Air quenching treatment method for liquid blast furnace slag

Abstract

The invention relates to the technical field of blast furnace slag air quenching treatment, in particular to a liquid blast furnace slag air quenching treatment method. Comprising the following steps that high-pressure atomized water and compressed air are mixed to serve as an air quenching medium to conduct blowing treatment on the liquid blast furnace slag, and a spherical particle product is obtained; wherein the pressure intensity of the adopted high-pressure atomized water ranges from 5 Mpa to 10 Mpa, and the pressure intensity of the compressed air ranges from 0.8 Mpa to 1.5 Mpa. By introducing a special air quenching medium formed by mixing high-pressure atomized water and compressed air, the liquid blast furnace slag is subjected to blowing treatment, the compressed air is in full contact with atomized water particles and liquid blast furnace slag particles in the air quenching process, the liquid drop cooling forming process is accelerated, generation of mineral wool is effectively reduced, and the service life of the liquid blast furnace slag is prolonged. The mineral wool problem basically does not influence the process and the product quality; and meanwhile, on the premise that the liquidity of the liquid blast furnace slag is not influenced and the pressure intensity of the injection medium is ensured, uniform particle size distribution of the air-quenched blast furnace slag product is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace slag air quenching treatment, in particular to a liquid blast furnace slag air quenching treatment method. Background Art

[0002] The treatment of iron and steel metallurgical solid waste, mainly steel slag and iron slag, is an important category of solid waste treatment. There are many treatment processes. The metallurgical slag air quenching process is a process treatment method that is gradually gaining attention in the current metallurgical slag treatment process. The high-temperature liquid flow of steel slag and blast furnace slag is air quenched, which has the advantages of short process, low cost and direct product formation.

[0003] Among them, due to its own characteristics, blast furnace slag will simultaneously produce mineral wool during the wind quenching process. The mineral wool is fibrous and will randomly float in open scenes. After landing, it will mix with the wind-quenched blast furnace slag products and is difficult to separate. The production of mineral wool affects product quality on the one hand, and will also cause greater environmental pressure.

[0004] Therefore, how to suppress the generation of mineral wool is an important issue that needs to be solved in the air quenching blast furnace slag process. Through experiments, lowering the temperature of liquid blast furnace slag can reduce the generation of mineral wool, but after the temperature is lowered, the fluidity of liquid blast furnace slag becomes worse, which seriously affects the air quenching effect and the yield; or increasing the compressed air volume while reducing the compressed air pressure can reduce the mineral wool yield slightly, but this solution also has the problems of low yield and uneven particle distribution (more large particles and fewer fine particles).

[0005] Therefore, the present invention is proposed. Summary of the invention

[0006] The object of the present invention is to provide a method for air quenching liquid blast furnace slag, which can reduce the generation of mineral wool and ensure uniform distribution of various particle sizes of the air quenched blast furnace slag product without affecting the fluidity of the liquid blast furnace slag.

[0007] The present invention provides a method for air quenching liquid blast furnace slag, comprising the following steps: using a mixture of high-pressure atomized water and compressed air as an air quenching medium to spray the liquid blast furnace slag to obtain a spherical particle product; wherein the pressure of the high-pressure atomized water used is 5-10MPa, and the pressure of the compressed air is 0.8-1.5MPa.

[0008] Preferably, the supply flow ratio of the high-pressure atomized water to the compressed air at normal pressure is (1:10)-(1:50).

[0009] Preferably, the high-pressure atomized water is provided by a high-pressure atomized water system, which includes a pressurizer connected to a high-pressure pipeline. A high-pressure nozzle is provided at the water outlet of the high-pressure pipeline, and the high-pressure nozzle is provided with an atomized water blowing port.

[0010] Preferably, the compressed air is provided by an air compressor or pipeline compressed air, and a compressed air blowing port is provided, and the compressed air is ejected from the compressed air blowing port.

[0011] Preferably, the atomized water injection port is arranged between the converter liquid slag outlet and the compressed air injection port.

[0012] Preferably, the distance between the atomized water blowing port and the compressed air blowing port does not exceed 5 mm.

[0013] Preferably, the distance between the atomized water injection port and the liquid slag flow chute of the converter is no more than 5 mm.

[0014] Preferably, the spray range of the high-pressure atomized water and the spray range of the compressed air are both larger than the flow width of the liquid blast-furnace slag.

[0015] In summary, compared with the prior art, the present invention has the following advantages:

[0016] The technical solution provided by the present invention introduces a special air quenching medium formed by a mixture of high-pressure atomized water and compressed air to perform a blowing treatment on liquid blast-furnace slag. During the air quenching process, the compressed air is in full contact with the atomized water particles and the liquid blast-furnace slag particles, thereby accelerating the cooling and forming process of the droplets and effectively reducing the generation of mineral wool. The mineral wool problem basically no longer affects the process and product quality. At the same time, without affecting the fluidity of the liquid blast-furnace slag and ensuring the pressure of the blowing medium, the particle size of the air-quenched blast-furnace slag product is ensured to be evenly distributed, thereby ensuring the quality of the air-quenched blast-furnace slag product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of wind quenching of liquid blast furnace slag in an embodiment of the present invention;

[0019] Figure 2 The figure is a particle size distribution diagram of the blast furnace slag product obtained by processing in the practical application of the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] Example

[0024] A method for treating liquid blast furnace slag with air quenching, the process is as follows:

[0025] A mixture of high-pressure atomized water and compressed air is used as a wind quenching medium to spray liquid blast furnace slag to obtain a spherical particle product; the pressure of the high-pressure atomized water is 5-10Mpa, and the pressure of the compressed air is 0.8-1.5Mpa; the flow ratio of the high-pressure atomized water to the compressed air (normal pressure volume) or the normal pressure supply flow ratio is (1:10)-(1:50).

[0026] The high-pressure atomized water used is provided by a high-pressure atomized water system, which includes a compressor connected to a high-pressure pipeline, a high-pressure nozzle is provided at the water outlet of the high-pressure pipeline, and the high-pressure nozzle is provided with an atomized water blowing port. Compressed air is provided by an air compressor or pipeline compressed air, and is provided with a compressed air blowing port, and the compressed air is ejected from the compressed air blowing port.

[0027] like Figure 1 As shown, during installation, the atomized water injection port is set between the converter liquid slag outlet and the compressed air injection port, the distance between the atomized water injection port and the compressed air injection port does not exceed 5mm, and the distance between the atomized water injection port and the converter liquid slag flow chute does not exceed 5mm. The injection range of atomized water and the injection range of compressed air are both larger than the liquid flow width of liquid blast furnace slag, and it is necessary to ensure that the cross-section of the high-pressure atomized water and compressed air injected from the injection port can cover the cross-section of the liquid blast furnace slag flow.

[0028] High-pressure atomized water and compressed air can be sprayed in a linear or fan-shaped manner. When sprayed in a linear manner, the length of the nozzle must be greater than the width of the liquid slag flow; when sprayed in a fan-shaped manner, the fan-shaped expansion angle and radius must ensure that the atomized water and compressed air can fully cover the liquid slag flow. The material of the nozzle must be resistant to high temperature, wear and corrosion to adapt to the environment of high-temperature liquid blast furnace slag and high-speed airflow.

[0029] The liquid blast furnace slag outlet, atomized water injection port and compressed air injection port are closely connected, with a spacing of no more than 5 mm. This closely connected layout enables the three substances to fully mix and react in the shortest time and space, thereby improving the wind quenching effect.

[0030] The specific process is as follows:

[0031] 1. Preparation

[0032] Start the high-pressure atomized water system, check whether the compressor, high-pressure pipeline and high-pressure nozzle are working properly, adjust the compressor to the set pressure, and ensure that the high-pressure atomized water can be stably supplied and the atomization effect is good;

[0033] Turn on the air compressor, check the operating status of the air compressor equipment, adjust it to the required pressure, and ensure a stable supply of compressed air and appropriate flow output.

[0034] Check the position of the atomized water injection port and the compressed air injection port, the tightness of the connection and the ability to cover the cross-section of the liquid blast furnace slag flow, and ensure that each injection port is free of blockage and leakage.

[0035] 2. Blowing treatment stage

[0036] After the liquid blast furnace slag flows out from the outlet, the high-pressure atomized water first contacts the liquid blast furnace slag. Due to the rapid cooling effect of the high-pressure atomized water, tiny droplets begin to form on the surface of the liquid blast furnace slag and are initially cooled; then, the compressed air blows away and further cools the initially cooled liquid blast furnace slag droplets, causing them to quickly solidify into spherical particles in the high-speed airflow. In this process, the high-pressure atomized water and compressed air are continuously supplied according to the set flow ratio to ensure that the liquid blast furnace slag can fully contact with the wind quenching medium and be evenly cooled.

[0037] During the spraying process, the flow rate and temperature of the liquid blast furnace slag, as well as the pressure, flow rate and other parameters of the high-pressure atomized water and compressed air must be monitored in real time, and fine-tuned according to actual conditions to ensure the stability of the wind quenching effect and the consistency of product quality.

[0038] 3. Product collection and subsequent processing stage

[0039] The spherical particles of blast furnace slag after air quenching are collected, and the quality of the collected blast furnace slag particles is tested, including the testing of particle size distribution, particle shape, chemical composition and other indicators. The process parameters can be further optimized and adjusted according to the test results to improve product quality and production efficiency.

[0040] Control and optimization of process parameters during air quenching

[0041] High-pressure atomizing water pressure control: Pressure is a key factor affecting the size of atomized water particles and the cooling effect. If the pressure is too low, the atomized water particles will be larger, the contact area with the liquid blast furnace slag will be small, and the cooling effect will be poor; if the pressure is too high, it may lead to increased equipment costs and excessive impact on the liquid blast furnace slag, affecting the wind quenching effect. Therefore, it needs to be controlled between 5-10MPa and adjusted appropriately according to the temperature, flow rate and parameters of the compressed air of the liquid blast furnace slag.

[0042] Compressed air pressure control: The compressed air pressure is within the range of 0.8-1.5MPa. The pressure should be sufficient to disperse the liquid blast furnace slag into uniform particles, but should not be too high to cause excessive mineral wool or uneven particle distribution. In actual operation, it can be optimized and adjusted according to the characteristics of the liquid blast furnace slag and the structure of the blowing device.

[0043] High-pressure atomized water and compressed air flow ratio control: The flow ratio is between 1:10-1:50. This ratio directly affects the cooling rate, particle formation process and final product particle size distribution during wind quenching. If the flow ratio deviates from this range, it may cause uneven cooling of liquid blast furnace slag, resulting in excessive large particles or fine particles. During the production process, the flow ratio should be dynamically adjusted according to the changes in the composition, temperature, etc. of different batches of liquid blast furnace slag.

[0044] Blowing port coverage and spacing control: High-pressure atomized water and compressed air must be able to cover the cross-section of the liquid blast furnace slag flow from the blowing outlet section, and the blowing ports must be closely connected with a spacing of no more than 5mm. The control of these two parameters can ensure the full mixing and rapid reaction of the air quenching medium and the liquid blast furnace slag, and improve the air quenching efficiency and product quality. During the installation and commissioning of the equipment, the operation must be carried out strictly in accordance with the requirements, and the status of the blowing port must be checked regularly to prevent the coverage effect from decreasing or the spacing from changing due to wear, blockage, etc.

[0045] Practical Application

[0046] The method provided by the present invention is used to carry out actual wind quenching of blast furnace slag on site, the pressure of high-pressure atomized water is 0.75MPa, the compressed air is 1.0MPa, and the normal pressure supply flow ratio of high-pressure atomized water to compressed air is 1:25. At the same time, two comparisons are set, one using only 0.8MPa compressed air and the other using only 1.0MPa compressed air.

[0047] After the air quenching is completed, the air quenched blast furnace slag product is sampled and analyzed. The mass proportion of mineral wool in the blast furnace slag product obtained by using only 0.8MPa compressed air is 7.6%; the mass proportion of mineral wool in the blast furnace slag product obtained by using only 1.0MPa compressed air is 9.2%; the mass proportion of mineral wool in the blast furnace slag product obtained by the method provided by the present invention is 2.8%, which significantly reduces the generation of mineral wool and ensures the product quality.

[0048] The particle size distribution of the air-quenched blast furnace slag product is as follows Figure 2 As shown, from Figure 2 It can be clearly seen that the particle size distribution of the blast furnace slag product obtained by the method provided by the present invention is more uniform.

[0049] The method provided by the present invention is used in conjunction with the wind quenching process of liquid metallurgical slag such as blast furnace slag. By providing a mixture of high-pressure atomized water and compressed air as a wind quenching medium, a better product is obtained than when compressed air is used as the single wind quenching medium, such as spherical particles of wind-quenched blast furnace slag with reduced mineral wool and more uniform particle size distribution.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for treating liquid blast furnace slag by air quenching, characterized in that: The following steps are involved: A mixture of high-pressure atomized water and compressed air is used as a wind quenching medium to spray liquid blast furnace slag to obtain a spherical particle product; the pressure of the high-pressure atomized water used is 5-10Mpa, and the pressure of the compressed air is 0.8-1.5Mpa.

2. The method for treating liquid blast furnace slag with air quenching according to claim 1, characterized in that: The supply flow ratio of the high-pressure atomized water to the normal-pressure compressed air is (1:10)-(1:50).

3. The method for treating liquid blast furnace slag with air quenching according to claim 1, characterized in that: The high-pressure atomized water is provided by a high-pressure atomized water system, which includes a pressurizer connected to a high-pressure pipeline. A high-pressure nozzle is provided at the water outlet of the high-pressure pipeline, and the high-pressure nozzle is provided with an atomized water blowing port.

4. The method for treating liquid blast furnace slag with air quenching according to claim 3, characterized in that: The compressed air is provided by an air compressor or pipeline compressed air, and is provided with a compressed air blowing port, from which the compressed air is ejected.

5. The method for treating liquid blast furnace slag with air quenching according to claim 4, characterized in that: The atomized water injection port is arranged between the converter liquid slag outlet and the compressed air injection port.

6. The method for treating liquid blast furnace slag with air quenching according to claim 5, characterized in that: The distance between the atomized water spray port and the compressed air spray port does not exceed 5 mm.

7. The method for treating liquid blast furnace slag with air quenching according to claim 6, characterized in that: The distance between the atomized water injection port and the liquid slag flow chute of the converter is no more than 5 mm.

8. The method for air quenching liquid blast furnace slag according to claim 1, characterized in that: The spray range of the high-pressure atomized water and the spray range of the compressed air are both larger than the liquid flow width of the liquid blast-furnace slag.

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