Cold pressing block converter heating agent and preparation method thereof, converter smelting method and converter smelting system

Abstract

The invention provides a cold pressing block converter heating agent, a preparation method thereof, a converter smelting method and a converter smelting system, and relates to the field of metallurgy. The temperature raising agent for the cold briquetting converter comprises the following raw materials in percentage by mass: 1-89% of an iron-containing material, 1-95% of biomass charcoal powder and 4-10% of an adhesive, the iron-containing material comprises one or more of oxide scale, slag iron, sintered ore and iron ore. The preparation method of the cold briquetting converter heating agent comprises the following steps: mixing the iron-containing material, the biomass charcoal powder and the adhesive, and then pressing into the cold briquetting converter heating agent. The converter smelting method comprises the step of adding the cold pressing block converter heating agent in the converter smelting process. The converter smelting system comprises a mixer, a briquetting device, a stock bin and a converter. According to the cold pressing block converter heating agent, the utilization efficiency of the converter on the heating agent biomass charcoal is improved, the smelting cost of the converter is reduced, and carbon emission is reduced.

Description

Technical Field

[0001] The present application relates to the field of metallurgy, and in particular to a cold-pressed briquette converter heating agent and a preparation method thereof, a converter smelting method and a converter smelting system. Background Art

[0002] High scrap ratio smelting in converter is an important method to reduce carbon emissions in the steel industry. However, when the scrap ratio is relatively high, the converter is prone to insufficient heat, which causes molten steel to form nodules during the smelting process, the final molten steel deviates too much from the target composition, and the proportion of recycled steel increases greatly. Therefore, in order to ensure smooth operation of the converter during high scrap ratio smelting, carbonaceous heating agents such as coke and anthracite are usually added to supplement heat. However, these heating agents float on the surface of the molten steel, and the chemical heat they provide is difficult to be absorbed by the molten steel. Their utilization rate is too low, resulting in increased oxygen consumption and carbon emissions.

[0003] Therefore, it is necessary to develop a new type of converter heating agent to solve the above problems. Summary of the invention

[0004] The purpose of the present application is to provide a cold-pressed briquette converter heating agent and a preparation method thereof, a converter smelting method and a converter smelting system to solve the above-mentioned problems.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] A cold pressed briquette converter heating agent, the raw materials of which, calculated by total mass as 100%, include:

[0007] Iron-containing material 1%-89%, biomass carbon powder 1%-95% and binder 4%-10%;

[0008] The iron-containing material includes one or more of iron oxide scale, slag iron, sintered ore and iron ore.

[0009] Preferably, the cold pressed briquette converter heating agent includes one or more of high carbon ratio cold pressed briquettes, medium carbon ratio cold pressed briquettes and low carbon ratio cold pressed briquettes;

[0010] The high carbon ratio cold pressed block, calculated with its total mass as 100%, comprises: 1%-15% of the iron-containing material, 79%-95% of the biomass carbon powder and 4%-6% of the binder;

[0011] The medium carbon ratio cold pressed block, calculated with its total mass as 100%, comprises: 15%-50% of the iron-containing material, 42%-79% of the biomass carbon powder and 6%-8% of the binder;

[0012] The low carbon ratio cold pressed block, with its total mass as 100%, comprises: 50%-89% of the iron-containing material, 1%-42% of the biomass carbon powder and 8%-10% of the adhesive.

[0013] Preferably, the compressive strength of the high carbon ratio cold pressed block, the medium carbon ratio cold pressed block and the low carbon ratio cold pressed block is not less than 1500N.

[0014] Preferably, the cold pressed briquette converter heating agent meets one or more of the following conditions:

[0015] A. The binder comprises sodium silicate and / or steelmaking sludge;

[0016] B. The total iron content of the iron-containing material is 40%-60%;

[0017] C. The biomass charcoal powder is obtained by pyrolyzing one or more of corn stalks, wheat stalks, and wood chips as raw materials.

[0018] The present application also provides a method for preparing the cold pressed briquette converter heating agent, comprising:

[0019] The iron-containing material, the biomass carbon powder and the binder are mixed and then pressed into the cold-pressed briquette converter heating agent.

[0020] Preferably, the iron-containing material is pre-crushed into a powdery iron-containing material with a fineness of 100-200 mesh before use;

[0021] and / or,

[0022] The linear pressure of the pressing is 40-150 kN / cm.

[0023] The present application also provides a converter smelting method, comprising: adding the cold pressed block converter heating agent during the converter smelting process.

[0024] Preferably, the cold pressed briquette converter heating agent includes high carbon ratio cold pressed briquettes, medium carbon ratio cold pressed briquettes and low carbon ratio cold pressed briquettes;

[0025] The joining satisfies one or more of the following conditions:

[0026] (1) adding the high carbon ratio cold pressed blocks in the early stage of converter smelting, the added amount being 60-90wt% of the total added amount;

[0027] (2) When the heat is sufficient during the converter smelting process, that is, the temperature measured by the TSC auxiliary gun is greater than 1580°C, but dry-out occurs in the middle stage, the low carbon ratio cold pressed block is added; when the heat is insufficient during the converter smelting process, that is, the temperature measured by the TSC auxiliary gun is less than 1580°C, but dry-out occurs in the middle stage, the medium carbon ratio cold pressed block is added;

[0028] (3) When the final carbon pulling temperature of the converter is too high, that is, the temperature measured by the TSO auxiliary gun is greater than 1650° C., the low carbon ratio cold pressed blocks are added;

[0029] (4) The relationship between the mass content of the biomass carbon powder in the high carbon ratio cold pressed block and the scrap steel ratio of the converter smelting is:

[0030] When the scrap steel ratio is 20-30%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 79-85%; when the scrap steel ratio is 30-35%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 85-90%; when the scrap steel ratio is 35-40%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 85-95%; when the scrap steel ratio is 40-45%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 90-95%;

[0031] (5) During the converter smelting process, top blowing O 2 Strength: 3.10-3.80Nm 3 / (min·t), bottom blowing intensity is 0.02-0.08Nm 3 / (min·t), bottom blowing gas is Ar, N 2 or CO 2 One of them.

[0032] The present application also provides a converter smelting system, comprising: a mixer, a briquetting device, a silo and a converter;

[0033] The mixer is used to mix the raw materials of the cold-pressed briquette converter heating agent, the briquetting device is used to press the raw materials into the cold-pressed briquette converter heating agent, the silo is used to store the cold-pressed briquette converter heating agent from the briquetting device and add the cold-pressed briquette converter heating agent to the converter, and the converter is used for smelting.

[0034] Preferably, the silos include a high carbon ratio cold pressed briquette silo, a medium carbon ratio cold pressed briquette silo and a low carbon ratio cold pressed briquette silo;

[0035] and / or,

[0036] The converter smelting system also includes a pulverizer for pulverizing iron-containing materials.

[0037] Compared with the prior art, the beneficial effects of this application include:

[0038] The cold-pressed briquette converter heating agent provided in the present application utilizes biochar and iron-containing materials to be briquette under the action of a binder, and is used as a converter heating agent, thereby improving the utilization efficiency of biochar in converter smelting, which is beneficial to reducing converter smelting costs and reducing carbon emissions.

[0039] The preparation method of the cold-pressed briquette converter heating agent provided in the present application is simple to operate.

[0040] The converter smelting method and system provided by the present application utilizes the above-mentioned cold pressed block converter heating agent, which is conducive to a more stable converter smelting process and reduces abnormal converter smelting heats. At the same time, the converter scrap ratio can be increased to 45%, and the amount of carbonaceous heating agent used per ton of steel can be reduced by 54-136kg, and CO per ton of steel can be reduced by 100%. 2 Emissions are reduced by 200-500kg. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0042] Figure 1 A schematic diagram of a converter smelting system provided in an embodiment.

[0043] Reference numerals:

[0044] 1-crushing machine, 2-mixer, 3-briquetting device, 4-high-level silo for cold-pressed briquettes, 4-1-high-level silo for cold-pressed briquettes with high carbon ratio, 4-2-high-level silo for cold-pressed briquettes with medium carbon ratio, 4-3-high-level silo for cold-pressed briquettes with low carbon ratio, 5-converter. DETAILED DESCRIPTION

[0045] In order to better explain the technical solution provided by this application, before the embodiments, the technical solution is first described as a whole, as follows:

[0046] A cold pressed briquette converter heating agent, the raw materials of which, calculated by total mass as 100%, include:

[0047] Iron-containing material 1%-89%, biomass carbon powder 1%-95% and binder 4%-10%;

[0048] The iron-containing material includes one or more of iron oxide scale, slag iron, sintered ore and iron ore.

[0049] Optionally, the cold pressed briquette converter heating agent, the raw materials of which are calculated based on the total mass as 100%, the amount of iron-containing materials can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 89% or any value between 1% and 89%, and the amount of biomass charcoal powder can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or any value between 1% and 95%, and the amount of adhesive can be 4%, 5%, 6%, 7%, 8%, 9%, 10% or any value between 4% and 10%.

[0050] Cold pressed briquettes are generally made of iron-containing materials with adhesives added. They can be used as coolants and fluxes in converter steelmaking because they can control the mixing ratio of slag, sintered ore, iron ore and steelmaking sludge, so that the total iron content in the cold pressed briquettes can be effectively controlled within a certain range.

[0051] As a carbon-neutral energy fuel, according to the life cycle theory, the net amount of carbon dioxide released when biochar is burned is considered to be 0. Compared with coke and anthracite, biochar contains lower sulfur and hydrogen content and better combustion reactivity, and has less pollution to molten steel.

[0052] Using biochar and iron-containing material briquettes as converter heating agents solves the problem that the heating agent is difficult to enter the surface of the molten steel to participate in the heating reaction, improves the utilization rate of the heating agent, and allows the converter scrap ratio to increase further. In addition, the slag melting and fluxing effect of iron oxides can be brought into play, which is beneficial to enhance the dephosphorization smelting effect in the early stage of the converter. Finally, using carbon-neutral biochar and iron-containing material briquettes can further reduce converter smelting carbon emissions, which is a measure for green and low-carbon production of converters.

[0053] In an optional embodiment, the cold briquette converter heating agent includes one or more of high carbon ratio cold briquette, medium carbon ratio cold briquette and low carbon ratio cold briquette;

[0054] The high carbon ratio cold pressed block, calculated with its total mass as 100%, comprises: 1%-15% of the iron-containing material, 79%-95% of the biomass carbon powder and 4%-6% of the binder;

[0055] High carbon ratio cold pressed briquettes are used as the main heating agent under converter high scrap ratio smelting conditions.

[0056] The medium carbon ratio cold pressed block, calculated with its total mass as 100%, comprises: 15%-50% of the iron-containing material, 42%-79% of the biomass carbon powder and 6%-8% of the binder;

[0057] The low carbon ratio cold pressed block, with its total mass as 100%, comprises: 50%-89% of the iron-containing material, 1%-42% of the biomass carbon powder and 8%-10% of the adhesive.

[0058] In an optional embodiment, the compressive strength of the high carbon ratio cold pressed block, the medium carbon ratio cold pressed block and the low carbon ratio cold pressed block is not less than 1500N.

[0059] The compressive strength of the cold pressed block is ensured to be above 1500N, thereby ensuring that the biochar-iron-containing material pressed block can enter the molten steel to participate in the reaction.

[0060] In an optional embodiment, the cold briquetting converter heating agent satisfies one or more of the following conditions:

[0061] A. The binder comprises sodium silicate and / or steelmaking sludge;

[0062] Sodium silicate is conducive to the rapid solidification of cold pressed pellets and obtains strong compressive strength. Its dosage can be greatly reduced compared with the use of inferior adhesives such as water glass, cement, asphalt, etc., and the silicon dioxide impurities brought in are reduced, which is conducive to the smooth operation of converter high scrap ratio smelting.

[0063] Steelmaking sludge contains a large amount of sodium silicate, which can be used instead of pure sodium silicate.

[0064] B. The total iron content of the iron-containing material is 40%-60%;

[0065] Total iron is abbreviated as TFe. The mass fraction of various iron-containing materials is expressed as. The calculation formula of total iron in iron-containing materials is:

[0066] TFe (含铁物料) =Wt (渣铁) ·TFe (渣铁) +Wt (氧化铁皮) ·TFe (氧化铁皮) +Wt (烧结矿) ·TFe (烧结矿) +...

[0067] Optionally, the total iron content of the iron-containing material may be 40%, 45%, 50%, 55%, 60% or any value between 40% and 60%;

[0068] C. The biomass charcoal powder is obtained by pyrolyzing one or more of corn stalks, wheat stalks, and wood chips as raw materials.

[0069] The present application also provides a method for preparing the cold pressed briquette converter heating agent, comprising:

[0070] The iron-containing material, the biomass carbon powder and the binder are mixed and then pressed into the cold-pressed briquette converter heating agent.

[0071] In an optional embodiment, the iron-containing material is pre-crushed into a powdery iron-containing material with a fineness of 100-200 mesh before use;

[0072] and / or,

[0073] The linear pressure of the pressing is 40-150 kN / cm.

[0074] Optionally, the pressing line pressure can be 40kN / cm, 50kN / cm, 60kN / cm, 70kN / cm, 80kN / cm, 90kN / cm, 100kN / cm, 110kN / cm, 120kN / cm, 130kN / cm, 140kN / cm, 150kN / cm or any value between 40-150kN / cm.

[0075] The present application also provides a converter smelting method, comprising: adding the cold pressed block converter heating agent during the converter smelting process.

[0076] In an optional embodiment, the cold pressed briquette converter heating agent includes high carbon ratio cold pressed briquettes, medium carbon ratio cold pressed briquettes and low carbon ratio cold pressed briquettes;

[0077] The joining satisfies one or more of the following conditions:

[0078] (1) adding the high carbon ratio cold pressed blocks in the early stage of converter smelting, the added amount being 60-90wt% of the total added amount;

[0079] Optionally, the high carbon ratio cold pressed blocks are added in the early stage of converter smelting, and the added amount can be 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 85wt%, 90wt% or any value between 60-90wt% of the total added amount;

[0080] (2) When the heat is sufficient during the converter smelting process, that is, the temperature measured by the TSC auxiliary gun is greater than 1580°C, but dry-out occurs in the middle stage, the low carbon ratio cold pressed block is added; when the heat is insufficient during the converter smelting process, that is, the temperature measured by the TSC auxiliary gun is less than 1580°C, but dry-out occurs in the middle stage, the medium carbon ratio cold pressed block is added;

[0081] (3) When the final carbon pulling temperature of the converter is too high, that is, the temperature measured by the TSO auxiliary gun is greater than 1650° C., the low carbon ratio cold pressed blocks are added;

[0082] The cold pressed blocks are mainly added to the converter in 2-3 times, which are the early stage and middle stage of converter smelting. When the terminal overblowing occurs, the cold pressed blocks can be added again.

[0083] (4) The relationship between the mass content of the biomass carbon powder in the high carbon ratio cold pressed block and the scrap steel ratio of the converter smelting is:

[0084] When the scrap steel ratio is 20-30%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 79-85%; when the scrap steel ratio is 30-35%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 85-90%; when the scrap steel ratio is 35-40%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 85-95%; when the scrap steel ratio is 40-45%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 90-95%;

[0085] Table 1 Relationship between biomass carbon content and scrap steel ratio in high carbon ratio cold pressed briquettes

[0086]

[0087] The mass content of biomass carbon powder in high carbon ratio cold pressed briquettes increases with the increase of scrap steel ratio. Basically, if the scrap steel ratio increases by 5%, the mass content of biomass carbon powder in the pressed briquettes will increase by 5%. At the same time, it can also be adjusted appropriately according to actual conditions.

[0088] (5) During the converter smelting process, top blowing O 2 Strength: 3.10-3.80Nm 3 / (min·t), bottom blowing intensity is 0.02-0.08Nm 3 / (min·t), bottom blowing gas is Ar, N 2 or CO 2 One of them.

[0089] Optional, top blowing O 2 Strength can be 3.10Nm 3 / (min·t),3.20Nm 3 / (min·t),3.30Nm 3 / (min·t),3.40Nm 3 / (min·t),3.50Nm 3 / (min·t),3.60Nm 3 / (min·t),3.70Nm 3 / (min·t),3.80Nm 3 / (min·t) or 3.10-3.80Nm 3 / (min·t) any value between, bottom blowing intensity can be 0.02Nm 3 / (min·t), 0.03Nm 3 / (min·t), 0.04Nm 3 / (min·t), 0.05Nm 3 / (min·t), 0.06Nm 3 / (min·t), 0.07Nm 3 / (min·t), 0.08Nm 3 / (min·t) or 0.02-0.08Nm 3 / (min·t) is any value between .

[0090] The present application also provides a converter smelting system, comprising: a mixer, a briquetting device, a silo and a converter;

[0091] The mixer is used to mix the raw materials of the cold-pressed briquette converter heating agent, the briquetting device is used to press the raw materials into the cold-pressed briquette converter heating agent, the silo is used to store the cold-pressed briquette converter heating agent from the briquetting device and add the cold-pressed briquette converter heating agent to the converter, and the converter is used for smelting.

[0092] In an optional embodiment, the silo includes a high carbon ratio cold briquette silo, a medium carbon ratio cold briquette silo and a low carbon ratio cold briquette silo;

[0093] In order to ensure smooth furnace conditions during the smelting process, three cold pressed briquette silos are used to store high carbon ratio cold pressed briquettes, medium carbon ratio cold pressed briquettes and low carbon ratio cold pressed briquettes respectively.

[0094] and / or,

[0095] The converter smelting system also includes a pulverizer for pulverizing iron-containing materials.

[0096] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0097] Example 1

[0098] like Figure 1 As shown, this embodiment provides a converter smelting system, which specifically includes: a crushing machine 1, a mixer 2, a briquetting device 3, a high-level silo for cold-pressed blocks 4 (a high-level silo for cold-pressed blocks with a high carbon ratio 4-1, a high-level silo for cold-pressed blocks with a medium carbon ratio 4-2, and a high-level silo for cold-pressed blocks with a low carbon ratio 4-3) and a converter 5.

[0099] In view of the converter smelting production of a 150t converter in a certain factory, the scrap steel ratio is 38%. A biomass charcoal and iron-containing material briquette is used as a converter heating agent. The preparation method and smelting method are as follows:

[0100] S1. The iron-containing materials in this plant are slag iron and iron ore, and the total iron content of the two is: Wt (渣铁) =16%~19%,Wt (铁矿石) =50%~58%. The total iron content of the iron-containing material is 48%. According to the formula, the addition ratio of slag iron is 0~24%, and the addition ratio of iron ore is 74%~94%.

[0101] The iron-containing material is crushed in the crushing machine 1 to form a powdery iron-containing material with a fineness of 100-200 meshes.

[0102] S2. Add the powdered iron-containing material, biomass powder and binder into the mixer 2 and stir for 2-3 minutes to fully mix.

[0103] According to the different types of cold pressed briquettes produced, there are three types of cold pressed briquettes, namely: high carbon ratio cold pressed briquettes, medium carbon ratio cold pressed briquettes and low carbon ratio cold pressed briquettes.

[0104] Because the scrap steel ratio of converter smelting is 38%, it can be found from Table 1 that the mass proportion of biomass charcoal with high carbon ratio cold pressed briquettes is 85% to 95%. According to the actual production of the plant, the material ratio of the three types of cold pressed briquettes is shown in Table 2:

[0105] Table 2 Main material proportions of 150t converter high scrap ratio cold briquetting

[0106] High carbon ratio cold pressed briquettes Medium carbon cold pressed briquettes Low carbon ratio cold pressed briquettes Iron-containing materials 1％～10％ 15～50％ 50～82％ Biochar 85％～95％ 42％～79％ 1％～42％ Adhesives 4％～5％ 6％～8％ 8％～10％

[0107] Sodium silicate accounts for about 87wt% of the binder raw material steelmaking sludge.

[0108] S3. The mixed briquetting raw materials are loaded into the briquetting device 3 and pressed into cold briquetting. The linear pressure of the briquetting machine is 85 kN / cm, and the compressive strength of the cold briquetting is guaranteed to be above 1800N.

[0109] S4. The pressed cold pressed blocks are respectively loaded into the high carbon ratio, medium carbon ratio and low carbon ratio cold pressed block high position silo 4 for standby use according to the different ratios of iron-containing materials and biomass carbon.

[0110] S5. The scrap steel ratio of the converter is 38%. In the early stage of smelting, high carbon ratio cold pressed blocks are added through the high carbon ratio cold pressed block high-level silo 4-1 to provide heat for the converter 5. The amount of cold pressed blocks added in the early stage is about 80% to 88% of the total amount added, and the added mass is between 1.7t and 1.9t.

[0111] There is sufficient heat during the converter smelting process, and there is a situation of drying out in the middle of the furnace. Low-carbon ratio cold pressed blocks are added to the slag through the low-carbon ratio cold pressed block high-level silo 4-3 to ensure the removal of impurity elements. The amount of low-carbon ratio cold pressed blocks added is about 12% to 20% of the total amount added, and the added mass is between 200kg and 475kg.

[0112] Normal blowing completes converter smelting, and during the process, the converter top blowing is controlled 2 Strength: 3.30Nm 3 / (min·t), bottom blowing intensity is 0.04Nm 3 / (min·t), where the bottom blowing gas is CO 2 .

[0113] The smelting results show that after adopting the heating agent briquetting method of this embodiment, the converter smelting process is stable, the number of abnormal end points is reduced, and the utilization rate of the heating agent is significantly increased. Among them: the converter scrap steel ratio is 38%, and the CO 2 Emissions are reduced by 360kg. Compared with using coke as a heating agent, the amount of coke used per ton of steel can be reduced by 98kg.

[0114] Example 2

[0115] For the converter smelting production of a 200t converter in a certain plant, the scrap steel ratio is 32%. A method of using a biomass charcoal and iron-containing material briquette as a converter heating agent is as follows:

[0116] S1. The iron-containing materials in this plant are iron ore, sintered ore and steelmaking sludge, and their total iron contents are: Wt (铁矿石) =48%~55%, Wt (烧结矿) =60%~64%,Wt (炼钢污泥) =22%~28%. The total iron content of the iron-containing material is 55%, the addition ratio of iron ore is 0~90%, the addition ratio of sintered ore is 0~78%, and the addition ratio of steelmaking sludge is 0~14%.

[0117] The iron-containing material is crushed in the crushing machine 1 to form a powdery iron-containing material with a fineness of 100-200 meshes.

[0118] S2. Add the powdered iron-containing material, biomass powder and binder into the mixer 2 and stir for 2-3 minutes to fully mix.

[0119] According to the different types of cold pressed briquettes produced, there are three types of cold pressed briquettes, namely: high carbon ratio cold pressed briquettes, medium carbon ratio cold pressed briquettes and low carbon ratio cold pressed briquettes.

[0120] Because the scrap steel ratio of converter smelting is 32%, it can be found from Table 1 that the mass proportion of biomass charcoal of high carbon ratio cold pressed briquettes is 85% to 90%. According to the actual production of the plant, the material ratio of the three types of cold pressed briquettes is shown in Table 3:

[0121] Table 3 Main material proportions of 200t converter high scrap ratio cold pressed briquettes

[0122] High carbon ratio cold pressed briquettes Medium carbon cold pressed briquettes Low carbon ratio cold pressed briquettes Iron-containing materials 6％～10％ 15～50％ 50～82％ Biochar 85％～90％ 42％～79％ 1％～42％ Adhesives 4％～5％ 6％～8％ 8％～10％

[0123] The binder raw material, steelmaking sludge, contains about 85 wt% sodium silicate.

[0124] S3. The mixed briquetting raw materials are loaded into the briquetting device 3 and pressed into cold briquetting. The linear pressure of the briquetting machine is 90 kN / cm, and the compressive strength of the cold briquetting is guaranteed to be above 1900N.

[0125] S4. The pressed cold pressed blocks are respectively loaded into the high carbon ratio, medium carbon ratio and low carbon ratio cold pressed block high position silo 4 for standby use according to the different ratios of iron-containing materials and biomass carbon.

[0126] S5. The scrap steel ratio of the converter is 32%. In the early stage of smelting, high carbon ratio cold pressed blocks are added through the high carbon ratio cold pressed block high-level silo 4-1 to provide heat for the converter 5. The amount of cold pressed blocks added in the early stage is about 80% to 85% of the total amount added, and the added mass is between 1.8t and 2.2t.

[0127] There is insufficient heat during the converter smelting process, and there is a situation of drying out in the middle of the furnace. Low carbon ratio cold pressed blocks are added to the high-level silo 4-2 of the medium carbon ratio cold pressed blocks to slag and ensure the removal of impurity elements. The amount of medium carbon ratio cold pressed blocks added is about 15% to 20% of the total amount added, and the added mass is between 270kg and 440kg.

[0128] Normal blowing completes converter smelting, and during the process, the converter top blowing is controlled 2 Strength: 3.50Nm 3 / (min·t), bottom blowing intensity is 0.05Nm 3 / (min·t), where the bottom blowing gas is CO 2 .

[0129] The smelting results show that after adopting the heating agent briquetting method of this embodiment, the converter smelting process is stable, the number of abnormal end points is reduced, and the utilization rate of the heating agent is significantly increased. Among them: the converter scrap steel ratio is 32%, and the CO 2 Emissions are reduced by 283kg. Compared with using coke as a heating agent, the amount of coke used per ton of steel can be reduced by 77kg.

[0130] Example 3

[0131] For the converter smelting production of a 300t converter in a certain plant, the scrap steel ratio is 42%. A method of using a biomass charcoal and iron-containing material briquette as a converter heating agent is as follows:

[0132] S1. The iron-containing materials in this plant are iron ore and sintered ore, and the total iron content of the two is: Wt (铁矿石) =45%~52%, Wt (烧结矿) =62%~66%. The total iron content of the iron-containing material is taken as 60%. According to the formula, the addition ratio of iron ore is 11%~42%, and the addition ratio of sintered ore is 58%~99%.

[0133] The iron-containing material is crushed in the crushing machine 1 to form a powdery iron-containing material with a fineness of 100-200 meshes.

[0134] S2. Add the powdered iron-containing material, biomass powder and binder into the mixer 2 and stir for 2-3 minutes to fully mix.

[0135] According to the different types of cold pressed briquettes produced, there are three types of cold pressed briquettes, namely: high carbon ratio cold pressed briquettes, medium carbon ratio cold pressed briquettes and low carbon ratio cold pressed briquettes.

[0136] Because the scrap steel ratio of converter smelting is 42%, it can be found from Table 1 that the mass proportion of biomass charcoal of high carbon ratio cold pressed briquettes is 90% to 95%. According to the actual production of the plant, the material ratio of the three types of cold pressed briquettes is shown in Table 4:

[0137] Table 4 Main material proportions of 300t converter high scrap ratio cold pressed briquettes

[0138] High carbon ratio cold pressed briquettes Medium carbon cold pressed briquettes Low carbon ratio cold pressed briquettes Iron-containing materials 1％～5％ 15～50％ 50～82％ Biochar 90％～95％ 42％～79％ 1％～42％ Adhesives 4％～5％ 6％～8％ 8％～10％

[0139] The binder raw material, steelmaking sludge, contains about 82 wt% sodium silicate.

[0140] S3. The mixed briquetting raw materials are loaded into the briquetting device 3 and pressed into cold briquetting. The linear pressure of the briquetting machine is 95 kN / cm, and the compressive strength of the cold briquetting is guaranteed to be above 1900N.

[0141] S4. The pressed cold pressed blocks are respectively loaded into the high carbon ratio, medium carbon ratio and low carbon ratio cold pressed block high position silo 4 for standby use according to the different ratios of iron-containing materials and biomass carbon.

[0142] S5. The scrap steel ratio of the converter is 42%. In the early stage of smelting, high carbon ratio cold pressed blocks are added through the high-level silo 4-1 to provide heat for the converter 5. The amount of cold pressed blocks added in the early stage is about 86% to 91% of the total amount added, and the added mass is between 3.5t and 4.3t.

[0143] There is insufficient heat during the converter smelting process, and there is a situation of drying out in the middle of the furnace. Low carbon ratio cold pressed blocks are added to the high-level silo 4-2 of medium carbon ratio cold pressed blocks to slag and ensure the removal of impurity elements. The amount of medium carbon ratio cold pressed blocks added is about 9% to 14% of the total amount added, and the added mass is between 315kg and 600kg.

[0144] During the smelting process, the final converter temperature of some furnaces is slightly higher. About 300 kg of low-carbon ratio cold pressed blocks are added through the low-carbon ratio cold pressed block high-level silo 4-3 to balance the residual heat at the converter end.

[0145] Normal blowing completes converter smelting, and during the process, the converter top blowing is controlled 2 Strength: 3.70Nm 3 / (min·t), bottom blowing intensity is 0.06Nm 3 / (min·t), where the bottom blowing gas is Ar.

[0146] The smelting results show that: after adopting the heating agent briquetting method of this embodiment, the converter smelting process is stable, the number of abnormal end points is reduced, and the utilization rate of the heating agent is significantly increased. Among them: the converter scrap steel ratio is 42%, and the CO 2 Emissions are reduced by 452kg. Compared with using coke as a heating agent, the amount of coke used per ton of steel can be reduced by 222kg.

[0147] Comparative Example 1

[0148] For the converter smelting production of a 210t converter in a certain factory, the scrap steel ratio is 30%. The traditional converter smelting process is adopted, and only coke is added at the furnace mouth as a heating agent to supplement the heat for converter smelting:

[0149] The density of coke blocks is relatively small, and the added heating agent is basically suspended on the surface of the molten steel. Statistically, the coke utilization rate is only about 20%.

[0150] When the scrap steel ratio is 30%, the amount of coke added per ton of steel is 18 kg, and the total amount of coke added is 3.0 to 3.8 tons. The loss of coke is too great because the heat of the coke cannot be fully absorbed by the molten steel.

[0151] When using coke as a converter heating agent in the smelting process, the oxygen consumption per ton of steel is 76.10Nm 3 , oxygen consumption per ton of steel increases by about 20Nm 3 .

[0152] Normal blowing completes converter smelting, and during the process, the converter top blowing is controlled 2 Strength: 3.50Nm 3 / (min·t), bottom blowing intensity is 0.05Nm 3 / (min·t), where the bottom blowing gas is N 2 .

[0153] The smelting results show that when coke is used as a heating agent, the utilization rate of the heating agent decreases with the increase of scrap steel ratio, and the amount of the heating agent increases significantly. When the scrap steel ratio is 30%, the amount of coke used is about 4 times that of biomass charcoal-iron-containing material cold pressed blocks. 2Emissions increased by 51kg, oxygen consumption per ton of steel increased by 20Nm 3 The smelting time of each furnace increased by about 5.7 minutes, which seriously slowed down the smelting rhythm.

[0154] Comparative Example 2

[0155] For the converter smelting production of a certain factory's 150t converter, the scrap steel ratio is 28%. A biomass charcoal and iron-containing material briquette is used as a converter heating agent. The method is as follows: only in the early stage of smelting, 260kg of high-carbon ratio cold briquette is added as a heating agent to supplement the heat for converter smelting.

[0156] There was insufficient heat during the converter smelting process. The temperature measured by the TSC sub-lance was 1542°C. Drying out occurred in the middle of the furnace. Heat was increased only by increasing the oxygen flow rate and promoting the carbon-oxygen reaction, resulting in severe splashing during the smelting process.

[0157] When the converter smelting reached the end point, the temperature measured by the TSO sub-gun was 1598℃, which was 22℃ lower than the set target minimum temperature. The heat was increased on site by spot blowing and burning the iron.

[0158] For the smelting process, top blowing O 2 Strength: 4.20Nm 3 / (min·t), and the point blowing operation was added in the later period, which made the smelting process not smooth and increased the blowing time.

[0159] The smelting results show that when only high carbon ratio cold pressed blocks are used as heating agents in the early stage, and other cold pressed blocks are not added according to the smelting process to adjust the converter smelting heat, the converter blowing time will increase by 3.2 minutes and the oxygen consumption per ton of steel will increase by 8.5 Nm 3 , because of splashing and spot blowing operations, the iron loss in the slag increases by 3.5kg per ton of steel.

[0160] According to the above method, similar phenomena will occur when low carbon ratio cold pressed blocks or medium carbon ratio cold pressed blocks are used alone.

[0161] Comparative Example 3

[0162] For the converter smelting production of a certain factory's 120t converter, the scrap steel ratio is 25%. A biomass charcoal and iron-containing material briquette is used as a converter heating agent. The method is as follows: in the early stage of converter smelting, no high-carbon ratio cold briquette is added as a heating agent to supplement heat for converter smelting. The scrap steel is only preheated by shaking the furnace after adding the scrap steel.

[0163] During the early blowing process, the start time of the carbon-oxygen reaction in the molten pool is delayed, the intensity of the carbon-oxygen reaction is weakened, and the oxygen utilization rate in the smelting process is reduced.

[0164] During the converter smelting process, the heat was seriously insufficient. The temperature measured by the TSC auxiliary gun was 1520℃. There was a dry-out situation in the middle of the furnace. At this time, 250kg of high carbon ratio cold pressed blocks were added as a heating agent to supplement the heat for converter smelting. Then, the heat was increased by increasing the oxygen flow rate to promote the carbon-oxygen reaction. Because the molten pool temperature was too low, the high carbon ratio cold pressed blocks dissolved slowly, and the converter heating rate slowed down.

[0165] When the converter smelting reached the end point, the temperature measured by the TSO sub-gun was 1580℃, which was 40℃ lower than the set target minimum temperature. The heat was increased on site by blowing and burning the iron for a long time.

[0166] For the smelting process, top blowing O 2 Strength: 4.15Nm 3 / (min·t), and the point blowing operation was added in the later period, which made the smelting process not smooth and increased the blowing time.

[0167] The smelting results show that when high carbon ratio cold pressed blocks are added in the middle and late stages of smelting, the melting of the scrap steel in the early stage will be uneven, the carbon-oxygen reaction will start to be delayed and the reaction intensity will be reduced, the converter blowing time will increase by 5.4 minutes, and the oxygen consumption per ton of steel will increase by 10.3Nm 3 Because the spot blowing operation causes the iron loss in the slag to increase by 2.5kg per ton of steel, and because a small amount of scrap steel is not melted, the residual scrap steel adheres to the bottom of the furnace, causing the bottom of the furnace to rise and the capacity ratio of the converter to decrease.

[0168] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A cold pressed briquette converter heating agent, characterized in that: The raw materials are calculated based on the total mass as 100%, including: Iron-containing material 1%-89%, biomass carbon powder 1%-95% and binder 4%-10%; The iron-containing material includes one or more of iron oxide scale, slag iron, sintered ore and iron ore.

2. The cold pressed briquette converter warming agent according to claim 1, characterized in that: The cold pressed briquette converter heating agent includes one or more of high carbon ratio cold pressed briquette, medium carbon ratio cold pressed briquette and low carbon ratio cold pressed briquette; The high carbon ratio cold pressed block, calculated with its total mass as 100%, comprises: 1%-15% of the iron-containing material, 79%-95% of the biomass carbon powder and 4%-6% of the binder; The medium carbon ratio cold pressed block, calculated with its total mass as 100%, comprises: 15%-50% of the iron-containing material, 42%-79% of the biomass carbon powder and 6%-8% of the binder; The low carbon ratio cold pressed block, with its total mass as 100%, comprises: 50%-89% of the iron-containing material, 1%-42% of the biomass carbon powder and 8%-10% of the adhesive.

3. The cold pressed briquette converter warming agent according to claim 2, characterized in that: The compressive strength of the high carbon ratio cold pressed block, the medium carbon ratio cold pressed block and the low carbon ratio cold pressed block is not less than 1500N.

4. The cold pressed briquette converter warming agent according to any one of claims 1 to 3, characterized in that: One or more of the following conditions are met: A. The binder comprises sodium silicate and / or steelmaking sludge; B. The total iron content of the iron-containing material is 40%-60%; C. The biomass charcoal powder is obtained by pyrolyzing one or more of corn stalks, wheat stalks, and wood chips as raw materials.

5. A method for preparing a cold pressed briquette converter warming agent according to any one of claims 1 to 4, characterized in that: include: The iron-containing material, the biomass carbon powder and the binder are mixed and then pressed into the cold-pressed briquette converter heating agent.

6. The method for preparing the cold briquetting converter warming agent according to claim 5, characterized in that: The iron-containing material is crushed into a powdery iron-containing material with a fineness of 100-200 mesh before use; and / or, The linear pressure of the pressing is 40-150 kN / cm.

7. A converter smelting method, characterized in that: include: The cold pressed briquette converter heating agent according to any one of claims 1 to 4 is added during converter smelting.

8. The converter smelting method according to claim 7, characterized in that: The cold pressed briquette converter heating agent includes high carbon ratio cold pressed briquette, medium carbon ratio cold pressed briquette and low carbon ratio cold pressed briquette; The joining satisfies one or more of the following conditions: (1) adding the high carbon ratio cold pressed blocks in the early stage of converter smelting, the added amount being 60-90wt% of the total added amount; (2) When the heat is sufficient during the converter smelting process, that is, the temperature measured by the TSC auxiliary gun is greater than 1580°C, but dry-out occurs in the middle stage, the low carbon ratio cold pressed block is added; when the heat is insufficient during the converter smelting process, that is, the temperature measured by the TSC auxiliary gun is less than 1580°C, but dry-out occurs in the middle stage, the medium carbon ratio cold pressed block is added; (3) When the final carbon pulling temperature of the converter is too high, that is, the temperature measured by the TSO auxiliary gun is greater than 1650° C., the low carbon ratio cold pressed blocks are added; (4) The relationship between the mass content of the biomass carbon powder in the high carbon ratio cold pressed briquettes and the scrap steel ratio of the converter smelting is: When the scrap steel ratio is 20-30%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 79-85%; when the scrap steel ratio is 30-35%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 85-90%; when the scrap steel ratio is 35-40%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 85-95%; when the scrap steel ratio is 40-45%, the mass content of the biomass carbon powder in the high carbon ratio cold pressed block is 90-95%; (5) During the converter smelting process, the top blowing O2 intensity is 3.10-3.80Nm 3 / (min·t), bottom blowing intensity is 0.02-0.08Nm 3 / (min·t), the bottom blowing gas is one of Ar, N2 or CO2.

9. A converter smelting system, characterized in that: include: Mixers, briquetting units, silos and converters; The mixer is used to mix the raw materials of the cold-pressed briquette converter heating agent, the briquetting device is used to press the raw materials into the cold-pressed briquette converter heating agent, the silo is used to store the cold-pressed briquette converter heating agent from the briquetting device and add the cold-pressed briquette converter heating agent to the converter, and the converter is used for smelting.

10. The converter smelting system according to claim 9, characterized in that: The silos include a high carbon ratio cold pressed briquette silo, a medium carbon ratio cold pressed briquette silo and a low carbon ratio cold pressed briquette silo; and / or, The converter smelting system also includes a pulverizer for pulverizing iron-containing materials.

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