relating to a method for smelting high-titanium vanadium-titanium magnetite in a hydrogen-rich carbon-cycle oxygen blast furnace. Background Technology

[0003] The vanadium-titanium magnetite deposits in the Panxi region are an important strategic mineral resource in my country and a crucial foundation for Sichuan Province's vanadium-titanium steel industry cluster. Vanadium-titanium magnetite has a low iron content and is difficult to smelt; blast furnace smelting technology is its most common and mature utilization process. Meanwhile, Sichuan Province is rich in hydrogen resources and possesses three major industrial support bases: hydrogen production through water electrolysis, hydrogen production from industrial by-products, and hydrogen production from fossil fuels. Under the "dual carbon" context, combining Sichuan Province's advantageous hydrogen resources with the characteristics of vanadium-titanium magnetite smelting, promoting hydrogen-rich blast furnace smelting technology for reducing carbon emissions from vanadium-titanium magnetite is an inevitable choice for the green and low-carbon development of Sichuan's vanadium-titanium steel industry.

[0004] Oxygen blast furnace is a new type of blast furnace ironmaking process with advantages such as significantly reducing the fuel ratio, reducing CO2 emissions, and improving iron production efficiency. Because oxygen combustion in the vortex zone releases a large amount of heat, and the reduced fuel ratio leads to a decrease in the amount of gas in the hearth, oxygen blast furnaces suffer from the problem of "cold at the top and hot at the bottom." Top gas circulation injection can provide the necessary heat to the upper part of the blast furnace while increasing the gas flow in the hearth, effectively solving the "cold at the top and hot at the bottom" problem. The blast furnace carbon circulation achieves full oxygen smelting, avoiding the accumulation of N2 in the circulation. After full oxygen blasting, the concentration of reducing gases approaches 100%; the indirect reduction degree of the ore is significantly improved. After full oxygen smelting, the operating conditions inside the blast furnace change dramatically, the fuel ratio is significantly reduced, and new requirements are placed on the performance of the furnace charge.

[0005] In existing technologies, there is considerable theoretical research on hydrogen-rich carbon recycling in blast furnaces, but relatively little experimental research. (Sweden 9m) 3 Research has been conducted on experimental blast furnaces, including the 4Nm blast furnace from NKK Corporation of Japan. 3 The experimental blast furnace has been tested as a simple oxygen blast furnace. In 2007, the ULCOS project was carried out at LKAB's 9m... 3 A seven-week experimental study was conducted on the blast furnace to test the injection of circulating gas into the hearth and furnace body. The experimental blast furnace used two rows of tuyeres in the lower part of the hearth and furnace body, with a circulating gas volume of 550 m³ / h at the hearth tuyeres. 3 / t (1250℃), the circulating gas volume at the lower tuyeres of the furnace is approximately 550m³. 3 Under conditions of 1000℃, while maintaining a pulverized coal injection ratio of 170 kg / t, the coke ratio decreased from 400-405 kg / t to 260-265 kg / t, resulting in a 24% reduction in carbon consumption. The Japanese COURSE50 low-carbon ironmaking technology project employed a completely different gas injection and top gas circulation process. In 2015, a 12m³ furnace was constructed at Nippon Steel & Sumitomo Metal Corporation's Kimitsu Plant. 3 The experimental blast furnace featured three types of tuyeres: hearth tuyeres, lower tuyeres, and upper tuyeres. Coke oven gas or modified coke oven gas was injected into the hearth and lower tuyeres, while top tuyeres, partially auto-ignited and heated, were injected into the upper tuyeres to regulate the charge temperature and thus the reduction rate. This process was successfully tested and achieved its intended purpose.

[0006] While these technologies have shown significant effects in reducing carbon emissions and improving efficiency during the pilot phase, most of them are still in the laboratory or small-scale testing stage. The transformation from pilot projects to large-scale industrial application faces challenges in many aspects, including technology maturity, equipment investment costs, safety assessments, and operational stability.

[0007] Application content

[0008] One technical problem to be solved by this invention is to provide a method for full oxygen-rich hydrogen-rich carbon cycle based on blast furnace smelting of high-titanium vanadium-titanium magnetite, which aims to further improve smelting intensity while reducing carbon emissions and to achieve efficient and comprehensive utilization of high-titanium vanadium-titanium magnetite.

[0009] To address the aforementioned technical problems, this invention provides a method for smelting high-titanium vanadium-titanium magnetite in a hydrogen-rich carbon-cycled oxygen blast furnace, the method comprising:

[0010] S1. Determine the furnace charge structure;

[0011] S2. Determine the fabric formulation;

[0012] S3. Determine the air supply system;

[0013] S4. Determine the thermal regime;

[0014] S5. Determine the slag formation system;

[0015] S6. Smelting high-titanium vanadium-titanium magnetite based on parameters related to S1 to S5;

[0016] The furnace charge structure includes ore, which includes vanadium-titanium sinter and vanadium-titanium pellets. By mass percentage, vanadium-titanium sinter accounts for 10% to 70%, and vanadium-titanium pellets account for 90% to 30%. Furthermore, the mass percentage of vanadium-titanium magnetite contained in the vanadium-titanium sinter and vanadium-titanium pellets is greater than 65%.

[0017] In some embodiments, by mass percentage, the vanadium-titanium sinter contains 0-45% vanadium-titanium concentrate, 5-15% imported ore, 49-51% total iron, 5-7% titanium dioxide, 0.2-0.5% vanadium pentoxide, and the remainder being additives and auxiliaries.

[0018] In some embodiments, by mass percentage, the vanadium-titanium pellets contain 95-99% vanadium-titanium concentrate and 1-5% flux and bentonite; the titanium dioxide content in the vanadium-titanium pellets is 9-11%, and the vanadium pentoxide content is 0.5-0.7%. It should be noted that the titanium dioxide content in the vanadium-titanium pellets refers to the total titanium dioxide content in the entire vanadium-titanium pellet, and the vanadium pentoxide content is also the mass percentage of vanadium pentoxide in the vanadium-titanium pellets, which are two different evaluation systems from those for vanadium-titanium concentrate, flux, and bentonite. In some embodiments, the basicity of the vanadium-titanium sinter is 1.9-2.7, and the basicity of the vanadium-titanium pellets is 0.2-1.3.

[0019] In some embodiments, the furnace charge structure further includes coke and coke briquettes, and S2 includes: the furnace charge structure in S1 has a charge rate of 5 to 10 batches / h, an ore batch weight of 40 to 45 t / batch, a coke and coke briquettes batch weight of 5 to 12 t / batch, a coke load of 4.0 to 5.0 t / t, and a charging coke and ore charge line depth of 1.5 m to 2.1 m.

[0020] In some embodiments, S3 includes determining the air intake area, wherein the air intake area is 0.2–0.3 m². 2 .

[0021] In some embodiments, S3 further includes determining the gas in the injection system and its injection rate, specifically including: injecting gas after CO2 removal by a circulating trap, the gas including oxygen and coke oven gas, and the gas injection rate being 400–800 m³. 3 / t of molten iron, with coke oven gas volume of 50-350 Nm³ 3 / t molten iron.

[0022] In some embodiments, S3 further includes determining air supply parameters, including: a total oxygen air volume of 15,000–20,000 m³ / h. 3 / t of molten iron, blast temperature 1200~1260℃, blast pressure 370~380kPa, blast speed 250~260m / s, blast kinetic energy 160~180kJ / s, pulverized coal injection ratio 80~150kg / t, furnace top temperature 140~170℃, furnace top pressure 190~220kPa.

[0023] In some embodiments, S4 includes determining the system's molten iron temperature state and the system's elemental content state. The system's molten iron temperature state includes maintaining the molten iron temperature in the system at 1420–1480°C. The system's elemental content state includes maintaining the V content in the system at 0.2–0.6% by mass, the Ti content at 0.10–0.40%, the Si content at 0.10–0.40%, and the S content at 0.05–0.20%.

[0024] In some embodiments, S5 includes determining slag parameters, which include a binary basicity R2 of 1.0 to 1.2, a ternary basicity R3 of 1.3 to 1.5, a CaO content of 23 to 28% by mass, a TiO2 content of 18 to 35%, a V2O5 content of 0.2 to 1.0%, a magnesium-aluminum ratio of 0.5 to 0.9, and a slag-iron ratio of 510 to 580 kg / t.

[0025] The beneficial effects of the present invention include at least the following:

[0026] This invention can further improve smelting intensity while reducing carbon emissions, and achieve efficient comprehensive utilization of high-titanium vanadium-titanium magnetite. It can save energy consumption, increase yield, and further realize efficient smelting of vanadium-titanium ore. Attached Figure Description

[0027] To gain a more complete understanding of the embodiments of the present invention, reference should be made to the embodiments described in more detail in the accompanying drawings and by way of example below, wherein:

[0028] Figure 1 shows a flowchart of a method for smelting high-titanium vanadium-titanium magnetite in a hydrogen-carbon cycle oxygen blast furnace according to some embodiments of the present invention. Detailed Implementation

[0029] Embodiments of the invention are described below. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms. The drawings are not necessarily drawn to scale; certain functions may be exaggerated or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to use the invention in various ways. As those skilled in the art will understand, various features shown and described with reference to any of the drawings may be combined with features shown in one or more other drawings to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, various combinations and modifications of features consistent with the teachings of the invention may be desired for certain particular applications or implementations.

[0030] Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements may include not only those elements but also elements not expressly listed or inherent to such process, method, article, or apparatus.

[0031] One or more embodiments of the present invention will now be described with reference to the accompanying drawings. The flowchart illustrates the process performed by the system according to the present invention. It is understood that the execution of the flowchart does not need to be sequential; one or more steps may be omitted, one or more steps may be added, and steps may be performed in sequential or reverse order. In some embodiments, one or more steps may even be performed simultaneously.

[0032] In this invention, "content" refers to "mass percentage". For example, a [V] content of 0.36% means that the mass of V in the liquid iron accounts for 0.36% of the total mass of the liquid iron, or a CaO content of 25.3% means that the mass of CaO in the slag accounts for 25.3% of the total mass of the slag, and so on.

[0033] In this invention, the total iron content (TFe) in vanadium-titanium sinter refers to the content of iron in vanadium-titanium concentrate, imported ore, and other additives in vanadium-titanium sinter, and the content is by mass.

[0034] In this invention, the imported ore is the kind of imported ore commonly used in the field, such as South African ore, which will not be described in detail here.

[0035] In this field, sintered ore contains not only iron but also components including silicon dioxide (SiO2), calcium oxide (CaO), magnesium oxide (MgO), aluminum oxide (Al2O3), vanadium pentoxide (V2O5), and titanium dioxide (TiO2).

[0036] The high-titanium vanadium-titanium magnetite in this invention refers to vanadium-titanium magnetite concentrate in which the content of titanium dioxide (TiO2) ranges from approximately 10% or more.

[0037] In this field, additives and auxiliaries are generally fluxes such as limestone and activated ash, containing oxides of elements such as Ca, Si, and Mg.

[0038] As shown in Figure 1, the present invention provides a method for smelting high-titanium vanadium-titanium magnetite in a hydrogen-rich carbon-cycled oxygen blast furnace, comprising:

[0039] S1. Determine the furnace charge structure;

[0040] S2. Determine the fabric formulation;

[0041] S3. Determine the air supply system;

[0042] S4. Determine the thermal regime;

[0043] S5. Determine the slag formation system;

[0044] S6. Smelting high-titanium vanadium-titanium magnetite based on parameters related to S1 to S5;

[0045] The furnace charge structure includes ore, which includes vanadium-titanium sinter and vanadium-titanium pellets. By mass percentage, vanadium-titanium sinter accounts for 10% to 70%, and vanadium-titanium pellets account for 90% to 30%. Furthermore, the mass percentage of vanadium-titanium magnetite contained in the vanadium-titanium sinter and vanadium-titanium pellets is greater than 65%.

[0046] This invention achieves effective recovery and utilization of vanadium, titanium and other elements in high-titanium vanadium-titanium magnetite by limiting the specific ratio of vanadium-titanium sinter and vanadium-titanium pellets, resulting in a titanium dioxide content in the slag exceeding 18%. At the same time, it optimizes the chemical reaction balance in the furnace, improves the overall efficiency and product quality of the smelting process, and reduces energy consumption.

[0047] In some embodiments, by mass percentage, the vanadium-titanium sinter contains 0-45% vanadium-titanium concentrate, 5-15% imported ore, 49-51% total iron, 5-7% titanium dioxide, 0.2-0.5% vanadium pentoxide, and the remainder being additives and auxiliaries.

[0048] By precisely controlling the proportions of various components in vanadium-titanium sinter, especially the content of vanadium-titanium concentrate and imported ore, this invention not only ensures the appropriate reduction performance of the furnace charge, but also promotes the efficient extraction of elements such as vanadium and titanium, reduces the residue of harmful impurities, and improves the comprehensive utilization rate of resources.

[0049] In some embodiments, by mass percentage, the vanadium-titanium pellets contain 95-99% vanadium-titanium concentrate and 1-5% flux and bentonite; the vanadium-titanium pellets contain 9-11% titanium dioxide and 0.5-0.7% vanadium pentoxide.

[0050] By strictly regulating the composition of vanadium-titanium pellets, this invention ensures good reducibility and fluidity of the pellets in the blast furnace, improves the reactivity of the pellets, and thus enhances the heat utilization efficiency and the uniformity of chemical reactions in the blast furnace, which helps to increase the output of molten iron.

[0051] In some embodiments, the basicity of vanadium-titanium sinter is 1.9 to 2.7, and the basicity of vanadium-titanium pellets is 0.2 to 1.3.

[0052] In some embodiments, the basicity of vanadium-titanium sinter is 1.9 to 2.55, and the basicity of vanadium-titanium pellets is 0.2 to 1.27.

[0053] Limiting the basicity range of vanadium-titanium sinter and vanadium-titanium pellets aims to optimize the physicochemical properties of slag, ensuring that the slag has good fluidity, desulfurization and dephosphorization capabilities, and a protective effect on the furnace lining. At the same time, it helps maintain stable operating conditions inside the furnace, reduce energy consumption, and improve production stability.

[0054] In some embodiments, the furnace charge structure further includes coke and coke briquettes, and S2 includes: the furnace charge structure in S1 has a charge rate of 5 to 10 batches / h, an ore batch weight of 40 to 45 t / batch, a coke and coke briquettes batch weight of 5 to 12 t / batch, a coke load of 4.0 to 5.0 t / t, and a charging coke and ore charge line depth of 1.5 m to 2.1 m.

[0055] By carefully designing the furnace charge structure and charging system, including charge rate, batch weight, coke load and charge depth, this invention not only optimizes the distribution of gas and heat exchange in the furnace, but also ensures the uniform descent of the charge, improves thermal energy utilization efficiency, and reduces production costs.

[0056] In some embodiments, the air supply system in S3 includes determining the air intake area, which is 0.2–0.3 m². 2 .

[0057] By precisely controlling the air inlet area, this invention can effectively regulate the airflow distribution inside the furnace, increase combustion efficiency, and reduce local overheating or cooling problems, thus ensuring the stable and efficient operation of the blast furnace.

[0058] In some embodiments, S3 further includes determining the gas in the injection system and its injection rate, specifically including: injecting gas after CO2 removal by a circulating trap, the gas including oxygen and coke oven gas, and the gas injection rate being 400–800 m³. 3 / t of molten iron, with coke oven gas volume of 50-350 Nm³3 / t molten iron.

[0059] In some embodiments, the coke oven gas volume is 70–100 Nm³. 3 / t molten iron.

[0060] By precisely controlling the type and amount of gas injected into the system, this invention not only significantly improves oxygen utilization and promotes more thorough combustion and reduction reactions, but also effectively controls carbon emissions during the smelting process by introducing coke oven gas and other means, laying the foundation for achieving green and low-carbon production.

[0061] In some embodiments, S3 further includes determining air supply parameters, including: a total oxygen air volume of 15,000–20,000 m³ / h. 3 / t of molten iron, blast temperature 1200~1260℃, blast pressure 370~380kPa, blast speed 250~260m / s, blast kinetic energy 160~180kJ / s, pulverized coal injection ratio 80~150kg / t, furnace top temperature 140~170℃, furnace top pressure 190~220kPa.

[0062] By setting scientific air supply parameters, this invention ensures high efficiency and low energy consumption in an all-oxygen smelting environment, while maintaining suitable furnace top temperature and pressure, creating favorable conditions for stable operation and optimized furnace reaction.

[0063] In some embodiments, S4 includes determining the system's molten iron temperature state and the system's elemental content state. The system's molten iron temperature state includes maintaining the molten iron temperature in the system at 1420–1480°C. The system's elemental content state includes maintaining the V content in the system at 0.2–0.6% by mass, the Ti content at 0.10–0.40%, the Si content at 0.10–0.40%, and the S content at 0.05–0.20%.

[0064] By precisely controlling the temperature and element content of molten iron, this invention not only ensures the quality of molten iron and meets the needs of subsequent processing, but also effectively controls the content of harmful elements, reduces post-processing costs, and improves the economic efficiency and environmental protection level of the entire steel production chain.

[0065] In some embodiments, S5 includes determining slag parameters, which include a binary basicity R2 of 1.0 to 1.2, a ternary basicity R3 of 1.3 to 1.5, a CaO content of 23 to 28% by mass, a TiO2 content of 18 to 35%, a V2O5 content of 0.2 to 1.0%, a magnesium-aluminum ratio of 0.5 to 0.9, and a slag-iron ratio of 510 to 580 kg / t.

[0066] In some embodiments, the binary basicity R2 is 1.0 to 1.1, and the ternary basicity R3 is 1.45 to 1.5.

[0067] By optimizing slag parameters, this invention not only improves the recycling rate of resources, but also ensures the environmental friendliness of the slag, meeting the requirements of green and sustainable development in the modern steel industry.

[0068] In some specific embodiments, the method of smelting high-titanium vanadium-titanium magnetite in a hydrogen-rich carbon-recycled oxygen blast furnace according to the present invention is as follows:

[0069] S1. Determine the furnace charge structure

[0070] In some embodiments, the furnace charge structure that can be smelted according to the present invention can specifically be the following:

[0071] ① The furnace charge structure consists of 70% vanadium-titanium sinter and 30% vanadium-titanium pellets. In the vanadium-titanium sinter, vanadium-titanium concentrate accounts for 35-45%, imported ore for 5-10%, TFe content is 49-50%, TiO2 content is 5-7%, V2O5 content is 0.2-0.5%, basicity is 2.0-2.3, and drum index is 75-80%. In the vanadium-titanium pellets, vanadium-titanium concentrate accounts for 95-99%, TiO2 content is 9-11%, V2O5 content is 0.5-0.7%, and basicity is 0.2-0.3. The proportion of vanadium-titanium magnetite in the furnace charge is 65.10%.

[0072] ② The furnace charge structure consists of 50% vanadium-titanium sinter and 50% vanadium-titanium pellets. In the vanadium-titanium sinter, vanadium-titanium concentrate accounts for 20-25%, imported ore for 5-10%, TFe content is 49.5-50.5%, TiO2 content is 2.8-3.0%, V2O5 content is 0.1-0.2%, basicity is 1.9-2.1, and drum index is 75-80%. In the vanadium-titanium pellets, vanadium-titanium concentrate accounts for 95-99%, TiO2 content is 9-11%, V2O5 content is 0.5-0.7%, and basicity is 0.2-0.3. The proportion of vanadium-titanium magnetite in the furnace charge is 65.44%.

[0073] ③ 45% vanadium-titanium sinter + 55% vanadium-titanium pellets. The vanadium-titanium sinter contains 10-20% vanadium-titanium concentrate, 5-10% imported ore, with a TFe content of 50.0-51.0%, TiO2 content of 1.9-2.1%, V2O5 content of 0.1-0.2%, basicity of 2.1-2.3, and drum index of 75-80%. The vanadium-titanium pellets contain 95-99% vanadium-titanium concentrate, with a TiO2 content of 9-11%, V2O5 content of 0.5-0.7%, and basicity of 0.2-0.3. The proportion of vanadium-titanium magnetite in the furnace is 65.42%.

[0074] ④ The vanadium-titanium sinter consists of 40% vanadium-titanium sinter and 60% vanadium-titanium pellets. The vanadium-titanium sinter contains 1-6% vanadium-titanium concentrate, 10-15% imported ore, with a TFe content of 49.0-51.0%, TiO2 content of 0.7-1.2%, V2O5 content of 0.1-0.2%, basicity of 2.2-2.5, and a drum index of 75-80%. The vanadium-titanium pellets contain 95-99% vanadium-titanium concentrate, with a TiO2 content of 9-11%, V2O5 content of 0.5-0.7%, and basicity of 0.2-0.3. The proportion of vanadium-titanium magnetite in the furnace is 66.03%.

[0075] ⑤ 10% sinter + 90% vanadium-titanium pellets, wherein the sinter contains 0% vanadium-titanium concentrate, 5-10% imported ore, TFe content of 49.0-51.0%, TiO2 content of 0-0.1%, V2O5 content of 0%, basicity of 2.4-2.7, and drum index of 75-80%. The vanadium-titanium pellets contain 95-99% vanadium-titanium concentrate, TiO2 content of 9-11%, and V2O5 content of 0.5-0.7%, and the pellets change from acidic to basic. The proportion of vanadium-titanium magnetite in the furnace is >90%.

[0076] The changes in the furnace charge structure must not affect the stable operation of the blast furnace, but also ensure that the grade of the charge, the slagging system and the thermal system remain basically unchanged. The proportion of vanadium-titanium concentrate in the sinter decreases as the proportion of pellets in the furnace increases.

[0077] S2. Determine the fabric regime

[0078] The S1 feed rate is 5-10 batches / h, the ore batch weight is 40-45t / batch, the coke / coke pellet batch weight is 5-12t / batch, and the coke load is 4.0-5.0t / t.

[0079] The fabric matrix is ​​as follows: It is suitable for furnace charge structure of 70-50% vanadium-titanium sinter + 30-50% vanadium-titanium pellets. As the proportion of pellets increases, the maximum ore charging angle can be reduced slightly, and the coke and ore charge line depth is between 1.5m and 2.1m.

[0080] The fabric matrix is ​​as follows: It is suitable for furnace charge structure of 50-10% vanadium-titanium sinter + 50-90% vanadium-titanium pellets. As the proportion of pellets increases, the maximum ore charging angle can be reduced slightly, and the coke and ore charge line depth is between 1.5m and 2.1m.

[0081] S3. Determine the air supply system

[0082] Air vent layout: 24 air vents, each with a length of 450mm*20+500mm*4, a diameter of 120mm*24, and an air intake area of ​​0.2~0.3m². 2 .

[0083] The gas, after being collected and de-CO2ed, is blown in through an air vent at a rate of 400–800 m³. 3 / t of molten iron, with coke oven gas injection rate of 50-350 Nm³ 3 The composition of molten iron and coke oven gas is shown in Table 1.

[0084] Air supply parameters: Total oxygen air volume is 15,000–20,000 m³ / h 3 / t of molten iron, blast temperature 1200~1260℃, blast pressure 370~380kPa, blast speed 250~260m / s, blast kinetic energy 160~180kJ / s, pulverized coal injection ratio 80~150kg / t, furnace top temperature 140~170℃, furnace top pressure 190~220kPa, theoretical combustion temperature 1600~2300℃.

[0085] S4. Determine the slag-making system

[0086] The binary basicity R2 of the slag is 1.0–1.2, the ternary basicity R3 is 1.3–1.5, and the CaO content is 23–28%, the TiO2 content is 18–35%, the V2O5 content is 0.2–1.0%, the magnesium-aluminum ratio is 0.5–0.9, and the slag-iron ratio is 510–580 kg / t (content is by mass percentage).

[0087] S5. Determine the thermal regime

[0088] The molten iron temperature is maintained at 1420–1480℃, with a [V] content of 0.2–0.6%, a [Ti] content of 0.10–0.40%, a [Si] content of 0.10–0.40%, and a [S] content of 0.05–0.20%.

[0089] S6. Smelting of high-titanium vanadium-titanium magnetite based on parameters related to S1 to S5.

[0090] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto:

[0091] In this invention, the coke oven gas composition includes the components shown in Table 1: wherein CmHn is the component excluding...

[0092] Alkanes other than methane, with the remainder being other gases:

[0093] Table 1. Composition of coke oven gas (volume content, %)

[0094] Unless otherwise specified, the contents of Examples 1 to 3 in this invention are all mass percentages.

[0095] Example 1:

[0096] At 1750m 3 Taking the furnace charge structure for blast furnace smelting of high-titanium vanadium-titanium magnetite as an example: 70% vanadium-titanium sinter + 30% vanadium-titanium pellets

[0097] The furnace charge consists of vanadium-titanium sinter (35% vanadium-titanium concentrate, 8% imported ore, TFe content 49.6%, TiO2 content 6.3%, V2O5 content 0.36%, basicity 2.01, drum index 77.5%) and vanadium-titanium pellets (98% vanadium-titanium concentrate, TiO2 content 9.75%, V2O5 content 0.56%, basicity 0.22). A mixture of coke and coke is incorporated into the 1750m³ furnace charge with a 70% vanadium-titanium sinter + 30% vanadium-titanium pellet structure. 3 The blast furnace, a hydrogen-rich carbon-recycled oxygen blast furnace, has a coke ratio of 350 kg / t. The charge grade is 51.6%, and the charging matrix is... The material feeding rate is 8.5 batches / h, the ore batch weight is 44.450t / batch, the coke / coke pellet batch weight is 9.2t / batch, and the coke load is 4.59t / t. A fan-shaped charging method is achieved through the blast furnace charging chute to control the material surface shape and form two airflow patterns at the edge and center. Because pellets have good rolling properties and a natural angle of repose of only 24-27°, the charging process in the blast furnace requires the use of charging chutes to achieve ring, fixed-point, and fan-shaped charging methods to control a reasonable material surface shape and develop a reasonable edge and center two-channel airflow pattern, ensuring that the blast furnace gas utilization rate is controlled above 44%.

[0098] 16500m 3 A total oxygen blast volume of [amount] t is heated to 1210℃ via a hot blast stove and then fed into the blast furnace through hot blast pipes. The blast pressure is 380 kPa, the blast velocity is 252 m / s, and the inlet area is 0.2714 m². 2 The blast energy is 170 kJ / s. The gas, after CO2 removal and recycling, is blown in through the duct at a rate of 400 m³ / s. 3 / t, and inject (the injection method is simultaneous injection of coke oven gas into the furnace body and the hearth) coke oven gas, with a coke oven gas volume of 70 Nm³. 3 Pulverized coal is injected through the tuyeres at a ratio of 100 kg / t. The furnace top temperature is controlled at 140℃, the furnace top pressure at 210 kPa, the pressure differential at 160 kPa, and the average temperature of the furnace throat at 130℃. This allows the coke and pulverized coal to participate in the indirect reduction reaction of high-titanium vanadium-titanium magnetite inside the blast furnace.

[0099] High-titanium vanadium-titanium magnetite undergoes indirect and direct reduction reactions sequentially through the blast furnace's blocky zone, softening zone, dripping zone, tuyeres combustion zone, and hearth, producing molten iron which is discharged from the furnace through the taphole at a temperature of 1450℃. The molten iron contains 0.36% [V], 0.24% [Ti], 0.22% [Si], and 0.11% [S]. The slag has a binary basicity R2 of 1.07, a ternary basicity R3 of 1.48, a CaO content of 25.3%, a TiO2 content of 21.5%, a V2O5 content of 0.38%, a magnesium-aluminum ratio of 0.62, and a slag-to-iron ratio of 530 kg / t.

[0100] Example 2:

[0101] At 1750m 3 Taking the furnace charge structure for blast furnace smelting of high-titanium vanadium-titanium magnetite with 50% vanadium-titanium sinter and 50% vanadium-titanium pellets as an example:

[0102] A mixture of vanadium-titanium sinter (21% vanadium-titanium concentrate, 8% imported ore, TFe content 49.5%, TiO2 content 2.9%, V2O5 content 0.15%, basicity 1.98, drum index 78%) and vanadium-titanium pellets (98% vanadium-titanium sinter, TiO2 content 9.75%, V2O5 content 0.56%, basicity 0.22) is prepared as a 50% vanadium-titanium sinter + 50% vanadium-titanium pellets charge, mixed with coke and coke pellets, and fed into a 1750m³ furnace. 3 The blast furnace, a hydrogen-rich carbon-recycled oxygen blast furnace, has a coke ratio of 330 kg / t. The charge grade is 51.8%, and the charging matrix is... The material flow rate is 8.5 batches / h, the ore batch weight is 44.40t / batch, the coke / coke pellet batch weight is 9t / batch, and the coke load is 4.58t / t. A fan-shaped material distribution method is achieved through the blast furnace charging chute to control the material surface shape and form two airflow patterns: one at the edge and one at the center. By developing a reasonable edge and center two-channel airflow pattern, the blast furnace gas utilization rate is controlled above 44%.

[0103] 16000m 3 A total oxygen blast volume of [amount] t is heated to 1210℃ via a hot blast stove and then fed into the blast furnace through hot blast pipes. The blast pressure is 380 kPa, the blast velocity is 252 m / s, and the inlet area is 0.2714 m². 2 The blast energy is 170 kJ / s. The gas, after CO2 removal and recycling, is blown in through the duct at a rate of 500 m³ / s. 3 / t, and inject (the injection method is simultaneous injection of coke oven gas into the furnace body and hearth) coke oven gas, with a coke oven gas volume of 80 Nm³. 3Pulverized coal is injected through the tuyeres at a ratio of 90 kg / t. The furnace top temperature is controlled at 140℃, the furnace top pressure at 210 kPa, the pressure differential at 160 kPa, and the average temperature of the furnace throat at 130℃. This allows the coke and pulverized coal to participate in the indirect reduction reaction of high-titanium vanadium-titanium magnetite inside the blast furnace.

[0104] High-titanium vanadium-titanium magnetite undergoes indirect and direct reduction reactions sequentially through the blast furnace's blocky zone, softening zone, dripping zone, tuyeres combustion zone, and hearth, producing molten iron which is discharged from the furnace through the taphole at a temperature of 1450℃. The molten iron contains 0.32% V, 0.22% Ti, 0.21% Si, and 0.05% S. The slag has a binary basicity R2 of 1.06, a ternary basicity R3 of 1.45, a CaO content of 25.5%, a TiO2 content of 22%, a V2O5 content of 0.35%, a magnesium-aluminum ratio of 0.60, and a slag-to-iron ratio of 525 kg / t.

[0105] Example 3:

[0106] At 1750m 3 Taking the furnace charge structure for blast furnace smelting of high-titanium vanadium-titanium magnetite with 10% vanadium-titanium sinter and 90% vanadium-titanium pellets as an example:

[0107] Vanadium-titanium sinter with a vanadium-titanium concentrate content of 0%, imported ore of 10%, TFe content of 49.8%, TiO2 content of 0.03%, V2O5 content of 0%, basicity of 2.55, and drum index of 80%, and vanadium-titanium pellets with a vanadium-titanium concentrate content of 98%, TiO2 content of 11.0%, V2O5 content of 0.68%, and basicity of 1.27, are mixed with coke and coke pellets in a furnace charge structure of 10% vanadium-titanium sinter and 90% vanadium-titanium pellets and fed into a 1750m³ furnace. 3 The blast furnace, a hydrogen-rich carbon-recycled oxygen blast furnace, has a coke ratio of 260 kg / t. The charge grade is 52.82%, and the charging matrix is... The material feeding rate is 8 batches / h, the ore batch weight is 44.10t / batch, the coke / coke pellet batch weight is 9t / batch, and the coke load is 4.88t / t. A fan-shaped material feeding method is achieved through the blast furnace charging chute to control the material surface shape and form two airflow patterns: one at the edge and one at the center. By developing a reasonable edge and center two-channel airflow pattern, the blast furnace gas utilization rate is controlled above 44%.

[0108] 19000m 3 A total oxygen blast volume of / t is heated to 1210℃ via a hot blast stove and then fed into the blast furnace through hot blast pipes. The blast pressure is 378kPa, the blast velocity is 255m / s, and the inlet area is 0.2714m². 2 The blast energy is 177 kJ / s. The gas, after CO2 removal and recycling, is blown in through the duct at a rate of 600 m³ / s. 3 / t, and inject (the injection method is simultaneous injection of coke oven gas into the furnace body and hearth) coke oven gas, with a coke oven gas volume of 100 Nm³. 3 Pulverized coal is injected through the tuyeres at a ratio of 80 kg / t. The furnace top temperature is controlled at 140℃, the furnace top pressure at 210 kPa, the pressure differential at 160 kPa, and the average temperature of the furnace throat at 130℃. This allows the coke and pulverized coal to participate in the indirect reduction reaction of high-titanium vanadium-titanium magnetite inside the blast furnace.

[0109] High-titanium vanadium-titanium magnetite undergoes indirect and direct reduction reactions sequentially through the blast furnace's blocky zone, softening zone, dripping zone, tuyeres combustion zone, and hearth, producing molten iron which is discharged from the furnace through the taphole at a temperature of 1450℃. The molten iron contains 0.46% [V], 0.23% [Ti], 0.15% [Si], and 0.06% [S]. The slag has a binary basicity R2 of 1.01, a ternary basicity R3 of 1.50, a CaO content of 20.7%, a TiO2 content of 31.2%, a V2O5 content of 0.57%, a magnesium-aluminum ratio of 0.75, and a slag-to-iron ratio of 520 kg / t.

[0110] Other iron ore with a charge structure of 70-10% vanadium-titanium sinter and 30-90% vanadium-titanium pellets is fed into the blast furnace. The smelting process is the same as in Example 1. Due to the increased pellet ratio, to ensure smooth blast furnace smelting, the coke batch weight and pulverized coal injection rate are adjusted. During the smelting process, the maximum ore feeding angle is reduced, and the blast volume is increased, while maintaining the charge grade, slagging regime, and thermal regime unchanged. In the hydrogen-rich carbon-circulating oxygen blast furnace smelting under the condition of increased vanadium-titanium pellet feed ratio, the softening zone shifts downward, the softening range widens, and the melting range narrows. The overall thinning of the softening zone causes significant changes in the permeability of the blast furnace charge, which is very different from traditional blast furnace smelting with a large proportion of sinter. This affects the indirect and direct reduction of the blast furnace charge, requiring careful control of the blast and thermal regimes.

[0111] Analysis of experimental results:

[0112] Based on the data from Examples 1 to 3 above, it can be concluded that the simultaneous injection of circulating gas to remove CO2 into the furnace body and hearth of the present invention can achieve a carbon saving rate of over 20% in oxygen blast furnaces. Compared with the traditional blast furnace ironmaking process, the coke oven gas injection process in an all-oxygen blast furnace can save 43% of coke, increase coal by 33%, and reduce the total fuel ratio by 20%.

[0113] A comprehensive mathematical model for an oxygen blast furnace was established, and calculations were performed based on actual blast furnace operation data in China. The results show that, compared with traditional blast furnaces, the process fuel consumption rate of the present invention is reduced by 24.7%, the direct reduction degree of the oxygen blast furnace is 0.16, and that of the traditional blast furnace is 0.5.

[0114] A two-dimensional CFD model of a top gas recirculation oxygen blast furnace was established to evaluate the impact of recirculated gas on the blast furnace's production capacity. Taking the process of Example 3 as an example, the results show that when the top gas recirculation rate is increased from 300 m³ / h... 3 / tHM increased to 600m 3 / tHM (i.e., the drum volume in Example 3 is 600m) 3 / t), the yield of oxygen blast furnace is 5.3% to 35.3% higher than that of conventional blast furnace.

[0115] Because this invention has industry-wide applicability, the blast furnaces used in this invention are not limited to the above-mentioned blast furnace volumes, and all blast furnaces of ironmaking volumes are included within the scope of this invention patent.

[0116] This invention document is intended to illustrate how to use the disclosed technology and various embodiments, and is not intended to limit its true scope and equivalent spirit. Furthermore, the foregoing description is not exhaustive of all possibilities or to limit the scope of protection to the precise forms disclosed. Changes and variations are possible in accordance with the foregoing teachings. The selected and illustrated embodiments provide the best illustration of the principles of the technology and its practical application, and enable those skilled in the art to use the disclosed technology for various conceivable specific applications with various modifications. Therefore, various changes and modifications made to the above embodiments without substantially departing from the spirit and principles of the technology described herein are intended to be included within the scope of this invention.

Claims

1. A method for smelting high-titanium vanadium-titanium magnetite in a hydrogen-rich carbon-cycled oxygen blast furnace, characterized in that, The method comprises: S1. determining a furnace charge structure; S2. determining a burdening system; S3. determining an air supply system; S4. determining a heat system; S5. determining a slagging system; S6. smelting the high-titanium vanadium-titanium magnetite based on parameters related to S1-S5; The furnace charge structure comprises ore, and the ore comprises vanadium-titanium sinter and vanadium-titanium pellet, wherein the vanadium-titanium sinter accounts for 10-70% and the vanadium-titanium pellet accounts for 90-30% by mass percentage, and the vanadium-titanium magnetite contained in the vanadium-titanium sinter and the vanadium-titanium pellet accounts for >65% by mass percentage.

2. The method of claim 1, wherein, The vanadium-titanium sinter contains 0-45% vanadium-titanium concentrate, 5-15% imported ore, 49-51% total iron, 5-7% titanium dioxide, 0.2-0.5% vanadium pentoxide, and the rest is additives and auxiliary agents by mass percentage.

3. The method of claim 1, wherein, The vanadium-titanium pellet contains 95-99% vanadium-titanium concentrate and 1-5% flux and bentonite by mass percentage; the vanadium-titanium pellet contains 9-11% titanium dioxide and 0.5-0.7% vanadium pentoxide.

4. The method of claim 1, wherein, The vanadium-titanium sinter has an alkalinity of 1.9-2.7, and the vanadium-titanium pellet has an alkalinity of 0.2-1.

3.

5. The method of claim 1, wherein, The furnace charge structure further comprises coke and coke butter, and S2 comprises: the material speed of the furnace charge structure in S1 is 5-10 batches / h, the batch weight of the ore is 40-45 t / batch, the batch weight of the coke and the coke butter is 5-12 t / batch, the coke load is 4.0-5.0 t / t, and the depth of the coke and the ore material line is 1.5-2.1 m.

6. The method of claim 1, wherein, The S3 includes determining the air inlet area, the air inlet area being 0.2-0.3 m 2 .

7. The method of claim 6, wherein, The S3 further comprises determining the coal gas in the blowing system and its blowing amount, specifically comprising: blowing the coal gas after the CO2 is captured and removed in the circulation, the coal gas comprising oxygen and coke oven gas, and the blowing amount of the coal gas being 400-800 m 3 / t mol of the molten iron, and the amount of the coke oven gas being 50-350 Nm 3 / t mol of the molten iron.

8. The method of claim 7, wherein, The S3 further comprises determining the air supply parameters, which include: the full oxygen air volume is 15000-20000m 3 / t hot metal, air temperature 1200-1260℃, air pressure 370-380kPa, air speed 250-260m / s, blast kinetic energy 160-180kJ / s, coal injection ratio 80-150kg / t, furnace top temperature 140-170℃, and furnace top pressure 190-220kPa.

9. The method of claim 1, wherein, S4 comprises determining the system molten iron temperature state and the system element content state, the system molten iron temperature state comprises: the molten iron temperature in the system is kept at 1420-1480℃, and the system element content state comprises: the V content is kept at 0.2-0.6%, the Ti content is kept at 0.10-0.40%, the Si content is kept at 0.10-0.40%, and the S content is kept at 0.05-0.20% by mass percentage.

10. The method of claim 1, wherein, S5 comprises determining the slag parameters, the slag parameters comprise: the binary basicity R2 of the slag is 1.0-1.2, the ternary basicity R3 is 1.3-1.5, the CaO content is 23-28% by mass percentage, the TiO2 content is 18-35% by mass percentage, the V2O5 content is 0.2-1.0% by mass percentage, the magnesium-aluminum ratio is 0.5-0.9, and the slag-iron ratio is 510-580 kg / t.

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