A low-carbon smelting method and device for vanadium-titanium ore 5R-GreenSt

Abstract

This invention relates to a low-carbon smelting method and apparatus for vanadium-titanium ore 5R-GreenSt, belonging to the field of low-carbon metallurgical technology. Iron-containing materials and solid fuel are continuously charged from the top of a PBF (Pulverized Borehole) furnace. Hot reducing gas is continuously injected from the gas injection port, along with oxygen and pulverized coal. The injected pulverized coal and solid fuel react with oxygen to generate hot reducing gas. The injected and generated hot reducing gas then react with the iron-containing materials in the furnace to produce metallic iron and slag. The heat from the reducing gas is transferred to the metallic iron and slag, generating liquid slag and molten iron. This invention employs a "vanadium-titanium ore hydrogen-rich carbon circulating PBF furnace" technology, injecting coke oven gas, natural gas, and H2 from the tuyeres to remove CO2 and H2O from the blast furnace top gas, resulting in purified gas. This purified gas is then heated and injected back into the blast furnace for recycling, achieving a final H2 utilization rate of over 95% and reducing CO2 emissions by 30-75%.

Description

Technical Field

[0001] The invention belongs to the technical field of low-carbon metallurgy, and in particular relates to a low-carbon smelting method and device for vanadium-titanium ore 5R-GreenSt. Background Art

[0002] At present, the main technically mature ironmaking processes include blast furnace ironmaking, smelting reduction (HIsmelt, COREX, Finex), direct reduction (gas-based direct reduction, coal-based direct reduction), etc. The existing processes have their own advantages and disadvantages, mainly:

[0003] (1) The blast furnace ironmaking process technology is mature and can achieve an annual production capacity of more than one million tons for a single device. However, its disadvantages are over-reliance on high-quality metallurgical coke; supporting construction of coking, sintering, and pelletizing is required, and the system investment is large; the blast furnace is difficult to operate and difficult to recover after abnormal and fluctuating furnace conditions; and the cost, carbon emissions, and energy consumption are high.

[0004] (2) Melt reduction

[0005] ①The heat transfer effect of HIsmelt process is not good. The temperature of molten iron in the molten pool is low, only 1400-1450℃. The flue gas volume is as high as 2700Nm3 / t iron, and the flue gas temperature reaches 1600℃. A large amount of physical heat is lost outside the furnace along with the flue gas. The iron loss is high, the fuel consumption is high, and the carbon emission is high.

[0006] ② The [Si] content of COREX and Finex molten iron is high, the amount of gas generated is too large, and the primary carbon consumption is high.

[0007] ③ The utilization rate of carbon's chemical energy is insufficient. Part of the carbon element escapes with the coal gas in the form of CO, and its chemical energy cannot be further utilized.

[0008] (3) Direct reduction

[0009] ① Hydrogen-based vertical furnaces have high requirements for ore quality. For low-grade ores with an Fe content of 52-55%, the gangue content is high. Under the condition of a metallization rate of 90%, the grade of the direct reduced iron produced is less than 70%, facing the problem of low utilization value or high back-end utilization cost.

[0010] ② Coal-based direct reduction requires solid fuel, so the carbon consumption is high; and there is the same problem as the gas-based vertical furnace in terms of high ore quality requirements.

[0011] Therefore, it is necessary to provide a green iron-making process with lower energy consumption, lower cost and less environmental pollution. Summary of the invention

[0012] In view of the above problems, the present invention provides a vanadium-titanium ore 5R-GreenSt low-carbon smelting method and device, wherein the vanadium-titanium ore 5R-GreenSt low-carbon smelting method includes adjusting the material structure to reduce carbon consumption (Reduce), recycling gas and solid carbon-containing waste (Recycle), utilizing the existing blast furnace converter and supporting main equipment of the steel plant (Reuse), using natural gas and clean electricity to replace fossil energy (replaces), and using cold pressed blocks, scrap steel and biomass metallurgy (Renewable), which has the advantages of high thermal energy utilization, low carbon emissions and energy consumption, low cost and low environmental pollution.

[0013] The first object of the present invention is to provide a low-carbon smelting method of vanadium-titanium ore 5R-GreenSt, comprising:

[0014] The iron-containing materials and solid fuel are continuously loaded from the top of the PBF furnace, and the gas is continuously injected from the gas injection port at a temperature of 1200-2300℃ and a flow rate of 980-1500Nm 3 / thm of hot reducing gas, and simultaneously continuously injecting oxygen and pulverized coal with a temperature of less than 50°C from the gas injection port, the injected pulverized coal and the solid fuel descending from the furnace top to the gas injection port and the injected oxygen undergo combustion reaction to generate hot reducing gas;

[0015] The injected hot reducing gas and the generated hot reducing gas undergo reduction reaction with the iron oxides in the iron-containing materials descending from the furnace top during the process of ascending in the furnace, thereby generating metallic iron and slag;

[0016] At the same time, the heat of the reducing gas is transferred to the metallic iron and slag, generating liquid slag and molten iron;

[0017] The gaseous product of the chemical reaction in the PBF furnace becomes the PBF furnace gas, which is discharged from the top of the PBF furnace and is removed by CO 2 , H 2 O. After purification, purified reducing gas is generated, and the purified reducing gas is recycled to form hot reducing gas.

[0018] In a specific embodiment of the present invention, the iron-containing material includes sintered ore, pelletized ore and cold-pressed briquettes; the solid fuel includes metallurgical coke, small coke and biomass carbon blocks; the mass percentage of sintered ore in the iron-containing material is ≤45%; the TiO 2 The mass percentage of the content is ≤3.5%; the pelletized ore is high-temperature roasted all-vanadium titanium concentrate.

[0019] In a specific embodiment of the present invention, the solid fuel is loaded into the throat of the PBF furnace, and the horizontal section of the throat is equally divided into 10 circular rings of equal area, which are numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10# rings from the center of the circle outward; when the PBF furnace top is loaded, the biomass carbonized fuel is loaded into the 9# to 10# ring positions, the metallurgical coke is loaded into the 1# to 3# ring positions with a quantity of 80kg / thm, and the 4# to 8# ring positions are loaded with small pieces of coke.

[0020] In a specific embodiment of the present invention, the cold pressed block is an iron-containing block material made by cold pressing scrap steel, iron oxide, iron filings, and iron concentrate powder; the cold pressed block is tested by GB / T 13242 low temperature pulverization test, and the low temperature reduction pulverization index RDI is +6.3 The amount of solid fuel added and the amount of coal powder injected are equal to 0.10-0.38 t / thm.

[0021] In a specific embodiment of the present invention, the TiO 2 The mass percentage of the content is 10 to 45%.

[0022] In a specific embodiment of the present invention, the relationship between the temperature and flow rate of the injected hot reducing gas, and the added amount of solid fuel and the total amount of injected coal powder is as follows:

[0023] When 1200℃≤T≤1500℃, 980Nm 3 / thm≤Q≤1090Nm 3 / thm,310kg / thm≤C≤380kg / thm;

[0024] When 1500℃≤T≤2000℃, 1090Nm 3 / thm≤Q≤1350Nm 3 / thm,140kg / thm≤C≤310kg / thm;

[0025] When 2000℃≤T≤2300℃, 1350Nm 3 / thm≤Q≤1500Nm 3 / thm,80kg / thm≤C≤140kg / thm;

[0026] Wherein, T is the temperature of the injected hot reducing gas, Q is the flow rate of the injected hot reducing gas, and C is the sum of the added amount of solid fuel and the injected amount of pulverized coal.

[0027] In a specific embodiment of the present invention, the purified reducing gas is recycled to form hot reducing gas, including:

[0028] The purified reducing gas is input into the reducing gas cabinet, and then outputted from the reducing gas cabinet to form reducing gas. The reducing gas is humidified and heated to generate hot reducing gas.

[0029] The gas sources of the reducing gas cabinet include purified reducing gas, coke oven gas, natural gas and hydrogen;

[0030] Among them, CH 4 The relationship between the flow rate and the humidification water vapor flow rate is Y = 0.8X, where X is the CH 4 Flow rate, in Nm 3 / min, Y is the humidification water vapor flow rate, unit is kg / min.

[0031] The second object of the present invention is to provide a 5R-GreenSt low-carbon smelting device, including a PBF furnace, the PBF furnace including a furnace top sealing and charging device arranged on the furnace top, a furnace top gas outlet pipe arranged on the furnace top and a PBF furnace body connected to the furnace top, the PBF furnace body including a furnace throat, a furnace body, a furnace waist, a furnace belly and a furnace hearth in order of vertical distance from the furnace top from small to large, the furnace hearth including a gas injection port and a slag iron discharge port in order of vertical distance from the furnace top from small to large, the gas injection port is located above the liquid slag iron liquid level, and also includes a gas circulation device connected to the PBF furnace pipeline;

[0032] The furnace top sealing and charging equipment is used for continuously charging iron-containing materials and solid fuel from the furnace top of the PBF furnace, and for sealing the coal gas at the furnace top of the PBF furnace;

[0033] The top gas outlet pipe is used to discharge the top gas of the PBF furnace from the top of the PBF furnace;

[0034] The gas injection port is used to inject hot reducing gas, oxygen and coal powder simultaneously;

[0035] The PBF furnace body is used for the injected pulverized coal and the solid fuel descending from the furnace top to the gas injection port to undergo combustion reaction with the injected oxygen to generate hot reducing gas; the injected hot reducing gas and the generated hot reducing gas undergo reduction reaction with the iron oxide in the iron-containing material descending from the furnace top during the rising process in the furnace to generate metallic iron and slag; at the same time, the heat of the reducing gas is transferred to the metallic iron and slag to generate liquid slag and molten iron;

[0036] The gas circulation device is used for purifying the PBF furnace gas, generating purified reducing gas, and recycling the purified reducing gas to form hot reducing gas.

[0037] In a specific embodiment of the present invention, the gas circulation device is connected with a gas purification device, a reducing gas cabinet and a reducing gas heating device in sequence in the flow direction of the discharged PBF furnace gas; a humidifying device is also connected to the connecting pipeline between the reducing gas cabinet and the reducing gas heating device.

[0038] In a specific embodiment of the present invention, the size relationship between the furnace throat, furnace body, furnace waist, furnace belly and furnace hearth is as follows:

[0039] D1 is 4.5-10m; H4 is 7-12m; the ratio of H4 to D1 is 1.2-1.6; the ratio of H1 to D1 is 0.4-0.6; the ratio of D3 to D1 is 1.1-1.2; the ratio of the sum of H2 and H3 to D1 is 0.45-0.85;

[0040] Among them, D1 is the furnace diameter, H1 is the furnace height; H2 is the furnace belly height; D3 is the furnace waist diameter, H3 is the furnace waist height; H4 is the furnace body height; D5 is the furnace throat diameter, H5 is the furnace throat height.

[0041] Beneficial effects of the present invention:

[0042] (1) Pure oxygen-carbon cycle blast furnace

[0043] Different from the traditional blast furnace (using atmospheric smelting), the pure oxygen-carbon cycle blast furnace uses pure oxygen smelting to convert the blast furnace top gas (mainly CO, CO 2 , without N 2 ) 2 After being removed, it becomes clean coal gas (main component CO). After being heated, the clean coal gas is sprayed back into the blast furnace for recycling, which can reduce CO 2 Emissions are 20% (compared with traditional blast furnaces, the same below).

[0044] (2) Hydrogen-rich injection

[0045] Compared with the traditional blast furnace hydrogen-rich injection (H 2 The utilization rate is only 45%, and the carbon reduction effect is less than 5%). The present invention adopts pure oxygen-carbon cycle and hydrogen-rich injection (hereinafter referred to as "hydrogen-rich carbon cycle"), and injects coke oven gas, natural gas, H 2 etc., the blast furnace (PBF furnace) top gas (main components CO, CO 2 , H 2 , H 2 CO in O 2 , H 2 O is removed to become clean coal gas (main components CO, H 2 ), after being heated, the clean coal gas is sprayed back into the blast furnace for recycling, H 2 The final utilization rate reaches more than 95%, which can reduce CO 2 Emission 30-75%.

[0046] (3) Clean Energy Metallurgy

[0047] Different from the traditional blast furnace (gas injection temperature of 1200℃), the Xichang clean energy metallurgical process heats the clean coal gas to 1800-2300℃ through plasma gas electric heating and other technologies, and then injects it into the hydrogen-rich carbon circulation blast furnace, so that the heat required for melting slag and iron in the furnace is provided by electricity, reducing the consumption of fossil energy in the blast furnace and reducing CO 2 Emissions 40-70%.

[0048] (4) High titanium slag smelting

[0049] Compared with traditional blast furnace (slag TiO 2 content = 22 ± 0.5%, molten iron vanadium content 0.31 ± 0.01%), in the smelting process of the present invention, due to the system N 2 Low partial pressure can greatly inhibit the formation of Ti(C,N), solve the problem of slag iron stickiness during high-titanium slag smelting, increase the vanadium content of molten iron to 0.33-0.50%, and improve the slag TiO 2 The content will reach 25-40%, which will be a big step forward in the industrial application of titanium extraction from blast furnace slag.

[0050] (5) Cold briquetting and biomass metallurgy

[0051] Different from the traditional blast furnace (using sintered ore, pelletized ore and high-quality metallurgical coke as raw materials and fuel), in the smelting process of the present invention, due to the furnace gas (mainly composed of CO, H 2 , without N 2 ) has a much higher reduction potential than conventional blast furnace bosh gas (containing 50% N 2 ), the metallization rate of Fe element in the blast furnace soft melting zone is as high as 90%, the coke loss in the furnace body is reduced, and the permeability of the blast furnace is improved. Therefore, relatively low-strength cold pressed blocks and biomass carbonized fuels can be used to partially replace sintering, pelletized ore and high-quality metallurgical coke, which can reduce CO 2 Emission 50-75%.

[0052] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 It shows a schematic structural diagram of a 5R-GreenSt low-carbon smelting device according to an embodiment of the present invention;

[0055] Figure 2 It shows a schematic structural diagram of a PBF furnace in a 5R-GreenSt low-carbon smelting device according to an embodiment of the present invention;

[0056] In the figure:

[0057] 1. Furnace throat; 2. Furnace body; 3. Furnace waist; 4. Furnace belly; 5. Furnace hearth; 6. Gas injection port; 7. Slag and iron discharge port; 8. Furnace top gas outlet pipe; 9. Furnace top sealing and charging equipment; 10. PBF furnace; 11. Reducing gas heating device; 12. Gas purification device; 13. Reducing gas cabinet; 14. Humidifying device. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] According to an embodiment of the present invention, a 5R-GreenSt low-carbon smelting method of vanadium-titanium ore is provided, wherein 5R is the abbreviation of Reduce, Recycle, Reuse, replaces and Renewable in English, Reduce refers to adjusting the material structure to reduce carbon consumption, Recycle refers to recycling gas and solid carbon-containing waste, Reuse refers to using the existing blast furnace converter and supporting main equipment of the steel plant, Replaces refers to using natural gas and clean electricity to replace fossil energy, Renewable refers to using cold pressed blocks, scrap steel and biomass energy metallurgy, and the 5R-GreenSt low-carbon smelting method of vanadium-titanium ore refers to adjusting the material structure to reduce carbon consumption, recycling gas and solid carbon-containing waste, using the existing blast furnace converter and supporting main equipment of the steel plant, using natural gas and clean electricity to replace fossil energy, and using cold pressed blocks, scrap steel and biomass energy metallurgy. GreenSt is the abbreviation of greensteel, which is green steel;

[0060] The low-carbon smelting method comprises:

[0061] The iron-containing material and solid fuel are continuously charged from the top of the PBF furnace 10, the hot reducing gas is continuously injected from the gas injection port 6, and at the same time, oxygen and pulverized coal are continuously injected from the gas injection port 6;

[0062] In the PBF furnace 10, the injected pulverized coal and the solid fuel descending from the furnace top to the gas injection port 6 react with the injected oxygen to generate hot reducing gas, and the chemical reaction formula is: 2 +2C=2CO;

[0063] The injected hot reducing gas and the generated hot reducing gas undergo reduction reaction with the iron oxides in the iron-containing materials descending from the furnace top during the process of ascending in the furnace, thereby generating metallic iron and slag;

[0064] At the same time, the heat of the reducing gas is transferred to the metallic iron and the slag, generating liquid slag and molten iron. The liquid slag enters the furnace cylinder 5 under the action of gravity and is layered in the furnace cylinder 5, with the liquid slag distributed in the upper layer and the liquid molten iron distributed in the lower layer. The liquid slag is continuously discharged from the furnace from the slag discharge port 7 to make room in the furnace, so that the charge is continuously and stably lowered.

[0065] The gaseous product of the chemical reaction in the PBF furnace 10 becomes the PBF furnace gas, which is discharged from the top of the PBF furnace 10 and, after purification, generates purified reducing gas, which is recycled to form hot reducing gas. After purification, the PBF furnace gas is freed of dust and CO 2 and H 2 O, and the purified reducing gas is obtained. The main components of the purified reducing gas are CO and H 2 .

[0066] In some embodiments of the present invention, the iron-containing materials include sintered ore, pelletized ore and cold-pressed blocks; the solid fuel includes metallurgical coke, small coke and biomass carbon blocks; the cold-pressed blocks are iron-containing block materials made by cold pressing scrap steel, iron oxide scale, iron filings and iron ore concentrate powder;

[0067] Among them, small coke is a special term in the field of traditional blast furnace ironmaking, generally referring to coke with a particle size of 5-25mm, and metallurgical coke refers to coke with a particle size of 25-80mm;

[0068] That is, in the embodiment of the present invention, the material structure is adjusted, the material is replaced with iron-containing materials and solid fuels, and biomass carbon blocks and cold-pressed blocks (including scrap steel, iron oxide sheets, iron filings and iron ore powder) are added, which not only reduces carbon consumption but also realizes the recycling of solid carbon-containing waste.

[0069] In some other embodiments of the present invention, in order to obtain a better carbon reduction effect, the mass percentage of the sintered ore content in the iron-containing material is ≤45%; the TiO 2 The mass percentage of the content is ≤3.5%; the pellets are obtained by roasting all-vanadium titanium concentrate, and the roasting temperature is common knowledge among personnel in the technical field, and the present invention does not make any further limitation here.

[0070] In some other embodiments of the present invention, in order to obtain a better carbon reduction effect, the cold pressed block is subjected to the GB / T 13242 low temperature pulverization test, and the low temperature reduction pulverization index RDI is +6.3 Greater than 80%, the reducibility index RI greater than 75%; the sum of the amount of solid fuel added and the amount of coal powder injected is equal to 0.10-0.38t / thm.

[0071] In some embodiments of the present invention, due to the system N 2 Low partial pressure can greatly inhibit the formation of Ti(C,N), solve the problem of slag iron stickiness during high-titanium slag smelting, increase the vanadium content of molten iron to 0.33-0.50%, and improve the slag TiO 2 The content of TiO in blast furnace slag is 25-40%, and the industrial application of titanium extraction from blast furnace slag will take a big step forward. 2 The mass percentage of the content is 10 to 45%.

[0072] In some other embodiments of the present invention, in order to obtain better carbon reduction effect, the solid fuel is loaded into the throat 1 of the PBF furnace 10, and the throat 1 is divided into 10 circular rings of equal area in the horizontal section, which are numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10# rings from the center of the circle outward; when the top of the PBF furnace 10 is loaded, the biomass carbonized fuel is loaded into the 9# to 10# ring positions, the metallurgical coke is loaded into the 1# to 3# ring positions with a quantity of 80kg / thm, and the 4# to 8# ring positions are loaded with small pieces of coke.

[0073] In some embodiments of the present invention, the temperature of the injected hot reducing gas is 1200-2300°C, and the injection flow rate is 980-1500Nm 3 / thm; the temperature of oxygen injection is less than 50℃; the temperature of coal powder injection is less than 50℃, so that the heat required for melting slag iron in the furnace is provided by electric energy, reducing the consumption of fossil energy in the blast furnace and reducing CO 2 Emissions 40-70%.

[0074] In some other embodiments of the present invention, in order to obtain a better carbon reduction effect, the relationship between the temperature and flow rate of the injected hot reducing gas, and the amount of solid fuel added and the total amount of coal powder injected (referred to as "solid fuel consumption") is as follows:

[0075] When 1200℃≤T≤1500℃, 980Nm 3 / thm≤Q≤1090Nm 3 / thm,310kg / thm≤C≤380kg / thm;

[0076] When 1500℃≤T≤2000℃, 1090Nm 3 / thm≤Q≤1350Nm 3 / thm,140kg / thm≤C≤310kg / thm;

[0077] When 2000℃≤T≤2300℃, 1350Nm 3 / thm≤Q≤1500Nm 3 / thm,80kg / thm≤C≤140kg / thm;

[0078] Wherein, T is the temperature of the injected hot reducing gas, Q is the flow rate of the injected hot reducing gas, and C is the sum of the added amount of solid fuel and the injected amount of pulverized coal.

[0079] In certain embodiments of the present invention, the purified reducing gas is recycled to form hot reducing gas, including:

[0080] The purified reducing gas is input into the reducing gas cabinet, and then outputted from the reducing gas cabinet to form reducing gas. The reducing gas is humidified and heated to generate hot reducing gas.

[0081] The gas sources of the reducing gas cabinet include purified reducing gas, coke oven gas, natural gas and hydrogen;

[0082] That is, the process of PBF furnace gas recycling is as follows:

[0083] The PBF furnace gas output from the furnace top gas outlet pipe 8 passes through the gas purification device 12 to remove dust, CO 2 and H 2 O, and the purified reducing gas is obtained. The main components of the purified reducing gas are CO and H 2 ; The purified reduction gas output from the gas purification device 12 is delivered to the reduction gas cabinet 13;

[0084] The gas from the reducing gas cabinet 13 is transported to the reducing gas heating device 14 through the reducing gas pipeline; the water vapor in the humidifying device 14 is transported to the reducing gas heating device 11 through the reducing gas pipeline. In the reducing gas heating device 11, all gases are heated and chemical reactions occur at the same time: CH 4 +H 2 O=3H 2 +CO, after the gas in the reducing gas heating device is heated to 1200-2300°C, it is injected into the PBF furnace from the gas injection port of the PBF furnace;

[0085] CH in reducing gas 4 The relationship between the flow rate and the humidification water vapor flow rate is Y = 0.8X, where X is the CH 4 Flow rate, in Nm 3 / min, Y is the humidification water vapor flow rate, unit is kg / min.

[0086] like Figure 1 As shown, according to a 5R-GreenSt low-carbon smelting device according to an embodiment of the present invention, the low-carbon smelting device includes a PBF furnace 10 and a gas circulation device connected to the PBF furnace pipeline, such as Figure 2 As shown, the PBF furnace 10 includes a furnace top sealing and charging device 9 arranged on the furnace top, a furnace top gas outlet pipe 8 arranged on the furnace top and a PBF furnace body connected to the furnace top. The PBF furnace body includes a furnace throat 1, a furnace body 2, a furnace waist 3, a furnace belly 4 and a furnace hearth 5 in order of vertical distance from the furnace top from small to large. The furnace hearth 5 includes a gas injection port 6 and a slag iron discharge port 7 in order of vertical distance from the furnace top from small to large. The gas injection port 7 is located above the liquid slag iron liquid level.

[0087] The furnace top sealing and charging equipment 9 is used for continuously charging iron-containing materials and solid fuel from the PBF furnace top, and for sealing the PBF furnace top gas;

[0088] The top gas is the mixed gas formed by all the gases generated by the reaction when the PBF furnace gas floats up to the top of the PBF furnace, as well as the raw gas, including dust, CO 2 , H 2 O, CO, and H 2 ;

[0089] The gas injection port 6 is used to inject hot reducing gas, oxygen and coal powder simultaneously;

[0090] The pulverized coal injected into the PBF furnace body and the solid fuel descending from the furnace top to the gas injection port 6 undergo combustion reaction with the injected oxygen to generate hot reducing gas; the injected hot reducing gas and the generated hot reducing gas undergo reduction reaction with the iron oxide in the iron-containing material descending from the furnace top during the rising process in the furnace to generate metallic iron and slag; at the same time, the heat of the reducing gas is transferred to the metallic iron and slag to generate liquid slag and molten iron;

[0091] The top gas outlet pipe 8 is used to discharge the top gas of the PBF furnace from the top of the PBF furnace;

[0092] The gas circulation device is used for purifying the PBF furnace gas, generating purified reducing gas, and recycling the purified reducing gas to form hot reducing gas.

[0093] like Figure 1 As shown, the gas circulation device is connected with a gas purification device 12, a reducing gas cabinet 13 and a reducing gas heating device 11 in sequence in the flow direction of the discharged PBF furnace gas; a humidifying device 14 is also connected to the connecting pipeline between the reducing gas cabinet 13 and the reducing gas heating device 11.

[0094] In some other embodiments of the present invention, in order to obtain a better carbon reduction effect, the size relationship between the furnace throat 1, furnace body 2, furnace waist 3, furnace belly 4 and furnace hearth 5 is as follows:

[0095] D1 is 4.5-10m; H4 is 7-12m; the ratio of H4 to D1 is 1.2-1.6; the ratio of H1 to D1 is 0.4-0.6; the ratio of D3 to D1 is 1.1-1.2; the ratio of the sum of H2 and H3 to D1 is 0.45-0.85;

[0096] Among them, D1 is the diameter of the furnace hearth 5, H1 is the height of the furnace hearth 5; H2 is the height of the furnace belly 4; D3 is the diameter of the furnace waist 3, H3 is the height of the furnace waist 3; H4 is the height of the furnace body 2; D5 is the diameter of the furnace throat 1, H5 is the height of the furnace throat 1.

[0097] Xichang Steel Vanadium Smelting Process Parameters:

[0098] Device: 5R-GreenSt low-carbon smelting device, including a PBF furnace 10 and a gas circulation device connected to the PBF furnace pipeline, the PBF furnace 10 includes a furnace top sealing and charging device 9 arranged on the furnace top, a furnace top gas outlet pipe 8 arranged on the furnace top and a PBF furnace body connected to the furnace top, the PBF furnace body includes a furnace throat 1, a furnace body 2, a furnace waist 3, a furnace belly 4 and a furnace hearth 5 in order of vertical distance from the furnace top from small to large, the furnace hearth 5 includes a gas injection port 6 and a slag iron discharge port 7 in order of vertical distance from the furnace top from small to large, and the gas injection port 7 is located above the liquid slag iron liquid surface;

[0099] The gas circulation device is connected with a gas purification device 12, a reduction gas cabinet 13 and a reduction gas heating device 11 in sequence in the flow direction of the discharged PBF furnace gas; a humidifying device 14 is also connected to the connecting pipeline between the reduction gas cabinet 13 and the reduction gas heating device 11;

[0100] The size relationship among the furnace throat 1, furnace body 2, furnace waist 3, furnace belly 4 and furnace hearth 5 is as follows:

[0101] D1 is 4.5-10m; H4 is 7-12m; the ratio of H4 to D1 is 1.2-1.6; the ratio of H1 to D1 is 0.4-0.6; the ratio of D3 to D1 is 1.1-1.2; the ratio of the sum of H2 and H3 to D1 is 0.45-0.85;

[0102] Among them, D1 is the diameter of the furnace hearth 5, H1 is the height of the furnace hearth 5; H2 is the height of the furnace belly 4; D3 is the diameter of the furnace waist 3, H3 is the height of the furnace waist 3; H4 is the height of the furnace body 2; D5 is the diameter of the furnace throat 1, H5 is the height of the furnace throat 1.

[0103] Method and process:

[0104] The iron-containing material and solid fuel are continuously loaded from the top of the PBF furnace 10, and the gas injection port 6 continuously injects gas at a temperature of 1200-2300°C and a flow rate of 980-1500Nm 3 / thm reducing gas, and simultaneously continuously injecting oxygen with a temperature of less than 50°C and pulverized coal with a temperature of less than 50°C from the gas injection port 6;

[0105] The iron-containing materials include sintered ore, pelletized ore and cold-pressed blocks; the solid fuel includes metallurgical coke, small coke and biomass carbon blocks; the mass percentage of sintered ore in the iron-containing materials is ≤45%; the TiO 2 The mass percentage of the content is ≤3.5%; the pellets are vanadium-titanium concentrates roasted at high temperature; the cold pressed blocks are iron-containing block materials made by cold pressing of scrap steel, iron oxide, iron filings, and iron concentrate powder; the cold pressed blocks have been tested by GB / T 13242 low-temperature pulverization test, and the low-temperature reduction pulverization index RDI +6.3 greater than 80%, and the reducibility index RI greater than 75%; the sum of the amount of solid fuel added and the amount of coal powder injected is equal to 0.10-0.38t / thm;

[0106] Charging process control: the solid fuel is loaded into the throat 1 of the PBF furnace 10, and the horizontal section of the throat 1 is equally divided into 10 circular rings of equal area, which are numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, 10# rings from the center of the circle outward; when charging the top of the PBF furnace 10, the biomass carbonized fuel is loaded into the 9-10# ring positions, the metallurgical coke is loaded into the 1-3# ring positions with a quantity of 80kg / thm, and the small coke is loaded into the 4-8# ring positions;

[0107] Process control: The relationship between the temperature and flow rate of the injected hot reducing gas, the amount of solid fuel added and the total amount of injected coal powder is as follows:

[0108] When 1200℃≤T≤1500℃, 980Nm 3 / thm≤Q≤1090Nm 3 / thm,310kg / thm≤C≤380kg / thm;

[0109] When 1500℃≤T≤2000℃, 1090Nm 3 / thm≤Q≤1350Nm 3 / thm,140kg / thm≤C≤310kg / thm;

[0110] When 2000℃≤T≤2300℃, 1350Nm 3 / thm≤Q≤1500Nm 3 / thm,80kg / thm≤C≤140kg / thm;

[0111] Wherein, T is the temperature of the injected hot reducing gas, Q is the flow rate of the injected hot reducing gas, and C is the sum of the amount of solid fuel added and the amount of coal powder injected;

[0112] CH in reducing gas 4 The relationship between the flow rate and the humidification water vapor flow rate is Y = 0.8X, where X is the CH 4 Flow rate, in Nm 3 / min, Y is the humidification water vapor flow rate, unit is kg / min.

[0113] Production shows:

[0114] (1) Pure oxygen-carbon cycle blast furnace

[0115] Different from the traditional blast furnace (using atmospheric smelting), the pure oxygen-carbon cycle blast furnace uses pure oxygen smelting to convert the blast furnace top gas (mainly CO, CO 2 , without N 2 ) 2 After being removed, it becomes clean coal gas (main component CO). After being heated, the clean coal gas is sprayed back into the blast furnace for recycling, which can reduce CO 2 Emissions are 20% (compared with traditional blast furnaces, the same below).

[0116] (2) Hydrogen-rich injection

[0117] Compared with the traditional blast furnace hydrogen-rich injection (H 2 Unlike the carbon utilization rate of only 45% and the carbon reduction effect of <5%), Xichang Steel and Vanadium adopts pure oxygen-carbon cycle + hydrogen-rich injection (hereinafter referred to as "hydrogen-rich carbon cycle"), injecting coke oven gas, natural gas, H 2 etc., the blast furnace top gas (main components CO, CO 2 , H 2 , H 2 CO in O 2 , H 2 O is removed to become clean coal gas (i.e. purified reducing gas) (main components CO, H 2 ), after being heated, the clean coal gas is sprayed back into the blast furnace for recycling, H 2 The final utilization rate reaches more than 95%, which can reduce CO 2 Emission 30-75%.

[0118] (3) Clean Energy Metallurgy

[0119] Different from the traditional blast furnace (gas injection temperature of 1200℃), the Xichang clean energy metallurgical process heats the clean coal gas to 1800-2300℃ through plasma gas electric heating and other technologies, and then injects it into the hydrogen-rich carbon circulation blast furnace, so that the heat required for melting slag and iron in the furnace is provided by electricity, reducing the consumption of fossil energy in the blast furnace and reducing CO 2 Emissions 40-70%.

[0120] (4) High titanium slag smelting

[0121] Compared with traditional blast furnace (slag TiO 2 Content = 22 ± 0.5%, hot metal vanadium content 0.31 ± 0.01%), Xichang hydrogen-rich carbon cycle blast furnace process, due to system N 2 Low partial pressure can greatly inhibit the formation of Ti(C,N), solve the problem of slag iron stickiness during high-titanium slag smelting, increase the vanadium content of molten iron to 0.33-0.50%, and improve the slag TiO 2 The content will reach 25-40%, which will be a big step forward in the industrial application of titanium extraction from blast furnace slag.

[0122] (5) Cold briquetting and biomass metallurgy

[0123] Unlike traditional blast furnaces (which use sintered ore, pelletized ore and high-quality metallurgical coke as raw materials and fuels), the Xichang hydrogen-rich carbon cycle blast furnace process uses furnace gas (mainly CO, H 2 , without N 2 ) has a much higher reduction potential than conventional blast furnace bosh gas (containing 50% N 2 ), the metallization rate of Fe element in the blast furnace soft melting zone is as high as 90%, the coke loss in the furnace body is reduced, and the permeability of the blast furnace is improved. Therefore, relatively low-strength cold pressed blocks and biomass carbonized fuels can be used to partially replace sintering, pelletized ore and high-quality metallurgical coke, which can reduce CO 2 Emission 50-75%.

[0124] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-carbon smelting method of vanadium-titanium ore 5R-GreenSt, characterized in that: include: The iron-containing materials and solid fuel are continuously loaded from the top of the PBF furnace, and the gas is continuously injected from the gas injection port at a temperature of 1200-2300℃ and a flow rate of 980-1500Nm 3 / thm of hot reducing gas, and simultaneously continuously injecting oxygen and pulverized coal with a temperature of less than 50°C from the gas injection port, the injected pulverized coal and the solid fuel descending from the furnace top to the gas injection port and the injected oxygen undergo combustion reaction to generate hot reducing gas; The injected hot reducing gas and the generated hot reducing gas undergo reduction reaction with the iron oxides in the iron-containing materials descending from the furnace top during the process of ascending in the furnace, thereby generating metallic iron and slag; At the same time, the heat of the reducing gas is transferred to the metallic iron and slag, generating liquid slag and molten iron; The gaseous product of the chemical reaction in the PBF furnace becomes the PBF furnace gas, which is discharged from the top of the PBF furnace. After removing CO2 and H2O and being purified, the purified reducing gas is generated. The purified reducing gas is recycled to form hot reducing gas. The solid fuel includes metallurgical coke, small coke and biomass carbon block; The solid fuel is loaded into the throat of the PBF furnace, and the horizontal section of the throat is equally divided into 10 circular rings of equal area, which are numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10# rings from the center of the circle outward; when the PBF furnace top is loaded, the biomass carbon blocks are loaded into the 9# to 10# rings, the metallurgical coke is loaded into the 1# to 3# rings with a weight of 80kg / thm, and the small coke is loaded into the 4# to 8# rings; The purified reducing gas is recycled to form hot reducing gas, including: The purified reducing gas is input into the reducing gas cabinet, and then outputted from the reducing gas cabinet to form reducing gas. The reducing gas is humidified and heated to generate hot reducing gas. The gas sources of the reducing gas cabinet include purified reducing gas, coke oven gas, natural gas and hydrogen; The relationship between the CH4 flow rate in the reducing gas and the humidified water vapor flow rate is Y=0.8X, where X is the CH4 flow rate in the reducing gas, in Nm 3 / min, Y is the humidification water vapor flow rate, unit is kg / min.

2. A low-carbon smelting method of vanadium-titanium ore 5R-GreenSt according to claim 1, characterized in that: The iron-containing material includes sintered ore, pellets and cold-pressed blocks; the mass percentage of sintered ore in the iron-containing material is ≤45%; the mass percentage of TiO2 in the sintered ore is ≤3.5%; and the pellets are obtained by roasting all-vanadium titanium concentrate.

3. A low-carbon smelting method of vanadium-titanium ore 5R-GreenSt according to claim 2, characterized in that: The cold pressed block is made of iron-containing block material made by cold pressing scrap steel, iron oxide, iron filings and iron concentrate powder; the cold pressed block has been tested by GB / T 13242 low temperature pulverization test, and the low temperature reduction pulverization index RDI +6.3 The amount of solid fuel added and the amount of coal powder injected are equal to 0.10-0.38 t / thm.

4. A low-carbon smelting method of vanadium-titanium ore 5R-GreenSt according to claim 1, characterized in that: The mass percentage of TiO2 content in the slag is 10-45%.

5. A low-carbon smelting method of vanadium-titanium ore 5R-GreenSt according to claim 1, characterized in that: The relationship between the temperature and flow rate of the injected hot reducing gas, and the total amount of solid fuel added and the injected coal powder is as follows: When 1200℃≤T≤1500℃, 980Nm 3 / thm≤Q≤1090Nm 3 / thm,310kg / thm≤C≤380kg / thm; When 1500℃≤T≤2000℃, 1090Nm 3 / thm≤Q≤1350Nm 3 / thm,140kg / thm≤C≤310kg / thm; When 2000℃≤T≤2300℃, 1350Nm 3 / thm≤Q≤1500Nm 3 / thm,80kg / thm≤C≤140kg / thm; Wherein, T is the temperature of the injected hot reducing gas, Q is the flow rate of the injected hot reducing gas, and C is the sum of the added amount of solid fuel and the injected amount of pulverized coal.

6. A device for the 5R-GreenSt low-carbon smelting method according to claim 1, comprising a PBF furnace, the PBF furnace comprising a furnace top sealing and charging device arranged on the furnace top, a furnace top gas outlet pipe arranged on the furnace top and a PBF furnace body connected to the furnace top, the PBF furnace body comprising a furnace throat, a furnace body, a furnace waist, a furnace belly and a furnace hearth in order of vertical distance from the furnace top from small to large, the furnace hearth comprising a gas injection port and a slag iron discharge port in order of vertical distance from the furnace top from small to large, the gas injection port being located above the liquid slag iron liquid level, characterized in that, Also included is a gas circulation device connected to the PBF furnace pipeline; The furnace top sealing and charging equipment is used for continuously charging iron-containing materials and solid fuel from the furnace top of the PBF furnace, and for sealing the coal gas at the furnace top of the PBF furnace; The top gas outlet pipe is used to discharge the top gas of the PBF furnace from the top of the PBF furnace; The gas injection port is used to inject hot reducing gas, oxygen and coal powder simultaneously; The PBF furnace body is used for the injected pulverized coal and the solid fuel descending from the furnace top to the gas injection port to undergo combustion reaction with the injected oxygen to generate hot reducing gas; the injected hot reducing gas and the generated hot reducing gas undergo reduction reaction with the iron oxide in the iron-containing material descending from the furnace top during the rising process in the furnace to generate metallic iron and slag; at the same time, the heat of the reducing gas is transferred to the metallic iron and slag to generate liquid slag and molten iron; The gas circulation device is used to purify the PBF furnace gas, generate purified reducing gas, and circulate the purified reducing gas to form hot reducing gas; The dimensional relationship between the furnace body and the furnace hearth is as follows: D1 is 4.5-10m; H4 is 7-12m; the ratio of H4 to D1 is 1.2-1.6; Among them, D1 is the diameter of the furnace and H4 is the height of the furnace body.

7. The device according to claim 6, characterized in that The gas circulation device is sequentially connected with a gas purification device, a reduction gas cabinet and a reduction gas heating device in the flow direction of the discharged PBF furnace gas; a humidifying device is also connected to the connecting pipeline between the reduction gas cabinet and the reduction gas heating device.

8. The device according to any one of claims 6-7, characterized in that: D1 is the diameter of the furnace, H1 is the height of the furnace; H2 is the height of the furnace belly; D3 is the diameter of the furnace waist, H3 is the height of the furnace waist; D5 is the diameter of the furnace throat, H5 is the height of the furnace throat; the size relationship between the furnace throat, furnace body, furnace waist, furnace belly and furnace is as follows: The ratio of H1 to D1 is 0.4-0.6; the ratio of D3 to D1 is 1.1-1.2; the ratio of the sum of H2 and H3 to D1 is 0.45-0.85.

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