Method for Utilizing CDQ Dust as Sintering Fuel

Abstract

The method for converting CDQ dust into sintering fuel according to the present invention comprises (a) a step of collecting CDQ dust, (b) a step of pelletizing the collected CDQ dust, and (c) a step of introducing the pelletized CDQ dust as fuel for an iron ore sintering process according to a preset mixing ratio, wherein step (c) can be mixed such that the weight of the pelletized CDQ dust is 5% or more to 20% or less with respect to the total weight of the sintering raw material including the pelletized CDQ dust.

Description

Technology Field

[0001] The present invention relates to a method for sintering CDQ dust into fuel. Background Technology

[0002] The Coke Dry Quenching (CDQ) process plays a crucial role in the coke production process, and the CDQ dust generated during this process has a composition similar to coke, characterized by high calorific value and low impurities.

[0003] In the steel manufacturing process, the sintering process is the process of agglomerating fine iron ore and other raw materials by supplying heat from a binder. Anthracite is primarily used as fuel in this sintering process, and CDQ dust has the potential to replace anthracite due to its characteristics.

[0004] However, if CDQ dust is directly fed into the sintering process, various problems arise.

[0005] Specifically, CDQ dust has a very fine particle size, which poses a problem in that a significant amount may be lost during transportation and input processes. In addition, if CDQ dust is input as fuel, it can reduce the permeability of the sintering bed, thereby lowering the productivity of the sintering process and degrading the quality of the sintered ore.

[0006] Due to these problems, the effective recycling of CDQ dust has been limited to date. Therefore, there is a need for a method to process CDQ dust into a form suitable for the sintering process while maintaining its characteristics. Prior art literature

[0007] Korean Published Patent No. 10-2003-0035700 The problem to be solved

[0008] The present invention aims to solve the aforementioned conventional problems by providing a method for effectively utilizing CDQ dust as fuel for a sintering process.

[0009] In addition, the present invention aims to increase resource efficiency and improve the economic feasibility of the sintering process through the recycling of CDQ dust, while simultaneously maintaining or improving the quality of the produced sintered ore.

[0010] The problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0011] A method for converting CDQ dust into sintered fuel according to one embodiment for solving the above problem comprises (a) a step of collecting CDQ dust, (b) a step of pelletizing the collected CDQ dust, and (c) a step of introducing the pelletized CDQ dust as fuel for an iron ore sintering process according to a preset mixing ratio, wherein step (c) can be mixed such that the weight of the pelletized CDQ dust is 5% or more to 20% or less with respect to the total weight of the sintering raw material including the pelletized CDQ dust.

[0012] And the above step (a) can capture CDQ dust generated during the dry cooling process of the coke production process.

[0013] In addition, step (b) above can be pelletized by mixing a binder into CDQ dust at 5% or less.

[0014] At this time, step (b) above can be pelletized by adjusting the moisture content of the CDQ dust to 10% or less.

[0015] In addition, after step (c) above, step (d) of sintering iron ore using sintering raw materials including pelletized CDQ dust may be further performed.

[0016] Meanwhile, after the above step (d), a step (e) for evaluating the quality of the sintered ore sintered by the above step (d) may be further performed.

[0017] In addition, quality evaluation items for sintered ore may include productivity (t / d / m²), drop strength (SI), average particle size (mm), and low-temperature reduction degradation index (RDI).

[0018] And, a system for converting CDQ dust into fuel according to one embodiment for solving the above problem includes a CDQ dust collection device for collecting CDQ dust, a pelletizing device for pelletizing the CDQ dust collected by the CDQ dust collection device, and a sintering device for feeding the CDQ dust pelletized by the pelletizing device as fuel for an iron ore sintering process according to a preset mixing ratio, wherein in the sintering device, the weight of the pelletized CDQ dust may be 5% or more to 20% or less relative to the total weight of the sintering raw material including the pelletized CDQ dust.

[0019] At this time, the CDQ dust collection device can collect CDQ dust generated during the dry cooling process of the coke production process.

[0020] In addition, the above pelletizing device can pelletize CDQ dust by mixing a binder at 5% or less.

[0021] In addition, the above pelletizing device can pelletize CDQ dust by adjusting its moisture content to 10% or less.

[0022] Meanwhile, the present invention may further include a quality evaluation module for evaluating sintered ore sintered in the sintering device.

[0023] At this time, the quality evaluation module may include at least one of a weight measuring device for measuring the productivity of the sintered ore sintered by the sintering device, a drop strength measuring device for measuring the drop strength of the sintered ore sintered by the sintering device, a particle size analyzer for analyzing the particle size of the sintered ore sintered by the sintering device, and a low-temperature reduction differentiation rate measuring device for measuring the low-temperature reduction differentiation rate of the sintered ore sintered by the sintering device. Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention

[0024] According to the method for converting CDQ dust into sintered fuel according to one embodiment of the present invention, by pelletizing CDQ dust and utilizing it as fuel for a sintering process, the recycling rate of CDQ dust, which was previously treated as waste, can be increased and resource efficiency can be significantly improved.

[0025] In addition, the present invention can solve the problem of reduced air permeability of the sintering bed and maintain or improve the productivity of the sintering process and the quality of the sintered ore by introducing pelletized CDQ dust into the sintering process at an appropriate mixing ratio.

[0026] Furthermore, the present invention has the advantage of minimizing loss during the transportation and input process of CDQ dust, thereby improving the working environment and reducing environmental pollution, while simultaneously preventing resource loss.

[0027] Furthermore, by replacing a portion of the existing sintering fuel with CDQ dust, the present invention can reduce the cost of the sintering process and improve the economic efficiency of the overall steel production process.

[0028] The effects according to the embodiments are not limited to those exemplified above, and a wider variety of effects are included in this specification. Brief explanation of the drawing

[0029] FIG. 1 is a diagram showing the entire process of a method for sintering CDQ dust into fuel according to one embodiment of the present invention. FIG. 2 is a diagram showing a process that can be additionally performed in a method for converting CDQ dust into fuel according to one embodiment of the present invention. FIG. 3 is a diagram conceptually illustrating the comprehensive process of a method for converting CDQ dust into sintered fuel according to one embodiment of the present invention. Specific details for implementing the invention

[0030] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0031] In this specification, where a component (or region, layer, part, etc.) is described as being "on," "connected," or "combined" with another component, it means that it may be directly placed / connected / combined with the other component, or that a third component may be placed between them.

[0032] Identical reference numerals denote identical components. Additionally, in the drawings, the thicknesses, proportions, and dimensions of the components are exaggerated for the effective illustration of the technical content.

[0033] "And / or" includes all one or more combinations that the associated configurations can define.

[0034] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0035] Additionally, terms such as "below," "lower side," "above," and "upper side" are used to describe the relationships between the components depicted in the drawings. These terms are relative concepts and are described based on the directions indicated in the drawings.

[0036] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Additionally, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and are explicitly defined herein unless interpreted in an ideal or overly formal sense.

[0037] Terms such as "include" or "have" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0038] FIG. 1 is a diagram showing the entire process of a method for sintering CDQ dust into fuel according to one embodiment of the present invention.

[0039] As illustrated in FIG. 1, the method for converting CDQ dust into sintered fuel in this embodiment may include (a) a step of collecting CDQ dust, (b) a step of pelletizing the collected CDQ dust, and (c) a step of feeding the pelletized CDQ dust as fuel for an iron ore sintering process according to a preset mixing ratio.

[0040] Through this process, the present embodiment can effectively utilize CDQ dust as fuel for the sintering process.

[0041] CDQ dust consists of fine particles generated during the dry cooling process of coke, and its characteristics suggest high potential for use as a sintering fuel. The chemical composition of CDQ dust generally consists of a carbon content of 80–90% and an ash content of 10–20%, with a relatively low sulfur content of less than 0.5%. Due to this high carbon content, the calorific value of CDQ dust ranges from approximately 6,500 to 7,500 kcal / kg, which is higher than that of ordinary coal.

[0042] In addition, the particle size distribution of CDQ dust consists mostly of fine particles of 100 μm or less, of which more than 50% are ultrafine particles of 10 μm or less. While such a fine particle size distribution can contribute to increasing the combustion efficiency of CDQ dust, it can also cause difficulties in handling and transportation processes.

[0043] In addition, CDQ dust has a low moisture content (generally less than 1%) and high porosity, which enables rapid ignition and effective heat transfer during the sintering process. These characteristics of CDQ dust increase its potential as a sintering fuel, and its utility can be further enhanced through the pelletization process proposed in this invention.

[0044] (a) Step is the process of capturing CDQ dust.

[0045] CDQ dust consists of fine particles generated during the dry cooling process of coke, and various dust collection devices can be utilized to effectively capture this dust.

[0046] In this case, the dust collection device may include cyclones, bag filters, electrostatic precipitators, etc., and it goes without saying that CDQ dust can also be collected through various other devices.

[0047] (b) Step is the process of pelletizing the captured CDQ dust.

[0048] Pelletization is a process of clumping fine particles of CDQ dust into granules of a uniform size and shape, which improves the handling of CDQ dust and allows it to be processed into a form suitable for the sintering process.

[0049] In addition, in this embodiment, various equipment such as disc pelletizers, drum pelletizers, and extruders may be utilized in the pelletization process, but the pelletization of CDQ dust can also be performed through various other devices.

[0050] (c) Step is the process of feeding pelletized CDQ dust as fuel into the iron ore sintering process according to a preset mixing ratio.

[0051] In this process, pelletized CDQ dust can be mixed at a predetermined weight ratio with respect to the total weight of the sintering raw material including pelletized CDQ dust.

[0052] In addition, in the case of this embodiment, the pelletized CDQ dust can be mixed such that the weight of the pelletized CDQ dust is 5% or more to 20% or less relative to the total weight of the sintering raw material including the pelletized CDQ dust.

[0053] In addition, such a mixing ratio can be set considering the efficiency of the sintering process and the quality of the sintered ore.

[0054] Below, each step of the present invention will be described in more detail.

[0055] In this embodiment, in step (a), CDQ dust generated during the dry cooling process of the coke production process can be collected. The coke dry cooling process is a process of cooling high-temperature coke with an inert gas, and the CDQ dust generated during this process has a high calorific value and a low impurity content. In the collection process, CDQ dust that is scattered along with the cooling gas can be effectively separated and collected.

[0056] And in step (b) of pelletizing CDQ dust, the CDQ dust can be pelletized by mixing a binder into the CDQ dust at a concentration of 5% or less. The binder mixed in this process serves to increase the strength of the pellet by binding the CDQ dust particles together.

[0057] In addition, various materials such as bentonite, lime, and water glass may be used as binders applicable in this embodiment, and these can be selected according to the characteristics of CDQ dust and the requirements of the sintering process.

[0058] In addition, in step (b), the moisture content of the CDQ dust can be adjusted to 10% or less to form pellets. Moisture content is an important factor affecting the formation and strength of pellets, and an appropriate moisture content promotes inter-particle bonding during the pelletization process and helps maintain the strength of the pellets after drying.

[0059] And through this process, CDQ dust can be pelletized to have a particle size of 2 to 3 mm.

[0060] FIG. 2 is a diagram showing a process that can be additionally performed in a method for converting CDQ dust into fuel according to one embodiment of the present invention.

[0061] As illustrated in FIG. 2, additional processes may be performed after step (c) in this embodiment. Such additional processes can assist in verifying and optimizing the effectiveness of the method for converting CDQ dust into sintered fuel.

[0062] After step (c), step (d) of sintering iron ore using sintering raw materials including pelletized CDQ dust can be performed.

[0063] The sintering process involves partially melting fine iron ore and other auxiliary materials at high temperatures to form lump-shaped sintered ore. In this process, pelletized CDQ dust acts as fuel to provide the heat required for sintering.

[0064] At the beginning of the sintering process, pelletized CDQ dust ignites rapidly due to its high porosity, which enables effective heat transfer from the top of the sintering bed. In addition, the combustion of pelletized CDQ dust is more uniform compared to ordinary pulverized coke, which contributes to forming an even temperature distribution across the entire sintering bed.

[0065] It was observed that the gas generated during the combustion process of pelletized CDQ dust is slowly released through the pores of the pellets, and does not significantly impede the permeability of the sintering bed. This solves the problem of reduced permeability that occurred when using conventional finely powdered CDQ dust directly.

[0066] Furthermore, the post-combustion residue of pelletized CDQ dust was found to effectively combine with surrounding iron ore particles, contributing to the improvement of the strength of the sintered ore. This is considered to be a factor that directly influences the improvement of the Reduction Degradation Index (RDI) of the sintered ore.

[0067] It was confirmed that such behavior of pelletized CDQ dust during the sintering process contributes to shortening the overall sintering time and improving the quality of the sintered ore. In particular, it was observed that sufficient heat was transferred to the bottom of the sintering bed, thereby reducing the occurrence of unsintered areas.

[0068] The behavioral characteristics of such pelletized CDQ dust during the sintering process support the fact that the method of the present invention can contribute to improving the efficiency of the sintering process and the quality of the sintered ore.

[0069] Meanwhile, after step (d), step (e) can be performed to evaluate the quality of the sintered ore sintered by step (d).

[0070] This course verifies the effectiveness of utilizing CDQ dust by analyzing the physical and chemical properties of sintered ore. By continuously analyzing data derived from repeated sintering processes, it enables the optimization of the pelletization process and the mixing ratio during the sintering process.

[0071] In addition, in this embodiment, the quality evaluation items of the sintered ore may include productivity (t / d / m²), drop strength (SI), average particle size (mm), and low-temperature reduction degradation index (RDI).

[0072] Productivity represents the amount of sintered ore produced per unit area per day and can be used as an indicator to evaluate process efficiency.

[0073] Drop strength is an indicator of the mechanical strength of sintered ore, and can be used to evaluate the durability of the sintered ore during transportation and handling processes.

[0074] Average particle size represents the size distribution of sintered ore and can affect permeability during blast furnace charging. Low-temperature reduction fractionation rate is an indicator of the degree of strength reduction of sintered ore within the melting furnace, which can affect the stability of melting furnace operations.

[0075] In addition, to verify the effectiveness of the method for converting CDQ dust into sintered fuel according to the embodiment of the present invention, a quality evaluation of the sintered ore was performed, and the results are shown in Table 1 below. Furthermore, these evaluation results can be presented by comparing the case where CDQ dust is not blended (Reference Example), the direct use of CDQ dust (Comparative Example), and the use after pellet processing (Treatment Example).

[0077]

[0079] First, a comparative analysis of the standard example and each treatment example is as follows.

[0080] Compared to the standard example's productivity of 36.2 t / d / m², Treatment Example 1 (5% blend) showed an improvement of about 4.7% to 37.9 t / d / m², and the RDI value improved by about 10.1% from 27.7% to 24.9%. This demonstrates that the efficiency of the sintering process can be improved even with the use of a small amount of pelletized CDQ dust.

[0081] In the case of Treatment Example 2 (10% blend), productivity was 37.0 t / d / ㎡, which is about 2.2% higher than the standard example, and the RDI value was 27.6%, maintaining a level similar to the standard example's 27.7%. This indicates that productivity can be improved while maintaining the quality of the sintered ore even when the blending ratio of CDQ dust is increased to 10%.

[0082] In Treatment Example 3 (20% mix), productivity was 34.8 t / d / ㎡, which is about 3.9% lower than the standard example, but this is a relatively small decrease compared to the standard example. The RDI value was 29.8%, which is about 7.6% higher than the standard example. However, this is a significantly improved result compared to Comparative Example 3 (RDI 32.2%) with the same mix ratio.

[0083] Overall, Treatment Example 1 and Treatment Example 2 showed superior productivity compared to the standard example, and in particular, Treatment Example 1 showed a significant improvement in the RDI value. In the case of Treatment Example 3, productivity and RDI values ​​decreased slightly, but this is considered acceptable given the high CDQ dust mixing ratio of 20%.

[0084] These results demonstrate that the pelletization treatment of CDQ dust according to the present invention can replace pulverized coke while maintaining or improving the efficiency of the sintering process and the quality of the sintered ore. In particular, it was confirmed that the best effect is achieved in a mixing ratio range of 5-10%.

[0085] In addition, when examining the pelletizing effect at each mixing ratio, the treated example consistently showed superior results compared to the comparative example at the same CDQ dust content. Under the 5% mixing condition, the productivity of Comparative Example 1 was 34.8 t / d / ㎡, whereas that of Treated Example 1 was 37.9 t / d / ㎡, an improvement of about 8.9%, and the RDI value also improved from 27.4% to 24.9%, an improvement of about 9.1%.

[0086] In the case of the 10% mixing condition, the productivity of Treatment Example 2 improved by approximately 7.6% from 34.4 t / d / ㎡ to 37.0 t / d / ㎡, and the RDI value also improved by approximately 12.1% from 31.4% to 27.6%. Even in the case of the 20% mixing condition, the productivity of Treatment Example 3 improved by approximately 12.3% from 31.0 t / d / ㎡ to 34.8 t / d / ㎡, and the RDI value also improved by approximately 7.5% from 32.2% to 29.8%.

[0087] Through these evaluation results, it can be confirmed that the pelletization treatment of CDQ dust according to the present invention has a significant effect on improving the productivity of the sintering process and the quality of the sintered ore, and it can be confirmed that the method of the present invention, which pelletizes CDQ dust and uses it as sintering fuel, can assist in improving the productivity of the sintering process and the quality of the sintered ore.

[0088] FIG. 3 is a diagram conceptually illustrating the comprehensive process of a method for converting CDQ dust into sintered fuel according to one embodiment of the present invention.

[0089] As illustrated in FIG. 3, the CDQ dust sintering fuel system of the present invention may include a CDQ dust collection device (20), a pelletizing device (30), a sintering device (40), and a quality evaluation module (50). Each of these components may be configured to perform a series of processes from the collection of CDQ dust to the quality evaluation of the sintered ore.

[0090] The CDQ dust collection device (20) can be connected to the outlet of the coke dry cooling facility (CDQ, 10). The CDQ dust collection device (20) may include a cyclone dust collector and a bag filter, and the cyclone dust collector may primarily collect large particles, while the bag filter may collect fine particles. The collected CDQ dust can be transported to a storage silo via a transport conveyor.

[0091] The pelletizing device (30) may include a storage silo, a weighing device, a mixer, a pellet molder, and a dryer.

[0092] The CDQ dust supplied from the storage silo can be accurately measured through a metering device, and the measured CDQ dust can be transferred to a mixer to which binder and water can be added.

[0093] In addition, the mixer can perform uniform mixing for a set period of time, and the mixed materials can be transferred to a pellet molder to be molded into pellets of a consistent size and shape. The molded pellets pass through a dryer to be adjusted to an appropriate moisture content.

[0094] The sintering device (40) may include a raw material charging system, a sintering bed, an ignition device, and a cooling device. In the raw material charging system, pelletized CDQ dust and other sintering raw materials may be mixed according to a predetermined mixing ratio and charged into the sintering bed. The upper part of the raw material is ignited by an ignition device located at the top of the sintering bed, and the sintering reaction may proceed by air supplied from the bottom. After sintering is completed, the generated sintered ore may be cooled by passing through a cooling device.

[0095] The quality evaluation module (50) may include equipment for measuring various characteristics of the sintered ore sintered by the sintering device (40). Specifically, the quality evaluation module (50) may include a weight measuring device for measuring productivity, a drop strength (SI) measuring device, a particle size analyzer, and a low-temperature reduction differentiation rate (RDI) measuring device.

[0096] Such a series of devices can be connected to each other to perform a continuous process, and each device can be integrated and managed by a central control system, thereby increasing the efficiency and stability of the entire process.

[0097] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing the technical concept or essential features thereof. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0098] 10: Coke Dry Cooling Equipment 20: CDQ Dust Collector 30: Pelletizing device 40: Sintering device 50: Quality Evaluation Module

Claims

Claim 1 A method for sintering CDQ dust as fuel, comprising: (a) a step of collecting CDQ dust; (b) a step of pelletizing the collected CDQ dust by mixing a binder at 5% or less; and (c) a step of feeding the pelletized CDQ dust as fuel for an iron ore sintering process according to a preset mixing ratio; wherein step (c) is a mixing step such that the weight of the pelletized CDQ dust is 5% or more to 10% or less relative to the total weight of the sintering raw material including the pelletized CDQ dust. Claim 2 In claim 1, the above step (a) is a method for sintering CDQ dust into fuel, wherein CDQ dust generated during the dry cooling process of a coke production process is captured. Claim 3 delete Claim 4 In claim 1, the above step (b) is a method for sintering CDQ dust into fuel by adjusting the moisture content of the CDQ dust to 10% or less and pelletizing it. Claim 5 A method for sintering CDQ dust into fuel according to claim 1, wherein, after step (c), step (d) of sintering iron ore using a sintering raw material including pelletized CDQ dust is further performed. Claim 6 A method for sintering CDQ dust into fuel according to claim 5, wherein after step (d), step (e) is further performed to evaluate the quality of the sintered ore sintered by step (d). Claim 7 A method for sintering CDQ dust into fuel, wherein, in claim 6, the quality evaluation items of the sintered ore include productivity (t / d / m²), drop strength (SI), average particle size (mm), and low-temperature reduction degradation index (RDI). Claim 8 A CDQ dust sintering fuel system comprising: a CDQ dust collection device for collecting CDQ dust; a pelletizing device for pelletizing CDQ dust collected by the CDQ dust collection device by mixing a binder at a ratio of 5% or less; and a sintering device for feeding the CDQ dust pelletized by the pelletizing device as fuel for an iron ore sintering process according to a preset mixing ratio; wherein, in the sintering device, the weight of the pelletized CDQ dust is mixed such that, with respect to the total weight of the sintering raw material including the pelletized CDQ dust, the weight of the pelletized CDQ dust is 5% or more to 10% or less. Claim 9 In claim 8, the CDQ dust collection device is a CDQ dust sintering fuel system that collects CDQ dust generated during the dry cooling process of a coke production process. Claim 10 delete Claim 11 In claim 8, the above pelletizing device is a CDQ dust sintering fuel system that pelletizes CDQ dust by controlling the moisture content of the CDQ dust to 10% or less. Claim 12 A CDQ dust sintering fuel system according to claim 8, further comprising a quality evaluation module for evaluating sintered ore sintered in the sintering device. Claim 13 In claim 12, the quality evaluation module comprises at least one of: a weight measuring device for measuring the productivity of the sintered ore sintered by the sintering device; a drop strength measuring device for measuring the drop strength of the sintered ore sintered by the sintering device; a particle size analyzer for analyzing the particle size of the sintered ore sintered by the sintering device; and a low-temperature reduction differentiation rate measuring device for measuring the low-temperature reduction differentiation rate of the sintered ore sintered by the sintering device; a CDQ dust sintering fuel system.

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