Hot briquette iron for blast furnace and manufacturing method thereof

Abstract

A hot briquette iron for a blast furnace and a manufacturing method thereof are provided. The hot briquette iron comprises a variety of materials, including metallic iron, calcium oxide, silicon dioxide, aluminum oxide, and magnesium oxide, wherein the density of the hot briquette iron is greater than

Description

[Technical Field]

[0001] This invention relates to a hot-pressed iron block and its manufacturing method, particularly a hot-pressed iron block for use in a blast furnace and its manufacturing method. [Previous Technology]

[0002] In the blast furnace ironmaking process, three types of ore materials—sintered ore, pelletized ore, and lump ore—are used in a ratio of 7:1:2 to undergo a redox reaction with coke. During this process, the carbon (C) in the coke reacts with the iron oxide in the ore materials to produce a large amount of carbon dioxide (CO2). In addition, the production process of sintered ore also releases large amounts of carbon dioxide (CO2), nitrogen oxides (NOx), sulfur dioxide (SO2), and dioxins. Considering all these factors, blast furnaces emit a significant amount of CO2 during ironmaking. To address the challenge of emission reduction, the blast furnace process urgently needs transformation to reduce its carbon dioxide (CO2) emissions. Among these methods, partially replacing sintered ore with hot-briquetted iron (HBI) has proven to be an effective carbon reduction approach.

[0003] However, the basicity of conventional hot-pressed iron blocks is too low (e.g., 0.03 or 0.4), and they still need to be mixed with sinter and pellets in the blast furnace to adjust the basicity. In addition, the carbon reduction reaction in the blast furnace requires control of the amount used, which limits the carbon reduction effect. If hot-pressed iron blocks are used instead of sinter, the reducibility of other iron oxide ores may be reduced, resulting in an excessively high iron oxide content in the ores, causing the slag to melt prematurely and ultimately reducing the iron production.

[0004] Therefore, in order to overcome the shortcomings and deficiencies in the existing technology, it is necessary to provide an improved hot-pressed iron block for blast furnace and its manufacturing method to solve the problems existing in the above-mentioned conventional technology. [Summary of the Invention]

[0005] The main objective of this invention is to provide a hot-pressed iron block for blast furnace and a method for manufacturing the same. By increasing the basicity of the hot-pressed iron block (HBI), the reduction rate of blast furnace ore can be effectively improved, thereby reducing carbon dioxide (CO2) emissions while increasing iron production.

[0006] To achieve the above objectives, the present invention provides a method for manufacturing hot-pressed iron blocks for blast furnaces, the method comprising a mixing step, a roasting step, a reduction step and a hot-pressing step. In the mixing step, multiple materials are mixed to generate multiple green pellets, including: ferric oxide (Fe2O3), calcium oxide (Calcium O3), silicon dioxide (Silica), aluminum oxide (Alumina), and magnesium oxide (MgO). In the calcination step, the green pellets are heated in a first stage and a second stage to generate multiple spheroids, wherein the heating temperature of the first stage is at least 900 degrees Celsius and the heating time of the first stage is at least 10 minutes, and the heating temperature of the second stage is higher than the heating temperature of the first stage and the heating time of the second stage is longer than the heating time of the first stage. In the reduction step, a reducing gas is provided to heat the spheroids to carry out a first reduction reaction, removing oxygen from the iron oxide in the spheroids to generate multiple reduced irons containing metallic iron. In the hot pressing step, the reduced irons are heated and pressurized to generate multiple hot-pressed iron blocks, wherein the density of the hot-pressed iron blocks is greater than 5.0 g / cm3 and the basicity of the hot-pressed iron blocks is between 0.8 and 1.6.

[0007] In one embodiment of the present invention, in the roasting step, the heating temperature of the second stage is 1200 degrees Celsius, and the heating time of the second stage is 20 minutes.

[0008] In one embodiment of the present invention, the spheroidal ore comprises ferric oxide (Fe₂O₃), calcium oxide (Calcium O₂), silicon dioxide (Silica), aluminum oxide (Alumina), and magnesium oxide (MgO), wherein the weight percentage of ferric oxide (Fe₂O₃) is 85wt.%-92wt.%, the weight percentage of calcium oxide (Calcium O₂) is 2.2wt.%-3.2wt.%, the weight percentage of silicon dioxide (Silica) is 2.0wt.%-3.2wt.%, the weight percentage of aluminum oxide (Alumina) is 0.4wt.%-0.6wt.%, and the weight percentage of magnesium oxide (MgO) is 0wt.%-0.4wt.%.

[0009] In one embodiment of the present invention, in the reduction step, the reducing gas includes carbon monoxide, methane and hydrogen, and the heating temperature for heating the spheroids is at least 1100 degrees Celsius and the heating time is at least 2 hours.

[0010] In one embodiment of the present invention, in the reduction step, the reduced iron comprises metallic iron (Fe), calcium oxide (Calcium), silicon dioxide (Silica), aluminum oxide (Aluminum), and magnesium oxide (MgO), wherein the weight percentage of metallic iron (Fe) is 80wt.%-92wt.%, the weight percentage of calcium oxide (Calcium) is 2.2wt.%-3.2wt.%, the weight percentage of silicon dioxide (Silica) is 2.0wt.%-3.2wt.%, the weight percentage of aluminum oxide (Aluminum) is 0.4wt.%-0.6wt.%, and the weight percentage of magnesium oxide (MgO) is 0wt.%-0.4wt.%.

[0011] In one embodiment of the present invention, in the hot pressing step, the heating temperature of the reduced iron is at least 800 degrees Celsius, the pressure applied to the reduced iron is in the range of 5000 psi to 5500 psi, and the pressing time is at least 1 second.

[0012] In one embodiment of the present invention, after the hot pressing step, the manufacturing method further includes a verification step in which ore and the hot-pressed iron blocks are mixed in a blast furnace and heated to generate reduced metallic iron, and the reduction rate of the reduced metallic iron is verified.

[0013] In one embodiment of the present invention, in the verification step, the heating of the ore and the hot-pressed iron blocks is carried out in a first stage, a second stage and a third stage. In the first stage, the temperature is raised from 25 degrees Celsius to 900 degrees Celsius at a rate of 10 degrees Celsius / minute. In the second stage, the temperature is raised from 900 degrees Celsius to 1200 degrees Celsius at a rate of 2 degrees Celsius / minute. In the third stage, the temperature is raised from 1200 degrees Celsius to 1550 degrees Celsius at a rate of 5 degrees Celsius / minute.

[0014] To achieve the above objectives, the present invention provides a hot-pressed iron block for a blast furnace, the hot-pressed iron block comprising a variety of materials, the materials comprising: metallic iron (), calcium oxide (), silicon dioxide (), aluminum oxide () and magnesium oxide (); wherein the density of the hot-pressed iron block is greater than 5.0 g / cm3, and the basicity of the hot-pressed iron block is between 0.8 and 1.6.

[0015] In one embodiment of the present invention, calcium oxide, silicon dioxide, aluminum oxide and magnesium oxide are slag, and the ratio of metallic iron to slag in these materials is 4:1, and metallic iron accounts for 80wt.%-92wt.%.

[0016] As described above, the present invention replaces part of the sintered ore raw material with hot-pressed iron blocks (HBI), and also increases the basicity of the slag of hot-pressed iron blocks (HBI) and reduces the content of alumina (Al2O3). In the process of sintering hot-pressed iron blocks (HBI) in the blast furnace, the reduction rate of blast furnace ore can be increased, thereby reducing carbon dioxide (CO2) emissions and increasing iron production.

Implementation Method

[0017] To make the above and other objects, features, and advantages of the present invention more apparent and understandable, embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings. Furthermore, the directional terms used in the present invention, such as up, down, top, bottom, front, back, left, right, inside, outside, side, surrounding, center, horizontal, transverse, vertical, longitudinal, axial, radial, uppermost, or lowermost, are merely for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrating and understanding the present invention, and not for limiting the present invention. It should be noted that the drawings are simplified schematic diagrams; therefore, only elements and combinations related to the present invention are shown to provide a clearer description of the basic structure or implementation method of the present invention, while the actual elements and layout may be more complex. In addition, for ease of explanation, the elements shown in the various drawings of the present invention are not drawn to scale according to the actual number, shape, and size; the detailed scale can be adjusted according to design requirements.

[0018] Please refer to Figure 1, which is a flowchart of an embodiment of the method for producing hot-pressed iron blocks for a blast furnace according to the present invention. The method includes a mixing step S201, a roasting step S202, a reduction step S203, a hot pressing step S204, and a verification step S205. The operation steps and operating principles of each process will be described in detail below.

[0019] In the mixing step S201, multiple materials are mixed to generate multiple green pellets. These materials include: ferric oxide (Fe2O3), calcium oxide (Calcium O3), silicon dioxide (Silicon Dioxide), aluminum oxide (Aluminum O3), and magnesium oxide (MgO). In this embodiment, these materials are dry-mixed in a certain proportion to ensure that all components are evenly distributed, so as to granulate into green pellets with a particle size of 5 mm to 15 mm.

[0020] As shown in Table 1 below, these materials are mixed uniformly according to the weight percentage ratio of samples A to F, wherein the basicity (i.e., C / S) of the raw materials used in the blast furnace for samples A to F are 0.4, 0.8, 1.0, 1.6, 1.0 and 1.0, respectively. In this embodiment, the source of ferric oxide (Fe2O3) can be iron ore sand, and the source of calcium oxide (Calcium Oxide) can be lime. sample Ratio of raw pellets (Table 1) Alkalinity (C / S) A 95.0 1.0 0.4 2.5 1.0 0.2 B 94.0 2.2 0.8 2.7 0.6 0.2 C 92.8 3.3 1.0 3.2 0.4 0.4 D 94.0 3.3 1.6 2.0 0.4 0.4 E 92.4 3.3 1.0 3.2 0.8 0.4 F 92.0 3.3 1.0 3.2 1.2 0.4

[0021] In the roasting step S202, the green pellets are heated in a first stage and a second stage to generate multiple pellets, wherein the heating temperature of the second stage is greater than the heating temperature of the first stage and the heating time of the second stage is longer than the heating time of the first stage. The heating temperature of the first stage is 900 degrees Celsius and the heating time is 10 minutes, and the heating temperature of the second stage is 1200 degrees Celsius and the heating time is 20 minutes, so as to roast the pellets. In this embodiment, the spheroidal ore comprises ferric oxide (Fe₂O₃), calcium oxide (Calcium O₂), silicon dioxide (Silica), aluminum oxide (Alumina), and magnesium oxide (MgO), wherein the weight percentage of ferric oxide (Fe₂O₃) is 85wt.%-92wt.%, the weight percentage of calcium oxide (Calcium O₂) is 2.2wt.%-3.2wt.%, the weight percentage of silicon dioxide (Silica) is 2.0wt.%-3.2wt.%, the weight percentage of aluminum oxide (Alumina) is 0.4wt.%-0.6wt.%, and the weight percentage of magnesium oxide (MgO) is 0wt.%-0.4wt.%.

[0022] In the reduction step S203, a reducing gas is provided to heat the spheroids to carry out a first reduction reaction, removing oxygen from the iron oxide in the spheroids to generate multiple Direct Reduced Iron (DRI) compounds containing metallic iron. The reducing gas can reduce the spheroids to DRI with a metallization rate of 80% or higher. In this embodiment, the reducing gas contains carbon monoxide, methane, and hydrogen, and the heating temperature for heating the spheroids is 1100 degrees Celsius, and the heating time is 2 hours. As shown in Table 2 below, the reduced iron comprises metallic iron (Fe), calcium oxide (Calcium), silicon dioxide (Silica), aluminum oxide (Aluminum), and magnesium oxide (Mg). The weight percentage of metallic iron (Fe) is 80 wt.%-92 wt.%, the weight percentage of calcium oxide (Calcium) is 2.2 wt.%-3.2 wt.%, the weight percentage of silicon dioxide (Silica) is 2.0 wt.%-3.2 wt.%, the weight percentage of aluminum oxide (Aluminum) is 0.4 wt.%-0.6 wt.%, and the weight percentage of magnesium oxide (Mg) is 0 wt.%-0.4 wt.%. The basicity of sample A of the conventional technique is 0.4, and the aluminum oxide content is 1.0 wt.%. sample Reduced iron (DRI) ratio (Table 2) Total iron content Alkalinity (C / S) A 91.5 80.5 13.2 1.0 2.5 0.4 1.0 0.2 B 91.8 83.5 10.8 2.2 2.7 0.8 0.6 0.2 C 90.5 82.8 10.0 3.3 3.2 1.0 0.4 0.4 D 91.3 81.9 12.1 3.3 2.0 1.6 0.4 0.4 E 89.5 80.8 11.2 3.3 3.2 1.0 0.8 0.4 F 89.9 81.5 10.9 3.3 3.2 1.0 1.2 0.4

[0023] In the hot pressing step S204, the reduced iron is heated and pressurized to generate multiple hot-pressed iron blocks, wherein the density of the hot-pressed iron blocks is greater than 5.0 g / cm³, and the basicity of the hot-pressed iron blocks is between 0.8 and 1.6. Referring to Figure 2, which shows the relationship between the density and pressure of the hot-pressed iron blocks in the method for producing hot-pressed iron blocks for blast furnaces according to the present invention, in this embodiment, the heating temperature for heating the reduced iron is 800 degrees Celsius, the pressure range for pressurizing the reduced iron is 5000 psi to 5500 psi, and the pressurization time is 1 second. It is worth noting that the metallization rate of the reduced iron (DRI) must reach more than 80% in order to achieve a density of more than 5.0 g / cm³ for the hot-pressed iron blocks (HBI). As shown in Table 3 below, the hot-pressed iron blocks contain metallic iron (Fe), calcium oxide (Calcium), silicon dioxide (Silicon), aluminum oxide (Aluminum), and magnesium oxide (Mg). The weight percentage of metallic iron (Fe) is 80wt.%-92wt.%, the weight percentage of calcium oxide (Calcium) is 2.2wt.%-3.2wt.%, the weight percentage of silicon dioxide (Silicon) is 2.0wt.%-3.2wt.%, the weight percentage of aluminum oxide (Aluminum) is 0.4wt.%-0.6wt.%, and the weight percentage of magnesium oxide (Mg) is 0wt.%-0.4wt.%. sample Hot-pressed iron block (HBI) ratio (Table 3) Total iron content Alkalinity (C / S) A 91.5 80.5 13.2 1.0 2.5 0.4 1.0 0.2 B 91.8 83.5 10.8 2.2 2.7 0.8 0.6 0.2 C 90.5 82.8 10.0 3.3 3.2 1.0 0.4 0.4 D 91.3 81.9 12.1 3.3 2.0 1.6 0.4 0.4 E 89.5 80.8 11.2 3.3 3.2 1.0 0.8 0.4 F 89.9 81.5 10.9 3.3 3.2 1.0 1.2 0.4

[0024] In the verification step S205, the ore and the hot-pressed iron blocks are mixed into a blast furnace and heated to generate reduced metallic iron, and the reduction rate of the reduced metallic iron is verified. In this embodiment, the heating of the ore and the hot-pressed iron blocks goes through a first stage, a second stage, and a third stage. In the first stage, the temperature is raised from 25 degrees Celsius to 900 degrees Celsius at a rate of 10 degrees Celsius / minute. In the second stage, the temperature is raised from 900 degrees Celsius to 1200 degrees Celsius at a rate of 2 degrees Celsius / minute. In the third stage, the temperature is raised from 1200 degrees Celsius to 1550 degrees Celsius at a rate of 5 degrees Celsius / minute.

[0025] In this embodiment, the results of incorporating the ore and the hot-pressed iron blocks (HBI) of the present invention are verified by reducing molten metallic iron at high temperature. The experimental ore formulation ratio is shown in Table 4 below. The total experimental weight is 150 grams. The heating conditions are divided into three stages as described above. In the first stage, the heating temperature is from 25 °C to 900 °C, the heating rate is 10 °C / min, and a mixed gas is introduced, which contains 60% nitrogen (N2), 25% carbon monoxide (CO), and 15% carbon dioxide (CO2), with a flow rate of 5 L / min. In the second stage, the heating temperature is from 900 °C to 1200 °C, the heating rate is 2 °C / min, and a mixed gas is introduced, which contains 60% nitrogen (N2) and 40% carbon monoxide (CO), with a flow rate of 5 L / min. The heating temperature in the third stage ranges from 1200 °C to 1550 °C, with a heating rate of 5 °C / min, and a mixed gas containing 60% nitrogen (N2) and 40% carbon monoxide (CO) is introduced at a flow rate of 5 L / min. Example (Table 4) Experimental mineral formulation Hot-pressed iron block HBI Before slag melting Reduction rate (%) Reduced metallic iron Total weight (g) slag Melting temperature (°C) Comparative Example 1 Sintered ore: Lump ore: Pellet ore = 7:2:1 none 52.5 45 1373 Comparative Example 2 Sintered ore: Sample A: Lump ore: Pellet ore = 5.5:1.5:2:1 Alkalinity = 0.4 =1.0 47.6 47 1312 Example 1 Sintered ore: Sample B: Lump ore: Pellet ore = 5.5:1.5:2:1 Alkalinity = 0.8 =0.6 67 105.18 1410 Example 2 Sintered ore: Sample C: Lump ore: Pellet ore = 5.5:1.5:2:1 Alkalinity = 1.0 =0.4 64.3 109.73 1418 Example 3 Sintered ore: Sample D: Lump ore: Pellet ore = 5.5:1.5:2:1 Alkalinity = 1.6 =0.4 62.8 106.4 1429 Comparative Example 3 Sintered ore: Sample E: Lump ore: Pellet ore = 5.5:1.5:2:1 Alkalinity = 1.0 =0.8 45.7 60.71 1314 Comparative Example 4 Sintered ore: Sample F: Lump ore: Pellet ore = 5.5:1.5:2:1 Alkalinity = 1.0 =1.2 44.8 31.46 1307

[0026] It should be noted that in Examples 1 to 3, hot-pressed iron blocks (HBI) with different slag formulations replaced 15 wt.% of sintered ore. Comparative Example 1 uses raw materials already used in existing blast furnaces. Comparative Example 2 has a basicity of 0.4 and an alumina content of 1.0 wt.%, and it can be seen that the slag melting point is 61 °C lower than that of Comparative Example 1, and the reduction rate is reduced by 4.9%. This is because the high alumina content results in a lower slag melting point, shortens the reduction time, and leads to a poorer reduction rate. In Examples 1 to 3, the basicity is between 0.8 and 1.6, and the alumina content is between 0.4 wt.% and 0.6 wt.%, and the average slag melting point is increased by 46 degrees. The reduction rate is significantly better than that of the original blast furnace ore in Comparative Example 1, with an average increase of 12.2% in the reduction rate. The alumina contents of Comparative Examples 3 and 4 were 0.8 wt.% and 1.2 wt.%, respectively. The excess alumina in these examples also resulted in a lower melting point of the slag, shortened the reduction time, and consequently, a poorer reduction rate. Therefore, compared to Examples 1 to 3, the compositions of Comparative Examples 2, 3, and 4 were less than expected.

[0027] In one embodiment, the present invention further provides a hot-pressed iron block for a blast furnace, the hot-pressed iron block comprising a variety of materials, including: metallic iron (Fe), calcium oxide (Calcium), silicon dioxide (Silica), aluminum oxide (Aluminum), and magnesium oxide (Mg); wherein the density of the hot-pressed iron block is greater than 5.0 g / cm³, and the basicity of the hot-pressed iron block is between 0.8 and 1.6. The ratio of metallic iron to slag in the materials is 4:1, and metallic iron (Fe) accounts for 80 wt.%-92 wt.%.

[0028] It is worth noting that the hot-pressed iron blocks of low-carbon iron-containing raw materials are reduced through the following process: First, reducing gas is used to reduce spheroidized ore, converting it into direct reduced iron (DRI). Then, the DRI is hot-pressed to form hot-pressed iron blocks. These hot-pressed iron blocks contain metallic iron and slag. Compared with the production process of sintered ore, the pollution emissions of hot-pressed iron blocks are lower. Replacing sintered ore with hot-pressed iron blocks can reduce carbon emissions at the raw material end and reduce the amount of coke used, further reducing the carbon emissions of the blast furnace. However, there are significant differences in composition and melting point between hot-pressed iron blocks and sintered ore. Therefore, replacing sintered ore with hot-pressed iron blocks will cause changes in the internal conditions of the blast furnace, leading to a widening of the temperature range between slag melting and metallic iron melting.

[0029] This invention controls the slag composition in the hot-pressed iron block to 20 wt.%, thereby increasing the basicity (CaO / SiO2) and decreasing the alumina (Al2O3) content of the slag, and conducts reduction melting experiments in accordance with the proportions of blast furnace ore. After replacing 15 wt.% of sintered ore with hot-pressed iron blocks, using high-basicity, low-alumina hot-pressed iron blocks can increase the reduction rate of blast furnace ore, increase the melting point of slag, and decrease the melting temperature of molten iron, thus achieving a good balance between the high melting point of slag and the low melting temperature of molten iron, to avoid the slag melting prematurely due to excessive iron oxide content in the ore.

[0030] As described above, in the present invention, when hot-pressed iron blocks (HBI) replace part of the sintered ore raw materials, the slag composition in the hot-pressed iron blocks (HBI) is also adjusted, thereby increasing the basicity of the slag and reducing the content of alumina (Al2O3). In the process of sintering hot-pressed iron blocks (HBI) in the blast furnace, the reduction rate of blast furnace ore can be increased, thereby reducing carbon dioxide (CO2) emissions and increasing iron production.

[0031] It should be noted that although some specific embodiments have been described in this invention, it should be understood that these embodiments can also be interpreted as descriptions of the corresponding methods. Therefore, system or structural elements should be considered as specific manifestations of the corresponding method steps or their features. Similarly, the types mentioned in the context of method steps can also be interpreted as descriptions of specific components or details of the corresponding device. Some or all of the method steps can be performed by hardware devices such as microcontrollers, programmable computers, or electronic circuits. In some embodiments, several main method steps may be performed by such devices.

[0032] Depending on specific implementation requirements, embodiments of the present invention can be implemented in hardware or software. When using digital storage media, it is possible to store electronically readable temperature anomaly signals, which can work in conjunction with a programmable computer system to execute corresponding methods. Therefore, the digital storage media must be computer-readable. Some embodiments of the present invention include a data carrier capable of being combined with a programmable computer system to execute any of the methods described herein. Generally, embodiments of the present invention can be implemented as a computer program product containing program code that, when run on a computer, can effectively execute any method. For example, the program code can also be stored on a machine-readable medium. Other embodiments include a computer program stored on a machine-readable medium for executing any of the methods described herein. In other words, one embodiment of the method of the present invention is a computer program containing program code for executing the methods described herein, which, when run on a computer, can achieve the above-mentioned functions. Furthermore, another embodiment of the method of the present invention is a data carrier (or digital storage media, computer-readable recording media) that records the computer program required to execute the methods described herein. Data carriers, digital storage media, or recording media are typically tangible or non-volatile. Another embodiment of the method of the present invention is a data stream or signal sequence, which may represent a computer program performing the above-described methods and may be configured to be transmitted via a data communication link, such as through a network. Further embodiments include processing units, such as telephones or programmable logic devices, configured or adapted to perform any of the methods described herein. Additionally, a computer program installed on a computer for performing the above-described methods is also included.

[0033] Another embodiment of the invention relates to an apparatus or system configured to transmit a computer program for performing at least one of the methods described herein to a receiver. For example, the transmission may be electrical or optical. For example, the receiver may be a computer, mobile device, storage device, or similar device. For example, the apparatus or system may include a file server for transmitting the computer program to the receiver. In some embodiments, a programmable logic device (FPGA) may be used to perform some or all of the functions of the methods described herein. In some embodiments, a field-programmable gate array (FPGA) may cooperate with a micro master console to perform any of the methods described herein. Typically, in some embodiments, these methods are performed by any hardware device. The hardware device may be any general-purpose hardware such as a processor (CPU) or method-specific hardware such as an application-specific integrated circuit (ASIC).

[0034] Although the present invention has been disclosed by way of embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims. [Simplified Explanation of the Diagram]

[0035] Figure 1 is a flowchart of an embodiment of the method for making hot-pressed iron blocks for blast furnaces according to the present invention.

[0036] Figure 2 is a graph showing the relationship between the density and pressure of the hot-pressed iron block in the method for making hot-pressed iron blocks for blast furnaces according to the present invention.

Claims

1. A method for producing hot-pressed iron blocks for a blast furnace, the method comprising: a mixing step, mixing multiple materials to generate multiple green pellets, the materials comprising: ferric oxide (Fe2O3), calcium oxide (Calcium O3), silicon dioxide (Silicon O3), aluminum oxide (Aluminum O3), and magnesium oxide (MgO); a calcination step, heating the green pellets in a first stage and a second stage to generate multiple spherical ore, wherein the heating temperature of the first stage is at least 900 degrees Celsius, the heating time of the first stage is at least 10 minutes, the heating temperature of the second stage is greater than the heating temperature of the first stage, and the heating time of the second stage is longer than the heating time of the first stage; A reduction step involves providing a reducing gas to heat the spheroids to carry out a first reduction reaction, removing oxygen from the spheroids from the iron oxide to generate a plurality of reduced irons having metallic iron content; and a hot pressing step involves heating and pressurizing the reduced irons to generate a plurality of hot-pressed iron blocks, wherein the density of the hot-pressed iron blocks is greater than 5.0 g / cm³, and the basicity of the hot-pressed iron blocks is between 0.8 and 1.

6.

2. The method for producing hot-pressed iron blocks for a blast furnace as described in claim 1, wherein in the firing step, the heating temperature of the second stage is 1200 degrees Celsius, and the heating time of the second stage is 20 minutes.

3. The method for producing hot-pressed iron blocks for a blast furnace as described in claim 1, wherein the spheroids comprise ferric oxide (Fe₂O₃), calcium oxide (Calcium O₂), silicon dioxide (Silica), aluminum oxide (Alumina), and magnesium oxide (MgO), wherein the weight percentage of ferric oxide (Fe₂O₃) is 85 wt.%-92 wt.%, the weight percentage of calcium oxide (Calcium O₂) is 2.2 wt.%-3.2 wt.%, the weight percentage of silicon dioxide (Silica) is 2.0 wt.%-3.2 wt.%, the weight percentage of aluminum oxide (Alumina) is 0.4 wt.%-0.6 wt.%, and the weight percentage of magnesium oxide (MgO) is 0 wt.%-0.4 wt.%.

4. The method for producing hot-pressed iron blocks for a blast furnace as described in claim 1, wherein in the reduction step, the reducing gas comprises carbon monoxide, methane and hydrogen, and the heating temperature for heating the pellets is at least 1100 degrees Celsius and the heating time is at least 2 hours.

5. The method for producing hot-pressed iron blocks for a blast furnace as described in claim 1, wherein in the reduction step, the reduced iron comprises metallic iron (Fe), calcium oxide (Calcium), silicon dioxide (Silica), aluminum oxide (Alumina), and magnesium oxide (MgO), wherein the weight percentage of metallic iron (Fe) is 80 wt.%-92 wt.%, the weight percentage of calcium oxide (Calcium) is 2.2 wt.%-3.2 wt.%, the weight percentage of silicon dioxide (Silica) is 2.0 wt.%-3.2 wt.%, the weight percentage of aluminum oxide (Alumina) is 0.4 wt.%-0.6 wt.%, and the weight percentage of magnesium oxide (MgO) is 0 wt.%-0.4 wt.%.

6. The method for producing hot-pressed iron blocks for a blast furnace as described in claim 1, wherein in the hot-pressing step, the heating temperature of the reduced iron is at least 800 degrees Celsius, the pressure applied to the reduced iron is in the range of 5000 psi to 5500 psi, and the pressurization time is at least 1 second.

7. The method for producing hot-pressed iron blocks for a blast furnace as described in claim 1, wherein after the hot-pressing step, the method further includes a verification step of mixing ore and the hot-pressed iron blocks in a blast furnace and heating them to generate reduced metallic iron, and verifying the reduction rate of the reduced metallic iron.

8. The method for producing hot-pressed iron blocks for a blast furnace as described in claim 7, wherein in the verification step, the ore and the hot-pressed iron blocks are heated in a first stage, a second stage and a third stage, wherein in the first stage the temperature is increased from 25 degrees Celsius to 900 degrees Celsius at a rate of 10 degrees Celsius / min, in the second stage the temperature is increased from 900 degrees Celsius to 1200 degrees Celsius at a rate of 2 degrees Celsius / min, and in the third stage the temperature is increased from 1200 degrees Celsius to 1550 degrees Celsius at a rate of 5 degrees Celsius / min.

9. A hot-pressed iron block for a blast furnace, comprising: multiple materials including: metallic iron, calcium oxide, silicon dioxide, aluminum oxide, and magnesium oxide, wherein the materials are mixed to form multiple green pellets, wherein the green pellets are heated in a first stage and a second stage to form multiple spheroids, wherein the heating temperature of the first stage is at least 900 degrees Celsius and the heating time of the first stage is at least 10 minutes, the heating temperature of the second stage is higher than the heating temperature of the first stage, and the heating time of the second stage is longer than the heating time of the first stage; wherein the hot-pressed iron block is formed by heating and pressurizing multiple reduced iron pellets, wherein the reduced iron pellets are formed by heating the spheroids with a reducing gas to carry out a first reduction reaction, and then removing oxygen from the iron oxide in the spheroids; the density of the hot-pressed iron block is greater than 5.0 g / cm3, and the basicity of the hot-pressed iron block is between 0.8 and 1.

6.

10. The hot-pressed iron block for blast furnace as described in claim 9, wherein calcium oxide, silicon dioxide, aluminum oxide and magnesium oxide are slag, the ratio of metallic iron to slag in the material is 4:1, and the metallic iron accounts for 80wt.%-92wt.%.

Images