Converter slag smelting method and converter slag smelting production line

Abstract

The invention discloses a converter slag smelting method and a converter slag smelting production line, which belongs to the technical field of converter slag smelting, and comprises the following steps: step 1, pressing the high-basicity sintered ore powder with a particle size of less than 10 mm screened out in the iron-making blast furnace process into a powder-coated scrap steel briquette by a scrap steel briquetting device; step 2, pouring out the slag after the converter taps out steel, and loading the powder-coated scrap steel briquette into the converter according to the total iron consumption; step 3, adding molten iron into the converter; step 4, shaking the converter body straight, and adding lime blocks in an amount of 1 / 3 of the total slag-making solvent; step 5, starting high-gun position blowing at the lower gun to prepare for blowing slag. The beneficial effects of the invention are: by pressing the high-basicity sintered ore powder into the powder-coated scrap steel briquette and adding it into the converter slag, the slag-making path and basicity control are optimized, the converter slag-making rate is accelerated, and the problem that the fine powder will be sucked away by the smoke hood airflow when adding high-basicity sintered ore powder into the converter slag is solved.

Description

Technical Field

[0001] The invention relates to the technical field of converter slag making and smelting, and in particular to a converter slag making and smelting method and a converter slag making and smelting production line. Background Art

[0002] Slag making is an essential part of the steelmaking and ironmaking process. Steelmaking and ironmaking require the reduction of impurities in steel. These impurities are separated and enter the slag. Because the slag has a light specific gravity and floats on the molten steel, it is easier to remove. In addition, the slag can protect the molten steel from direct contact with the atmosphere. Slag making is the addition of steelmaking substances called slag-forming agents, such as calcium fluoride or calcium oxide, in the steelmaking process to form slag. The difference between steel and iron is the different amount of impurities they contain. In the steelmaking process, the carbon content must be reduced, and the content of sulfur, phosphorus, etc. must also be reduced. This requires "slag making" to remove them in the form of slag. Common slag-forming agents are: converter low-carbon slag-forming agent, low-carbon submerged arc slag-forming agent, and medium-high carbon submerged arc slag-forming agent.

[0003] Converter slag is mainly produced by the oxidation of Si, P, Mn, and Fe in molten iron and the dissolution of added lime. Others include added dolomite, blast furnace slag brought into the furnace, corroded furnace lining, etc. The removal of harmful sulfur and phosphorus in molten iron during converter smelting is even more important, which directly affects the quality of molten steel. Exceeding internal control standards and national standards will lead to scrap steel quality accidents. Low-cost clean steel theory is the economic and technological development trend of the modern metallurgical industry. Reducing the sulfur and phosphorus content of HRB400E high-strength earthquake-resistant steel bars is necessary to ensure that the cold bending and extension tests of high-strength earthquake-resistant steel bars are qualified. Optimizing the basicity of converter slag by adding powdered sintered ore is the optimal cost-effective route for "iron slag formation" to control harmful sulfur and phosphorus elements in HRB400E steel: the FeO content in the sintered ore powder is about 11%, and the calcium ferrite content is about 25%. At the same time, the fine powder particles accelerate the converter slag making rate, which is a necessary way to achieve high-quality high-strength earthquake-resistant steel bars.

[0004] Desulfurization: [FeS] + (CaO) = (CaS) + (FeO) The slag has a high (CaO) content and a low (FeO) content, which is conducive to the desulfurization reaction; the bottleneck problem is that due to the oxygen supply in the molten pool, the furnace is in an oxidizing atmosphere, the (FeO) content in the slag is not low, and the converter desulfurization capacity is limited. The desulfurization effect is improved by making full use of the thermodynamic conditions of desulfurization during the blowing process, slagging well at high temperature, ensuring that lime is dissolved into slag, and optimizing the technical route of increasing basicity or increasing slag volume.

[0005] Dephosphorization: 2[P]+5(FeO)+n(CaO)=(nCaO.P2O5)+5FeThe high content of (FeO) and (CaO) in the slag is conducive to the removal of phosphorus. In the later stage of blowing, the slag basicity and (FeO) are well controlled to stabilize phosphorus in the slag and prevent rephosphorization.

[0006] By adding powdered high-basicity sintered ore, a high-FeO slag formation pathway is selected, and the FeO content in the slag is kept high during the blowing process, and a high lance position or bottom blowing with low gas supply intensity is adopted. The slag composition changes maintain good fluidity in the low melting point area, the lime dissolves quickly, and the basicity increases rapidly, achieving the purpose of removing harmful sulfur and phosphorus elements.

[0007] In the prior art, sintered ore with a particle size of 10mm-40mm is added to the converter slag making, and there is no case of adding powdered sintered ore with a particle size of less than 10mm at the charging port above the converter mouth. The fine sintered ore powder will be sucked away by the smoke hood airflow, and the sintered ore powder with a size of less than 10mm that is vibrated and screened out from the ore trough of the iron-making blast furnace cannot participate in the blast furnace reduction smelting, which will affect the permeability of the blast furnace charge column. At the same time, it cannot be added into the converter furnace to participate in slag making according to the normal method of adding slag-making agents for converter steelmaking. Summary of the invention

[0008] In order to overcome the problem that there is no case in the prior art to add powdered sintered ore with a diameter less than 10 mm at the charging port above the converter furnace mouth, the fine sintered ore powder will be sucked away by the airflow of the smoke hood, and the sintered ore powder with a diameter less than 10 mm screened by the ore trough of the iron-making blast furnace cannot be used for blast furnace reduction smelting, which will affect the air permeability of the blast furnace charge column, and at the same time, it cannot be added into the converter furnace to participate in slag making according to the normal converter steelmaking slag making agent adding method. The present invention provides a converter slag making and smelting method, wherein the first step is to add the particles screened out from the iron-making blast furnace process to the converter furnace, and the fine sintered ore powder with a diameter less than 10 mm is sucked away by the airflow of the smoke hood, and the sintered ore powder with a diameter less than 10 mm screened by the ore trough of the iron-making blast furnace cannot be used for blast furnace reduction smelting, which will affect the air permeability of the blast furnace charge column, and at the same time, it cannot be added into the converter furnace to participate in slag making according to the normal converter steelmaking slag making agent adding method. The high-basicity sintered ore powder with a fineness below 10mm is pressed into powder-coated scrap steel briquettes by a powder-coated scrap steel briquetting device; step two, pouring out the slag after the converter is tapped, and loading an appropriate amount of powder-coated scrap steel briquettes into the converter according to the total iron consumption, and the powder-coated scrap steel briquettes are sampled and sheared by a shearing device before adding; step three, adding molten iron into the converter; step four, shaking the converter body straight, and adding lime blocks in an amount of 1 / 3 of the total slag-making solvent; step five, lowering the gun and starting high-gun position blowing to prepare for blowing and slag making.

[0009] By adding powdered sintered ore to make slag in the converter, a new way of utilizing blast furnace waste to form "iron slag" in the converter is achieved, which has practical and strong economic value, and is a new way to achieve low-cost production of economical clean steel. By using light and thin scrap steel to press high-basicity sintered ore powder into powder-coated scrap steel briquettes to participate in the slag making in the converter, the problem of adding high-basicity sintered ore powder with a particle size of less than 10 mm in the converter slag making is solved, and the fine sintered ore powder will be sucked away by the smoke hood airflow and cannot be added to the converter furnace to participate in slag making according to the normal method of adding slag-making agents for converter steelmaking is solved.

[0010] Preferably, in step 1, the powder-coated scrap steel briquettes account for 10-20% of the total amount of slag-making materials, and the powder-coated scrap steel briquettes are cylindrical with a diameter of 300-400 mm and a height of 150-250 mm.

[0011] Preferably, in step 1, the high-basicity sintered ore powder with a particle size of less than 10 mm is vibrated and screened from the ore trough of the iron-making blast furnace, pressed into powder-coated scrap steel briquettes through scrap steel, and loaded into the converter using a scrap steel bucket.

[0012] Preferably, in terms of mass percentage, the FeO content of the high basicity sintered ore powder in step 1 is 10-12%, and the calcium ferrite content is 22-28%.

[0013] Preferably, in step 3, the temperature of the molten iron when entering the furnace is ≥1250°C, and the amount of slag in the molten iron is not more than 0.5%.

[0014] Preferably, in terms of mass percentage, the contents of the elements in the molten iron in step 3 meet the following conditions:

[0015] The C content is not less than 3.5%, the Si content is 0.45-0.85%, the P content is not more than 0.15%, the S content is not more than 0.07%, and the rest is Fe.

[0016] Preferably, the oxygen lance nozzle in the blowing in step 5 is a five-hole Laval nozzle, the oxygen lance cooling water flow rate is ≥230m3 / h, and the blowing time is controlled at 1-3min.

[0017] Preferably, the blowing in step five adopts a constant pressure variable gun position operation. Within 3 minutes of blowing, the scrap steel on the surface of the briquette melts, and the powdered sintered ore is stirred by the oxygen flow of the oxygen lance during the floating process to fully react chemically with harmful impurities in the molten iron to form slag. The oxygen pressure is controlled at 0.8-1.2MPa, and the basic gun position is 1800-2000mm, the fluctuating gun position is 1200-2600mm, and the gun position change amplitude is ≤200mm when the gun is lowered.

[0018] The present invention also discloses a converter slag smelting production line adopting the converter slag smelting method, comprising a powder core scrap steel briquetting device and a converter arranged in front and behind, the powder core scrap steel briquetting device comprising a support frame, a mold assembly and a briquetting mechanism, a mold assembly is arranged in the middle of the support frame, the mold assembly comprises a mold and a plurality of hydraulic push rods, and the plurality of hydraulic push rods are evenly distributed on the outer wall of the mold, the mold is a cylindrical mold and is spliced ​​by a plurality of semi-mold grooves arranged to match each other, the top of the support frame is provided with the briquetting mechanism, the briquetting mechanism comprises a track plate, a movable plate, a down-pressing assembly and a die rod assembly, a through opening is arranged in the middle of the top of the support frame and two parallel track plates are arranged on both sides of the opening, two movable plates are slidably installed between the two track plates, the down-pressing assembly and the die rod assembly are respectively installed on the two movable plates and can drive the down-pressing assembly and the die rod assembly to move along the track plate direction, the down-pressing assembly and the die rod assembly are arranged at a position above the mold, and a bottom support assembly is arranged at the bottom of the mold.

[0019] Powder-core scrap steel briquettes are produced through a special powder-core scrap steel briquetting device. With the alternating cooperation of the down-pressing assembly and the die rod assembly, the powder-core scrap steel briquettes can be quickly extruded and formed, which greatly improves the processing efficiency of the powder-core scrap steel briquettes and reduces the labor intensity of the staff.

[0020] The invention also includes a shearing device for shearing the powder-coated scrap steel briquette made by the powder-coated scrap steel briquette device, the shearing device includes a shearing frame, a moving trolley, a fixing assembly and a cutting assembly, a cutting fixing ring is arranged below the shearing frame, a plurality of evenly distributed cutting assemblies are arranged on the inner side of the cutting fixing ring, a track is arranged at the position below the plurality of cutting assemblies, the top of the track is connected with the moving trolley, a fixing assembly is arranged between the moving trolley and the shearing frame, the fixing assembly includes a hydraulic electric lifting rod, a supporting plate, a hydraulic cylinder and a lower pressing plate, two hydraulic electric lifting rods are installed on the top of the moving trolley, the tops of the two hydraulic electric lifting rods are connected with a supporting plate, a rotating assembly is arranged on the supporting plate and a powder-coated scrap steel briquette is arranged on the top of the supporting plate, the hydraulic cylinder is installed on the top of the shearing frame, the movable end of the hydraulic cylinder is provided with a rotatable lower pressing plate through the lower surface of the shearing frame, and an electromagnet for adsorbing the top of the powder-coated scrap steel briquette is arranged inside the lower pressing plate.

[0021] Before an appropriate amount of the powder core scrap steel briquettes enter the converter, they need to be sampled and cut by a shearing device, and then the internal scrap steel structure and the chemical composition of the core powder are extracted and tested to ensure that they meet the technical requirements.

[0022] Beneficial effects:

[0023] The beneficial effects produced by the technical solution of the present invention are as follows:

[0024] (1) By adding powdered sintered ore to the converter slag making, the blast furnace waste is applied to the new way of "iron slag making" in the converter, which has practical and strong economic value, and realizes a new way to produce economical clean steel at low cost. By using light and thin scrap steel to press high-basicity sintered ore powder into powder-coated scrap steel briquettes to participate in the converter slag making, the problem of adding high-basicity sintered ore powder with a particle size of less than 10 mm in the converter slag making is solved. The fine sintered ore powder will be sucked away by the smoke hood airflow and cannot be added to the converter furnace to participate in slag making according to the normal method of adding slag-making agents for converter steelmaking is solved.

[0025] (2) The control of slag oxidation and slag basicity during converter slag making was optimized, and the removal of harmful element phosphorus was solved in advance. Then the removal of harmful element sulfur was focused on, while maintaining a certain FeO content in the slag to prevent the slag from drying out and returning to phosphorus.

[0026] (3) The powder-coated scrap steel briquetting device is used to produce the powder-coated scrap steel briquetting. With the alternating cooperation of the lower pressing assembly and the die rod assembly, the powder-coated scrap steel briquetting can be quickly extruded and formed, which greatly improves the processing efficiency of the powder-coated scrap steel briquetting and reduces the labor intensity of the staff.

[0027] (4) The powder-core scrap steel briquettes are processed by a special shearing device, and the outer wall of the powder-core scrap steel briquettes can be cut at multiple points. At the same time, the rotating assembly arranged below the powder-core scrap steel briquettes can be controlled to rotate and cooperate with the cutting assembly to achieve circular cutting, which saves time and effort, greatly reduces the labor intensity of the staff, and greatly improves the cutting efficiency of the powder-core scrap steel briquettes. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, 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 invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a flow chart of the converter slag smelting method of the present invention;

[0030] Figure 2 It is a structural schematic diagram of a scrap steel briquetting device with powder core in a converter slag smelting production line of the present invention;

[0031] Figure 3 It is a partial structural schematic diagram of a briquetting mechanism of a powder cored scrap steel briquetting device in a converter slag smelting production line of the present invention;

[0032] Figure 4 It is a structural schematic diagram of a shearing device in a converter slag smelting production line of the present invention.

[0033] In the figure: 1. Support frame; 2. Mold; 3. Hydraulic push rod; 4. Block forming mechanism; 5. Bottom cover assembly; 6. Track plate; 7. Movable plate; 8. Down-pressing assembly; 9. Mold rod assembly; 10. Shear frame; 11. Track; 12. Moving trolley; 13. Hydraulic electric lifting rod; 14. Support plate; 15. Cutting assembly; 16. Hydraulic cylinder; 17. Down-pressing plate; 18. Electromagnet; 19. Cutting fixing ring; 20. Rotating assembly. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions 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. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. 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.

[0035] This implementation method uses powdered sintered ore to make converter slag, and uses blast furnace waste to apply to the new way of "iron slag formation" in the converter. It has practical and strong economic value, and realizes a new way to produce economical clean steel at low cost. By using light and thin scrap steel to press high-basicity sintered ore powder into powder-coated scrap steel briquettes to participate in converter slag making, it solves the problem that when adding high-basicity sintered ore powder with a particle size of less than 10mm in converter slag making, the fine sintered ore powder will be sucked away by the smoke hood airflow and cannot be added to the converter furnace to participate in slag making according to the normal converter steelmaking slag making agent addition method. The specific implementation method is as follows:

[0036] like Figure 1 As shown, a converter slag smelting method comprises the following steps:

[0037] Step S101, the high-basicity sintered ore powder with a particle size of less than 10 mm screened out in the ironmaking blast furnace process is pressed into powder-coated scrap steel briquettes by a powder-coated scrap steel briquetting device;

[0038] Step S102, after the converter taps out steel, the slag is dumped, and according to the total iron consumption, an appropriate amount of powder-cored scrap steel briquettes are loaded into the converter, and the powder-cored scrap steel briquettes are sent into the converter by the scrap steel bucket. Before adding, the powder-cored scrap steel briquettes are sampled and sheared by a shearing device.

[0039] Step S103, adding molten iron into the converter;

[0040] Step S104, straighten the converter body and add lime blocks in an amount equal to 1 / 3 of the total slag-making solvent;

[0041] Step S105, lower the lance and start high-lance blowing to prepare for blowing and slag making.

[0042] As a preferred embodiment, the powder-coated scrap steel briquette is composed of light and thin scrap steel, and the light and thin scrap steel is mostly recycled galvanized color-coated sheet crushed, and the pressing process of the powder-coated scrap steel briquette is completed by the device.

[0043] As a preferred embodiment, in step S101, the powder-cored scrap steel briquettes account for 10-20% of the total slag material, the powder-cored scrap steel briquettes are cylindrical, with a cylindrical diameter of 300-400 mm and a height of 150-250 mm. In terms of mass percentage, the FeO content of the high-basicity sintered ore powder is 10-12%, and the calcium ferrite content is 22-28%. During the random inspection in step S102, the shearing process of the powder-cored scrap steel briquettes is completed by a shearing device.

[0044] As a preferred embodiment, in step S103, the temperature of the molten iron when entering the furnace is ≥1250°C, the amount of slag in the molten iron is not more than 0.5%, and the content of each element in the molten iron in step S103 satisfies the following conditions by mass percentage:

[0045] The C content is not less than 3.5%, the Si content is 0.45-0.85%, the P content is not more than 0.15%, the S content is not more than 0.07%, and the rest is Fe.

[0046] As a preferred implementation, the calculation formula for the amount of lime added in step S104 is:

[0047]

[0048] Final slag ternary basicity:

[0049] CaO (effective)-----------The effective CaO content in lime.

[0050] W-------------Amount of molten iron (tons).

[0051] As a preferred embodiment, the process control during blowing is the same as that of conventional operation. In step S105, the blowing oxygen lance nozzle is a five-hole Laval nozzle, the cooling water flow rate of the oxygen lance is ≥230m3 / h, the blowing time is controlled at 1-3min, and the blowing adopts constant pressure variable lance position operation. Within 3 minutes of blowing, the scrap steel on the surface of the briquette melts, and the powdered sintered ore is stirred by the oxygen flow of the oxygen lance during the floating process to fully react chemically with harmful impurities in the molten iron and form slag. The oxygen pressure is controlled at 0.8-1.2MPa, and the basic lance position is 1800-2000mm, the fluctuating lance position is 1200-2600mm, and the lance position change amplitude is ≤200mm when the lance is lowered.

[0052] Sintered ore powder comes from the material under the sieve of the blast furnace high-rise vibrating screen, with 1mm-2mm particle size accounting for 40%, 3mm-6.3mm accounting for 35%, and 6.3mm-10mm accounting for 25%. The conventional treatment is to return it to the sintering process as recycled material for batching, mixing, firing, screening and other processes again, and then feed the blast furnace for ironmaking again. The self-recycling rate of the sintering process accounts for about 15%, which consumes carbon energy and affects the quality of the sintered ore.

[0053] The FeO content of sintered ore powder is about 11%, and the calcium ferrite content is about 25%. At the same time, the fine powder particles accelerate the slag-making rate of the converter. This is the biggest application prospect of powdered sintered ore in steel enterprises. However, there are problems: the negative pressure of the smoke hood above the converter mouth is -10Kpa, and the negative pressure of the secondary dust removal smoke hood is -6kpa. The sintered ore powder with a particle size of 1mm-2mm, accounting for 40%, will be sucked away and enter the flue and dust removal duct, causing losses far greater than the benefits brought by the addition of sintered ore powder.

[0054] The oxygen flow ejected by the oxygen lance is a supersonic jet with a pressure of 8.5Mpa. The powdered material floats on the molten iron due to its specific gravity and will be blown away by the airflow, affecting the effective participation of the powdered sintered ore in the converter slag making, resulting in waste.

[0055] The FeO content in the sintered ore powder is about 11%, and the calcium ferrite content is about 25%. The dephosphorization reaction is: 2[P]+5(FeO)+n(CaO)=(nCaO.)+5Fe. After adding the sintered ore powder, the (FeO) and (CaO) contents in the slag are high, which is conducive to the removal of phosphorus. In the later stage of blowing, the slag basicity and (FeO) are well controlled to stabilize the phosphorus in the slag without rephosphorization. The presence of calcium ferrite in the powdered high-basicity sintered ore has extremely high reactivity to the harmful element phosphorus, which increases the dephosphorization capacity in advance.

[0056] During the blowing process, the favorable conditions of high temperature, high basicity and low oxidation (FeO) in the middle and late stages of the blowing process are utilized to remove harmful elemental sulfur. The desulfurization reaction is: FeS+CaO=CaS+FeO. The slag has a high CaO content and a low FeO content, which is conducive to the desulfurization reaction.

[0057] The final slag basicity is controlled in the range of 3.0-3.5, ensuring that the finished steel bars rolled from this grade of steel meet the composition and performance requirements of the new national standard GB / T1499.2-2018 hot-rolled ribbed steel bars for reinforced concrete, optimizing the control of slag oxidation and slag basicity in converter slag making, solving the removal of harmful element phosphorus in advance, and then focusing on the removal of harmful element sulfur, while maintaining a certain FeO content in the slag to prevent the slag from drying out and returning to phosphorus.

[0058] like Figure 2-4 As shown, the present embodiment also provides a converter slag smelting production line adopting the above-mentioned converter slag smelting method, including a powder cored scrap steel briquetting device and a converter arranged in front and behind, the powder cored scrap steel briquetting device includes a support frame 1, a mold assembly and a briquetting mechanism 4, a mold assembly is arranged in the middle of the support frame 1, the mold assembly includes a mold 2 and a plurality of hydraulic push rods 3, and the plurality of hydraulic push rods 3 are evenly distributed on the outer wall of the mold 2, the mold 2 is a cylindrical mold and is spliced ​​by a plurality of half mold grooves arranged in a matching manner, a briquetting mechanism 4 is arranged on the top of the support frame 1, the briquetting mechanism 4 includes a track plate 6, a movable plate 7, a down-pressing assembly 8 and a mold rod assembly 9, a through opening is arranged in the middle of the top of the support frame 1 and two parallel track plates 6 are arranged on both sides of the opening, two movable plates 7 are slidably installed between the two track plates 6, and the two movable plates 7 are respectively installed with the down-pressing assembly 8 and the mold rod assembly 9 and can drive the down-pressing assembly 8 and the mold rod assembly 9 along the track The plate moves in the direction of 6 degrees, the pressing assembly 8 and the die rod assembly 9 are arranged above the die 2, and a bottom support assembly 5 is arranged at the bottom of the die 2. The die 2 is controlled by the hydraulic push rod to slowly merge into a cylindrical space. With the cooperation of the briquetting mechanism, the powder core scrap steel briquetting can be extruded and formed. First, the scrap steel is put into the die to lay the bottom, and the bottom material is compacted by the pressing assembly. Then the pressing assembly is moved aside, and then the die rod assembly is moved to the top of the die and the die rod is lowered into the die. At the same time, scrap steel is continued to be put in to fill the gap between the die rod and the die. Under the action of the extrusion force of the die merging inward and the die rod, the filled scrap steel can be squeezed into a cylindrical shape. Then the die rod is withdrawn and the pressing assembly is moved to the top of the die again. At the same time, sintered ore powder is put into the middle of the cylindrical scrap steel. After the middle of the cylindrical scrap steel is filled, the scrap steel is spread on the top of the cylindrical scrap steel. Finally, the pressing assembly is controlled to extrude downward, so as to realize the extrusion and forming of the powder core scrap steel briquetting. The bottom support assembly can be used to avoid leakage at the bottom of the die.

[0059] As a preferred embodiment, it also includes a shearing device for shearing the powder-cored scrap steel briquette made by the powder-cored scrap steel briquetting device, the shearing device includes a shearing frame 10, a moving trolley 12, a fixing component and a cutting component 15, a cutting fixing ring 19 is arranged below the shearing frame 10, a plurality of evenly distributed cutting components 15 are arranged on the inner side of the cutting fixing ring 19, a track 11 is arranged below the plurality of cutting components 15, a moving trolley 12 is connected to the top of the track 11, a fixing component is arranged between the moving trolley 12 and the shearing frame 10, the fixing component includes a hydraulic electric lifting rod 13, a support plate 14, a hydraulic cylinder 16 and a lower pressing plate 17, two hydraulic electric lifting rods 13 are installed on the top of the moving trolley 12, the tops of the two hydraulic electric lifting rods 13 are connected to the support plate 14, a rotating component 20 is arranged on the support plate 14 and a powder-cored scrap steel briquette is arranged on the top of the support plate 14, the hydraulic cylinder 16 is installed on the top of the shearing frame 10, the hydraulic The movable end of the cylinder 16 is provided with a rotatable lower pressure plate 17 through the lower surface of the shearing frame 10, and the interior of the lower pressure plate 17 is provided with an electromagnet 18 for adsorbing the top of the powder-coated scrap steel briquettes. Before an appropriate amount of powder-coated scrap steel briquettes enter the converter, it is necessary to conduct random inspections and cut the inspected powder-coated scrap steel briquettes through a shearing device, and then extract and detect the internal scrap steel structure and the chemical composition of the core powder to ensure that they meet the technical requirements. The powder-coated scrap steel briquettes are supported and transported by a mobile trolley. When the powder-coated scrap steel briquettes are transferred to the bottom of the support frame, the powder-coated scrap steel briquettes can be fixed up and down by a fixing component, and the powder-coated scrap steel briquettes can be placed in a cutting fixing ring. By using the cutting component in the cutting fixing ring, the outer wall of the powder-coated scrap steel briquettes can be cut at multiple points. At the same time, by using a rotating component provided below the powder-coated scrap steel briquettes, the powder-coated scrap steel briquettes can be controlled to rotate and cooperate with the cutting component to achieve ring cutting, which saves time and effort and greatly reduces the labor intensity of the staff.

[0060] Working principle: By adding powdered sintered ore to make converter slag, the new way of using blast furnace waste to make "iron slag" in converter is practical and has strong economic value. It is a new way to achieve low-cost production of economical clean steel. By using light and thin scrap steel to press high-basicity sintered ore powder into powder-coated scrap steel briquettes to participate in converter slag making, the problem of adding high-basicity sintered ore powder with a particle size of less than 10mm in converter slag making is solved. The fine sintered ore powder will be sucked away by the smoke hood airflow and cannot be added to the converter furnace to participate in slag making according to the normal converter steelmaking slag making agent addition method is optimized. Control and control of slag alkalinity, solve the removal of harmful element phosphorus in advance, and then focus on the removal of harmful element sulfur, while maintaining a certain FeO content in the slag to prevent the slag from drying and returning to phosphorus. Powder-coated scrap steel briquettes are made through a special powder-coated scrap steel briquetting device. With the alternating cooperation of the lower pressure component and the die rod component, the powder-coated scrap steel briquettes can be quickly extruded and formed, which greatly improves the processing efficiency of the powder-coated scrap steel briquettes. Through the special shearing device of the powder-coated scrap steel briquettes, the powder-coated scrap steel briquettes can be cut in an annular manner, which greatly improves the cutting efficiency of the powder-coated scrap steel briquettes.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A converter slag smelting method, characterized in that: The following steps are involved: Step 1: The high-basicity sintered ore powder with a particle size of less than 10 mm screened out in the ironmaking blast furnace process is pressed into powder-coated scrap steel briquettes by a powder-coated scrap steel briquetting device; Step 2: After the converter is tapped, the slag is dumped, and according to the total iron consumption, an appropriate amount of powder-coated scrap steel briquettes are loaded into the converter, and the powder-coated scrap steel briquettes are sampled and sheared by a shearing device before loading; Step 3, adding molten iron into the converter; Step 4: Shake the converter body straight and add lime blocks in an amount equal to 1 / 3 of the total slag-making solvent; Step 5: Lower the lance and start blowing at high lance position to prepare for blowing and slag making; In step 1, the high basicity sintered ore powder has a FeO content of 10-12% and a calcium ferrite content of 22-28%; In step 3, the temperature of the molten iron when entering the furnace is ≥1250°C, and the amount of slag in the molten iron is not more than 0.5%; The powder cored scrap steel briquetting device comprises a mould and a briquetting forming mechanism arranged above the mould, wherein the briquetting forming mechanism comprises a track plate, a movable plate, a pressing assembly and a die rod assembly, two movable plates are slidably installed between the two track plates, the pressing assembly and the die rod assembly are respectively installed on the two movable plates and can drive the pressing assembly and the die rod assembly to move along the length direction of the track plate, and the powder cored scrap steel briquetting is extruded and formed with the cooperation of the briquetting forming mechanism, firstly, the scrap steel is put into the mould to lay the bottom, and the bottom material is compacted by the pressing assembly, and then the pressing assembly is moved aside, and at the same time, the scrap steel is continuously put in to fill the gap between the die rod assembly and the mould, and under the combined inward extrusion force of the mould and the action of the die rod assembly, the filled scrap steel is extruded into a cylindrical shape, and then the die rod assembly is withdrawn and the pressing assembly is moved again to the top of the mould, and at the same time, sintered ore powder is put into the middle of the cylindrical scrap steel, and after the middle of the cylindrical scrap steel is filled, the scrap steel is spread on the top of the cylindrical scrap steel, and finally the pressing assembly is controlled to extrude downward, so as to realize the extrusion forming of the powder cored scrap steel briquetting.

2. A converter slag smelting method according to claim 1, characterized in that: In step 1, the powder-coated scrap steel briquettes account for 10-20% of the total slag-making material, and the powder-coated scrap steel briquettes are cylindrical with a diameter of 300-400 mm and a height of 150-250 mm.

3. A converter slag smelting method according to claim 1, characterized in that: In step 1, high-basicity sintered ore powder with a particle size of less than 10 mm is vibrated and screened from the ore trough of the iron-making blast furnace, pressed into powder-coated scrap steel briquettes through scrap steel, and loaded into the converter using a scrap steel bucket.

4. A converter slag smelting method according to claim 1, characterized in that: The oxygen lance nozzle in the blowing process in step 5 is a five-hole Laval nozzle, the oxygen lance cooling water flow rate is ≥230m3 / h, and the blowing time is controlled at 1-3min.

5. The converter slag smelting method according to claim 1, characterized in that: In step five, the blowing adopts a constant pressure variable gun position operation. Within 3 minutes of blowing, the scrap steel on the surface of the briquette melts, and the powdered sintered ore is stirred by the oxygen flow of the oxygen lance during the floating process, fully reacts chemically with the harmful impurities in the molten iron, and forms slag. The oxygen pressure is controlled at 0.8-1.2MPa, and the basic gun position is 1800-2000mm, the fluctuating gun position is 1200-2600mm, and the gun position change amplitude is ≤200mm when the gun is lowered.

6. A converter slag smelting production line using the converter slag smelting method according to any one of claims 1 to 5, characterized in that: The invention comprises a powder cored scrap steel briquetting device and a converter arranged in front and back, the powder cored scrap steel briquetting device comprising a support frame (1), a mold assembly and a briquetting mechanism (4), the mold assembly being arranged in the middle of the support frame (1), the mold assembly comprising a mold (2) and a plurality of hydraulic push rods (3), the plurality of hydraulic push rods (3) being evenly distributed on the outer wall of the mold (2), the mold (2) being a cylindrical mold and being formed by splicing a plurality of half mold grooves arranged in a matching manner, the briquetting mechanism (4) being arranged on the top of the support frame (1), the briquetting mechanism (4) comprising a track plate (6), a movable plate (7 ), a pressing assembly (8) and a mold rod assembly (9), a through opening is provided in the middle of the top of the support frame (1) and two parallel track plates (6) are provided on both sides of the opening, two movable plates (7) are slidably installed between the two track plates (6), the pressing assembly (8) and the mold rod assembly (9) are respectively installed on the two movable plates (7) and can drive the pressing assembly (8) and the mold rod assembly (9) to move along the track plates (6) degrees, the pressing assembly (8) and the mold rod assembly (9) are arranged at a position above the mold (2), and a bottom support assembly (5) is provided at the bottom of the mold (2).

7. A converter slag smelting production line according to claim 6, characterized in that: The invention also comprises a shearing device for sampling and shearing the powder-coated scrap steel briquette produced by the powder-coated scrap steel briquette device, wherein the shearing device comprises a shearing frame (10), a moving trolley (12), a fixing assembly and a cutting assembly (15), wherein a cutting fixing ring (19) is arranged below the shearing frame (10), a plurality of evenly distributed cutting assemblies (15) are arranged inside the cutting fixing ring (19), a track (11) is arranged below the plurality of cutting assemblies (15), the top of the track (11) is connected to the moving trolley (12), a fixing assembly is arranged between the moving trolley (12) and the shearing frame (10), and the fixing assembly comprises a hydraulic electric lifting rod. (13), a support plate (14), a hydraulic cylinder (16) and a lower pressure plate (17), the top of the mobile trolley (12) is equipped with two hydraulic electric lifting rods (13), the tops of the two hydraulic electric lifting rods (13) are connected to the support plate (14), the support plate (14) is provided with a rotating component (20) and the top of the support plate (14) is provided with a powder-core scrap steel briquette, the hydraulic cylinder (16) is installed on the top of the shearing frame (10), the movable end of the hydraulic cylinder (16) passes through the lower surface of the shearing frame (10) and is provided with a rotatable lower pressure plate (17), and the interior of the lower pressure plate (17) is provided with an electromagnet (18) for adsorbing the top of the powder-core scrap steel briquette.

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