Metallurgical dust cold press molding device and method

Abstract

The invention relates to the technical field of ferrous metallurgy, in particular to a metallurgical dust cold press molding device and method. Comprising a mold, the mold is formed by buckling a first half mold and a second half mold which can be separated, and inner cavities of the first half mold and the second half mold jointly form a straight barrel section and a spherical cavity connected with the straight barrel section; convex teeth are arranged on the joint surface of the first half die, grooves matched with the convex teeth in size are formed in the joint surface of the second half die, and when the first half die and the second half die are buckled, the convex teeth and the grooves are mutually embedded; the shape of the pressing rod is matched with the inner shape of the straight barrel section of the mold, the bottom of the pressing rod is a spherical surface, and the spherical surface is matched with the inner surface of the spherical cavity of the mold; and the pressure supporting seat is used for supporting and fixing the buckled mold. Annular pressing seams of finished pellets are fundamentally eliminated, so that the finished pellets obtain a uniform and compact integral structure, and the harsh requirement of blast furnace smelting for strength is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel metallurgy, in particular to a metallurgical dust cold-pressing forming device and method. BACKGROUND

[0002] In the production process of steel enterprises, various smelting solid wastes such as steel slag, iron oxide scale, sludge, and dust removal ash are generated. These powdery materials contain a large amount of valuable elements such as iron and have significant recycling value. Processing them into cold-pressed pellets with certain strength as blast furnace raw materials or steelmaking coolants is an effective way to realize resource recycling and reduce production costs.

[0003] However, due to their physical properties, powdery materials such as iron oxide scale cannot be directly used for ironmaking or steelmaking and must be pretreated by mixing, sintering, etc. to produce sintered ore before being used in the furnace. This process is high in energy consumption and long in process flow. If the powder can be directly pressed into pellets by a ball pressing device and the sintering process is omitted to be directly used in the blast furnace, the process flow can be significantly shortened, and a large amount of energy and cost can be saved.

[0004] However, the key bottleneck for realizing this technical route is the existing ball pressing device. The commonly used split die ball pressing method, as shown in Figure 6 , will form a ring-shaped pressing seam at the middle joint of the finished pellet. This pressing seam significantly reduces the structural strength of the pellet at this point, which is easily broken and powdered in the harsh environment of the blast furnace, thus failing to meet the strength requirements of the blast furnace and limiting the direct application of cold-pressed pellets.

[0005] Therefore, there is an urgent need in the prior art for a device and method that can fundamentally eliminate the pressing seam and produce high-strength cold-pressed pellets. SUMMARY

[0006] In order to overcome the shortcomings of the prior art, the present application provides a metallurgical dust cold-pressing forming device and method. The ring-shaped pressing seam of the finished pellet is fundamentally eliminated, and it obtains a uniform and dense overall structure, thereby meeting the stringent strength requirements of the blast furnace.

[0007] In order to achieve the above purpose, the present application adopts the following technical solutions: A metallurgical dust cold-pressing forming device, comprising: a mold, the mold being formed by buckling a first mold half and a second mold half, the inner cavities of the first mold half and the second mold half jointly forming a straight cylinder section and a spherical cavity connected to the straight cylinder section; a joint surface of the first mold half being provided with a protruding tooth, a joint surface of the second mold half being provided with a groove matching the size of the protruding tooth, the protruding tooth and the groove being mutually embedded when the first mold half and the second mold half are buckled; a pressing rod, the shape of the pressing rod being matched with the inner shape of the straight cylinder section of the mold, the bottom of the pressing rod being a spherical surface, the spherical surface being matched with the inner surface of the spherical cavity of the mold; a pressure support seat for supporting and fixing the buckled mold.

[0008] Further, the gap between the pressing rod and the inner wall of the straight cylinder section of the mold is not more than 1 mm.

[0009] Further, the cross section of the protruding tooth is rectangular, being a rectangular protrusion; the cross section of the groove is rectangular, being a rectangular groove.

[0010] Further, the length of the straight cylinder section of the mold is configured so that the material contained therein can reach the predetermined density requirement after being pressed.

[0011] Further, the device integrates multiple molds, pressing rods and pressure support seats to form a ball press.

[0012] A method for metallurgical dust cold-pressing forming using the above device, comprising the following steps: S1 mold buckling: the first mold half and the second mold half of the mold are buckled by the way of mutual embedding of the protruding tooth and the groove, and the buckled mold is placed on the pressure support seat.

[0013] S2 lateral locking: lateral pressure is applied to the first mold half and the second mold half from both sides of the mold to ensure that the mold remains tightly closed during the pressing process; S3 material filling: according to the target quality of the finished ball, the ball pressing material is filled into the straight cylinder section of the mold; S4 pressing forming: the pressing rod is inserted into the straight cylinder section of the mold, and axial pressure is applied to the pressing rod, so that the ball pressing material in the straight cylinder section is completely pressed into the spherical cavity until the bottom spherical surface of the pressing rod is completely matched with the inner surface of the spherical cavity of the mold, forming a dense ball.

[0014] Further, in step S2, the lateral pressure applied is 8-12 MPa.

[0015] Further, in step S2, the axial pressure applied is 8-12 MPa.

[0016] Further, the ball pressing material is iron oxide scale.

[0017] Compared with the prior art, the present application has the following advantages: 1. The forming mechanism of the pellets is completely changed, and the structural weakness of the annular compression joint is fundamentally eliminated.

[0018] The prior art relies on the two-way extrusion of the material by the two hemispherical dies when they are closed, and the joint surface is the parting surface, which will inevitably form a continuous annular compression joint at the equatorial position of the pellets. The present application innovatively adopts a forming method of first filling the material into the straight cylinder section, and then pushing and compressing the material from the straight cylinder section into the lower spherical cavity in a one-way and continuous manner by the compression rod like a piston. This process makes the pellets form as a whole in a closed cavity that is locked by the concave-convex structure, completely avoiding the interface of the "collision" combination of the materials of the two hemispherical dies in the traditional process. Therefore, the finished pellets are a complete and uniform whole, and there is no annular structural weak surface, and the compression strength, drop strength and wear resistance are essentially improved.

[0019] 2. Higher compression density and more uniform internal structure are achieved, and the quality of the pellets is significantly better than that of the traditional counter-pressure type pellets.

[0020] In the "piston pushing" process, the material is forced to be extruded into the spherical cavity and finally formed after being pre-compressed in the straight cylinder section under the strong axial pressure of the compression rod. This one-way and continuous pressure application method is beneficial to the gas discharge in the material and the tight rearrangement between the particles, avoiding the problem of uneven density caused by the violent flow of the material from the center to the periphery in the traditional counter-pressure process. Therefore, the pellets prepared by the present application have higher overall density and more uniform structure, and have more excellent metallurgical properties.

[0021] 3. The forming process is stable and reliable, and provides a guarantee for the uniformity of the pellet quality. Since the die is locked by the lateral pressure and does not move during the compression process, and the compression rod and the straight cylinder section are precisely matched, the entire forming process is carried out in a closed cavity with stable size. The stroke and the final form (the spherical surface of the compression rod and the spherical cavity) of each compression are fixed, thereby ensuring that each pellet in batch production has high consistency in weight, size and density, meeting the requirements of industrial large-scale production for product quality stability.

[0022] 4. The technical path of short process and low-cost direct reuse of metallurgical dust is successfully opened. Based on the above effects, the seamless and high-strength cold-pressed pellets prepared by the present application have mechanical properties that fully meet the harsh requirements of direct charging into the blast furnace. This makes it possible to eliminate the energy-intensive sintering process, realizes the shortest process connection from the powdery solid waste to the blast furnace raw material, directly saves the equipment, energy consumption and operating cost required for mixing and sintering, and brings huge economic benefits.

[0023] 5. It has wide applicability and good environmental benefits. The device and method of this invention are not only applicable to iron oxide scale, but also to the treatment of steelmaking sludge, dust collector ash, and other metallurgical dusts, with a wide range of applications. By realizing the high-value-added resource utilization of solid waste, it reduces environmental pollution caused by solid waste accumulation at the source, which is in line with the clean production direction of the steel industry. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of the present invention, showing the first half-mold and the second half-mold in the snap-fit ​​state.

[0026] Figure 3 This is a schematic diagram of the three-dimensional structure of the first half-mold of the present invention.

[0027] Figure 4 This is a schematic diagram of the three-dimensional structure of the second half-mold of the present invention.

[0028] Figure 5 This is a schematic diagram of the three-dimensional structure of the pressure bar of the present invention.

[0029] Figure 6 This is a schematic diagram of an existing finished briquetting product.

[0030] In the diagram: 1. Mold; 2. Pressure rod; 3. Pressure support seat; 4. Pressure ball material; 11. First half mold; 12. Second half mold; 13. Protruding tooth; 14. Groove. Detailed Implementation

[0031] The embodiments of the present invention are described in detail below. To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of the application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0033] In the description of the application, it needs to be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0034] In the description of the application, it needs to be noted that the terms used herein are only for the purpose of describing the specific embodiments, and are not intended to limit the exemplary embodiments according to the application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0035] Unless otherwise specifically stated, the relative arrangement of parts and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the application. At the same time, it should be clear that the size of each part shown in the drawings is not drawn in proportion to the actual proportion relationship. The technology, methods and devices known to those skilled in the relevant art can not be discussed in detail, but under appropriate circumstances, the technology, methods and devices should be considered as part of the authorized description. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0036] In addition, it should be noted that the use of the terms "first", "second" and the like to qualify parts is only for the convenience of distinguishing the corresponding parts, and the above terms have no special meaning unless otherwise stated, and therefore cannot be understood as a limitation on the scope of protection of the application.

[0037] Embodiment: This embodiment takes the treatment of iron oxide scale generated by steel enterprises as an example to specifically explain the implementation process of the present application.

[0038] First, referring to Figures 1 to 5 , a metallurgical dust cold pressing forming device of the present application is prepared. The device mainly includes a mold 1, a pressing rod 2 and a pressure support seat 3. The mold 1 is formed by buckling a first half mold 11 and a second half mold 12, a rectangular protrusion 13 is arranged on the joint surface of the first half mold 11, and a rectangular groove 14 that tightly matches the protrusion 13 is arranged on the joint surface of the second half mold 12. When the first half mold 11 and the second half mold 12 are buckled, the protrusion 13 and the groove 14 are embedded with each other to form a complete inner cavity, which is composed of an upper straight cylinder section and a lower spherical cavity connected with each other.

[0039] In this embodiment, the target finished product is iron oxide scale cold-pressed pellets, and the density thereof is required to reach 6.0 g / cm³. According to this requirement, the diameter of the lower spherical cavity of the mold 1 is designed to be 1 cm, and the length of the upper straight cylinder section is designed to be 5 cm and the diameter thereof is designed to be 0.6 cm. The diameter of the pressing rod 2 that is matched therewith is 0.58 cm, so as to ensure that the gap between the pressing rod 2 and the inner wall of the straight cylinder section is not more than 1 mm, which effectively prevents the material from overflowing. The bottom of the pressing rod 2 is processed into a spherical surface, and the curvature radius thereof is completely the same as that of the inner surface of the lower spherical cavity of the mold 1.

[0040] A method for cold pressing forming of metallurgical dust using the above device, comprising the following steps: S1, mold buckling and installation: The first half mold 11 and the second half mold 12 of the mold 1 are aligned by embedding the protrusion 13 and the groove 14 thereon with each other, and the buckling is completed. Subsequently, the buckled mold 1 is stably placed on the pressure support seat 3.

[0041] S2, lateral locking: Lateral pressure is applied to the mold 1 from both sides thereof to lock the mold. In this embodiment, the applied lateral pressure is 10 MPa. The pressure is sufficient to ensure that the mold 1 will not be opened due to the huge reaction force of the internal material in the subsequent axial pressing process, and to ensure the size stability and sealing performance of the forming cavity.

[0042] S3, material filling: According to the target quality of the finished pellets, the iron oxide scale (i.e. the ball pressing material 4) is accurately weighed and filled into the straight cylinder section of the mold 1. The volume of the straight cylinder section is accurately calculated to ensure that the filled material can reach the predetermined density requirement after pressing.

[0043] S4, pressing forming: The driving pressure rod 2 is inserted axially along the straight cylinder section of the mold 1. Axial pressure is applied to the pressure rod 2, which in this embodiment is 10 MPa. Under the piston pushing of the pressure rod 2, the oxide scale in the straight cylinder section is completely extruded and densified, and finally all is pushed into and fills the lower spherical cavity. The limit position of the pressure rod 2 is that the bottom spherical surface of the pressure rod 2 is completely fitted with the inner surface of the spherical cavity of the mold 1, at this time, a structure dense, no annular compression joint is formed in the closed cavity.

[0044] S5, demolding: The locking pressure applied to both sides of the mold 1 is released, and the first half mold 11 and the second half mold 12 are separated, so that the finally formed high-strength oxide scale cold-pressed pellets can be taken out.

[0045] It should be noted that the above embodiments are only preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. For example, the cross-sectional shape of the convex teeth and the grooves can also be trapezoidal, zigzag and other shapes that can achieve interlocking; the lateral and axial pressure applied can be adjusted within the range of 8-12 MPa according to different material properties; the device can also integrate multiple forming units to form an automatic and high-efficiency pellet press. Any person skilled in the art within the technical scope disclosed by the present application, according to the technical scheme and inventive concept of the present application, can make equivalent replacement or change, which should be covered within the protection scope of the present application.

Claims

1. A metallurgical dust cold briquetting device, characterized by, The device comprises: a mold (1) formed by the buckling of a separable first half mold (11) and a second half mold (12), the inner cavities of the first half mold (11) and the second half mold (12) together forming a straight cylinder section and a spherical cavity connected to the straight cylinder section; a convex tooth (13) is arranged on the joint surface of the first half mold (11), and a groove (14) with a size matched with the convex tooth is arranged on the joint surface of the second half mold (12), when the first half mold (11) and the second half mold (12) are buckled, the convex tooth (13) and the groove (14) are embedded with each other; a pressure rod (2) whose shape is matched with the inner shape of the straight cylinder section of the mold (1), the bottom of the pressure rod (2) is a spherical surface which is matched with the inner surface of the spherical cavity of the mold (1); a pressure support seat (3) for supporting and fixing the buckled mold (1).

2. The metallurgical dust cold pressure forming device according to claim 1, wherein the gap between the pressure rod (2) and the inner wall of the straight cylinder section of the mold (1) is not more than 1mm.

3. The metallurgical dust cold pressure forming device according to claim 1, wherein the cross section of the convex tooth (13) is rectangular, which is a rectangular protrusion; the cross section of the groove (14) is rectangular, which is a rectangular groove.

4. The metallurgical dust cold pressure forming device according to claim 1, wherein the length of the straight cylinder section of the mold (1) is configured to meet the predetermined density requirement of the final formed pellets after the material contained therein is pressed.

5. The metallurgical dust cold pressure forming device according to claim 1, wherein the device is integrated with a plurality of molds (1), pressure rods (2) and pressure support seats (3) as claimed in any one of claims 1-4 to form a pellet press. The device comprises the following steps: S1 mold buckling: the first half mold (11) and the second half mold (12) of the mold (1) are buckled by embedding the convex tooth (13) and the groove (14) with each other, and the buckled mold (1) is placed on the pressure support seat (3); S2 lateral locking: lateral pressure is applied to the first half mold (11) and the second half mold (12) from both sides of the mold (1) to ensure that the mold (1) remains tightly closed during the pressing process; S3 material filling: according to the target quality of the finished pellets, the pellet material (4) is filled into the straight cylinder section of the mold (1); 6. A method of cold briquetting of metallurgical dusts using the device according to any of claims 1-4, characterized in that, S4 pressing and forming: the pressure rod (2) is inserted into the straight cylinder section of the mold (1), and axial pressure is applied to the pressure rod (2) to completely press the pellet material (4) in the straight cylinder section into the spherical cavity until the bottom spherical surface of the pressure rod (2) is completely matched with the inner surface of the spherical cavity of the mold (1), forming a dense pellet.

7. The method for cold pressure forming of metallurgical dust according to claim 6, wherein in step S2, the lateral pressure applied is 8-12MPa.

8. The method for cold pressure forming of metallurgical dust according to claim 6, wherein in step S2, the axial pressure applied is 8-12MPa. ​ ​ ​ ​ ​ ​ 9. A method of cold briquetting of metallurgical dust according to claim 6, characterized in that, the briquetting material (4) is mill scale.

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