Efficient and environment-friendly direct reduction ironmaking method

Abstract

The invention discloses an efficient and environment-friendly direct reduction ironmaking method. A smelting furnace for ironmaking is a rotary stirring type smelting electric furnace with a built-in stirring impeller; a certain proportion of iron ore dispersed materials and coke or coal dispersed materials are added into the furnace, carbon monoxide gas is introduced into the furnace at the initial stage of iron making, an electric heating element in the furnace is started to heat the temperature in the furnace to the reduction iron making temperature, and the iron making temperature is reduced to the reduction iron making temperature under the action of rotation of the rotary stirring type electric smelting furnace and rotation of a stirring impeller. The raw materials in the furnace are fully stirred, mixed and uniformly heated, and the iron ore is gradually reduced into iron; carbon monoxide and carbon dioxide gas generated in the furnace are separated through a gas separator, and the separated carbon monoxide is sent back into the furnace through a gas separation circulation pipeline to continue to participate in the reduction reaction until the raw materials in the furnace are converted into iron with high proportion content. The production efficiency of direct reduction ironmaking is improved, and the equipment investment cost of direct reduction ironmaking is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of smelting, and in particular to a highly efficient and environmentally friendly direct reduction ironmaking method. Background Art

[0002] The traditional ironmaking method is to use blast furnaces. During the blast furnace ironmaking reduction process, when iron and oxygen in iron ore are separated, a considerable amount of Si, Mn, C and other elements will enter the molten iron. Therefore, the molten iron must be oxidized and refined to remove excess elements and impurity elements. The refined molten steel must also be deoxidized, which complicates the smelting process, produces more polluting gases, and causes unnecessary energy and raw material consumption.

[0003] The recently developed short-process hydrogen-based vertical furnace-electric furnace smelting process uses a hydrogen-based vertical furnace for ironmaking, using hydrogen and coke oven gas as reducing agents to reduce the iron in the iron ore particles in the vertical furnace, and then put it into an electric arc furnace for further smelting into steel. This short-process smelting process can significantly reduce energy consumption and is environmentally friendly.

[0004] However, the above production line using hydrogen-based vertical furnace-electric furnace still has the disadvantage of large equipment investment. In addition, during the process of reducing iron in the hydrogen-based vertical furnace, the raw materials are in a piled state in the vertical furnace, resulting in the flow of air in the furnace not being smooth, which greatly reduces the uniformity of heating of the raw materials and the speed of the reduction reaction, resulting in a long reduction reaction time and low production efficiency. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes an efficient and environmentally friendly direct reduction ironmaking method, which aims to improve the production efficiency of direct reduction ironmaking and reduce the equipment investment cost of direct reduction ironmaking. The specific technical solution is as follows:

[0006] A highly efficient and environmentally friendly direct reduction ironmaking method, wherein the raw materials for ironmaking are dispersed iron ore, dispersed coke or coal, and carbon monoxide gas, and the smelting furnace for ironmaking is a rotary stirring smelting electric furnace, and a stirring impeller is provided in the rotary stirring smelting electric furnace in a direction opposite to that of the rotary stirring smelting electric furnace, and an electric heating element for heating the raw materials in the furnace is also provided in the rotary stirring smelting electric furnace, and the rotary stirring smelting electric furnace is connected to a gas separator through a gas separation circulation pipeline, and the gas separator is a gas separator for separating carbon monoxide from the gas in the furnace body; by adding a certain proportion of dispersed iron ore, and coke or coal in the furnace, The dispersed material is prepared, and carbon monoxide gas is introduced into the furnace at the initial stage of iron smelting. The electric heating element in the furnace is turned on to heat the temperature in the furnace to the reduction iron smelting temperature. Under the action of the rotation of the rotary stirring smelting electric furnace and the rotation of the stirring impeller, the raw materials in the furnace are fully stirred and mixed and evenly heated, the iron ore is gradually reduced to iron, and carbon monoxide and carbon dioxide gases are generated; wherein, the carbon monoxide and carbon dioxide gases generated in the furnace are led out to the gas separator through the gas separation circulation pipeline to separate the carbon monoxide gas from the carbon dioxide gas, and the separated carbon monoxide is returned to the furnace through the gas separation circulation pipeline to continue to participate in the reduction reaction until the raw materials in the furnace are converted into iron with a high proportion of content.

[0007] Preferably, during the iron-making process, a certain amount of carbon monoxide is additionally input into the furnace to maintain a balance in the carbon monoxide gas content and a balance in the pressure in the furnace.

[0008] Preferably, the iron ore dispersed material is iron ore particles with a diameter of 3 to 20 mm.

[0009] Preferably, the reduction ironmaking temperature in the direct reduction ironmaking method is 900-1300°C.

[0010] Preferably, the carbon monoxide and carbon dioxide gases generated in the furnace are cooled before entering the gas separator.

[0011] Preferably, the gas collection pipeline is provided with a waste heat utilization device for cooling the gas and realizing waste heat utilization.

[0012] Preferably, the waste heat utilization device is a heat exchange device for preheating dispersed iron ore; during ironmaking, dispersed iron ore is preheated by the waste heat utilization device and then added into the furnace through a conveying device.

[0013] In the present invention, the rotary stirring smelting electric furnace includes a rotatably arranged vertical furnace body, a furnace cover plate arranged at the mouth of the furnace body, a stirring shaft passing through the furnace cover plate and inserted into the furnace body, and a stirring impeller arranged on the stirring shaft and located in the furnace body, a first fluid dynamic sealing assembly is arranged between the furnace cover plate and the mouth of the furnace body, a second fluid dynamic sealing assembly is arranged on the furnace cover plate between the insertion position of the stirring shaft and the stirring shaft, and an electric heating element for heating the raw materials inside the furnace body is arranged on the side of the furnace cover plate facing the inside of the furnace body.

[0014] Preferably, the first fluid dynamic sealing assembly and the second fluid dynamic sealing assembly can be liquid dynamic sealing assemblies (such as water fluid dynamic sealing assemblies, etc.) or gas dynamic sealing assemblies (such as carbon dioxide gas dynamic sealing assemblies, etc.).

[0015] In the present invention, the rotary stirring smelting electric furnace also includes a base, a pair of columns arranged on the base, and a cross beam plate arranged on the pair of columns. The furnace body is rotatably arranged on the base, and the furnace body cover plate is connected to the lower position of the cross beam plate; the stirring shaft is arranged on the cross beam plate, and a stirring shaft mounting hole is arranged on the furnace body cover plate. The stirring shaft passes through the stirring shaft mounting hole and enters the furnace body, and the second fluid dynamic sealing assembly is arranged at a position between the stirring shaft mounting hole and the stirring shaft; a rotating drive mechanism for driving the stirring shaft to rotate is arranged on the cross beam plate; the rotating drive mechanism is one of a direct drive motor, a belt drive mechanism driven by a reduction motor, and a gear drive mechanism driven by a reduction motor.

[0016] Preferably, the first fluid dynamic sealing assembly includes a first annular water groove, which is arranged on the furnace body cover plate, and a first annular ring inserted into the first annular water groove is installed on the furnace body to form a water seal between the furnace body cover plate and the furnace body, and a first cooling device is arranged on the first annular water groove.

[0017] Preferably, the second fluid dynamic sealing assembly includes a second annular ring arranged on the stirring shaft and a second annular water groove arranged on the upper part of the furnace body cover plate, the second annular ring is inserted into the second annular water groove to achieve water sealing between the stirring shaft and the stirring shaft mounting hole of the furnace body cover plate, and a second cooling device is arranged on the second annular water groove.

[0018] Preferably, a first overflow gas negative pressure recovery cover is arranged on the periphery of the first fluid dynamic sealing component; and a second overflow gas negative pressure recovery cover is arranged on the periphery of the second fluid dynamic sealing component.

[0019] The beneficial effects of the present invention are:

[0020] First, the present invention is a highly efficient and environmentally friendly direct reduction iron-making method. By configuring the furnace body as a rotating furnace body and cooperating with a rotating stirring impeller arranged in the furnace body, the smelting materials (such as iron ore particles, and dispersed materials of coke or coal) are vigorously mixed and turned in the high-temperature environment inside the furnace body, thereby greatly improving the uniformity of heating of the smelting materials in the furnace body and the speed of heat transfer, and allowing the smelting materials to fully contact with the reducing gas, the smelting reaction time is short and the speed is fast, thereby improving the production efficiency of the smelting reaction.

[0021] Secondly, the efficient and environmentally friendly direct reduction ironmaking method of the present invention can also break up the smelting materials themselves and the sticky lumps that may be formed in the smelting reaction through the rotation of the furnace body and the rotation of the stirring impeller, thereby further improving the uniformity of heating of the smelting materials in the furnace body and the speed of heat transfer, thereby further improving the production efficiency of the smelting reaction.

[0022] Third, the present invention is an efficient and environmentally friendly direct reduction iron-making method, which is provided with a gas separator. The separated carbon monoxide gas can be returned to the furnace body to continue to participate in the smelting reaction, thereby saving a large amount of carbon monoxide gas resources and reducing the emission of harmful gases, and has good environmental performance.

[0023] Fourth, in the present invention, a highly efficient and environmentally friendly direct reduction ironmaking method is provided with a fluid dynamic sealing assembly between the furnace cover and the furnace body, and between the stirring shaft and the furnace cover, which can isolate the smelting reaction space in the furnace from the outside air, so that the reduction reaction is carried out in a closed space without oxygen, ensuring the normal progress of the smelting reaction in the furnace and reducing the generation of harmful gases. In addition, the fluid dynamic sealing assembly can also prevent the pressure in the furnace from being too high, thereby improving the safety of the smelting reaction.

[0024] Fifth, in the present invention, a highly efficient and environmentally friendly direct reduction ironmaking method is provided with a cooling device on the fluid dynamic seal assembly, thereby preventing the fluid (cooling water) from evaporating rapidly and ensuring the reliability of the seal.

[0025] Sixth, the present invention provides an efficient and environmentally friendly direct reduction ironmaking method. The first annular water trough and the second annular water trough adopt dual cooling of water circulation cooling and heat exchange cooling of spiral heat exchange tubes, which greatly improves the cooling speed of the annular water trough and is conducive to further improving the reliability of water sealing.

[0026] Seventh, the present invention provides an efficient and environmentally friendly direct reduction iron-making method. The smelting gas overflowing from the water tank in the furnace body is specially collected and processed by the overflow gas negative pressure recovery cover and the waste heat is utilized, which will not have an adverse effect on the surrounding environment.

[0027] Eighth, the efficient and environmentally friendly direct reduction ironmaking method of the present invention has a short process flow and greatly reduces the emission of harmful gases compared to the traditional blast furnace-converter ironmaking method, and has good environmental performance.

[0028] Ninth, the present invention is an efficient and environmentally friendly direct reduction ironmaking method, whose overall structure is simpler than that of a hydrogen-based vertical furnace structure, and the investment cost is relatively low. It can also achieve small- and medium-scale production of 100,000 tons per year with a single set of equipment, thereby reducing the total investment cost of the project and reducing investment risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a principle diagram of a highly efficient and environmentally friendly direct reduction ironmaking method of the present invention;

[0030] Figure 2 It is a structural schematic diagram of a rotary stirring type smelting electric furnace used in a highly efficient and environmentally friendly direct reduction ironmaking method of the present invention (the rotary drive mechanism adopts a belt transmission mechanism or a gear transmission mechanism);

[0031] Figure 3 is Figure 2 A structural schematic diagram of a first cooling device connected to a first fluid sealing assembly;

[0032] Figure 4 is Figure 2 A structural schematic diagram of a second cooling device connected to a second fluid sealing assembly;

[0033] Figure 5 It is a modified structure of the first fluid dynamic sealing assembly (the first annular water tank is arranged on the furnace body, and the first annular ring is arranged on the furnace body cover plate);

[0034] Figure 6 It is another variation of the first fluid dynamic sealing assembly (the first annular water tank is provided separately, and the first annular ring is provided on the furnace body and the furnace body cover plate respectively);

[0035] Figure 7 yes Figure 2 Schematic diagram of the change structure of the rotary stirring smelting electric furnace (the rotary drive mechanism adopts a direct drive motor);

[0036] Figure 8 It is a working principle diagram of a furnace cover plate connected to a gas separator and an annular gas supply chamber and an annular gas collecting chamber being arranged on the furnace cover plate.

[0037] In the figure: 1, furnace body, 2, furnace body cover, 3, stirring shaft, 4, stirring impeller, 5, first fluid dynamic sealing assembly, 6, second fluid dynamic sealing assembly, 7, electric heating element, 8, gas separation circulation device, 9, gas separation circulation pipeline, 10, gas separator, 11, gas collection pipeline, 12, gas recycling pipeline, 13, base, 14, column, 15, cross beam plate, 16, turntable, 17, rotary drive mechanism, 18, direct drive motor, 19, belt transmission mechanism or gear transmission mechanism, 20, coupling, 21, bearing seat component, 22, first annular water tank, 23, first annular ring, 24, first cooling device, 25, first cooling circulation pipeline, 26, refrigerator or cooling tower, 27, first overflow gas negative pressure recovery hood, 28, first spiral heat exchange tube, 29, second annular ring, 30, second annular water trough, 31, second cooling device, 32, second cooling circulation pipeline, 33, second spiral heat exchange tube, 34, second overflow gas negative pressure recovery hood, 35, scraper, 36, refractory material layer, 37, feeding port, 38, feeding cover, 39, discharge port, 40, discharge door, 41, connecting arm, 42, first gas supply pipeline (carbon monoxide supply pipeline), 43, waste heat utilization device, 44, annular gas supply chamber, 45, annular gas collecting chamber, 46, air vent, 47, second gas separation output pipeline (carbon dioxide gas separation output pipeline). DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0039] like Figures 1 to 8The figure shows an embodiment of a highly efficient and environmentally friendly direct reduction ironmaking method of the present invention, wherein the raw materials for ironmaking are dispersed iron ore, dispersed coke or coal, and carbon monoxide gas, and the smelting furnace for ironmaking is a rotary stirring smelting electric furnace, and a stirring impeller 4 is provided in the rotary stirring smelting electric furnace in a direction opposite to that of the rotary stirring smelting electric furnace, and the rotary stirring smelting electric furnace is also provided with an electric heating element 7 for heating the raw materials in the furnace, and the rotary stirring smelting electric furnace is connected to a gas separator 10 through a gas separation circulation pipeline 9, and the gas separator 10 is a gas separator 10 for separating carbon monoxide from the gas in the furnace body; by adding a certain proportion of iron ore dispersed material in the furnace The raw materials in the furnace are fully stirred and mixed and evenly heated under the action of the rotation of the rotary stirring smelting electric furnace and the rotation of the stirring impeller 4, and carbon monoxide and carbon dioxide gases are generated; wherein, the carbon monoxide and carbon dioxide gases generated in the furnace are led out to the gas separator through the gas separation circulation pipeline 9 to separate the carbon monoxide gas and the carbon dioxide gas, and the separated carbon monoxide is then returned to the furnace through the gas separation circulation pipeline 9 to continue to participate in the reduction reaction until the raw materials in the furnace are converted into iron with a high proportion of content.

[0040] Preferably, during the iron-making process, a certain amount of carbon monoxide is additionally input into the furnace to maintain a balance in the carbon monoxide gas content and a balance in the pressure in the furnace.

[0041] Preferably, the iron ore dispersed material is iron ore particles with a diameter of 3 to 20 mm.

[0042] Preferably, the reduction ironmaking temperature in the direct reduction ironmaking method is 900-1300°C.

[0043] Preferably, the carbon monoxide and carbon dioxide gases generated in the furnace are cooled before entering the gas separator 10 .

[0044] Preferably, the gas collection pipeline 11 is provided with a waste heat utilization device 43 for cooling the gas and realizing waste heat utilization.

[0045] Preferably, the waste heat utilization device 43 is a heat exchange device for preheating dispersed iron ore; during ironmaking, dispersed iron ore is preheated by the waste heat utilization device and then added into the furnace through a conveying device.

[0046] In the present invention, the rotary stirring smelting electric furnace includes a rotatably arranged vertical furnace body 1, a furnace body cover plate 2 arranged at the mouth of the furnace body 1, a stirring shaft 3 passing through the furnace body cover plate 2 and inserted into the furnace body 1, and a stirring impeller 4 arranged on the stirring shaft 3 for stirring the discrete smelting material inside the furnace body 1, a first fluid dynamic sealing assembly 5 is arranged between the furnace body cover plate 2 and the mouth of the furnace body 1, a second fluid dynamic sealing assembly 6 is arranged on the furnace body cover plate 2 between the insertion portion of the stirring shaft 3 and the stirring shaft 3, and an electric heating element 7 for heating the smelting material inside the furnace body 1 is arranged on the side of the furnace body cover plate 2 facing the inside of the furnace body 1.

[0047] Preferably, the rotary stirring smelting electric furnace is also equipped with a gas separation circulation device 8 for treating the gas in the furnace body 1, and the gas separation circulation device 8 includes a gas separation circulation pipeline 9 whose two ends are respectively connected to the interior of the furnace body 1, and a gas separator 10 arranged on the gas separation circulation pipeline 9.

[0048] Preferably, both ends of the gas separation circulation pipeline 9 respectively pass through the furnace cover plate 2 and enter into the furnace body 1 so as to be connected with the interior of the furnace body 1 .

[0049] In the present invention, the gas in the furnace body 1 includes a first gas used to participate in the smelting reaction and a second gas as a smelting waste gas. The gas separation circulation pipeline 9 includes a gas collecting pipeline 10 and a gas recycling pipeline 12. The inlet of the gas collecting pipeline 11 is connected to the interior of the furnace body 1, and the outlet of the gas collecting pipeline 11 is connected to the inlet of the gas separator 10. The gas separator 10 is provided with a first gas separation port and a second gas separation port. The first gas separation port of the gas separator 10 is connected to the inlet of the gas recycling pipeline 12, and the outlet of the gas recycling pipeline 12 is connected to the interior of the furnace body 1.

[0050] Wherein, the first gas is carbon monoxide, the second gas is carbon dioxide, and the gas separator is a gas separator for separating carbon dioxide and carbon monoxide.

[0051] In the present invention, the rotary stirring smelting electric furnace also includes a base 13, a pair of columns 14 arranged on the base 13, and a cross beam 15 arranged on the pair of columns 14. The furnace body 1 is rotatably arranged on the base 13, and the furnace body cover 2 is connected to the lower position of the cross beam 15.

[0052] Preferably, the furnace cover plate 2 is directly connected to the cross beam plate 15 , or the furnace cover plate 2 is indirectly connected to the cross beam plate 15 via a number of connecting arms 41 .

[0053] Preferably, a turntable 16 driven by a reduction motor is provided on the base 13 , and the furnace body 1 is mounted on the turntable 16 .

[0054] Preferably, there are multiple stirring shafts 3 and they are arranged separately from each other.

[0055] In order to ensure uniform stirring of the smelting materials inside the furnace body 1 , it is necessary to provide a plurality of stirring shafts 3 on the large furnace body 1 .

[0056] In this embodiment, the rotation direction of the furnace body 1 is opposite to the rotation direction of the stirring shaft 3 .

[0057] In this embodiment, the furnace body 1 is a vertical furnace body, and the vertical furnace body is arranged horizontally or inclined relative to the horizontal direction.

[0058] When the vertical furnace body is tilted at 15 to 35 degrees, the smelting materials inside the furnace body 1 can be evenly stirred, thereby improving the stirring efficiency.

[0059] In this embodiment, a stirring shaft mounting hole is provided on the furnace body cover plate 2, and the stirring shaft 3 enters into the furnace body 1 after passing through the stirring shaft mounting hole, and the second fluid dynamic sealing assembly 6 is arranged between the stirring shaft mounting hole and the stirring shaft 3.

[0060] In this embodiment, a rotation driving mechanism 17 for driving the stirring shaft 3 to rotate is disposed on the cross beam plate 15 .

[0061] Preferably, the rotary drive mechanism 17 is one of a direct drive motor 18, a belt drive mechanism 19 driven by a reduction motor, and a gear drive mechanism 19 driven by a reduction motor.

[0062] When a direct-drive motor 18 is used as the rotation driving mechanism 17 , the motor shaft of the direct-drive motor 18 is directly connected to the stirring shaft 3 in an integrated manner, or is directly connected to the stirring shaft 3 via a coupling 20 .

[0063] When a belt transmission mechanism or a gear transmission mechanism 19 is used as the rotation driving mechanism 17, a bearing seat component 21 is arranged on the cross beam plate 15 or the furnace cover plate 2, and the upper part of the stirring shaft 3 is rotatably arranged in the bearing seat component 21, and a transmission connection is realized between the belt transmission mechanism or the gear transmission mechanism 19 driven by the reduction motor and the upper part of the stirring shaft 3.

[0064] As one of the preferred schemes of the first fluid dynamic sealing assembly in this embodiment, the first fluid dynamic sealing assembly 5 includes a first annular water groove 22, which is arranged on the furnace body 1, and the furnace body cover plate 2 is provided with a first annular ring 23 inserted into the first annular water groove 22, thereby forming a water seal between the furnace body cover plate 2 and the furnace body 1, and the first annular water groove 22 is provided with a first cooling device 24.

[0065] As the second preferred solution of the first fluid dynamic sealing assembly in this embodiment, the first fluid dynamic sealing assembly 5 includes a first annular water groove 22, which is arranged on the furnace body cover plate 2, and a first annular ring 23 inserted into the first annular water groove 22 is installed on the furnace body 1, thereby forming a water seal between the furnace body cover plate 2 and the furnace body 1, and a first cooling device 24 is arranged on the first annular water groove 22.

[0066] As the third preferred solution of the first fluid dynamic sealing component in this embodiment, the first fluid dynamic sealing component 5 includes a first annular water groove 22, which is arranged on the periphery of the furnace body 1, and the furnace body 1 and the furnace body cover plate 2 are respectively provided with a first annular ring 23 inserted into the first annular water groove 22, thereby forming a water seal between the furnace body cover plate 2 and the furnace body 1, and the first annular water groove 22 is provided with a first cooling device 24.

[0067] In this embodiment, the first cooling device 24 includes a first cooling circulation pipeline 25 connected to the first annular water tank 22 , and the first cooling circulation pipeline 25 is connected to a refrigerator or a cooling tower 26 .

[0068] Preferably, a first overflow gas negative pressure recovery cover 27 is provided on the periphery of the first fluid dynamic sealing assembly 5 .

[0069] The first overflow gas negative pressure recovery cover 27 is connected to a negative pressure pipeline, so as to form a negative pressure in the first overflow gas negative pressure recovery cover 27 to prevent possible overflow of smelting gas.

[0070] In order to further increase the cooling speed of the water in the first annular water tank 22 , a first spiral heat exchange tube 28 is disposed in the first annular water tank 22 , and the first spiral heat exchange tube 28 is connected to the first cooling circulation pipeline 25 .

[0071] In this embodiment, the number of the first cooling circulation pipelines 25 is set to two pairs, one pair of the first cooling circulation pipelines 25 is correspondingly connected to the first annular water tank 22, and the other pair of the first cooling circulation pipelines 25 is correspondingly connected to the two ports of the first spiral heat exchange tube 28.

[0072] As one of the preferred schemes of the second fluid dynamic sealing assembly in this embodiment, the second fluid dynamic sealing assembly 6 includes a second annular ring 29 arranged on the stirring shaft 3 and a second annular water groove 30 arranged on the upper part of the furnace body cover plate 2. The second annular ring 29 is inserted into the second annular water groove 30 to achieve water sealing between the stirring shaft 3 and the stirring shaft mounting hole of the furnace body cover plate 2. A second cooling device 31 is arranged on the second annular water groove 30.

[0073] As the second preferred scheme of the second fluid dynamic sealing assembly in this embodiment, the second fluid dynamic sealing assembly 6 includes a second annular water groove 22 arranged on the stirring shaft 3 and a second annular ring 29 arranged on the upper part of the furnace body cover 2. The second annular ring 29 is inserted into the second annular water groove 30 to achieve water sealing between the stirring shaft 3 and the stirring shaft mounting hole of the furnace body cover 2. A second cooling device 31 is arranged on the second annular water groove 30.

[0074] In this embodiment, the second cooling device 31 includes a second cooling circulation pipe 32 connected to the second annular water tank 30 , and the second cooling circulation pipe 32 is connected to a refrigerator or a cooling tower 26 .

[0075] In order to further increase the cooling speed of the water in the second annular water tank 30 , a second spiral heat exchange tube 33 is disposed in the second annular water tank 30 , and the second spiral heat exchange tube 33 is connected to the second cooling circulation tube 32 .

[0076] In this embodiment, the number of the second cooling circulation pipelines 32 is set to two pairs, one pair of the second cooling circulation pipelines 32 is correspondingly connected to the second annular water tank 30, and the other pair of the second cooling circulation pipelines 32 is correspondingly connected to the two ports of the second spiral heat exchange tube 32.

[0077] Preferably, a second overflow gas negative pressure recovery cover 34 is provided on the periphery of the second fluid dynamic sealing assembly 6 .

[0078] The second overflow gas negative pressure recovery cover 34 is connected to a negative pressure pipeline, so as to form a negative pressure in the second overflow gas negative pressure recovery cover 34 to prevent possible overflow of smelting gas.

[0079] Preferably, a scraper 35 is also provided in the furnace body 1 for preventing metallurgical materials from sticking to the furnace body 1, the lower edge of the scraper 35 is close to the bottom of the furnace body 1, the side of the scraper 35 is close to the inner side wall of the furnace body 1, and the upper part of the scraper 35 is connected to the furnace body cover 2.

[0080] Preferably, the furnace body 1 comprises a shell made of high temperature resistant steel and a refractory material layer 36 cast on the inner wall of the shell.

[0081] Preferably, the stirring impeller 4 and the stirring shaft 3 are made of high-temperature resistant steel and are integrally connected, and a layer of refractory material is cast on the outer surface of the stirring impeller 4 and the stirring shaft 3, and a layer of refractory material is cast on the side of the furnace body cover plate 2 facing the furnace body 1.

[0082] Preferably, the scraper 35 comprises a scraper body made of high temperature resistant steel and a refractory material layer cast on the outer surface of the scraper body.

[0083] Preferably, the scraper 35 is integrally connected to the furnace cover 2 .

[0084] In this embodiment, a feeding port 37 is provided on the furnace cover plate 2 , and a feeding cover 38 is provided on the feeding port 37 ; a discharge port 39 is provided on the furnace body 1 , and a discharge door 40 is provided on the discharge port 39 .

[0085] Preferably, a gas circulation pump is provided on the gas separation circulation pipeline 9 of the gas separator 10 .

[0086] Preferably, a gas cooling device is provided on the gas separation circulation pipeline 9 of the gas separator 10 .

[0087] Preferably, a first gas supply pipeline for replenishing the first gas inside the furnace body 1 is provided on the furnace body cover plate 2 .

[0088] Preferably, a pressure measuring tube is provided on the furnace cover plate 2 , and a pressure transmitter for detecting the gas pressure in the furnace body 1 is provided on the pressure measuring tube.

[0089] Preferably, the first fluid dynamic sealing assembly 5 and the second fluid dynamic sealing assembly 6 are respectively provided with a fluid level sensor and a fluid replenishing tube for replenishing water to the first annular water groove 22 and the first annular water groove 30 to maintain the water level height in the first annular water groove 22 and the second annular water groove 30.

[0090] The working principle of the rotary stirring smelting electric furnace in the present invention is as follows: iron ore particles and coke (or coal) are added into the furnace body 1 in proportion, and a certain amount of carbon monoxide is added through the first gas supply pipeline (added at the beginning, and the first gas supply pipeline can be closed when the reaction reaches equilibrium in the later stage), the electric heating element 7 is turned on, and the furnace body 1 and the stirring shaft 3 are driven to rotate respectively, the iron ore particles, coke (or coal) and carbon monoxide gas are fully mixed in the furnace body and heated to the reduction reaction temperature, and reduced iron, carbon monoxide and carbon dioxide are gradually generated in the furnace body 1 through the reduction reaction. The carbon monoxide and carbon dioxide mixed gas in the furnace body 1 is separated by the gas separator 10, and the separated carbon monoxide is returned to the furnace body 1 to continue to participate in the reduction reaction to achieve the self-balance of carbon monoxide supply in the furnace body, and the separated carbon dioxide is recovered or discharged after waste heat utilization. The final product in the furnace body 1 is solid dispersed reduced iron with a purity of more than 90%, which can be used as a raw material for subsequent steelmaking.

[0091] In this embodiment, the gas separator 10 is provided with a carbon dioxide gas separation output pipeline 47 .

[0092] Preferably, a waste heat utilization device 43 is provided on the carbon dioxide gas separation output pipeline 47 .

[0093] Preferably, the waste heat utilization device 43 is a heat exchange device for preheating dispersed iron ore.

[0094] As a further improvement of the present embodiment, an annular air supply chamber 44 and an annular air collecting chamber 45 are respectively provided on the furnace body cover plate 2, and the annular air supply chamber 44 and the annular air collecting chamber 45 are respectively densely covered with air vents 46 connected to the interior of the furnace body 1; the carbon monoxide supply pipeline 42 and the gas return pipeline 12 are respectively connected to the annular air supply chamber 44, and the gas collection pipeline 11 is connected to the annular air collecting chamber 45.

[0095] Preferably, the annular air supply chamber 44 and the annular air collecting chamber 45 are one large and one small and are arranged roughly concentrically; wherein the annular air supply chamber 44 is located at the periphery of the annular air collecting chamber 45, or the annular air collecting chamber 45 is located at the periphery of the annular air supply chamber 44.

[0096] Preferably, in order to avoid other elements on the furnace cover 2 (such as electric heating elements, feeding port components, etc.), the annular air supply chamber 44 and the annular air collecting chamber 45 are not necessarily circular in shape, but can also be curved closed rings or curved semi-closed rings.

[0097] Preferably, the heat exchange device is a heat exchange storage tank, and the heat exchange storage tank is connected to the feeding port component on the furnace cover plate 2.

[0098] It should be pointed out that the rotary stirring smelting electric furnace of the present invention, in addition to being used as a direct reduction furnace for iron ore ironmaking, can also be used for the smelting of other special metals to reduce special metals such as nickel, titanium, etc. from special ores.

[0099] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An efficient and environmentally friendly direct reduction ironmaking method, characterized in that: The raw materials for ironmaking are dispersed iron ore, dispersed coke or coal, and carbon monoxide gas. The smelting furnace for ironmaking is a rotary stirring smelting electric furnace, and a stirring impeller is provided in the rotary stirring smelting electric furnace in the opposite direction of rotation to the rotary stirring smelting electric furnace. The rotary stirring smelting electric furnace is also provided with an electric heating element for heating the raw materials in the furnace, and the rotary stirring smelting electric furnace is connected to a gas separator through a gas separation circulation pipeline. The gas separator is a gas separator for separating carbon monoxide from the gas in the furnace body; by adding a certain proportion of dispersed iron ore and dispersed coke or coal in the furnace, and In the initial stage of iron production, carbon monoxide gas is introduced into the furnace, and the electric heating elements in the furnace are turned on to heat the temperature in the furnace to the reduction ironmaking temperature. Under the action of the rotation of the rotary stirring smelting electric furnace and the rotation of the stirring impeller, the raw materials in the furnace are fully stirred and mixed and evenly heated, and the iron ore is gradually reduced to iron, and carbon monoxide and carbon dioxide gases are generated; wherein, the carbon monoxide and carbon dioxide gases generated in the furnace are led out to the gas separator through a gas separation circulation pipeline to separate the carbon monoxide gas from the carbon dioxide gas, and the separated carbon monoxide is returned to the furnace through the gas separation circulation pipeline to continue to participate in the reduction reaction until the raw materials in the furnace are converted into iron with a high proportion of content.

2. The efficient and environmentally friendly direct reduction ironmaking method according to claim 1, characterized in that: During the iron-making process, a certain amount of carbon monoxide is added to the furnace to maintain the balance of the carbon monoxide gas content and the pressure in the furnace.

3. The efficient and environmentally friendly direct reduction ironmaking method according to claim 1, characterized in that: The iron ore dispersed material is iron ore particles with a diameter of 3 to 20 mm.

4. The efficient and environmentally friendly direct reduction ironmaking method according to claim 1, characterized in that: The reduction ironmaking temperature in the direct reduction ironmaking method is 900-1300°C.

5. The efficient and environmentally friendly direct reduction ironmaking method according to claim 1, characterized in that: The carbon monoxide and carbon dioxide gases generated in the furnace are cooled and then enter the gas separator.

6. The efficient and environmentally friendly direct reduction ironmaking method according to claim 5, characterized in that: The waste heat utilization device is a heat exchange device for preheating dispersed iron ore; during ironmaking, dispersed iron ore is preheated by the waste heat utilization device and then added into the furnace through the conveying device.

7. The efficient and environmentally friendly direct reduction ironmaking method according to claim 1, characterized in that: The rotary stirring smelting electric furnace includes a rotatably arranged vertical furnace body, a furnace cover plate arranged at the furnace body mouth, a stirring shaft passing through the furnace cover plate and inserted into the furnace body, and a stirring impeller arranged on the stirring shaft and located in the furnace body. A first fluid dynamic sealing assembly is arranged between the furnace cover plate and the furnace body mouth, a second fluid dynamic sealing assembly is arranged on the furnace cover plate between the insertion position of the stirring shaft and the stirring shaft, and an electric heating element for heating raw materials inside the furnace body is arranged on the side of the furnace cover plate facing the inside of the furnace body.

8. The efficient and environmentally friendly direct reduction ironmaking method according to claim 7, characterized in that: The rotary stirring smelting electric furnace also includes a base, a pair of columns arranged on the base, and a crossbeam plate arranged on the pair of columns. The furnace body is rotatably arranged on the base, and the furnace body cover is connected to the lower position of the crossbeam plate; the stirring shaft is arranged on the crossbeam plate, and a stirring shaft mounting hole is arranged on the furnace body cover. The stirring shaft passes through the stirring shaft mounting hole and enters the furnace body, and the second fluid dynamic sealing assembly is arranged at a position between the stirring shaft mounting hole and the stirring shaft; a rotating drive mechanism for driving the stirring shaft to rotate is arranged on the crossbeam plate; the rotating drive mechanism is one of a direct drive motor, a belt drive mechanism driven by a reduction motor, and a gear drive mechanism driven by a reduction motor.

9. The efficient and environmentally friendly direct reduction ironmaking method according to claim 7, characterized in that: The first fluid dynamic sealing assembly includes a first annular water groove, which is arranged on the furnace body cover plate. A first annular ring inserted into the first annular water groove is installed on the furnace body to form a water seal between the furnace body cover plate and the furnace body. A first cooling device is arranged on the first annular water groove.

10. The efficient and environmentally friendly direct reduction ironmaking method according to claim 7, characterized in that: The second fluid dynamic sealing assembly includes a second annular ring arranged on the stirring shaft and a second annular water groove arranged on the upper part of the furnace body cover plate. The second annular ring is inserted into the second annular water groove to achieve water sealing between the stirring shaft and the stirring shaft mounting hole of the furnace body cover plate. A second cooling device is arranged on the second annular water groove.

11. The efficient and environmentally friendly direct reduction ironmaking method according to claim 7, characterized in that: A first overflow gas negative pressure recovery cover is arranged on the periphery of the first fluid dynamic sealing component; and a second overflow gas negative pressure recovery cover is arranged on the periphery of the second fluid dynamic sealing component.

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