Vanadium-titanium ore smelting process with high coke-briquette ratio
By functionalizing and grading the coke-butane ratio, the problems of permeability, slag performance and desulfurization capacity caused by the increase of the coke-butane ratio in vanadium-titanium ore smelting were solved, and stable smelting and cost reduction under high coke-butane ratio were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SICHUAN DESHENG GRP VANADIUM & TITANIUM CO LTD
- Filing Date
- 2026-05-28
- Publication Date
- 2026-07-14
AI Technical Summary
In vanadium-titanium ore smelting, increasing the coke-butane ratio leads to a decrease in the permeability and liquid permeability of the charge column, a deterioration in slag performance, and a weakening of desulfurization capacity. Existing technologies cannot safely and stably break through the upper limit of the coke-butane ratio, resulting in the failure to fully realize the cost advantage.
By functionalizing coke and performing particle size classification, composite coke with different particle sizes is used in different areas to serve as physical support and chemical reaction carrier, respectively, thus optimizing the material distribution space. Additives such as CaO and MgO are introduced to improve slag performance and desulfurization capacity.
Without altering the main blast furnace equipment and smelting process, the coke-to-butane ratio can be steadily increased to 40%-50%, significantly reducing fuel costs, maintaining smooth furnace operation, and improving the quality of molten iron.
Abstract
Description
Technical Field
[0001] This invention relates to the field of metallurgical technology, specifically to a vanadium-titanium ore smelting process with a high coke-to-but ratio in a blast furnace. Background Technology
[0002] In the blast furnace smelting of vanadium-titanium magnetite, the slag contains a large amount of TiO2, resulting in poor high-temperature performance, easy foaming, and poor fluidity. This places extremely high demands on the activity of the hearth and the permeability of the charge column. Coke, as the main skeleton and fuel in the blast furnace, is of paramount importance in terms of its quality and proportion. Coke briquettes, a byproduct of coke screening, are significantly cheaper than metallurgical coke. Therefore, increasing the proportion of coke briquettes used is an effective way to reduce ironmaking costs.
[0003] However, increasing the coke-to-coke ratio in vanadium-titanium ore smelting faces significant challenges: (1) Deterioration of physical properties: A large amount of small-particle coke (<25mm) entering the furnace will severely fill the pores between large pieces of coke, significantly deteriorating the lower material column, especially the permeability and liquid permeability of the coke bed in the hearth, resulting in uneven airflow distribution and difficulty in molten iron penetration, which can easily lead to hearth accumulation and endanger smooth operation. (2) Deterioration of slag properties: Vanadium-titanium ore itself has a high TiO2 content, and the slag is viscous. If the operation is not done properly after increasing the coke-to-coke ratio, it is easy to cause insufficient physical heat in the hearth. In order to ensure smooth operation, the furnace temperature is forced to be increased, which will aggravate the over-reduction of TiO2, generating high-melting-point Ti(C,N), further deteriorating the slag properties and forming a vicious cycle. (3) Weakened desulfurization capacity: High-titanium slag has low desulfurization efficiency. If the operation of high coke-to-coke ratio causes fluctuations in furnace temperature or slag basicity, it will directly affect the thermodynamic and kinetic conditions of the desulfurization reaction, leading to an increased risk of excessive sulfur content in molten iron.
[0004] Therefore, to ensure the smooth operation of vanadium-titanium ore smelting, existing technologies typically strictly limit the coke-to-butane ratio to below 20%, or even lower, preventing the full realization of cost advantages. Simply exceeding this limit and directly increasing the coke-to-butane ratio often leads to rapid furnace malfunctions, such as increased pressure differential, insufficient physical heat of molten iron, and a sharp deterioration in slag fluidity. This forces operators to adjust the coke-to-butane ratio and increase coke load to restore furnace conditions, ultimately resulting in more harm than good.
[0005] Therefore, there is an urgent need for a vanadium-titanium ore smelting method that can safely and stably break through the existing upper limit of the coke-to-butane ratio. Summary of the Invention
[0006] To address the shortcomings of existing technologies, this invention provides a vanadium-titanium ore smelting process with a high coke-to-butane ratio in blast furnaces. Addressing the complex technical challenges of reduced charge permeability, deteriorated slag performance, and weakened desulfurization capacity associated with increasing the coke-to-butane ratio in vanadium-titanium ore smelting, this invention provides a smelting method that deeply integrates coke-to-butane functionalization, particle size classification, and optimized charge distribution space, thereby achieving long-term stable operation and high-quality, low-consumption blast furnace smelting with a high coke-to-butane ratio.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a vanadium-titanium ore smelting process with a high coke-to-but ratio in blast furnaces, comprising the following steps: The furnace charge is fed into the blast furnace for smelting. The furnace charge includes vanadium-titanium iron ore, fuel, flux, and oxidizing materials. The fuel consists of coke, pulverized coal, and composite coke. The composite coke accounts for 40-50% of the mass of the fuel. The composite coke includes composite coke with a particle size of 18-24 mm and composite coke with a particle size of 8-14 mm. The composite char is obtained by compounding char with composite additives, followed by drying and sieving. The composite additives include, by weight, 100-250 parts of calcium compound, 30-100 parts of magnesium compound, 10-40 parts of binder, 1-5 parts of thickener, and 700-900 parts of flux.
[0008] Preferably, the composite additive comprises, by weight, 200-250 parts of calcium compound, 100-100 parts of magnesium compound, 30-40 parts of binder, 3-5 parts of tackifier, and 800-900 parts of flux.
[0009] Preferably, the preparation process of the composite additive is as follows: under a high-speed shear stirring environment of 5000~8000 rpm, flux, thickener and binder are added in sequence and stirred until completely dispersed and uniform; then calcium-containing compound and magnesium-containing compound powder are added, and stirring is continued after the addition is completed to form a uniform and stable suspension slurry.
[0010] Preferably, the calcium-containing compound is selected from one or more of calcium oxide, calcium hydroxide, calcium carbonate, limestone powder, and dolomite powder. It reacts with sulfides such as H2S in the gas in the upper part of the blast furnace to achieve pre-desulfurization, and adjusts the slag alkalinity in the hearth zone to promote final desulfurization.
[0011] Preferably, the magnesium-containing compound is selected from one or more of magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesite powder, and dolomite powder. Providing MgO improves the fluidity and stability of the high-titanium slag, lowers the melting temperature, and inhibits the over-reduction of titanium.
[0012] Preferably, the binder is selected from nano-silica sol, nano-alumina sol, or mixtures thereof. As a binder phase, it fixes the additive particles on the surface of the charcoal, forming a protective film and regulating the release rate of the additive within the furnace.
[0013] Preferably, the thickener is selected from one or more of sodium carboxymethyl cellulose, xanthan gum, polyvinyl alcohol, and bentonite. This increases the solution viscosity, thereby increasing the amount of tar that adheres to the tar; it also prevents solid particles from settling and maintains a uniform and stable slurry.
[0014] Preferably, before the charcoal is compounded with the composite additive, it needs to be pretreated to remove impurities and dry.
[0015] Preferably, the composite treatment process adopts the dynamic impregnation method in an impregnation tank, with a treatment pressure of atmospheric pressure, a treatment temperature of 25~60℃, and a treatment time of 15~45min.
[0016] Preferably, the composite char is dried by a stepped temperature increase process after being compounded with composite additives. The first stage of drying is at a temperature of 80~120℃ for 1~2 hours, and the second stage of drying is at a temperature of 120~180℃ for 1~3 hours.
[0017] Preferably, the vanadium-titanium iron ore comprises, by mass percentage, 60-75% vanadium-titanium sinter, 15-25% vanadium-titanium pellets, and 10-20% lump ore.
[0018] Preferably, the coke accounts for 40-52% of the total mass of the fuel.
[0019] Preferably, the pulverized coal accounts for 8-12% of the total mass of the fuel.
[0020] Preferably, the mass ratio of the composite coke with a particle size of 18-24 mm to the composite coke with a particle size of 8-14 mm is (6-8):(2-4).
[0021] Preferably, the mass of the fuel is 25-30% of the mass of vanadium-titanium iron ore.
[0022] Preferably, the flux includes one or more of limestone, fluorite, and manganese ore powder.
[0023] Preferably, the flux is 2-6% of the mass of the pulverized coal.
[0024] Preferably, the oxidizing material accounts for 0.5 to 1.2% of the mass of vanadium-titanium iron ore.
[0025] Preferably, the oxidizing material is Fe2O3.
[0026] Preferably, in the smelting process, composite coke with a particle size of 8-14 mm is mixed with some crushed sinter and distributed in the middle ring of the furnace throat, while composite coke with a particle size of 18-24 mm is distributed in the edge and central area of the furnace throat. Other furnace materials are charged conventionally. Through material distribution control, the composite coke with a particle size of 8-14 mm is locked into the furnace in the middle ring area of the furnace throat, which corresponds precisely to the chemical reaction zone in the middle of the furnace body, achieving spatial coupling between the "reaction carrier" and the "reaction zone". Through material distribution control, the composite coke with a particle size of 18-24 mm is directionally conveyed to the edge and central area of the furnace throat. These two areas are the "life channels" for maintaining the gas flow and molten iron penetration of the entire charge column, achieving spatial coupling between the "physical framework" and the "critical channel".
[0027] Preferably, the smelting conditions are: blast temperature of 1130~1180℃ and oxygen enrichment rate of 2.5~3.2%.
[0028] The beneficial effects of this invention are: This invention introduces specially functionalized and graded coke butadiene within the framework of conventional smelting processes. By loading functional additives such as CaO and MgO onto the coke butadiene, it acquires the inherent ability to improve slag performance. Through particle size classification, the coke butadiene is used according to functional differences, fundamentally alleviating the contradiction between a high coke-to-butadiene ratio and the permeability of the burden and slag performance. Without changing the main blast furnace equipment and basic smelting process, the functional composite coke butadiene of this invention can safely and stably increase the coke-to-butadiene ratio to a high level of 40%-50%, directly resulting in a significant reduction in fuel costs. This invention only upgrades the coke butadiene component in the fuel; the burden composition and smelting operations are compatible with conventional processes, facilitating rapid application and promotion in existing blast furnaces with low investment costs.
[0029] In traditional vanadium-titanium ore smelting, all coke and briquettes are considered a homogeneous "small lump fuel," and their use is limited only by total quantity. However, through in-depth research, this invention has for the first time recognized that under high coke-to-briquette ratio conditions, the core functions of coke and briquettes in different areas and smelting stages of the blast furnace are fundamentally contradictory. Simple mixing will lead to systemic deterioration, such as in the hearth and lower charge column: this area requires a robust, moderately sized solid skeleton to maintain extremely high permeability and liquid permeability, ensuring the uniform rise of high-temperature gas flow and the smooth dripping of molten iron. The main role of coke and briquettes here is as a "physical support." Coke and briquettes with a particle size of less than 15mm will severely clog the pores in this area, leading to a catastrophic decrease in permeability and liquid permeability. Upper and middle sections of the furnace: This region has a suitable temperature (~800℃-1400℃) and is a key area for indirect reduction, initial slag formation, and the action of additives. Coke butadiene here serves as an excellent "chemical reaction carrier." The CaO, MgO, and other additives loaded on it need to participate in the reaction to the maximum extent in this region to improve slag properties and perform pre-desulfurization. Coke butadiene with small particle size and large specific surface area has a greater advantage in reaction kinetics here. If functional coke butadiene of a single particle size (especially small particle size) is used and a large amount is distributed into the furnace to meet the chemical reaction requirements, they will inevitably enter the hearth, thus destroying the lower physical framework. Conversely, if a larger particle size is used to ensure the framework, the chemical reaction efficiency will be sacrificed. Based on this, the present invention performs sieving and grading of composite coke to obtain large-particle-size composite coke with a particle size of 18-24 mm and small-particle-size composite coke with a particle size of 8-14 mm. The large-particle-size composite coke prioritizes physical support, with its particle size designed to be close to that of small pieces of coke, sufficient to form stable pore channels in the furnace charge. Its loaded additives (especially CaO and slow-release nano-SiO2) primarily serve the hearth region, stabilizing the basicity of the hearth slag, assisting in final desulfurization, and delaying its own dissolution in the high-temperature zone through a nanofilm, extending its service life as a framework. The small-particle-size composite coke prioritizes its function as a chemical reaction carrier. Its small particle size provides a large specific surface area, allowing its loaded additives to quickly and fully react with the gas and primary slag. Its main task is to release modifiers such as MgO in the upper part of the furnace body, optimize the performance of the primary slag, inhibit the unfavorable conversion of TiO2, and perform gas desulfurization. Because it is largely consumed in the upper part, it will not cause substantial damage to the lower hearth framework. Detailed Implementation
[0030] To enable those skilled in the art to better understand the technical solution of the invention, the invention will be further described in detail below with reference to specific embodiments.
[0031] The following examples are in kilograms.
[0032] Example 1 This embodiment provides a vanadium-titanium ore smelting process with a high coke-to-butane ratio in a blast furnace, at a depth of 3200m.3 This embodiment is implemented on a blast furnace for vanadium-titanium ore smelting.
[0033] The smelting process in this embodiment includes the following steps: 1. Pretreatment of charcoal The conventional coke (initial particle size is usually ≤25mm) is initially screened to remove excessively fine powder (<3mm) and impurities, resulting in relatively clean raw coke. This step can reduce ineffective load and subsequent solution contamination.
[0034] The cleaned charred pieces are then fed into a drying device (such as a rotary dryer or fluidized bed dryer) and preheated at 120°C to reduce their moisture content to below 2% by mass. This aims to remove adsorbed water from the surface of the charred pieces, open their microporous structure, and significantly improve their subsequent adsorption capacity and penetration depth for additive solutions.
[0035] 2. Preparation of composite pyroxene (1) Preparation of compound additives Formula: 100 parts calcium compound (fine limestone powder), 30 parts magnesium compound (fine magnesium oxide powder), 10 parts binder (nano silica sol, solid content 30%), 1 part tackifier (sodium carboxymethyl cellulose), and 700 parts flux (water).
[0036] Preparation process: In a reactor equipped with high-speed (5000 rpm) shear stirring, first add the metered flux, start stirring, and then add the thickener and binder in sequence, stirring until completely dispersed and uniform; then, under continuous high-speed shear, slowly add calcium-containing compound and magnesium-containing compound powders, and continue stirring for 50 minutes after the addition is complete to form a uniform and stable suspension slurry.
[0037] (2) Preparation of wet composite pyroxene Dynamic impregnation method in an impregnation tank: The dried coke from step 1 is placed into an inclined rotary drum or vertical impregnation tank with a porous inner liner; the prepared composite additive solution is pumped into the tank, and the liquid surface completely submerges the coke; the rotary drum or the internal circulation pump is started, and dynamic impregnation is carried out under mild conditions of normal pressure and 25°C for 45 minutes. Dynamic stirring ensures that each coke is in full contact with the solution, and the solution penetrates into the pores of the coke under the action of capillary action; after impregnation, the excess solution is drained to obtain wet composite coke.
[0038] (3) Drying and curing The wet composite coke is transferred to a vibrating screen or draining area to remove excess liquid droplets from the surface. Then it is fed into a drying device (such as a fluidized bed dryer or belt dryer) using a stepped heating program: first stage: 80℃, drying for 1 hour, mainly to remove free water; second stage: 120℃, drying for 1 hour, to promote the gelation of nano-silica sol and form a firm adhesion layer on the surface and pore walls of the coke together with the additive particles. The maximum temperature in this process must be controlled below 200℃ to prevent the large amount of volatiles from precipitating out and the tar from softening and sticking together. After drying, the coke is cooled to room temperature and then sieved to separate large-particle-size composite coke (18~24mm) and small-particle-size composite coke (8~14mm).
[0039] 3. Equipped with furnace charge Vanadium-titanium iron ore: 65% vanadium-titanium sinter, 25% vanadium-titanium pellets, and 10% lump ore; Fuel: Coke (>25mm) accounts for 40% of the total fuel mass, pulverized coal (injected) accounts for 10% of the total fuel mass, and the large-particle-size composite coke (18~24mm) and small-particle-size composite coke (8~14mm) obtained in step 2 together account for 50% of the total fuel mass (combined coke-to-coke ratio); the mass ratio of the large-particle-size composite coke to the small-particle-size composite coke is 7:3; the mass of the fuel is 30% of the mass of vanadium-titanium iron ore; Flux: 60% limestone and 40% fluorite; the flux is 2% of the mass of the pulverized coal. Oxidizing materials: Add 0.5% Fe2O3 powder by mass of vanadium titanate.
[0040] 4. Smelting operations: Small-particle-size composite coke and some crushed sinter are mixed and distributed in the middle ring of the furnace throat, while large-particle-size composite coke and sinter are distributed in the edge and central area of the furnace throat. Other furnace materials are charged as usual. The blast temperature is 1130℃, the oxygen enrichment rate is 2.5%, and pulverized coal is injected as usual.
[0041] Operating results: The blast furnace operated stably. Compared with the traditional method using ordinary coke and coke ratio of 18%, this method achieved comparable furnace smoothness, qualified molten iron quality, and reduced fuel cost per ton of iron by about 10% when the coke ratio reached 50%.
[0042] Example 2 This embodiment provides a vanadium-titanium ore smelting process with a high coke-to-butane ratio in a blast furnace, at a depth of 3200m. 3 This embodiment is implemented on a blast furnace for vanadium-titanium ore smelting.
[0043] The smelting process in this embodiment includes the following steps: 1. Pretreatment of charcoal The conventional coke (initial particle size is usually ≤25mm) is initially screened to remove excessively fine powder (<3mm) and impurities, resulting in relatively clean raw coke. This step can reduce ineffective load and subsequent solution contamination.
[0044] The cleaned charred pieces are then fed into a drying device (such as a rotary dryer or fluidized bed dryer) and preheated at 160°C to reduce their moisture content to below 2% by mass. This aims to remove adsorbed water from the surface of the charred pieces, open their microporous structure, and significantly improve their subsequent adsorption capacity and penetration depth for additive solutions.
[0045] 2. Preparation of composite pyroxene (1) Preparation of compound additives Formula: 200 parts calcium compound (calcium oxide), 70 parts magnesium compound (magnesium hydroxide), 30 parts binder (nano silica sol, solid content 30%), 3 parts tackifier (xanthan gum), and 800 parts flux (water).
[0046] Preparation process: In a reactor equipped with high-speed (8000 rpm) shear stirring, the metered flux is first added, stirring is started, and the thickener and binder are added in sequence and stirred until completely dispersed and uniform; then, under continuous high-speed shear, calcium-containing compound and magnesium-containing compound powders are slowly added, and stirring is continued for 30 minutes after the addition is completed to form a uniform and stable suspension slurry.
[0047] (2) Preparation of wet composite pyroxene Dynamic impregnation method in an impregnation tank: The dried coke from step 1 is placed into an inclined rotary drum or vertical impregnation tank with a porous inner liner; the prepared composite additive solution is pumped into the tank, and the liquid surface completely submerges the coke; the rotary drum or the internal circulation pump is started, and dynamic impregnation is carried out under mild conditions of normal pressure and 60°C for 15 minutes. Dynamic stirring ensures that each coke is in full contact with the solution, and the solution penetrates into the pores of the coke under the action of capillary action; after impregnation, the excess solution is drained to obtain wet composite coke.
[0048] (3) Drying and curing The wet composite coke is transferred to a vibrating screen or draining area to remove excess liquid droplets from the surface. Then it is fed into a drying device (such as a fluidized bed dryer or belt dryer) using a stepped heating program: first stage: 100℃, drying for 1.5 hours, mainly to remove free water; second stage: 160℃, drying for 2 hours, to promote the gelation of nano-silica sol and form a firm adhesion layer on the surface and pore walls of the coke together with the additive particles. The maximum temperature in this process must be controlled below 200℃ to prevent the large amount of volatiles from precipitating out and the tar from softening and sticking together. After drying, the coke is cooled to room temperature and then sieved to separate large-particle-size composite coke (18~24mm) and small-particle-size composite coke (8~14mm).
[0049] 3. Equipped with furnace charge Vanadium-titanium iron ore: 75% vanadium-titanium sinter, 15% vanadium-titanium pellets, and 10% lump ore; Fuel: Coke (>25mm) accounts for 52% of the total fuel mass, pulverized coal (injected) accounts for 8% of the total fuel mass, and the large-particle-size composite coke (18~24mm) and small-particle-size composite coke (8~14mm) obtained in step 2 together account for 40% of the total fuel mass (combined coke-to-coke ratio); the mass ratio of the large-particle-size composite coke to the small-particle-size composite coke is 8:2; the mass of the fuel is 25% of the mass of vanadium-titanium iron ore; Flux: 70% limestone and 30% fluorite; the flux is 5% of the mass of the pulverized coal. Oxidizing materials: Add 1.0% Fe2O3 powder by mass of vanadium titanite.
[0050] 4. Smelting operations: Small-particle-size composite coke and some crushed sinter are mixed and distributed in the middle ring of the furnace throat, while large-particle-size composite coke is distributed in the edge and central area of the furnace throat. Other furnace materials are charged as usual. The blast temperature is 1150℃, the oxygen enrichment rate is 3.0%, and pulverized coal is injected as usual.
[0051] Operating results: The blast furnace operated stably. Compared with the traditional method using ordinary coke and coke ratio of 18%, this method achieved comparable furnace smoothness, qualified molten iron quality, and reduced fuel cost per ton of iron by about 12% when the coke ratio reached 40%.
[0052] Example 3 This embodiment provides a vanadium-titanium ore smelting process with a high coke-to-butane ratio in a blast furnace, at a depth of 3200m. 3 This embodiment is implemented on a blast furnace for vanadium-titanium ore smelting.
[0053] The smelting process in this embodiment includes the following steps: 1. Pretreatment of charcoal The conventional coke (initial particle size is usually ≤25mm) is initially screened to remove excessively fine powder (<3mm) and impurities, resulting in relatively clean raw coke. This step can reduce ineffective load and subsequent solution contamination.
[0054] The cleaned charred pieces are then fed into a drying device (such as a rotary dryer or fluidized bed dryer) and preheated at 180°C to reduce their moisture content to below 2% by mass. This aims to remove adsorbed water from the surface of the charred pieces, open their microporous structure, and significantly improve their subsequent adsorption capacity and penetration depth for additive solutions.
[0055] 2. Preparation of composite pyroxene (1) Preparation of compound additives Formula: 250 parts calcium compound (calcium carbonate), 100 parts magnesium compound (magnesium carbonate), 40 parts binder (nano alumina sol, solid content 30%), 5 parts tackifier (sodium carboxymethyl cellulose), and 900 parts flux (water).
[0056] Preparation process: In a reactor equipped with high-speed (6000 rpm) shear stirring, the metered flux is first added, stirring is started, and the thickener and binder are added in sequence and stirred until completely dispersed and uniform; then, under continuous high-speed shear, calcium-containing compound and magnesium-containing compound powders are slowly added, and stirring is continued for 60 minutes after the addition is completed to form a uniform and stable suspension slurry.
[0057] (2) Preparation of wet composite pyroxene Conveyor belt spraying method: The dried coke from step 1 is loaded into an inclined rotary drum or vertical impregnation tank with a porous inner liner; the prepared composite additive solution is pumped into the tank, and the liquid surface completely submerges the coke; the rotary drum or tank circulation pump is started, and dynamic impregnation is carried out under mild conditions of normal pressure and 40°C for 30 minutes. Dynamic stirring ensures that each coke is in full contact with the solution, and the solution penetrates into the pores of the coke under the action of capillary action; after impregnation, the excess solution is drained to obtain wet composite coke.
[0058] (3) Drying and curing The wet composite coke is transferred to a vibrating screen or draining area to remove excess liquid droplets from the surface. Then it is sent to a drying device (such as a fluidized bed dryer or belt dryer) using a stepped heating program: the first stage is 120°C for 2 hours to remove free water, and the second stage is 180°C for 3 hours to promote the gelation of nano-silica sol and form a firm adhesion layer on the surface and pore walls of the coke together with the additive particles. The maximum temperature in this process must be controlled below 200°C to prevent the large amount of volatiles from precipitating out and the tar from softening and sticking together. After drying, the coke is cooled to room temperature and then sieved to separate large-particle-size composite coke (18~24mm) and small-particle-size composite coke (8~14mm).
[0059] 3. Equipped with furnace charge Vanadium-titanium iron ore: 60% vanadium-titanium sinter, 20% vanadium-titanium pellets, and 20% lump ore; Fuel: Coke (>25mm) accounts for 45% of the total fuel mass, pulverized coal (injected) accounts for 12% of the total fuel mass, and the large-particle-size composite coke (18~24mm) and small-particle-size composite coke (8~14mm) obtained in step 2 together account for 43% of the total fuel mass (combined coke-to-coke ratio); the mass ratio of the large-particle-size composite coke to the small-particle-size composite coke is 6:4; the mass of the fuel is 28% of the mass of vanadium-titanium iron ore; Flux: 80% limestone and 20% fluorite; the flux is 6% of the mass of the pulverized coal. Oxidizing materials: Add Fe2O3 powder at 1.2% of the mass of vanadium titanate.
[0060] 4. Smelting operations: Small-particle-size composite coke and some crushed sinter are mixed and distributed in the middle ring of the furnace throat, while large-particle-size composite coke is distributed in the edge and central area of the furnace throat. Other furnace materials are charged as usual. The blast temperature is 1180℃, the oxygen enrichment rate is 3.2%, and pulverized coal is injected as usual.
[0061] Operating results: The blast furnace operated stably. Compared with the traditional method using ordinary coke and coke ratio of 18%, this method achieved a similar smoothness of furnace operation, qualified molten iron quality, and reduced fuel cost per ton of iron by about 11% when the coke ratio reached 43%.
[0062] Comparative Example 1 Same as Example 1, except that steps 1 and 2 are omitted, and the composite coke-butadiene in step 3 is replaced with conventional coke-butadiene. After operation, the furnace stability decreased and the pressure differential increased, forcing a reduction in the coke-butadiene ratio to below 25% to maintain smooth operation.
[0063] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, 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 considered within the scope of protection of the present invention.
Claims
1. A blast furnace vanadium-titanium ore smelting process with a high coke-to-but ratio, characterized in that, Includes the following steps: The furnace charge is fed into the blast furnace for smelting. The furnace charge includes vanadium-titanium iron ore, fuel, flux, and oxidizing materials. The fuel consists of coke, pulverized coal, and composite coke. The composite coke accounts for 40-50% of the mass of the fuel. The composite coke includes composite coke with a particle size of 18-24 mm and composite coke with a particle size of 8-14 mm. The composite char is obtained by compounding char with composite additives, followed by drying and sieving. The composite additives include, by weight, 100-250 parts of calcium compound, 30-100 parts of magnesium compound, 10-40 parts of binder, 1-5 parts of thickener, and 700-900 parts of flux.
2. The smelting process according to claim 1, characterized in that, The preparation process of the composite additive is as follows: under a high-speed shear stirring environment of 5000~8000 rpm, flux, thickener and binder are added in sequence and stirred until completely dispersed and uniform; then calcium compound and magnesium compound are added, and stirring is continued after the addition is completed to form a uniform and stable suspension slurry.
3. The smelting process according to claim 1, characterized in that, The calcium-containing compound is selected from one or more of calcium oxide, calcium hydroxide, calcium carbonate, limestone powder, and dolomite powder.
4. The smelting process according to claim 1, characterized in that, The magnesium-containing compound is selected from one or more of magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesite powder, and dolomite powder.
5. The smelting process according to claim 1, characterized in that, The adhesive is selected from nano silica sol, nano alumina sol, or a mixture thereof.
6. The smelting process according to claim 1, characterized in that, The thickener is selected from one or more of sodium carboxymethyl cellulose, xanthan gum, polyvinyl alcohol, and bentonite.
7. The smelting process according to claim 1, characterized in that, The composite treatment process adopts the dynamic impregnation method in an impregnation tank, with a treatment pressure of atmospheric pressure, a treatment temperature of 25~60℃, and a treatment time of 15~45min.
8. The smelting process according to claim 1, characterized in that, The composite char is produced by combining char with composite additives and then drying it using a stepped temperature increase process. The first stage of drying is at a temperature of 80~120℃ for 1~2 hours, and the second stage is at a temperature of 120~180℃ for 1~3 hours.
9. The smelting process according to claim 1, characterized in that, The mass ratio of the composite coke with a particle size of 18-24 mm to the composite coke with a particle size of 8-14 mm is (6-8):(2-4).
10. The smelting process according to claim 1, characterized in that, In the smelting process, composite coke with a particle size of 8-14 mm is mixed with some crushed sinter and then distributed in the middle ring of the furnace throat, while composite coke with a particle size of 18-24 mm is distributed in the edge and central area of the furnace throat.