A device and method for determining the reactivity of coke-iron oxide coupling

Abstract

This invention relates to an apparatus and method for determining the coupling reactivity of coke iron oxides. The apparatus includes a reactor body, a heating device, a pressurizing device, a molten iron receiving crucible, and a coupling reaction crucible. From top to bottom, the reactor body has a coupling reaction crucible, a molten iron receiving crucible, and a gas preheating zone. A first heating zone surrounds the gas preheating zone, and a second heating zone surrounds the coupling reaction crucible. This invention primarily addresses the problem of distortion in existing coke evaluation methods, accurately describing the coupling reaction (gas-liquid-solid reaction) process of ore, coke, gas, and molten iron within the blast furnace, thus providing more rational and scientific guidance for coke use. The apparatus described in this invention is used to determine the high-temperature reactivity of coke. It employs a counter-current reactor, preheating the gas through heating at both ends to simulate the furnace environment of high-temperature gas and low-temperature solid, which is more consistent with the actual conditions inside the blast furnace.

Description

Technical Field

[0001] This invention relates to the field of high-temperature reaction performance testing technology for coke, and in particular to an apparatus and method for testing the coupling reactivity of iron oxides in coke. Background Technology

[0002] Coke, as one of the main raw materials for smelting, plays a crucial and irreplaceable role in the stable and smooth operation of blast furnaces. Gasification loss of coke in the blast furnace leads to coke deterioration, which in turn affects the smelting efficiency of the blast furnace, and in severe cases, results in poor gas and liquid permeability and abnormal furnace operation. The atmosphere and temperature of the coke gasification loss reaction constantly change as the coke moves within the blast furnace. Existing studies on the gasification loss behavior of blast furnace coke all assume that the atmosphere and temperature surrounding the coke remain constant, i.e., they do not consider the synergistic effects of molten iron, iron ore, and atmosphere on the coke. This leads to distorted evaluations of coke, failing to accurately describe the gasification loss process of coke in the blast furnace, and introducing biases into guiding the rational use of coke.

[0003] The mechanism of iron oxide reduction in iron ore by carbon is complex, generally occurring in two ways: one is the direct reaction between iron oxides and carbon, such as in the initial stage of reduction in carbon-containing pellets; the other is a coupling phenomenon resulting from the addition of reactions on their respective surfaces. When a blast furnace uses a separate charging method, the gas flow passes through the iron ore layer and the coke layer sequentially from bottom to top. During this process, the reduction of iron ore and the gasification of coke mainly occur, i.e., the ore-coke coupling phenomenon. Inside the blast furnace, the reduction reaction of iron ore includes indirect and direct reduction reactions. Coke participates in the direct reduction reaction of iron ore and other metals, undergoes a melting reaction with the gases inside the blast furnace (carbon dioxide and water vapor), and also participates in the carburizing reaction of molten iron. Currently, coke quality is evaluated only based on the quality of coke after the melting reaction with the internal gases (carbon dioxide and water vapor), without considering the actual environment of the blast furnace.

[0004] The direct reduction reaction in a blast furnace mainly consists of the gasification reaction of coke and the indirect reduction reaction of iron ore. Extensive research has shown that the direct reduction reaction in a blast furnace is closely related to blast furnace production and heat exchange. Therefore, studying the influence of different iron ores or cokes on the ore-coke coupling reaction (gas-liquid-solid) has always been a research hotspot in metallurgical work. However, the influence of different iron ores, molten iron, gas phase, or coke on the ore-coke coupling reaction (gas-liquid-solid) is not yet fully clear. This is mainly because there is a lack of suitable equipment and methods to test and evaluate the properties of the coke-ore-coke and molten iron coupling reaction (gas-liquid-solid).

[0005] As a counter-current reactor, the blast furnace's heat is provided by internal reaction heat. At the lower tuyere, the intense combustion of fuel and air or oxygen heats the gas to over 2000°C. Above the tuyere, the high-temperature gas inside the blast furnace transfers heat to the gradually descending solid materials. However, current conventional coke reactivity testing equipment heats the material to a high temperature and then introduces room-temperature gas to induce a reaction, which is the opposite of the actual conditions inside a blast furnace. In other words, below the blast furnace's heat reserve zone (900°C–1000°C), there is actually a state of high-temperature gas and low-temperature solids, while current testing equipment simulates this, thus not reflecting the actual conditions inside the blast furnace. Summary of the Invention

[0006] This invention provides an apparatus and method for determining the coupled reactivity of coke iron oxides, mainly addressing the problem of distortion in existing coke evaluation methods. It accurately describes the coupled reaction (gas-liquid-solid reaction) process of ore, coke, gas, and molten iron within the blast furnace, thus providing more rational and scientific guidance for coke use. The apparatus described in this invention is used to determine the high-temperature reactivity of coke. It employs a counter-current reactor, preheating the gas through heating at both ends to simulate the furnace environment of high-temperature gas and low-temperature solid, which is more consistent with the actual internal conditions of the blast furnace.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] An apparatus for determining the coupling reactivity of coke iron oxides includes a reactor body, a heating device, a pressurizing device, a molten iron receiving crucible, and a coupling reaction crucible. The reactor body has an inlet at the bottom and an outlet at the top. From top to bottom, the middle of the reactor body contains the coupling reaction crucible, the molten iron receiving crucible, and a gas preheating zone. A heat storage body is installed within the gas preheating zone. The reactor body is interconnected from bottom to top, and the bottom of the coupling reaction crucible has multiple through holes for molten iron to flow into the molten iron receiving crucible below. A first heating zone surrounds the gas preheating zone, and a second heating zone surrounds the coupling reaction crucible. The heating device consists of a heating device one located in the first heating zone and a heating device two located in the second heating zone. A pressurizing device is installed within the reactor body above the coupling reaction crucible.

[0009] An apparatus for determining the coupling reactivity of coke iron oxides further includes a detection device; the detection device includes a displacement detection device, a temperature detection device, and a pressure detection device; the displacement detection device is disposed on a pressurizing device; the temperature detection device includes a thermocouple one for detecting the temperature of the material in the coupling reaction crucible, a thermocouple two for detecting the temperature of the second heating zone, and a thermocouple three for detecting the temperature of the first heating zone; the pressure detection device includes a pressure sensor one disposed on the pressurizing device and a pressure sensor two disposed at the bottom of the reactor body.

[0010] Furthermore, the gas preheating zone consists of a preheating zone bottom plate, a heat storage body, and a preheating zone top plate; dense through holes are opened on both the preheating zone bottom plate and the preheating zone top plate; the heat storage body is composed of filler material with a regular shape, and the filler material is corundum or high-temperature alloy; the filler material forms a large number of irregular gas passages between the preheating zone bottom plate and the preheating zone top plate.

[0011] Furthermore, the gas preheating zone consists of a preheating zone bottom plate, a heat storage body, and a preheating zone top plate; dense through holes are opened on both the preheating zone bottom plate and the preheating zone top plate; the heat storage body is an integrally cast filler; the filler is made of graphite, corundum, or high-temperature alloy; the filler has a large number of pores inside, and the pores are interconnected to form a large number of irregular gas passages.

[0012] Furthermore, the reactor body is a corundum tube.

[0013] Furthermore, both heating device one and heating device two consist of multiple electric heating rods arranged circumferentially.

[0014] Furthermore, a crucible support is provided inside the reactor body, and the crucible support is fixedly connected to the side wall of the reactor body; the coupling reaction crucible is placed on the crucible support.

[0015] Furthermore, the upper side wall of the molten iron receiving crucible is densely covered with ventilation holes along the circumference, and the diameter of the ventilation holes is 1 to 10 mm.

[0016] A method for determining the coupling reactivity of iron oxides in coke includes the following steps:

[0017] 1) Place iron ore and coke into a coupling reaction crucible according to a set mass ratio, with coke in the lower layer and iron ore in the upper layer; both coke and iron ore are pre-treated by crushing and screening, with the particle size of coke being 10-40 mm and the particle size of iron ore being 10-20 mm; record the weight of coke and iron ore, with the weight of coke recorded as m1 and the weight of iron ore recorded as m2;

[0018] 2) A layer of coke is laid on top of the iron ore in the coupling reaction crucible to avoid direct contact between the displacement detection device and the pressure detection device and the iron ore. The weight of the coke is recorded as m3.

[0019] 3) Design the experimental regime, including the heating temperature and atmosphere of the coupled reaction crucible, and the pressure applied by the pressurizing device at each stage;

[0020] 4) The heating temperature regime of the gas preheating zone is 200-300°C higher than the corresponding heating temperature of the coupling reaction crucible. The gas preheating zone is preheated before the coupling reaction crucible is heated; the gas preheating zone stops heating when the coupling reaction crucible cools down.

[0021] 5) After the coupled reaction crucible starts to heat up, record all test data, including displacement, temperature and pressure difference;

[0022] 6) After the coupled reaction crucible is cooled, it is taken out and the coke inside is weighed and recorded as m4. The reactivity of the coke is calculated according to the formula (m1+m3-m4) / (m1+m3). The coke after reaction is placed in a type I rotating drum and its crush resistance and wear resistance after reaction are measured.

[0023] Furthermore, the heating temperature and atmosphere of the coupling reaction crucible are controlled as follows:

[0024] Heating temperature from 20℃ to 200℃, heating rate from 1 to 10℃ / min, atmosphere 100% N2; heating temperature from 200℃ to 500℃, heating rate from 5 to 15℃ / min, atmosphere 100% N2; heating temperature from 500℃ to 1200℃, heating rate from 5 to 15℃ / min, atmosphere 50% N2 + 20% CO2 + 30% CO; heating temperature from 1200℃ to 1500℃, heating rate from 5 to 15℃ / min, atmosphere 50% N2 + 10% CO2 + 40% CO; heating to 1500℃ and holding for 25 to 35 minutes, atmosphere 50% N2 + 10% CO2 + 40% CO; heating temperature from 1500℃ to 20℃, cooling rate from 5 to 15℃ / min, atmosphere 100% N2.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1) This invention mainly solves the problem of distortion in existing coke evaluation methods, and can accurately describe the coupled reaction (gas-liquid-solid reaction) process of ore, coke, gas and molten iron in the blast furnace, thereby providing more reasonable and scientific guidance for the use of coke;

[0027] 2) The device described in this invention is used to determine the high-temperature reactivity of coke. It adopts a counter-current reactor and preheats the gas by heating at both ends to simulate the furnace environment of high-temperature gas and low-temperature solid, which is more in line with the actual situation inside the blast furnace.

[0028] 3) The method described in this invention can accurately characterize the quality of blast furnace coke, which helps to reduce the operational burden on the ironmaking production site, reduce the coke ratio, reduce carbon dioxide emissions, increase molten iron production, and at the same time ensure the stable operation of the blast furnace.

[0029] 4) It helps reduce the discrepancies between the ironmaking and coking processes regarding coke quality, and avoids the meaningless pursuit of excessively high CSR and CRI indicators; it provides strong technical support for expanding coking coal resources, reducing coal blending costs, and improving the profitability of coking enterprises. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the device for determining the coupling reactivity of coke iron oxides according to the present invention.

[0031] Figure 2 This refers to the heating temperature regime of the coupled reaction crucible described in the embodiments of the present invention.

[0032] In the diagram: 1. Air inlet; 2. Pressure sensor 2; 3. Reactor body; 4. Preheating zone bottom plate; 5. Gas preheating zone; 6. Preheating zone top plate; 7. First heating zone; 8. Molten iron receiving crucible; 9. Second heating zone; 10. Crucible support; 11. Coupled reaction crucible; 12. Pressurization device; 13. Air outlet; 14. Thermocouple 1; 15. Thermocouple 2; 16. Thermocouple 3 Detailed Implementation

[0033] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0034] like Figure 1 As shown, the apparatus for determining the coupling reactivity of coke iron oxides according to the present invention includes a reactor body 3, a heating device, a pressurizing device 12, a molten iron receiving crucible 8, and a coupling reaction crucible 11; the reactor body 3 has an air inlet 1 at the bottom and an air outlet 13 at the top; the middle part of the reactor body 3 is provided with the coupling reaction crucible 11, the molten iron receiving crucible 8, and a gas preheating zone 5 from top to bottom; a heat storage body is provided in the gas preheating zone 5; the reactor body 3 is connected from bottom to top with gas, and the bottom of the coupling reaction crucible 11 has multiple through holes for molten iron to flow into the molten iron receiving crucible 8 below; a first heating zone 7 is provided around the gas preheating zone 5, and a second heating zone 9 is provided around the coupling reaction crucible 11; the heating device consists of a heating device one provided in the first heating zone 7 and a heating device two provided in the second heating zone 9; the pressurizing device 12 is provided inside the reactor body 3 above the coupling reaction crucible 11.

[0035] Furthermore, the apparatus for determining the coupling reactivity of coke iron oxides according to the present invention also includes a detection device; the detection device includes a displacement detection device, a temperature detection device, and a pressure detection device; the displacement detection device is disposed on the pressurizing device 12; the temperature detection device includes a thermocouple 14 for detecting the temperature of the material in the coupling reaction crucible 11, a thermocouple 15 for detecting the temperature of the second heating zone 9, and a thermocouple 16 for detecting the temperature of the first heating zone 7; the pressure detection device includes a pressure sensor 1 disposed on the pressurizing device 12 and a pressure sensor 2 disposed at the bottom of the reactor body 3.

[0036] Furthermore, the gas preheating zone 5 is composed of a preheating zone bottom plate 4, a heat storage body, and a preheating zone top plate 6; dense through holes are opened on both the preheating zone bottom plate 4 and the preheating zone top plate 6; the heat storage body is composed of filler material with a regular shape, and the filler material is corundum or high-temperature alloy; the filler material forms a large number of irregular gas passages between the preheating zone bottom plate 4 and the preheating zone top plate 6.

[0037] Furthermore, the gas preheating zone 5 is composed of a preheating zone bottom plate 4, a heat storage body, and a preheating zone top plate 6; both the preheating zone bottom plate 4 and the preheating zone top plate 6 are densely perforated; the heat storage body is an integrally cast filler; the filler is made of graphite, corundum, or high-temperature alloy; the filler has a large number of pores inside, and the pores are interconnected to form a large number of irregular gas passages.

[0038] Furthermore, the reactor body 3 is a corundum tube.

[0039] Furthermore, both heating device one and heating device two consist of multiple electric heating rods arranged circumferentially.

[0040] Furthermore, the reactor body 3 is provided with a crucible support 10, which is fixedly connected to the side wall of the reactor body 3; the coupling reaction crucible 11 is placed on the crucible support 10.

[0041] Furthermore, the upper side wall of the molten iron receiving crucible 8 is densely covered with ventilation holes along the circumference, and the diameter of the ventilation holes is 1 to 10 mm.

[0042] The method for determining the coupling reactivity of coke iron oxides according to the present invention includes the following steps:

[0043] 1) Place iron ore and coke into the coupling reaction crucible 11 according to the set mass ratio, with coke placed in the lower layer and iron ore placed in the upper layer; both coke and iron ore are pre-treated by crushing and screening, with the particle size of coke being 10-40 mm and the particle size of iron ore being 10-20 mm; record the weight of coke and iron ore, with the weight of coke recorded as m1 and the weight of iron ore recorded as m2;

[0044] 2) A layer of coke is laid on top of the iron ore in the coupling reaction crucible 11 to avoid direct contact between the displacement detection device and the pressure detection device and the iron ore. The weight of the coke is recorded as m3.

[0045] 3) Design the experimental regime, including the heating temperature and atmosphere of the coupled reaction crucible 11, and the pressure applied by the pressurizing device 12 at each stage;

[0046] 4) The heating temperature regime of the gas preheating zone 5 is increased by 200-300°C based on the heating temperature corresponding to the coupling reaction crucible 11. Before heating the coupling reaction crucible 11, the gas preheating zone 5 is preheated; when the coupling reaction crucible 11 cools down, the gas preheating zone 5 stops heating.

[0047] 5) After the coupled reaction crucible 11 starts to heat up, record various test data including displacement, temperature and pressure difference;

[0048] 6) After the coupling reaction crucible 11 is cooled, it is taken out and the coke inside is weighed and recorded as m4. The reactivity of the coke is calculated according to the formula (m1+m3-m4) / (m1+m3). The coke after reaction is placed in the type I rotating drum and its crush resistance and wear resistance after reaction are measured.

[0049] Furthermore, the heating temperature and atmosphere of the coupling reaction crucible are controlled as follows:

[0050] Heating temperature from 20℃ to 200℃, heating rate from 1 to 10℃ / min, atmosphere 100% N2; heating temperature from 200℃ to 500℃, heating rate from 5 to 15℃ / min, atmosphere 100% N2; heating temperature from 500℃ to 1200℃, heating rate from 5 to 15℃ / min, atmosphere 50% N2 + 20% CO2 + 30% CO; heating temperature from 1200℃ to 1500℃, heating rate from 5 to 15℃ / min, atmosphere 50% N2 + 10% CO2 + 40% CO; heating to 1500℃ and holding for 25 to 35 minutes, atmosphere 50% N2 + 10% CO2 + 40% CO; heating temperature from 1500℃ to 20℃, cooling rate from 5 to 15℃ / min, atmosphere 100% N2.

[0051] The device for determining the coupling reactivity of coke iron oxides described in this invention can be automatically controlled by a control system. The signal input terminal of the control system is connected to the signal output terminal of the detection device, and the control signal output terminal of the control system is connected to the control terminals of the heating device and the pressurizing device.

[0052] The following embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0053]

Example

[0054] like Figure 1 As shown, in this embodiment, the device for determining the coupling reactivity of coke iron oxides includes a reactor body 3, a heating device, a pressurizing device 12, a detection device, a molten iron receiving crucible 8, a coupling reaction crucible 11, and a control system.

[0055] The reactor body 3 has an air inlet 1 at the bottom and an air outlet 13 at the top. The middle part of the reactor body 3 is provided with a coupling reaction crucible 11, a molten iron receiving crucible 8 and a gas preheating zone 5 from top to bottom. A heat storage body is provided in the gas preheating zone 5. The reactor body 3 is connected from bottom to top. The bottom of the coupling reaction crucible 11 is provided with multiple through holes for molten iron to flow into the molten iron receiving crucible 8 below. A first heating zone is provided around the gas preheating zone 5 and a second heating zone is provided around the coupling reaction crucible 11.

[0056] The heating device consists of a heating device 1 located in the first heating zone 7 and a heating device 2 located in the second heating zone 9; a pressurizing device 12 is provided on the top of the reactor body 3.

[0057] The detection device includes a displacement detection device, a temperature detection device, and a pressure detection device; wherein, the displacement detection device is located on the pressurizing device 12; the temperature detection device includes thermocouple 14 for detecting the temperature of the material in the coupled reaction crucible 11, thermocouple 15 for detecting the temperature of the second heating zone 9, and thermocouple 16 for detecting the temperature of the first heating zone 7; the pressure sensor 2 is located at the bottom of the reactor body 3 and is used to measure the pressure at the bottom of the reactor body 3.

[0058] In this embodiment, the reactor body 3 is made of corundum tube; the bottom plate 4 of the preheating zone is the lower interface of the gas preheating zone 5, and a large number of through holes are formed on it for gas to flow into the gas preheating zone 5. In this embodiment, the gas preheating zone 5 is equipped with a heat storage body, which is composed of a large number of corundum ball packing materials, so that a large number of irregular gas passages are formed inside the gas preheating zone 5. After the gas enters the gas preheating zone 5, it comes into full contact with the packing material and is heated. The top plate 6 of the preheating zone is the upper interface of the gas preheating zone 5, and a large number of through holes are formed on it for gas to flow out of the gas preheating zone 5.

[0059] In this embodiment, the first heating zone 7 is provided with multiple silicon molybdenum rods for heating the gas preheating zone 5, and the second heating zone 9 is provided with multiple silicon molybdenum rods for heating the coupling reaction crucible 11.

[0060] The molten iron receiving crucible 8 is used to receive the molten iron flowing down after the iron ore is reduced. A large number of 5mm vent holes are opened in the upper part of the side wall of the molten iron receiving crucible 8 for gas circulation.

[0061] The crucible support 10 supports the coupling reaction crucible 11 and is fixedly connected to the side wall of the corundum tube. The coupling reaction crucible 11 is used to hold the iron ore and coke for the experiment. Numerous 3mm diameter through holes are opened at the bottom of the coupling reaction crucible 11 for molten iron to flow out and gas to flow upwards; the hole diameter is greater than 2mm. The pressurizing device 12 applies pressure to the material inside the coupling reaction crucible 11, and simultaneously records the displacement during pressurization and the gas pressure at the top of the reactor body 3 using a displacement detection device and a pressure sensor. Thermocouple 14 measures the temperature of the material inside the coupling reaction crucible 11; thermocouple 15 measures the temperature of the second heating zone 7; and thermocouple 16 measures the temperature of the second heating zone 9.

[0062] In this embodiment, the process for determining the coupling reactivity of coke iron oxides is as follows:

[0063] 1. Place iron ore and coke in a coupling reaction crucible 11 at a mass ratio of 8:2, with coke in the lower layer and iron ore in the upper layer. The coke and iron ore should be pre-treated by crushing and screening; the coke particle size should be 10mm–40mm, and the iron ore particle size should be 10–20mm. Record the weights of the coke and iron ore as m1 and m2, respectively.

[0064] 2. Cover the iron ore in the coupling reaction crucible 11 with another layer of coke to prevent the displacement detection device and pressure detection device from directly contacting the iron ore. Record the weight of the coke layer as m3.

[0065] 3. The experimental regime was designed with reference to the actual conditions of the blast furnace. The heating temperature regime of the coupled reaction crucible 11 is shown in Table 1 and... Figure 2 As shown in Table 1, the atmosphere for each heating stage is listed. During the test, the pressurizing device 12 applies the corresponding pressure as required by the test (set according to existing standards).

[0066] Table 1

[0067] Heating regime or insulation temperature Heating rate / Holding time / Cooling rate atmosphere 20℃～200℃ 5℃ / min <![CDATA[100%N2]]> 200℃～500℃ 10℃ / min <![CDATA[100%N2]]> 500℃～1200℃ 10℃ / min <![CDATA[50%N2+20%CO2+30%CO]]> 1200℃～1500℃ 5℃ / min <![CDATA[50%N2+10%CO2+40%CO]]> 1500℃ heat preservation 30min <![CDATA[50%N2+10%CO2+40%CO]]> 1500℃～20℃ 10℃ / min <![CDATA[100%N2]]>

[0068] 4. The heating temperature regime of the gas preheating zone 5 is consistent with that of the coupled reaction crucible 11. At each stage, the temperature of the gas preheating zone 5 is increased by 200°C based on the heating temperature of the coupled reaction crucible 11. The gas preheating zone 5 is preheated before the coupled reaction crucible 11 is heated. Heating in the gas preheating zone 5 is stopped when the coupled reaction crucible 11 cools down.

[0069] 5. After heating and temperature rise, the system automatically records relevant test data such as displacement, temperature, and pressure difference.

[0070] 6. After the coupling reaction crucible 11 is cooled, it is taken out and the coke after reaction is weighed and recorded as m4. The reactivity of the coke is calculated according to the formula (m1+m3-m4) / (m1+m3). The coke after reaction is placed in the type I rotating drum and its crush resistance and wear resistance after reaction are measured.

[0071] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for determining the coupling reactivity of coke iron oxides, implemented using an apparatus for determining the coupling reactivity of coke iron oxides; characterized in that, The apparatus for determining the coupling reactivity of coke iron oxides includes a reactor body, a heating device, a pressurizing device, a molten iron receiving crucible, and a coupling reaction crucible. The reactor body has an inlet at the bottom and an outlet at the top. From top to bottom, the middle of the reactor body contains the coupling reaction crucible, the molten iron receiving crucible, and a gas preheating zone. A heat storage body is installed within the gas preheating zone. The reactor body is interconnected from bottom to top. Multiple through-holes at the bottom of the coupling reaction crucible allow molten iron to flow into the molten iron receiving crucible below. A first heating zone surrounds the gas preheating zone, and a second heating zone surrounds the coupling reaction crucible. The heating device consists of a heating device one located in the first heating zone and a heating device two located in the second heating zone. A pressurizing device is installed within the reactor body above the coupling reaction crucible. The method for determining the coupling reactivity of coke iron oxides includes the following steps: 1) Place iron ore and coke into a coupling reaction crucible according to a set mass ratio, with coke placed in the lower layer and iron ore in the upper layer; both coke and iron ore are pre-treated by crushing and screening, with the particle size of coke being 10-40 mm and the particle size of iron ore being 10-20 mm; record the weight of coke and iron ore, with the weight of coke recorded as m1 and the weight of iron ore recorded as m2; 2) A layer of coke is laid on top of the iron ore in the coupling reaction crucible to avoid direct contact between the displacement detection device and the pressure detection device and the iron ore. The weight of the coke is recorded as m3. 3) Design the experimental regime, including the heating temperature and atmosphere of the coupled reaction crucible, and the pressure applied by the pressurizing device at each stage; 4) The heating temperature regime of the gas preheating zone is 200-300°C higher than the corresponding heating temperature of the coupling reaction crucible. The gas preheating zone is preheated before the coupling reaction crucible is heated; the gas preheating zone stops heating when the coupling reaction crucible cools down. 5) After the coupled reaction crucible starts to heat up, record all test data, including displacement, temperature and pressure difference; 6) After the coupled reaction crucible is cooled, it is taken out and the coke inside is weighed and recorded as m4. The reactivity of the coke is calculated according to the formula (m1+m3-m4) / (m1+m3). The coke after reaction is placed in a type I rotating drum and its crush resistance and wear resistance after reaction are measured.

2. The method for determining the coupling reactivity of coke iron oxides according to claim 1, characterized in that, It also includes a detection device; the detection device includes a displacement detection device, a temperature detection device, and a pressure detection device; the displacement detection device is located on the pressurizing device; the temperature detection device includes a thermocouple one for detecting the temperature of the material in the coupling reaction crucible, a thermocouple two for detecting the temperature of the second heating zone, and a thermocouple three for detecting the temperature of the first heating zone; the pressure detection device includes a pressure sensor one located on the pressurizing device and a pressure sensor two located at the bottom of the reactor body.

3. The method for determining the coupling reactivity of coke iron oxides according to claim 1, characterized in that, The gas preheating zone consists of a preheating zone bottom plate, a heat storage body, and a preheating zone top plate; dense through holes are opened on both the preheating zone bottom plate and the preheating zone top plate; the heat storage body is composed of filler material with a regular shape, and the filler material is corundum or high-temperature alloy; the filler material forms a large number of irregular gas passages between the preheating zone bottom plate and the preheating zone top plate.

4. The method for determining the coupling reactivity of coke iron oxides according to claim 3, characterized in that, The gas preheating zone consists of a preheating zone bottom plate, a heat storage body, and a preheating zone top plate; dense through holes are opened on both the preheating zone bottom plate and the preheating zone top plate; the heat storage body is an integrally cast filler; the filler is made of graphite, corundum, or high-temperature alloy; the filler has a large number of pores inside, and the pores are interconnected to form a large number of irregular gas passages.

5. The method for determining the coupling reactivity of coke iron oxides according to claim 3, characterized in that, The reactor body is a corundum tube.

6. The method for determining the coupling reactivity of coke iron oxides according to claim 1, characterized in that, Both heating device one and heating device two consist of multiple electric heating rods arranged circumferentially.

7. The method for determining the coupling reactivity of coke iron oxides according to claim 1, characterized in that, The reactor body is equipped with a crucible support, which is fixedly connected to the side wall of the reactor body; the coupling reaction crucible is placed on the crucible support.

8. The method for determining the coupling reactivity of coke iron oxides according to claim 1, characterized in that, The upper side wall of the molten iron receiving crucible has densely arranged ventilation holes along the circumference, with a diameter of 1 to 10 mm.

9. The method for determining the coupling reactivity of coke iron oxides according to claim 1, characterized in that, The heating temperature and atmosphere control of the coupling reaction crucible are as follows: Heating temperature from 20℃ to 200℃, heating rate from 1 to 10℃ / min, atmosphere 100% N2; heating temperature from 200℃ to 500℃, heating rate from 5 to 15℃ / min, atmosphere 100% N2; heating temperature from 500℃ to 1200℃, heating rate from 5 to 15℃ / min, atmosphere 50% N2 + 20% CO2 + 30% CO; heating temperature from 1200℃ to 1500℃, heating rate from 5 to 15℃ / min, atmosphere 50% N2 + 10% CO2 + 40% CO; heating to 1500℃ and holding for 25 to 35 minutes, atmosphere 50% N2 + 10% CO2 + 40% CO; heating temperature from 1500℃ to 20℃, cooling rate from 5 to 15℃ / min, atmosphere 100% N2.

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