A 1kg-level high-temperature electrolytic ironmaking experimental device and experimental method

Abstract

The present invention discloses a 1kg-level high-temperature electrolytic ironmaking experimental device and experimental method, which relate to the technical field of molten oxide electrolytic ironmaking, and are intended to solve the problem that the existing high-temperature electrolytic ironmaking lacks experimental equipment for production; the upper and lower ends of the heating furnace of the experimental device of the present invention are respectively provided with a top lifting device and a bottom lifting device, and the top lifting device is inserted with a cathode, a stirring paddle and an anode, and the cathode and the anode are electrically connected to an electrochemical analyzer; a bottom opening is provided at the lower part of the heating furnace, and a bottom refractory platform is provided at the upper end of the bottom lifting device, an electrolysis container is provided at the upper end, and a furnace bottom block is fixed at the lower end, and a plurality of holes are provided on the bottom refractory platform and the furnace bottom block to connect the inside and outside of the heating furnace, which are used to introduce protective gas into the heating furnace, and an exhaust pipe is also provided on the upper part of the heating furnace for exhausting gas; the present invention can study the influence of different factors on the behavior of high-temperature electrolytic iron, explore the process parameters of high-temperature electrolytic ironmaking, and provide a new way for green and low-carbon ironmaking.

Description

Technical Field

[0001] The present invention relates to the technical field of molten oxide electrolytic ironmaking, in particular to a 1kg-level high-temperature electrolytic ironmaking experimental device and an experimental method. Background Art

[0002] The steel industry is energy-intensive and highly polluting. The traditional blast furnace process consumes approximately 350 kg of coke and 150 kg of pulverized coal to produce one ton of pig iron. The use of fossil fuels results in significant CO2 and CO emissions during ironmaking and steelmaking. The traditional blast furnace process dominates ironmaking, using raw materials such as sintered ore, pelletized ore, lump ore, coke, and PCI (pulverized coal injection), with sintered ore and coke being the primary raw materials. However, sintering and coking processes carry a high environmental burden, and coking requires high-quality coking coal, a resource that is becoming increasingly scarce. To reduce CO2 emissions in the steel industry, carbon input can be reduced or even eliminated as a reducing agent. High-temperature electrolytic ironmaking is a cutting-edge, low-carbon ironmaking technology. In theory, iron ore powder is heated to a molten state. Electricity is then applied to two electrodes inserted into the melt, producing pure iron near the cathode and pure oxygen near the anode.

[0003] At present, there is little research in the field of high-temperature electrolytic ironmaking technology, and related thermodynamics, material balance and other calculations are mainly carried out in theory. It is necessary to develop a high-temperature electrolytic ironmaking experimental device and experimental method to facilitate more in-depth and more targeted experimental research to serve production, and provide more reliable data support for green and low-carbon ironmaking. Summary of the Invention

[0004] The purpose of the present invention is to provide a 1kg-level high-temperature electrolytic ironmaking experimental device and experimental method to solve the problem that the existing high-temperature electrolytic ironmaking lacks experimental equipment for production.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a 1kg-level high-temperature electrolytic ironmaking experimental device, comprising a heating furnace and an electrochemical analyzer, wherein a top lifting device and a bottom lifting device are respectively provided at the upper and lower ends of the heating furnace, wherein a plurality of insertion holes are opened at positions corresponding to the upper end of the heating furnace on the top lifting device, into which a cathode, a stirring paddle and an anode are respectively inserted, and the lifting movement of the top lifting device is used to drive the lower ends of the cathode, the stirring paddle and the anode to be lifted and lowered in the heating furnace, and the cathode and the anode are respectively electrically connected to the negative electrode and the positive electrode of the electrochemical analyzer through the cathode lead and the anode lead; A bottom opening is provided at the lower part of the furnace, and a bottom refractory platform is provided at the upper end of the bottom lifting device for entering and exiting the heating furnace through the bottom opening by lifting; an electrolysis container is provided at the upper end of the bottom refractory platform, and the movement range of the lower ends of the cathode, stirring paddle and anode are all within the range surrounded by the inner walls of the electrolysis container. A furnace bottom block is fixed at the lower end of the bottom refractory platform, and its shape and size match the bottom opening, which is used to seal the bottom opening when the electrolysis container is lifted into place. A plurality of holes are also provided on the bottom refractory platform and the furnace bottom block for connecting the inside and outside of the heating furnace, which are used to introduce protective gas into the heating furnace. An exhaust pipe is also provided on the upper part of the heating furnace for exhausting gas.

[0006] Preferably, the heating furnace is provided with an observation window made of high-temperature resistant transparent material for viewing the internal conditions.

[0007] Preferably, the bottom lifting device is lifted and lowered by a screw rod, and the screw rods are arranged on both sides of the bottom of the heating furnace and are respectively connected to the two sides of the bottom lifting device for transmission.

[0008] Preferably, the heating furnace is provided with a plurality of silicon-molybdenum rods for heating, and the heating furnace is also provided with a temperature measuring thermocouple for measuring the internal temperature.

[0009] Preferably, the electrolysis container is a crucible made of oxidation-resistant material.

[0010] Preferably, a bottom air inlet is fixedly provided at the lower end of the bottom lifting device, which is connected to multiple air pipes through an air distribution device, and respectively penetrates and is fixed in the holes opened on the bottom refractory platform and the furnace bottom block.

[0011] Preferably, the experimental device also includes a computer control system, which is signal-connected to the top lifting device, the bottom lifting device, the stirring paddle, the electrochemical analyzer, the temperature measuring thermocouple, the electric heating system of the silicon molybdenum rod, and the protective gas supply system.

[0012] Preferably, the materials of the cathode and the anode include but are not limited to one or more of graphite, molybdenum, and chromium-iron alloy.

[0013] Another technical solution provided by the present invention is a 1kg-level high-temperature electrolytic ironmaking experimental method, which uses the above-mentioned experimental device and includes the following specific steps:

[0014] S1 Test raw material configuration: According to the specific chemical composition of the experimental iron ore powder, analytically pure CaO, SiO2, Al2O3, and MgO reagents are added to adjust the chemical composition range of the test raw materials to ensure that the melt has good flow properties at high temperatures and does not affect the electron transport of the electrolyte;

[0015] S2 Device Preparation: Place the test raw materials into the electrolytic container, place it on the bottom refractory platform, start the bottom lifting device, and raise the electrolytic container into the heating furnace until the bottom opening is sealed tightly by the furnace bottom block;

[0016] S3: Shielding gas is passed through the holes on the bottom refractory platform and the bottom block to continuously introduce shielding gas into the heating furnace;

[0017] S4: Heating the furnace to increase temperature; according to the CaO-MgO-SiO2-Al2O3 quaternary slag system diagram, determine the theoretical melting temperature of the test raw materials, control the heating rate between 5 and 15 ° C / min, and when the temperature reaches the theoretical melting temperature +, but not exceeding 1600 ° C, lower the stirring paddle into the melt to stir and mix the melt thoroughly;

[0018] S5: Electrolysis begins. After stirring for a while, the stirring paddle ensures that the cathode and the lower end of the anode are located in the melt. The electrochemical analyzer is started. During the experiment, the effects of different experimental conditions on the behavior of high-temperature electrolytic iron are recorded and analyzed.

[0019] After the S6 electrolysis reaction is completed, the electrolysis container is taken out from the bottom port and the chemical composition of the iron is analyzed.

[0020] Preferably, in step S1, the chemical composition of the test raw materials is adjusted to control the binary basicity R2 (CaO / SiO2) of the final melt to be between 0.9 and 1.2, and the quaternary basicity R4 (CaO+MgO / SiO2+Al2O3) to be between 1.0 and 1.1.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The 1kg-level high-temperature electrolytic ironmaking experimental device has a simple and reasonable structure. It uses two sets of lifting devices to control the movement of the stirring device, electrodes, and electrolysis container relative to the heating furnace, thereby realizing operations such as raw material feeding, stirring, and electrolysis, and is easy to operate.

[0023] 2. This 1kg-level high-temperature electrolytic ironmaking experimental method has simple steps and is easy to operate. By conducting experimental research on high-temperature electrolytic ironmaking, we can study the effects of various factors such as different voltages, electrode insertion depth into the melt, melt alkalinity, and anode atmosphere on the behavior of high-temperature electrolytic iron, explore the process parameters of high-temperature electrolytic ironmaking, and provide a new path for green and low-carbon ironmaking. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of the experimental device of the present invention.

[0025] In the figure: 1 screw; 2 observation window; 3 heating furnace; 4 top lifting device; 5 cathode lead; 6 cathode; 7 stirring paddle; 8 anode; 9 anode lead; 10 gas outlet pipe; 11 electrochemical analyzer; 12 silicon molybdenum rod; 13 crucible; 14 temperature measuring thermocouple; 15 bottom refractory platform; 16 furnace bottom block; 17 bottom lifting device; 18 bottom air inlet. DETAILED DESCRIPTION

[0026] like Figure 1 As shown, a 1kg-level high-temperature electrolytic ironmaking experimental device includes a heating furnace 3 and an electrochemical analyzer 11, and a top lifting device 4 and a bottom lifting device 17 are respectively provided at the upper and lower ends of the heating furnace 3, wherein the top lifting device 4 is provided with a plurality of insertion holes at positions corresponding to the upper end of the heating furnace 3, and a cathode 6, a stirring paddle 7 and an anode 8 are respectively inserted (the materials of the cathode 6 and the anode 8 are not limited to graphite, molybdenum, chromium-iron alloy, etc.), and the lifting movement of the top lifting device 4 is used to drive the lower ends of the cathode 6, the stirring paddle 7 and the anode 8 to be lifted and lowered in the heating furnace 3 (similarly, the stirring paddle 7 can also be provided with another lifting device separately, so that the electrode does not enter the raw material for stirring, which is conducive to uniform stirring. After stirring for a period of time, the electrode is lowered into the electrolysis container by the electrode lifting device), and the cathode 6 and the anode 8 are respectively connected to the negative electrode and the positive electrode of the electrochemical analyzer 11 through the cathode The lead 5 and the anode lead 9 are electrically connected; a bottom opening is provided at the lower part of the heating furnace 3, and a bottom refractory platform 15 is provided at the upper end of the bottom lifting device 17 for entering and exiting the heating furnace 3 through the bottom opening by lifting; an electrolysis container is provided at the upper end of the bottom refractory platform 15, and the electrolysis container can adopt a crucible 13 of oxidation-resistant material, and the material can be specifically graphite, molybdenum, tungsten, iridium, etc. The moving range of the lower ends of the cathode 6, the stirring paddle 7 and the anode 8 are all within the range surrounded by the inner walls of the electrolysis container, and a furnace bottom block 16 is fixed at the lower end of the bottom refractory platform 15, and its shape and size are matched with the bottom opening, and it is used to seal the bottom opening when the electrolysis container is lifted into place, and a plurality of holes are provided on the bottom refractory platform 15 and the furnace bottom block 16 to connect the inside and outside of the heating furnace 3, for introducing protective gas, such as nitrogen or argon, into the heating furnace 3. An exhaust pipe 10 is also provided on the upper part of the heating furnace 3 for exhausting the experimental exhaust gas.

[0027] The bottom lifting device 17 can be lifted and lowered by a screw rod 1. The screw rod 1 can be set on both sides of the bottom of the heating furnace 3 and respectively connected to the two sides of the bottom lifting device 17. Of course, an electric hydraulic cylinder can also be used for lifting. For reference, the net lifting height can be 500 to 1000 mm, and the diameter of the bottom refractory platform should be 300 to 600 mm. Similarly, the top lifting device 4 can also be driven by a screw rod. Of course, it is not limited to this, as long as the lifting is stable and reliable, the speed is adjustable, and the in-and-out furnace positioning is accurate.

[0028] For the heating method of the heating furnace 3, the following common structure can be adopted: a number of silicon-molybdenum rods 12 are fixed for heating, such as 6-8 silicon-molybdenum rods distributed in a circular array and fixed around the top of the furnace. The heating rate can generally be adjusted within 0-20°C / min. Other structures can also be used, as long as the ability to heat the furnace to 1700°C is met and the normal operating temperature is stabilized at 1600°C (≥5h); in order to facilitate monitoring and adjustment of the specific heating temperature, the heating furnace 3 can also be fixed with a temperature measuring thermocouple 14 for measuring the internal temperature, which can be located on one side wall of the heating furnace 3, or multiple temperature measuring points can be evenly arranged in the heating furnace 3 to take the average value, and the temperature control accuracy is preferably ±1°C.

[0029] In a preferred embodiment, the specific protective gas supply system may include the following structure, a bottom air inlet 18 is fixedly provided at the lower end of the bottom lifting device 17, which is connected to multiple air pipes through a gas distribution device, and respectively penetrates and is fixed in the holes opened on the bottom refractory platform 15 and the furnace bottom block 16. In addition, the bottom air inlet 18 can be connected to the air circuit, and the air circuit is generally also provided with a flow meter, a pressure gauge, etc., and the protective gas supply amount can also be controlled by a valve. The specific air circuits are common existing technologies, so they will not be repeated here; for reference, the holes opened on the air pipe and the bottom refractory platform 15 and the furnace bottom block 16 can be 6 evenly distributed. During the experiment, the flow rate of protective gas should be controlled to 3-5L / min to ensure that the protective gas fills the entire furnace during the experiment.

[0030] The experimental device may further include a computer control system, which can be signal-connected to the top lifting device 4, the bottom lifting device 17, the stirring paddle 7, the electrochemical analyzer 11, the temperature measuring thermocouple 14, the electric heating system of the silicon-molybdenum rod 12, and the protective gas supply system; for reference, the computer control system can display and control the furnace temperature online in real time; control the lifting and lowering of the top lifting device and the bottom lifting device, and the electrolysis behavior of the iron ore powder, and the computer screen can display the lifting height value; can control the start and shut down of the electrochemical analyzer, and the computer screen obtains the open circuit voltage-time curve, linear scan curve, current I-time t curve, and can save historical data for retrospective comparison, etc.; the computer control system may also have over-temperature alarm and thermocouple breakage alarm functions, and can automatically cut off the power supply in case of danger, etc., to provide reliable protection; the above specific control operations are not difficult to think of based on the device provided by the present invention, so on the basis of the present invention, it is also expected to continue to make relevant control improvements and improvements.

[0031] For reference, the heating furnace 3 can adopt a three-layer full-fiber lining. The first layer: 1800 type polycrystalline alumina ceramic fiber, which ensures sufficient strength of the furnace and excellent thermal insulation effect; the second layer: 1430 type polycrystalline alumina ceramic fiber; the third layer: some thermal insulation cotton.

[0032] In addition, the heating furnace 3 can also be provided with an observation window 2 made of high-temperature resistant transparent material for checking the internal situation, such as whether experimental raw materials splash out of the electrolysis container, etc. The position can be at the top or on the side, preferably in the middle of the side.

[0033] The experimental method for high-temperature electrolytic ironmaking using the above experimental device can be referred to as follows:

[0034] S1 Test raw material configuration: According to the specific chemical composition of the experimental iron ore powder, add analytically pure CaO, SiO2, Al2O3, and MgO reagents to adjust the chemical composition range of the test raw materials to ensure that the melt has good flow properties at high temperatures and does not affect the electron transport of the electrolyte. For reference only, the chemical composition of the test raw materials can be adjusted to control the binary basicity R2 (CaO / SiO2) of the final melt to be between 0.9 and 1.2, and the quaternary basicity R4 (CaO+MgO / SiO2+Al2O3) to be between 1.0 and 1.1;

[0035] S2 Device Preparation: Place the test raw materials into the electrolytic container, place it on the bottom refractory platform, start the bottom lifting device, and raise the electrolytic container into the heating furnace until the bottom opening is sealed tightly by the furnace bottom block;

[0036] S3: Protective gas is passed through the holes on the bottom refractory platform and the furnace bottom block to continuously pass protective gas into the heating furnace to ensure that the electrolysis container and electrodes are not oxidized and corroded during the experiment. At the same time, the partial pressure of O2 generated by anode electrolysis under high temperature power is reduced to promote the continuous electrolysis reaction.

[0037] S4: The heating furnace is heated; according to the CaO-MgO-SiO2-Al2O3 quaternary slag system diagram, the theoretical melting temperature of the test raw material is determined, and the heating rate is controlled between 5 and 15°C / min. When the temperature reaches the theoretical melting temperature + 20 to 50°C and does not exceed 1600°C, the stirring paddle is lowered into the melt to stir and mix the melt thoroughly. The specific lowering height of the stirring paddle can be controlled by the computer control system;

[0038] S5 starts electrolysis; after the stirring paddle stirs for a period of time (e.g., 30 to 60 minutes), ensure that the lower ends of the cathode and anode are located in the melt, or further ensure that they reach a specific position (according to experimental needs or other specified goals), start the electrochemical analyzer, power the electrodes, and record and analyze the effects of different experimental conditions on the behavior of high-temperature electrolytic iron during the experiment, such as current, voltage, electrode insertion depth into the melt, melt alkalinity, anode atmosphere, etc.;

[0039] After the S6 electrolysis reaction is completed, the electrolysis container is taken out from the bottom port and the chemical composition of the iron is analyzed.

[0040] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined by the claims.

[0041] Any matters not described in detail in the present invention are well-known technologies to those skilled in the art.

Claims

1. A 1kg-level high-temperature electrolytic ironmaking experimental method, characterized by: The experimental device used includes a heating furnace (3) and an electrochemical analyzer (11). A top lifting device (4) and a bottom lifting device (17) are respectively provided at the upper and lower ends of the heating furnace (3). A plurality of insertion holes are provided at the positions of the top lifting device (4) corresponding to the upper end of the heating furnace (3), and cathodes (6), stirring paddles (7) and anodes (8) are respectively inserted therein. The lifting movement of the top lifting device (4) is used to drive the lower ends of the cathodes (6), stirring paddles (7) and anodes (8) to lift and lower in the heating furnace (3). The cathodes (6) and anodes (8) are respectively electrically connected to the negative and positive electrodes of the electrochemical analyzer (11) through cathode leads (5) and anode leads (9). The bottom of the heating furnace (3) is provided with a bottom hole. The bottom lifting device (17) is provided with a bottom refractory platform (15) at the upper end thereof for entering and exiting the heating furnace (3) through the bottom opening by lifting; an electrolysis container is provided at the upper end of the bottom refractory platform (15); the movement range of the lower ends of the cathode (6), the stirring paddle (7) and the anode (8) are all within the range surrounded by the inner walls of the electrolysis container; a furnace bottom blocking block (16) is fixed at the lower end of the bottom refractory platform (15), the shape and size of which match the bottom opening, and is used to seal the bottom opening when the electrolysis container is lifted into place; the bottom refractory platform (15) and the furnace bottom blocking block (16) are also provided with a plurality of holes connecting the inside and outside of the heating furnace (3) for introducing protective gas into the heating furnace (3); an air outlet pipe (10) is also provided at the upper part of the heating furnace (3) for exhausting gas; The experimental method comprises the following steps: S1 Test raw material configuration: According to the specific chemical composition of the experimental iron ore powder, analytically pure CaO, SiO2, Al2O3, and MgO reagents are added to adjust the chemical composition range of the test raw materials to ensure that the melt has good flow properties at high temperatures and does not affect the electron transport of the electrolyte; S2 Device Preparation: Place the test raw materials into the electrolytic container, place it on the bottom refractory platform, start the bottom lifting device, and raise the electrolytic container into the heating furnace until the bottom opening is sealed tightly by the furnace bottom block; S3: Shielding gas is passed through the holes on the bottom refractory platform and the bottom block to continuously introduce shielding gas into the heating furnace; S4: The heating furnace is heated; according to the CaO-MgO-SiO2-Al2O3 quaternary slag system diagram, the theoretical melting temperature of the test raw material is determined, and the heating rate is controlled between 5 and 15°C / min. When the temperature reaches the theoretical melting temperature + 20 to 50°C and does not exceed 1600°C, the stirring paddle is lowered into the melt to stir and mix the melt thoroughly; S5: Electrolysis begins. After stirring for a while, the stirring paddle ensures that the cathode and the lower end of the anode are located in the melt. The electrochemical analyzer is started. During the experiment, the effects of different experimental conditions on the behavior of high-temperature electrolytic iron are recorded and analyzed. After the S6 electrolysis reaction is completed, the electrolysis container is taken out from the bottom port and the chemical composition of the iron is analyzed.

2. A 1kg-level high-temperature electrolytic ironmaking experimental method according to claim 1, characterized in that: The heating furnace (3) is provided with an observation window (2) made of a high-temperature resistant transparent material for viewing the internal conditions.

3. The 1kg-level high-temperature electrolytic ironmaking experimental method according to claim 1, characterized in that: The bottom lifting device (17) is driven by a screw rod (1) for lifting. The screw rod (1) is arranged at both sides of the bottom of the heating furnace (3) and is respectively connected to both sides of the bottom lifting device (17) for driving.

4. The 1kg-level high-temperature electrolytic ironmaking experimental method according to claim 1, characterized in that: The heating furnace (3) is fixedly provided with a plurality of silicon molybdenum rods (12) for heating, and the heating furnace (3) is also fixedly provided with a temperature measuring thermocouple (14) for measuring the internal temperature.

5. The 1kg-level high-temperature electrolytic ironmaking experimental method according to claim 1, characterized in that: The electrolysis container uses a crucible (13) made of oxidation-resistant material.

6. The 1kg-level high-temperature electrolytic ironmaking experimental method according to claim 1, characterized in that: The bottom lifting device (17) is fixedly provided with a bottom air inlet (18) at the lower end, which is connected to multiple air pipes through an air distribution device, and respectively penetrates and is fixed in the holes opened on the bottom refractory platform (15) and the furnace bottom block (16).

7. A 1kg-level high-temperature electrolytic ironmaking experimental method according to claim 4, characterized in that: The experimental device also includes a computer control system, which is signal-connected to the top lifting device (4), the bottom lifting device (17), the stirring paddle (7), the electrochemical analyzer (11), the temperature measuring thermocouple (14), the electric heating system of the silicon molybdenum rod (12), and the protective gas supply system.

8. The 1kg-level high-temperature electrolytic ironmaking experimental method according to claim 4, characterized in that: The materials of the cathode (6) and the anode (8) include one or more of graphite, molybdenum, and chromium-iron alloy.

9. The 1kg-level high-temperature electrolytic ironmaking experimental method according to claim 1, characterized in that: In the step S1, the chemical composition of the test raw materials is adjusted to control the binary basicity R2: CaO / SiO2 of the final melt to be 0.9-1.2, and the quaternary basicity R4: CaO+MgO / SiO2+Al2O3 to be 1.0-1.1.

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