Device for continuously producing Fe3C by adopting low-carbon-activity reducing gas
By adopting a low-carbon-activity CO-CO2 mixed gas and a uniform gas contact design, the problem of unstable Fe3C production was solved, achieving efficient and stable Fe3C preparation. This provides high-purity Fe3C raw materials for electric arc furnace steelmaking and solves the environmental and resource problems of traditional steelmaking processes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-13
- Publication Date
- 2026-03-17
AI Technical Summary
Existing technologies cannot stably produce Fe3C, mainly because the reaction is uneven due to the high carbon activity of the CO-CO2 mixed gas, resulting in low and unstable production efficiency.
Using a low-carbon-activity CO-CO2 mixed gas, and through a uniformly distributed stage and gas inlet pipe design, the gas flow rate and concentration are controlled to ensure uniform gas contact with the reactants. A quartz tube and silicone sealed structure are used to achieve continuous production of Fe3C.
It has achieved efficient and stable Fe3C production, providing high-purity Fe3C to replace scrap steel, suitable for electric arc furnace steelmaking to manufacture high-grade steel, and solving the environmental and resource depletion problems of the traditional blast furnace-converter process.
Smart Images
Figure CN223996090U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to technologies for significantly reducing carbon dioxide emissions in the steel industry and to the field of raw materials for the production of high-grade steel, specifically to a device for the continuous production of Fe3C using a low-carbon activity reducing gas. Background Technology
[0002] The traditional blast furnace-converter steelmaking process suffers from excessive carbon dioxide emissions and depletion of mineral resources. In China, the amount of scrap steel produced annually continues to increase, while the current blast furnace-converter method generates significant amounts of CO2. To address these issues, steel companies are considering transitioning to electric arc furnace (EAF) steelmaking. EAF scrap smelting is widely considered the steelmaking method with the lowest CO2 emissions and has become the mainstream method in the US and EU. However, high-grade steels produced using the blast furnace-converter method, such as automotive steel sheets, cannot be manufactured using EAF steelmaking, which primarily uses scrap steel. When scrap steel is used as an EAF feedstock, the accumulation of impurities such as Cu in the steel products becomes a major problem, necessitating the use of an iron source free of reducing iron and other impurities to reduce impurity concentration. Therefore, a new iron source is needed to replace scrap steel in the production of these high-grade steels in EAFs.
[0003] Fe3C (cementite) typically exists in granular, flaky, or network forms. It is chemically stable at room temperature and does not readily ignite, making it safe for transportation and storage. In high-temperature molten steel, although affected by the temperature and composition of the steel, cementite dissolves rapidly. In actual production, its uniform dissolution in molten steel can be achieved by controlling the addition rate and temperature. Furthermore, the decomposition of cementite produces fine bubbles that can be stirred to form steel. Steel baths possess several excellent properties, such as balancing internal temperature and promoting denitrification reactions, making them an ideal choice for replacing scrap steel. However, due to the thermodynamic instability of Fe3C, stable industrial production has not yet been achieved. To date, Fe3C production has utilized CO-CO2 mixed gases with a carbon activity above 1000, which cannot suppress carbon precipitation, a major reason for the lack of stable production. Utility Model Content
[0004] To address the aforementioned shortcomings of existing Fe3C production processes, the purpose of this invention is to provide an apparatus for the continuous production of Fe3C using a low-carbon activity reducing gas. This apparatus uses iron oxide as raw material and employs a method for the stable production of Fe3C using a low-carbon activity reducing gas. This process has a short flow rate and low energy consumption, achieving technological innovation in Fe3C production.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0006] According to the technical solution of this utility model, an apparatus for continuous production of Fe3C using a low-carbon activity reducing gas is provided. The apparatus includes: a reactor body, a furnace cover, a platform, and a low-carbon activity reducing gas inlet pipe.
[0007] The reactor body is a cylindrical tubular structure with a furnace cover at the top and a platform at the bottom.
[0008] The feed pipe is inserted into the center opening of the furnace cover, and a thermocouple is placed in the opening next to the feed pipe.
[0009] The stage has multiple micropores evenly distributed on it, and the lower part of the stage is connected to the inlet pipe for the low-carbon activity reducing gas.
[0010] Furthermore, the low-carbon-activity reducing gas introduced into the pipeline is a CO-CO2 mixture with a carbon activity of 1.5 to 5.
[0011] Here, the thermocouple is used to measure the temperature of the furnace charge inside the reactor during the experiment.
[0012] Furthermore, during the experiment, the inlet of the feed pipe was sealed with a silicone plug.
[0013] Furthermore, the reactor body is a quartz tube with a diameter of 30 mm and a height of 600 mm.
[0014] Furthermore, the furnace cover is made of silicone material.
[0015] Furthermore, the gas outlet is provided near the top of the main body of the reactor, and the material outlet is provided at the bottom.
[0016] Furthermore, the stage has the same diameter as the reactor body, which is 30 mm; its thickness is 5 mm, and its surface is uniformly distributed with multiple holes of 30-50 micrometers.
[0017] In existing technologies, reduction reactions are often achieved by directly introducing gas. However, due to gas inhomogeneity, the reaction time is long and the reaction efficiency is low. Therefore, to address the adverse effects of gas inhomogeneity on reaction time and efficiency, based on theoretical analysis and experimental verification, the applicant has combined the aforementioned thickness and aperture to propose a device with a stage featuring multiple uniformly distributed holes. This device ensures a stable and uniform flow of gas into the furnace while preventing the penetration and fall of solid reactants, thus maximizing reaction efficiency.
[0018] Furthermore, the height of the air outlet near the furnace cover is 500-800mm, preferably 500mm. This height ensures the smooth discharge of exhaust gas.
[0019] Furthermore, the lower end of the thermocouple is adjacent to the surface of the furnace charge.
[0020] Furthermore, the discharge port is located adjacent to the inner bottom surface of the reactor body. This proximity ensures the smooth discharge of the reacted material.
[0021] Furthermore, the lower end of the feed pipe is 550-1000mm above the inner bottom surface of the reactor body, preferably 600mm.
[0022] Furthermore, the gas outlet is connected to a gas analyzer.
[0023] During the experiment, the gas concentration, flow rate, and velocity were adjusted by measuring the composition of the gas at the outlet using a connected gas analyzer. After the gas analyzer measured the composition, the initial gas concentration, flow rate, and velocity settings were monitored and verified to ensure their rationality. Furthermore, the changes in gas component concentration detected during the reaction were analyzed and adjusted accordingly.
[0024] The beneficial effects of this utility model are as follows:
[0025] This device enables control over the carbon concentration in the gas while allowing for stable gas flow contact with the experimental sample. It also controls the carbon concentration in the gas during the reaction process, achieving the goal of preparing Fe3C using low-carbon-activity gas under these conditions. This allows for the stable and continuous preparation of Fe3C for industrial production. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0027] Figure 1 This is a schematic diagram of the apparatus for the continuous production of Fe3C using a low-carbon activity reducing gas according to Embodiment 1 of the present invention.
[0028] Figure 2 The image shows the XRD pattern of Fe3C prepared by thermal reduction of powdered iron oxide in Example 1 of this invention.
[0029] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0030] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0031] This invention utilizes a low-carbon-concentration CO-CO2 mixed gas to produce Fe3C, enabling stable production of high-purity Fe3C. The preparation process is simple and provides a stable, high-quality Fe source for the electric arc furnace (EAF) process in producing high-grade steel. Faced with the environmental problems inherent in the traditional blast furnace-converter steelmaking process, the steel industry is gradually adopting the EAF method. To manufacture high-grade steel, high-purity Fe3C is needed to replace scrap steel. The structure involved in this invention enables the production of Fe3C using a low-carbon-concentration CO-CO2 mixed gas, achieving both low-carbon metallurgy and a stable supply of raw materials for blast furnace smelting of high-grade steel.
[0032] Specifically, this utility model provides an apparatus for the continuous production of Fe3C using a low-carbon activity reducing gas. The apparatus includes: a reactor body, a furnace cover, a platform, and a gas inlet pipe.
[0033] The reactor body is a cylindrical tubular structure with a furnace cover at the top and a platform at the bottom.
[0034] The feed pipe is inserted into the center opening of the furnace cover, and a thermocouple is placed in the opening next to the feed pipe.
[0035] The stage is uniformly distributed with micropores, allowing CO-CO2 mixed gas to be introduced into the reactor body through the gas inlet pipe at the bottom of the stage.
[0036] In a preferred embodiment, the thermocouple is used to measure the temperature of the sample inside the reactor body during the experiment.
[0037] In a preferred embodiment, the inlet of the feed pipe is sealed with a silicone plug during the experiment.
[0038] In a preferred embodiment, the reactor body is a quartz tube with a diameter of 30 mm and a height of 600 mm.
[0039] In a preferred embodiment, the furnace cover is a silicone cover.
[0040] In a preferred embodiment, the gas outlet is located near the top of the main body of the reactor, and the material outlet is located at the bottom.
[0041] In a preferred embodiment, the stage is approximately 5 mm thick.
[0042] In a preferred embodiment, during the experiment, the gas concentration, flow rate, and velocity are adjusted by measuring the composition of the gas outlet.
[0043] Example 1
[0044] like Figure 1 As shown, the reactor body used in this embodiment is a quartz tube 1 with a diameter of 30mm and a height of 600mm. A silicone cap is used at the top of the quartz tube to ensure a tight seal. A feed pipe 2 is inserted through a central opening in the cap, and a thermocouple 3 is placed next to the feed pipe. Thermocouple 3 is used to measure the temperature of the sample during the experiment. The feed pipe opening is sealed with a silicone plug during the experiment. An outlet 4 is inserted near the top of the quartz tube body, and the bottom opening is designated as the discharge port 5. A breathable quartz stage 6, approximately 5mm thick, is located at the bottom of the quartz tube. This stage has evenly distributed micropores, enabling uniform gas dispersion and stable airflow, while also providing a carrying function. During the experiment, the gas concentration and flow rate are adjusted by measuring the composition of the gas at the outlet.
[0045] Using the above apparatus, the Fe3C preparation method in this embodiment includes the following steps:
[0046] (1) Powdered iron oxide 7 is placed at the bottom of the device from the top through the feed pipe 2 and is supported by the platform;
[0047] (2) Mix CO and CO2 gas mixture 8, and control the carbon activity of the mixed gas at 5;
[0048] (3) The mixed gas is introduced into the fluidized bed from bottom to top;
[0049] (4) Control the fluidized bed temperature to 700℃ and keep it at that temperature for 60 minutes.
[0050] (5) After the system cools down to room temperature, turn off the CO-CO2 mixed gas and release the reduction product from the outlet 5.
[0051] The products prepared in the examples were structurally characterized.
[0052] Figure 2 The image shows the XRD pattern of Fe3C prepared by thermal reduction of powdered iron oxide in Example 1. The diffraction peaks of Fe3C in the sample can all be indexed to the tetragonal Fe3C structure (JCPDS No. 89-7271), which indicates that the prepared product has the structural framework of Fe3C.
[0053] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model and using the contents of the present utility model specification, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.
Claims
1. An apparatus for continuous production of Fe3C using a low-carbon activity reducing gas, characterized by, The device comprises a reaction furnace body, a furnace body cover, a carrier and a low-carbon activity reducing gas inlet pipeline, The reaction furnace body is a cylindrical tubular structure, the top end is provided with the furnace body cover, and the lower end is provided with the carrier; The center hole of the furnace body cover is inserted into the feeding pipeline, and the hot thermocouple is placed beside the hole of the feeding pipeline; The carrier is uniformly distributed with a plurality of micropores, and the lower part of the carrier is communicated with the low-carbon activity reducing gas inlet pipeline.
2. The apparatus for continuous production of Fe3C using low-carbon activity reducing gas according to claim 1, characterized by, The low-carbon activity reducing gas inlet pipeline is internally filled with CO-CO2 mixed gas with carbon activity of 1.5-5.
3. The apparatus for continuous production of Fe3C using low-carbon activity reducing gas according to claim 1, characterized by, The nozzle of the feeding pipeline is sealed with silica gel plug.
4. The apparatus for continuous production of Fe3C using low-carbon activity reducing gas according to claim 1, characterized by, The main body of the reaction furnace body is provided with a gas outlet near the top end and a discharge port at the bottom end.
5. The apparatus for continuous production of Fe3C using low-carbon activity reducing gas according to claim 4, characterized by, The diameter of the carrier is the same as that of the reaction furnace body, the thickness is 5mm, and the surface is uniformly distributed with a plurality of 30-50 microns holes; The height of the position of the gas outlet close to the furnace body cover is 500-800mm; The height of the lower end of the feeding pipeline from the inner bottom surface of the reaction furnace body is 550-1000mm.
6. The apparatus for continuous production of Fe3C using low-carbon activity reducing gas according to claim 5, characterized by, The gas outlet is communicated with a gas analyzer.
7. The apparatus for continuous production of Fe3C using low-carbon activity reducing gas according to claim 1, characterized by, The reaction furnace body is a quartz tube, the diameter of the quartz tube is 30mm, and the height is 600mm.
8. The apparatus for continuous production of Fe3C using low-carbon activity reducing gas according to claim 1, characterized by, The furnace body cover is a silica gel cover.
9. The apparatus for continuous production of Fe3C using low-carbon activity reducing gas according to claim 1, characterized by, The lower end of the hot thermocouple is adjacent to the surface of the furnace charge.
10. The apparatus for continuous production of Fe3C using low-carbon activity reducing gas according to claim 4, characterized by, The discharge port is adjacent to the inner bottom surface of the reaction furnace body.