Apparatus and method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere

Abstract

The present invention provides an apparatus and method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere. [Solution] The apparatus includes an airtight heating device for heating a reaction sample, an intake device connected to the airtight heating device for introducing an inert gas and / or reducing gas into the airtight heating device, a gas analyzer for analyzing a portion of the discharged gas, a thermogravimetric analyzer for analyzing weight changes due to reduction, a gas convection mitigation unit provided between the airtight heating device and the thermogravimetric analyzer to reduce turbulence in the gas reflux relative to the measurement of the thermogravimetric analyzer, and a gas diversion device provided between the gas convection mitigation unit and the gas analyzer to divert the discharged gas and maintain the discharged gas at a constant flow velocity or constant flow rate. Based on the measured values ​​of the gas analyzer and the thermogravimetric analyzer, the degree of reduction of iron ore under different reducing atmospheres is calculated.

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for calculating the degree of reduction of iron ore, and more specifically, to an apparatus and method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere. [Background technology]

[0002] In conventional steelmaking processes, carbon-based metallurgy methods result in massive emissions of carbon dioxide, making them a major cause of global warming. In the international market, a carbon tax system may be introduced in the future, which would be particularly detrimental to the sustainable development of carbon-based metallurgy.

[0003] As an alternative technological means, hydrogen is generally considered to be used as an alternative reducing agent because the byproduct of hydrogen-based reduction is harmless water (H2O), and both its applicability and environmental protection properties have been well demonstrated. Using hydrogen instead of carbon in the steelmaking process can fundamentally eliminate the environmental problems caused by carbon dioxide gas emissions.

[0004] Conventional technologies in the steel industry include several hydrogen gas-based direct iron reduction technologies, such as HYL and Midrex, which use hydrogen-rich gas mixtures as reducing agents, in order to reduce carbon dioxide emissions. Oxygen blast furnaces, top gas recovery, and the COREX process also feature gases with high carbon monoxide and hydrogen content. Since all of these processes carry out reduction reactions in a mixed atmosphere of high-concentration hydrogen and some carbon-based gases, evaluating the reduction rate of iron ore in a hydrogen-carbon monoxide mixed atmosphere is an important research topic. While the reduction reaction of iron oxide using pure hydrogen and pure carbon monoxide has been widely studied, research on the kinetics of reduction reactions using hydrogen-carbon monoxide mixed gases under mixed gas conditions is still insufficient.

[0005] In the iron ore reduction process using reducing gas, the reaction between iron oxide (FeO) and carbon monoxide (CO) can be represented by the following reaction equation (1). FeO + CO → Fe + CO2 (1)

[0006] By introducing a small amount of hydrogen as a reducing gas, the reduction reaction with hydrogen can be carried out not only according to reaction equation (1) but also according to the following reaction equation (2). FeO + H2 → Fe + H2O (2)

[0007] However, since the amount of oxygen weight loss measured by existing thermogravimetric analysis (TGA) techniques is the same regardless of whether reaction equation (1) or (2) is used, it is impossible to determine which reduction reaction the iron ore is undergoing. Furthermore, the introduction of a small amount of hydrogen also triggers a partial reverse water-gas shift reaction, which can be represented by the following reaction equation (3). [ka]

[0008] As a result, the overall reaction in equation (2) + (3) is the same as that in equation (1). This means that the reduction reaction with hydrogen can be carried out not by the individual reactions in equation (1), but by combining reaction (2) and the reverse water-gas shift reaction (3). The situation where the reaction pathways are different but the overall reaction equation is the same presents a significant challenge in understanding the evaluation of iron ore reduction under mixed gas conditions. Therefore, developing technical methods that can accurately evaluate specific reaction pathways is key to the development of hydrogen-based mixed gas reduction technology. The development of methods or apparatus that can individually calculate the reaction intensity with different reducing gases and their respective contributions to the degree of reduction would have great applicability and importance.

[0009] Existing thermogravimetric analysis techniques can analyze the rate of reduction reactions by tracking the degree of reduction based on the weight change of reactants, but they cannot specifically determine which reduction reaction is taking place. In cases where multiple reducing gases react simultaneously, such as reduction with a hydrogen-carbon monoxide mixture, existing methods can only measure the total degree of reduction from all reactions, and cannot distinguish the individual contribution of each reaction.

[0010] The limitations of conventional thermogravimetric analysis techniques are detrimental to the future development of any technology related to reduction reactions using hydrogen and carbon-based gas mixtures. However, if the contribution of each reaction cannot be determined, a detailed understanding and control of the reduction process are severely limited, making it difficult to precisely control chemical reaction conditions and optimize production efficiency. Currently, hydrogen reduction technologies that are attracting attention use either a hydrogen-carbon monoxide mixture, and it is necessary to accurately evaluate the influence of hydrogen and carbon monoxide on the degree of reduction in order to precisely optimize the gas component ratio of the mixed reducing gas and optimize reaction conditions and process design.

[0011] Therefore, in order to solve the problems that exist in the prior art, it is necessary to provide an apparatus and method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere. [Overview of the project] [Problems that the invention aims to solve]

[0012] In view of this, one object of the present invention is to provide an apparatus and method for calculating the degree of iron ore reduction under a mixed reducing atmosphere in order to solve the difficulties in evaluating the iron ore reduction reaction in the case of mixed gases, and to overcome the technical obstacles in the analysis of mixed gases using conventional thermogravimetric analysis techniques by providing an innovative analytical apparatus and method that can accurately distinguish and quantify the reaction contributions of multiple reducing gases (e.g., carbon monoxide and hydrogen).

[0013] Another object of the present invention is to provide an apparatus and method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere, which, by combining the innovative thermogravimetric analysis technique and discharge gas analysis technique of the present invention, can accurately monitor and analyze the differences in gas components entering and leaving the furnace chamber and directly calculate the degree of reduction of iron ore. The advantage of such a method is that it can not only track and identify changes in the composition of different reducing gases in real time, but also instantly calculate the contribution of various reduction reactions to the degree of reduction. This makes it possible to accurately calculate the specific reduction rate of each chemical reaction even in complex situations where multiple reducing gases are mixed (for example, calculating the contributions of the carbon monoxide CO-CO2 reduction reaction and the H2-H2O reduction reaction, respectively), thereby making the monitoring and control of the kinetics of reduction reactions by mixed gases more accurate and efficient. [Means for solving the problem]

[0014] To achieve the above objective, the present invention provides an apparatus for calculating the degree of iron ore reduction under a mixed reducing atmosphere, comprising: an airtight heating device configured to heat a reaction sample; an intake device connected to the airtight heating device and configured to introduce an inert gas and / or reducing gas into the airtight heating device; a gas analyzer configured to analyze a portion of the discharge gas generated by the airtight heating device; a thermogravimetric analyzer configured to analyze the weight change of the airtight heating device due to reduction; a gas convection mitigation unit provided between the airtight heating device and the thermogravimetric analyzer and configured to reduce turbulence in the gas reflux for measurement by the thermogravimetric analyzer; and a gas diversion device provided between the airtight heating device and the gas analyzer and configured to divert the discharge gas generated by the airtight heating device and maintain a portion of the discharge gas introduced into the gas analyzer at a constant flow rate or constant flow rate, wherein the apparatus calculates the degree of iron ore reduction of the reaction sample under different reducing atmospheres based on the measured values ​​of the gas analyzer and the thermogravimetric analyzer.

[0015] In some embodiments of the present invention, the gas convection relaxation part includes a gas convection relaxation region and a constant pressure region. The constant pressure region is provided on the side close to the thermogravimetric analyzer. The gas convection relaxation region has a convection gas discharge port configured to discharge the convection gas in the gas convection relaxation region.

[0016] In some embodiments of the present invention, the pressure of the constant pressure region is controlled to be atmospheric pressure.

[0017] In some embodiments of the present invention, the airtight heating device includes a reaction sample placement device configured to place the reaction sample. The reaction sample is an iron ore to be measured.

[0018] In some embodiments of the present invention, the constant pressure region includes an airtight member, and inside the airtight member, a connecting member is provided with one end connected to the thermogravimetric analyzer and the other end connected to the reaction sample placement device.

[0019] Furthermore, the present invention provides a method for calculating the reduction degree of iron ore in a mixed reduction atmosphere by using the above device, including the steps of placing the reaction sample in the airtight heating device and heating the reaction sample, introducing the inert gas and / or the reducing gas into the airtight heating device, introducing a part of the discharged gas generated by the airtight heating device into a gas analyzer, and calculating the iron ore reduction degree of the reaction sample under different reduction atmospheres respectively based on the measured values of the gas analyzer and the thermogravimetric analyzer.

[0020] In some embodiments of the present invention, the calculation of the reduction degree is achieved by analyzing the change of the thermogravimetric loss by the thermogravimetric analyzer to calculate the iron ore reduction degree, and analyzing the change of the discharged gas components by the gas analyzer to calculate the iron ore reduction degree under different reduction atmospheres respectively.

[0021] In some embodiments of the present invention, the calculation of the reduction degree of iron ore using the change in thermogravimetric loss is performed by the following formula:

Equation

[0022] In some embodiments of the present invention, analyzing the components of the discharged gas by the gas analyzer using the change in the atmosphere and calculating the reduction degree of iron ore under different reducing atmospheres respectively is performed by the following formula:

Equation

[0023] <所 ; In some embodiments of the present invention, the accuracy of the reduction degree calculation is verified by comparing the measurement value of the gas analyzer with the measurement value of the thermogravimetric analyzer.

Advantages of the Invention

[0024] In this invention, the calculation of the degree of reduction is not limited by whether or not the iron ore has been completely reduced, thus improving the flexibility and adaptability of the technology's application. Even if the iron ore has not been completely reduced or the reduction reaction has not been interrupted, the reduction process can be accurately evaluated, and specific process parameters can be adjusted to improve production efficiency. [Brief explanation of the drawing]

[0025] [Figure 1] This is a schematic diagram of an apparatus for calculating the degree of reduction of iron ore under a mixed reducing atmosphere according to one embodiment of the present invention. [Figure 2] This is a schematic diagram of an apparatus for calculating the degree of reduction of iron ore under a mixed reducing atmosphere, according to one specific embodiment of the present invention. [Figure 3] Figure 1 is a schematic perspective view of the airtight heating device, gas convection mitigation section, and thermogravimetric analyzer included in the figure. [Figure 4] Figure 3 is a schematic cross-sectional view of the airtight heating device, gas convection mitigation section, and thermogravimetric analyzer shown in the diagram. [Figure 5] This is a perspective view of a gas convection mitigation unit and a thermogravimetric analyzer according to another embodiment of the present invention. [Figure 6] This is a schematic diagram showing the steps of a method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere according to one embodiment of the present invention. [Figure 7] The degree of reduction of iron ore under four isothermal conditions, measured using a thermogravimetric analyzer and a mass spectrometer, respectively, under a mixed reducing atmosphere (35% CO, 10% H2, 55% Ar) according to one embodiment of the present invention, is shown. [Figure 8] This shows the respective contribution rates of CO gas and H2 gas to the degree of iron ore reduction, calculated from discharge gas analysis data under a mixed reducing atmosphere (35% CO, 10% H2, 55% Ar) according to one embodiment of the present invention. [Figure 9] This paper shows the effect on thermogravimetric analysis in conventional technology that does not eliminate high-temperature gas turbulence, and the effect on thermogravimetric analysis in the present invention that eliminates high-temperature gas turbulence. [Modes for carrying out the invention]

[0026] The technical means in embodiments of the present invention will be described clearly and completely below, in conjunction with the drawings accompanying the embodiments. Furthermore, in order to better illustrate the present invention, many specific details will be provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be carried out even without specific details.

[0027] The core of the technological innovation of this invention lies in its ability to accurately measure the composition, concentration, and flow rate of gas by combining thermogravimetric analysis technology with a discharge gas analysis and monitoring device, thereby accurately converting the measured components of the discharge gas into crucial information regarding the degree of iron ore reduction. This method is particularly suitable for reduction reactions under mixed atmospheres, effectively overcoming the technical barriers of conventional solutions and offering the following advantages (1) to (3): (1) Regarding the advantage of improving the accuracy of mixed gas reduction analysis, this invention not only accurately distinguishes the contribution of each reduction reaction but also allows for the calculation and comparison of the degree of reduction using thermogravimetric analysis technology and discharge gas analysis technology. This cross-verification method not only improves the reliability of the analysis but also provides a deeper analysis of the reaction mechanism. (2) Regarding the advantage of eliminating interference from weight changes due to non-reducing reactions, in addition to reduction reactions, non-reducing reactions such as the gasification reaction of coke (CO2 + C → 2CO) and the formation of Fe3C by the carbonization reaction of metallic iron also cause weight changes in reactants. These interfering factors, which were difficult to eliminate in conventional experiments, are completely resolved by the apparatus and method of this invention, ensuring the purity and accuracy of the measurement results. (3) Regarding the advantages of eliminating pendulum disturbance of the reaction sample holder due to high-temperature gas convection, in conventional methods, the reaction sample holder is usually suspended in the heating furnace by a thin wire, and this arrangement is susceptible to the effects of gas convection, which easily causes slight vibrations in the reaction sample holder. This vibration indirectly affects the measurement accuracy of thermogravimetric analysis and leads to measurement errors. The technology of the present invention solves the above problem, completely overcoming measurement errors caused by vibrations of the reaction sample holder and improving the accuracy and reliability of experimental data.

[0028] Refer to Figures 1 to 5. Figure 1 is a schematic diagram of an apparatus for calculating the degree of reduction of iron ore under a mixed reducing atmosphere according to one embodiment of the present invention. Figure 2 is a schematic diagram of an apparatus for calculating the degree of reduction of iron ore under a mixed reducing atmosphere according to one specific embodiment of the present invention. Figure 3 is a perspective schematic diagram of the airtight heating device, gas convection mitigation unit, and thermogravimetric analyzer included in Figure 1. Figure 4 is a cross-sectional schematic diagram of the airtight heating device, gas convection mitigation unit, and thermogravimetric analyzer in Figure 3. Figure 5 is a perspective perspective view of the gas convection mitigation unit and thermogravimetric analyzer according to another embodiment of the present invention. Figure 6 is a schematic diagram showing the steps of a method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere according to one embodiment of the present invention.

[0029] As shown in Figure 1, the apparatus 10 for calculating the degree of reduction of iron ore under a mixed reducing atmosphere according to the present invention comprises: an airtight heating device 100 configured to heat a reaction sample; an intake device 110 connected to the airtight heating device 100 and configured to introduce an inert gas and / or reducing gas into the airtight heating device 100; a gas analyzer 120 configured to analyze a portion of the discharge gas generated by the airtight heating device 100; a thermogravimetric analyzer 130 configured to analyze the weight change of the airtight heating device 100 due to reduction; and the airtight heating device 100 and the thermogravimetric analyzer 130. The system includes a gas convection mitigation unit 140 provided between the thermogravimetric analyzer 130 and configured to reduce turbulence in the gas reflux for measurement by the thermogravimetric analyzer 130, and a gas diversion device 150 provided between the gas convection mitigation unit 140 and the gas analyzer 120 and configured to divert the discharge gas generated by the airtight heating device 100 and maintain a portion of the discharge gas introduced into the gas analyzer 120 at a constant flow rate or constant flow rate. Based on the measurements from the gas analyzer 120 and the thermogravimetric analyzer 130, the degree of iron ore reduction of the reaction sample under different reducing atmospheres is calculated.

[0030] Specifically, as shown in Figure 2, the intake device 110 may be, but is not limited to, at least one gas cylinder or gas storage tank, or other device that can be used to introduce at least one inert gas and / or reducing gas into the airtight heating device 100. The intake device 110 is preferably connected to an intake pretreatment device 160 (e.g., an intake flow rate control device 1601, an intake mixing device 1602, an intake preheating device 1603, etc., but is not limited to these). The intake flow rate control device 1601 can control the flow rate of the intake device 110. The intake mixing device 1602 can mix multiple gas sources. The intake preheating device 1603 can preheat the inert gas and / or reducing gas introduced into the airtight heating device 100.

[0031] Furthermore, the gas diversion device 150 includes a discharge gas inflow rate / pressure control device, which allows a portion of the discharge gas introduced into the gas analyzer 120 to be maintained at a constant flow rate or constant flow rate, while the remaining discharge gas is discharged from the discharge gas branch pipeline 106. The convective gas in the gas convection mitigation section 140 is discharged from the convective gas outlet 141.

[0032] Furthermore, as shown in Figures 3 and 4, the airtight heating device 100 may also include a reaction sample placement device 102 and an airtight reaction chamber 103. In one example, the reaction sample placement device 102 may include a crucible, and the airtight reaction chamber 103 may be piping for maintaining a sealed reaction environment. The airtight heating device 100 provides the high-temperature environment necessary for the chemical reaction, and the airtight reaction chamber 103 maintains the high temperature and the necessary sealed system.

[0033] The reaction sample holder 102 may be loaded with iron ore of a certain weight and specific particle size for the reaction. A thermogravimetric analyzer 130 (e.g., a weight sensor) tracks the weight change of the reaction sample holder 102 during the reaction process. The thermogravimetric analyzer 130 can measure the weight change of the reaction sample holder 102 in real time by being connected to the reaction sample holder 102 via a connecting member 104 (e.g., a suspension wire). In the experimental process, the gas required for the reaction is supplied by an intake device 110. After moisture pretreatment, the intake gas passes through an intake connection line, and its composition and flow rate are adjusted by an intake flow rate control device 1601. The gas of the predetermined composition is mixed by an intake mixer 1602, and the mixed gas is preheated by an intake preheater 1603 before entering an airtight heating device through an intake port 105. To monitor the reaction conditions inside the reactor chamber in real time, the apparatus is equipped with a series of discharge gas treatment systems. The reaction gas is discharged from the outlet, diverted and recovered through a diversion pipeline, a portion of the discharge gas is processed through the discharge gas branch pipeline 106, and a small amount of discharge gas passes through the gas diversion device 150 to the gas analyzer 120 for discharge gas analysis. By maintaining a stable gas flow rate and temperature with the gas diversion device 150, condensation of water vapor in the pipeline can be prevented. Finally, the gas components are analyzed using the gas analyzer 120. All measurement data, including discharge gas analysis and weight change data, can be recorded and subsequently processed by computer. The highly integrated design of the apparatus allows for evaluation of the degree of iron ore reduction under various temperature and reducing atmosphere conditions.

[0034] Furthermore, the apparatus of the present invention is designed with a particularly airtight reaction chamber (i.e., airtight heating device 100) and provides a gas convection mitigation section 140 above the discharge gas outlet, thereby effectively reducing turbulence in the reaction sample placement device 102 due to high-pressure, high-velocity, and high-temperature gas reflux, while also achieving deceleration, depressurization, and cooling effects. The gas after depressurization is safely discharged from the convection gas outlet 141. The gas convection mitigation section 140 may include a gas convection mitigation region 142 and a constant-pressure region 143. The gas convection mitigation region 142 may be a tubular column structure including a gas convection mitigation chamber, and the constant-pressure region 143 is provided above the gas convection mitigation region 142. The constant-pressure region 143 may be part of an airtight high-temperature hose connected to the tubular column structure of the gas convection mitigation region 142, and the gas in the constant-pressure region 143 may be close to, for example, room temperature and atmospheric pressure.

[0035] Furthermore, as shown in Figure 5, in one embodiment, an airtight upper cover 144 connected to a connecting component 145 (for example, an S-shaped hook and a connecting suspension rod) is provided above the constant pressure region 143, and the thermogravimetric analyzer 130 is connected to the reaction sample placement device 102 by a suspension wire, thereby not being affected by turbulent airflow. By suspending the reaction sample placement device 102 inside the airtight heating device 100 by the suspension wire, the thermogravimetric analyzer 130 can accurately measure the weight change in the reaction process. In addition, by providing a protective cover on the outside of the thermogravimetric analyzer 130, it is possible to avoid the airflow affecting the thermogravimetric analyzer 130. The reaction gas convection path in Figure 5 shows the path of gas from the airtight reaction chamber 103 inside the airtight heating device 100 to the gas convection mitigation section 140, and finally discharged from the convection gas outlet 141 in the gas convection mitigation region 142.

[0036] The highly airtight reaction chamber within the airtight heating device 100 of the present invention can prevent external gas intrusion or reaction gas leakage from affecting the accuracy of discharge gas analysis. However, the inventors have further found that, compared to the design of a conventional non-airtight chamber, this design is more likely to cause gas convection to interfere with the weight sensor of the upper thermogravimetric analyzer 130, leading to measurement errors in thermogravimetric analysis. Therefore, in the present invention, by providing a gas convection mitigation region 142 in particular above the discharge gas discharge branch pipe 106, turbulence to the reaction sample placement device 102 due to high-pressure, high-velocity, and high-temperature gas reflux is effectively reduced, while also achieving deceleration, depressurization, and cooling effects, and avoiding thermal damage to the electronic components of the weight sensor due to high-temperature gas. The depressurized gas is discharged from the convection gas outlet 141, and a constant pressure region 143 (for example, an airtight high-temperature hose) is designed above the convection gas outlet 141 for connection. At this time, the gas in the constant pressure region 143 is close to room temperature and atmospheric pressure, and the interference of airflow to the weight sensor is greatly reduced and can be ignored. By connecting the reaction sample placement device 102 in the airtight chamber to the thermogravimetric analyzer 130 with connecting components, the device is not affected by turbulence in the airflow.

[0037] Reactants The reactant is mainly iron ore, which may be hematite (Fe2O3), magnetite (Fe3O4), and / or wustite (FeO), and may also contain oxides such as silicon, aluminum, magnesium, and calcium. Furthermore, in order to ensure uniform particle size of the reactants and avoid the influence of non-uniform particle size on the measurement of the reaction rate, the iron ore reactant can be sieved through 7.0, 9.5, 12.7, and 15.9 mm sieves to obtain four types of reactants with different particle sizes. Specifically, four types of reactants with different particle sizes of 7.0-9.5 mm, 9.5-12.7 mm, 12.7-15.9 mm, and over 15.9 mm can be obtained. The iron ore reactant may be placed, for example, flat in a single layer and placed without stacking in a reaction sample placement device 102 (e.g., a crucible) with an inner diameter of 55 mm. This placement method helps to avoid clogging of the airflow due to stacking, which would further affect the accurate measurement of the reaction rate. Furthermore, the bottom of the reaction sample holder 102 may be specially designed with strip-shaped grid holes to ensure that the reaction gas is uniformly introduced from the bottom of the reaction sample holder 102 and reacts sufficiently with the reactants.

[0038] Furthermore, the method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere using the apparatus described above according to the present invention includes the steps of: placing an iron ore sample in the airtight heating device and heating the iron ore sample (S11); introducing the inert gas and / or the reducing gas into the airtight heating device (S12); and introducing a portion of the discharged gas generated by the airtight heating device into a gas analyzer and calculating the degree of reduction of the iron ore of the reaction sample under different reducing atmospheres based on the measured values ​​of the gas analyzer and the thermogravimetric analyzer (S13).

[0039] Step (S11) above may include the steps of: placing the sieved iron ore reactant (in this example, iron ore with a particle size of 9.5 to 12.7 mm and a weight of 34.0 grams) in the reaction sample mounting device 102 (e.g., an alumina crucible) according to the aforementioned mounting method in order to eliminate interference to the reduction rate measurement due to differences in the particle size of the iron ore; and placing the reaction sample mounting device 102 with the reactant on it in the airtight heating device 100, starting the gas preheating and pretreatment device, setting the flow rate, pressure and temperature when discharging the discharge gas, and calibrating the gas analyzer to ensure that the components of the discharge gas measured from the furnace outlet of the airtight heating device 100 before the start of the experiment match the composition of the atmosphere into which it was introduced. In addition, the weight sensor of the thermogravimetric analyzer 130 is reset to zero to ensure that the mass change in the iron ore reduction process can be accurately reflected.

[0040] Step (S12) above may include: controlling the intake device 110 to continuously supply an inert gas such as nitrogen or argon into the airtight heating device 100 at a heating rate of 10°C / min; switching to a specific reducing atmosphere after reaching a predetermined experimental temperature and maintaining that temperature for 120 minutes; when the experimental temperature reaches predetermined temperature maintenance conditions (in this example, the temperature is maintained under four isothermal conditions of 700°C, 800°C, 900°C, and 1000°C respectively), switching the gas to a predetermined mixed reducing atmosphere (in this example, a mixed gas consisting of 35% carbon monoxide, 10% hydrogen, and 55% argon is used to simulate a mixed gas atmosphere similar to that of blast furnace ironmaking), setting the flow rate to 5 liters / min, and maintaining the temperature for 120 minutes; and introducing argon at 5 liters / min to cool.

[0041] Step (S13) described above may include the steps of: calculating data acquired and recorded in real time by a computer, converting the thermogravimetric data from the thermogravimetric analyzer 130 and the discharge gas analysis data from the gas analyzer (e.g., discharge gas analysis data from a mass spectrometer (MS)) into reduction degrees to obtain an iron ore reduction degree curve; and removing the material after the experiment from the reaction sample holder 102, performing a secondary gravimetric measurement, and ensuring that the change matches the data recorded by the thermogravimetric analyzer 130 and that the error is controlled to within 0.2 grams. Subsequently, material analysis such as X-ray diffraction analysis (XRD) is performed to verify that the fraction of each iron ore phase in the product matches the reduction degree data.

[0042] Results of reduction products Extraction and data processing of reduction products In the reduction reaction of the present invention, thermogravimetric change data and discharge gas component data were obtained and analyzed, and the results of the change in the degree of iron ore reduction over time were calculated, and the results are shown in Figures 7 and 8.

[0043] The degree of iron ore reduction (RD%) is calculated using the change in thermal gravimetric loss.

number

[0044] By utilizing the change in atmosphere, the reduction degree (RD%) of iron ore under different reducing atmospheres was calculated.

number

[0045] As shown in Figures 7 and 8, the reduction degree calculated using weight change obtained by thermogravimetric analysis (shown as a black dashed line in the figures) and the change in discharged gas obtained by mass spectrometry (shown as a black-gray solid line in the figures) are compared. If the error between the two is less than 5%, the data of the reduction experiment is considered reliable. Since thermogravimetric analysis data is susceptible to the effects of weight change due to non-reducing reactions and turbulence of high-temperature gases, the final reduction degree is mainly determined using data from discharged gas analysis. These two different calculation methods allow for mutual verification of the accuracy of reduction degree calculations. The present invention utilizes the advantage of calculating the reduction degree by discharged gas analysis to individually calculate the contribution of different atmospheric compositions to the reduction degree, which is particularly useful for evaluating iron ore reduction reactions under future mixed gas conditions, and allows for the clear identification of the respective contribution rates of carbon monoxide reduction and hydrogen reduction to the reduction degree under a mixed atmosphere of carbon monoxide and hydrogen.

[0046] Figure 9 shows the effect on thermogravimetric analysis before and after eliminating turbulence in the high-temperature gas. Figure 9 demonstrates that the design of the present invention can prevent gas convection and crucible oscillation (pendulum effect) caused by heating in the furnace from affecting the measurement of the weight sensor of the thermogravimetric analyzer.

[0047] The advantages of the present invention are as follows:

[0048] 1. Regarding the combination of thermogravimetric analysis and discharge gas analysis, the present invention combines a thermogravimetric analysis (TGA) device and a discharge gas analyzer to simultaneously perform physicochemical analysis of the iron ore reduction process, and by calculating the degree of reduction from two perspectives, mutual verification or information complementation can be achieved.

[0049] 2. Regarding airtight design and pressure mitigation, the present invention employs a highly airtight reaction chamber design and provides a gas convection mitigation chamber above the discharge gas outlet. This effectively reduces turbulence in the reaction crucible caused by high-pressure, high-velocity, and high-temperature gas reflux, thereby achieving gas deceleration, pressure reduction, and cooling, and ensuring the accuracy of thermogravimetric analysis and discharge gas analysis.

[0050] 3. Regarding real-time monitoring of changes in the reaction atmosphere, an external gas analysis and monitoring device can be used to monitor the actual reaction atmosphere inside the reactor chamber in real time, including changes in gas composition, concentration, and flow rate.

[0051] 4. Regarding the accurate calculation of the degree of reduction, by analyzing the components of the discharged gas, it is possible to accurately convert it to the degree of reduction of iron ore and distinguish the contributions of different reducing gas reactions such as CO-CO2 and H2-H2O.

[0052] 5. Regarding the avoidance of interference from non-reducing reactions, the design of the present invention eliminates the influence of non-reducing reactions such as coke gasification and the formation of Fe3C by carbonization of Fe on gravimetric measurements, thereby improving the accuracy of experiments.

[0053] 6. To eliminate the effects of turbulence in high-temperature gases, the discharge gas analysis method can prevent gas convection due to heating inside the furnace and the shaking of the crucible (pendulum effect) from affecting balance measurements.

[0054] 7. Regarding the data processing method, the present invention includes a series of data processing methods for extracting and calculating the degree of iron ore reduction and the contribution rates of various gas reactions from the discharge gas analysis results.

[0055] 8. Suitable for experiments under mixed atmospheres: It can accurately analyze iron ore reduction experiments conducted under mixed atmospheres containing multiple reducing gases, providing a more flexible and comprehensive range of applications.

[0056] The present invention is characterized by at least (1) realizing real-time and accurate monitoring of the reaction atmosphere and reduction degree by combining discharge gas analysis technology and thermogravimetric analysis technology, (2) improving measurement accuracy by ensuring airtightness through airtight design and pressure relief chamber mechanism design while effectively reducing the effect of shaking on the reaction crucible due to high temperature and high pressure gas, and (3) being suitable for situations in which multiple reducing gases react simultaneously, and by distinguishing the contribution of each different reduction reaction to the reduction degree through discharge gas analysis.

[0057] Those skilled in the art can implement the present invention by various modifications without departing from the essence and spirit of the invention, and the above description is merely a preferred embodiment of the present invention and does not limit the scope of the claims of the present invention. All equivalent modifications made using the contents of the specification and drawings of the present invention are included in the scope of the claims of the present invention. [Explanation of symbols]

[0058] 10 equipment 100 Airtight heating device 102 Reaction sample placement device 103 Airtight reaction chamber 104 Connecting Member 105 Intake 106 Discharge gas discharge branch pipeline 110 Intake system 120 Gas analyzer 130 Thermogravimetric analyzer 140 Gas convection mitigation section 141 Convection gas outlet 142 Gas convection relaxation region 143 Constant pressure region 144 Airtight upper cover 145 Connecting parts 150 Gas flow divider 160 Intake pretreatment device 1601 Intake Air Flow Control Device 1602 Intake Mixing Device 1603 Intake Preheating Device S11~S13 Step

Claims

1. An airtight heating device configured to heat a reaction sample, An intake device connected to the aforementioned airtight heating device and configured to introduce an inert gas and / or reducing gas into the airtight heating device, A gas analyzer configured to analyze a portion of the discharged gas generated by the aforementioned airtight heating device, A thermogravimetric analyzer configured to analyze the weight change of the airtight heating device due to reduction, A gas convection mitigation unit is provided between the airtight heating device and the thermogravimetric analyzer and is configured to reduce turbulence in the gas reflux during measurement by the thermogravimetric analyzer. The system includes a gas diversion device provided between the airtight heating device and the gas analyzer, configured to divert the discharged gas generated by the airtight heating device and maintain a portion of the discharged gas introduced into the gas analyzer at a constant flow velocity or flow rate, Based on the measurements from the gas analyzer and the thermogravimetric analyzer, the degree of iron ore reduction of the reaction sample under different reducing atmospheres is calculated. A device for calculating the degree of reduction of iron ore under a mixed reducing atmosphere.

2. The gas convection mitigation section includes a gas convection mitigation region and a constant pressure region, the constant pressure region being provided on the side adjacent to the thermogravimetric analyzer, and the gas convection mitigation region having a convection gas outlet configured to discharge the convection gas within the gas convection mitigation region. The apparatus according to claim 1.

3. The pressure in the aforementioned constant-pressure region is controlled to be equal to atmospheric pressure. The apparatus according to claim 2.

4. The airtight heating device includes a reaction sample holder configured to hold the reaction sample, wherein the reaction sample is the iron ore to be measured. The apparatus according to claim 2.

5. The constant-pressure region includes an airtight member, and inside the airtight member is provided a connecting member, one end of which is connected to the thermogravimetric analyzer and the other end of which is connected to the reaction sample placement device. The apparatus according to claim 4.

6. A method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere using the apparatus described in any one of claims 1 to 5, The steps include: placing the reaction sample in the airtight heating device and heating the reaction sample; The steps include introducing the inert gas and / or the reducing gas into the airtight heating device, The process includes the step of introducing a portion of the discharged gas generated by the airtight heating device into a gas analyzer, and calculating the degree of iron ore reduction of the reaction sample under different reducing atmospheres based on the measurements from the gas analyzer and the thermogravimetric analyzer. A method for calculating the degree of reduction of iron ore under a mixed reducing atmosphere.

7. The calculation of the reduction degree is achieved by analyzing the change in thermogravimetric loss using the thermogravimetric analyzer to calculate the reduction degree of iron ore, and by analyzing the change in the discharged gas components using the gas analyzer to calculate the reduction degree of iron ore under different reducing atmospheres. The method according to claim 6.

8. The degree of iron ore reduction, which utilizes the change in thermal gravimetric loss, is calculated using the following formula: [Math 1] In the formula, RD% represents the degree of iron ore reduction (%), M ０ This represents the total mass of iron ore, W １ This represents the FeO content (%) in the iron ore, W ２ This represents the total iron content (TFe) (%) of the iron ore, M １ This represents the total weight of iron ore at time t=0 of the experiment, and M ｔ The method according to claim 7, wherein represents the total weight of the iron ore at time t of the experiment.

9. By utilizing the change in atmosphere and analyzing the components of the discharged gas using the aforementioned gas analyzer, the degree of iron ore reduction under different reducing atmospheres can be calculated using the following formula: [Math 2] where RD% represents the reduction degree of iron ore (%), M ０ represents the total mass of the iron ore, N ＣＯ represents the number of moles of CO gas contained in the discharged gas component, N ＣＯ２ represents the number of moles of CO ２ gas contained in the discharged gas component, N 導入されたＣＯ represents the number of moles of CO gas contained in the introduced gas, N 導入されたＣＯ２ represents the number of moles of CO ２ gas contained in the introduced gas, N Ｈ２ represents the number of moles of H ２ gas contained in the discharged gas component, N Ｈ２Ｏ represents the number of moles of H ２ O gas contained in the discharged gas component, N 導入されたＨ２ represents the number of moles of H ２ gas contained in the introduced gas, N 導入されたＨ２Ｏ represents the number of moles of H ２ O gas contained in the introduced gas, W １ represents the content (%) of FeO in the iron ore, W ２ represents the total iron content rate (TFe) (%) of the iron ore. The method according to claim 7.

10. The accuracy of the reduction degree calculation is verified by comparing the measurement values ​​from the gas analyzer and the thermogravimetric analyzer. The method according to claim 6.

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