A lining plate for a super-fine powder ball mill and a manufacturing method thereof

Abstract

The application discloses a kind of preparation superfine powder ball mill's lining plate and its manufacturing method, belong to powder processing technical field.The lining plate of a kind of preparation superfine powder ball mill of the application, the top surface of lining plate bottom plate is grinding work surface, grinding work surface is the arc curved surface of involute type, and one grinding medium lifting flow guide strip is cast on each grinding work surface.The application solves the problem that the movement and circulation state of grinding medium in the existing ball mill are not good, which leads to the material not being ground into superfine powder well, and the grinding area is small, which makes the grinding efficiency low.The application makes the grinding work surface be groove structure, so there is always material between the grinding medium and the lining plate bottom plate, and therefore the sliding friction can be fully utilized for grinding.Each grinding medium grinds and impacts within a certain angle range, avoids direct contact of metal, and can further improve the grinding and impact efficiency.The grinding medium and the grinding work surface change from point contact to arc contact, which increases the grinding area.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of powder processing, in particular to a liner plate of a superfine powder ball mill and a manufacturing method thereof. BACKGROUND

[0002] The superfine powder industry is a new industry that has developed with the development of modern high technology and new material industry. After material is superfine crushed, it shows unique properties different from macroscopic substances in optics, thermology, magnetism, electricity, chemical activity, surface effect, etc. These properties can be fully utilized to maximize the role of materials and manufacture new materials with excellent performance. There are many types of superfine crushing equipment, among which the ball mill is widely used because it has better adaptability and adjustment space and can effectively grind finer particle sizes.

[0003] The motion state of the grinding medium depends on the rotational speed of the mill cylinder, while the grinding process requires the grinding medium in the bin to have different motion states, which contradicts the same rotational speed of the mill cylinder. The solution to this contradiction is to use a liner plate with different shapes to change the motion state of the grinding medium to meet the requirements of the material grinding process, thereby improving the grinding efficiency, increasing the yield, and reducing metal consumption. However, the current large-scale ball mill is mainly used in the cement, slag powder, and steel slag powder industries, and the structure of the liner plate is mainly suitable for the production of products with a specific surface area of less than 420 m2 / kg. There are few special liner plates for superfine powder grinding.

[0004] Chinese patent No. 201910805498.1 discloses a ball mill liner structure for superfine ball milling, which enhances the lifting capacity of the liner plate and improves the wear resistance of the surface. However, increasing the throw of the grinding body may reduce the grinding capacity, thereby failing to meet the grinding requirements of superfine powder. In addition, the wear-resistant treatment of the surface of the liner plate makes the surface more rough, forming a large number of pits, reducing the grinding surface between the liner plate surface and the grinding body, and reducing the grinding efficiency. SUMMARY

[0005] The present application aims to provide a liner plate of a superfine powder ball mill and a manufacturing method thereof. By setting an annular involute type groove grinding working surface on the liner plate bottom plate of the ball mill and setting a grinding medium lifting guide strip on the top surface, the residence time of the material in the ball mill is prolonged, the grinding state is changed from point grinding to line grinding, the grinding area is increased, the grinding efficiency is improved, the circulation of the grinding medium is promoted, and the motion state of the grinding medium is more likely to form a falling state, so that the material can be better crushed into superfine powder, solving the problems raised in the above background.

[0006] To achieve the above object, the present application provides the following technical solutions.

[0007] A kind of lining of superfine powder ball mill, including lining bottom plate, the lining bottom plate is fixed on the inner side wall of ball mill barrel by bolt, the top surface of lining bottom plate is grinding work surface, each lining bottom plate is equipped with 2-4 grinding work surfaces, grinding work surface is the arc curved surface of involute, the direction of involute is consistent with the flow direction of material in ball mill, grinding medium lifting flow guide strip is arranged on each grinding work surface, grinding medium lifting flow guide strip is the involute type boss along the axis of ball mill cast on grinding work surface.

[0008] Preferably, the outer diameter of the lining bottom plate is equal to the inner diameter of the ball mill barrel, the minimum thickness of the lining bottom plate is 20-50 mm, and the length of the lining bottom plate is 150-600 mm.

[0009] Preferably, the middle part of the lining bottom plate is provided with a mounting hole, and the mounting hole is located at the middle position of the intersection line of the two grinding work surfaces.

[0010] Preferably, the diameter of the base circle of the involute of the grinding work surface is 2-5 times the maximum ball diameter of the grinding medium microspheres.

[0011] Preferably, the grinding work surface is a smooth surface, and the surface hardness of the grinding work surface is HRC≥55.

[0012] Preferably, the width of the grinding medium lifting flow guide strip is 20-50 mm, and the height is 10-40 mm.

[0013] Preferably, the lower end point of the grinding medium lifting flow guide strip is located at one fifth of the lower edge of the grinding work surface, and the opening direction of the grinding medium lifting flow guide strip is consistent with the rotation direction of the ball mill.

[0014] Preferably, the surface of the grinding medium lifting flow guide strip is provided with a hard alloy surfacing wear-resistant layer, and the thickness of the wear-resistant layer is 2 mm.

[0015] A manufacturing method of a lining of superfine powder ball mill, based on a lining of superfine powder ball mill, comprising the following steps:

[0016] Step one, the lining bottom plate is made of high manganese steel, alloy steel, ductile cast iron, high chromium steel or high chromium cast iron, a groove is milled on the top of the lining bottom plate and polished to form a grinding work surface;

[0017] Step two, a mounting hole is formed in the middle of the intersection line of the grinding work surface;

[0018] Step three, grinding medium lifting flow guide strip is welded at the corresponding position of the grinding work surface;

[0019] Step four, the liner bottom plate is preheated at 400-500 DEG C for 2 hours, the electrode is baked at 300 DEG C for at least 1 hour or more, and after baking, the electrode is used to build up welding on the grinding medium lifting guide bar with grinding medium, a wear-resistant layer with a thickness of about 2mm is formed, and slow cooling is carried out after welding.

[0020] Compared with the prior art, the beneficial effects of the present application are:

[0021] 1、In the present application, the grinding working surface is a groove structure, so that there is always material between the grinding medium and the liner bottom plate, and therefore the sliding friction can be fully utilized for grinding; each grinding medium grinds and impacts within a certain angle range, and direct metal contact is avoided, so that the grinding and impact efficiency can be further improved.

[0022] 2、In the present application, the involute type grinding medium lifting guide bar and the groove type grinding working surface change the contact between the grinding medium and the grinding working surface from point contact to arc contact, change the grinding state from point grinding to line grinding, increase the grinding area, and improve the grinding efficiency.

[0023] 3、In the present application, the grinding medium slides down along the convex grinding medium lifting guide bar, moves as a whole to the grinding head direction, and the upper grinding medium is filled down, so as to promote the self-circulation of the grinding medium and strengthen the grinding effect, thereby improving the grinding efficiency.

[0024] 4、In the present application, the liner bottom plate has different radial curvatures along the grinding cylinder, which causes different disengagement angles of the grinding medium, and the variable disengagement angles enhance the penetration and mixing of the grinding medium and the material, the alternating corner points of the grinding medium promote the alternating falling of the grinding medium, and the grinding effect is enhanced, so that the material is more easily crushed into ultrafine powder. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the axial view of the liner bottom plate of the present application;

[0026] Figure 2 is the side view of the liner bottom plate of the present application;

[0027] Figure 3 is the top view of the liner bottom plate of the present application;

[0028] Figure 4 is the central angle diagram of the liner bottom plate of the present application;

[0029] Figure 5 is the assembly diagram of the liner bottom plate in the ball mill of the present application;

[0030] Figure 6 is the product particle size distribution diagram of Example 1 of the present application;

[0031] Figure 7This is a particle size distribution diagram of the product of Example 2 of the present invention;

[0032] Figure 8 This is the particle size distribution diagram of the product of Example 3 of the present invention;

[0033] Figure 9 This is the product particle size distribution diagram of Example 4 of the present invention.

[0034] In the figure: 1. Liner base; 2. Grinding working surface; 3. Grinding medium lifting guide strip; 4. Wear-resistant layer; 5. Mounting hole. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] In order to solve the problem that the movement and circulation of the grinding media in the ball mill are not good, which leads to the inability to grind the material into ultrafine powder, and the grinding area is small, which leads to low grinding efficiency, please refer to Figure 1-5 , this embodiment provides the following technical solutions:

[0037] A liner for a ball mill for preparing ultrafine powders includes a liner base plate 1, which is bolted to the inner wall of the ball mill cylinder. The outer diameter of the liner base plate 1 is equal to the inner diameter of the ball mill cylinder. The minimum thickness of the liner base plate 1 is 20-50 mm, and the length of the liner base plate 1 is 150-600 mm. When the inner diameter of the ball mill is Φ≤2.5 m, the length L of the liner base plate 1 is ≤300 mm; when the inner diameter is greater than Φ2.5 m, the length L of the liner base plate 1 is greater than 300 mm. The central angle α of the arc formed by the liner base plate 1 is 24-25 / D. When the diameter D of the ball mill is large, the numerator value is relatively small. The number of liner base plates 1 used in a single-turn ball mill is n = 360 ÷ α, where n is rounded upward.

[0038] The top surface of the liner bottom plate 1 is a grinding working surface 2, each liner bottom plate 5 is provided with 2-4 grinding working surfaces 2, when the diameter of the ball mill is large, the number of grinding working surfaces 2 on the liner bottom plate 1 is small, and vice versa; the grinding working surface 2 is an involute arc curved surface, and the involute direction is consistent with the material flow direction in the ball mill. The involute base circle diameter of the grinding working surface 2 is 2-5 times the maximum ball diameter of the grinding medium microsphere; the preparation of ultra-fine powder is mainly grinding, and the grinding medium has little impact on the liner bottom plate 1, therefore, the liner bottom plate 1 is made of a material with large hardness and wear resistance, the surface hardness is HRC≥55, and the surface of the grinding working surface 2 is relatively smooth, so that the material on the grinding working surface 2 can be easily contacted with the grinding medium, and the grinding area is increased as much as possible; since the grinding working surface 2 is a groove structure, there is always material between the grinding medium and the liner bottom plate 1, therefore, the grinding can be fully carried out by sliding friction; each grinding medium grinds and impacts within a certain angle range, direct metal contact is avoided, and the grinding and impact efficiency can be further improved.

[0039] Each grinding working surface 2 is provided with a grinding medium lifting guide strip 3, the grinding medium lifting guide strip 3 is a involute type boss cast on the grinding working surface 2 along the axial direction of the ball mill, the width of the grinding medium lifting guide strip 3 is 20-50 mm, and the height is 10-40 mm; the lower end point of the grinding medium lifting guide strip 3 is located at one-fifth of the lower edge of the grinding working surface 2, and the opening direction of the grinding medium lifting guide strip 3 is consistent with the rotation direction of the ball mill; when the ball mill is running, the grinding medium lifting guide strip 3 lifts the grinding medium, at the same time, the grinding medium slides down along the grinding medium lifting guide strip 3, and moves to the grinding head direction as a whole, and the upper grinding medium is filled down, so that the self-circulation of the grinding medium is promoted, the grinding effect is strengthened, the involute type grinding medium lifting guide strip 3 and the groove type grinding working surface 2 change the point contact between the grinding medium and the grinding working surface into arc line contact, the grinding area is increased, and the grinding efficiency is improved.

[0040] According to the above scheme, embodiments with different parameters are listed, and the corresponding product particle size distribution is as follows:

[0041] Specific embodiment one, ball mill Φ3.2x16m, the number of liner bottom plates 1 per unit ring is 48, the involute equation base circle diameter is 30 mm, the length L of a single liner bottom plate 1 is 350 mm, the minimum thickness a of the liner bottom plate 1 is 30 mm; the width c of the grinding medium lifting guide strip 3 is 25 mm, the height h is 30 mm; the grinding medium filling rate is 37%, the material ball weight ratio is 5%; the mill speed is 18 r / min, the feed particle size is 76 μm, and the product particle size distribution is as shown in Figure 6 ;

[0042] Specific embodiment two, ball mill Φ2.5x12.5m, the number of each unit circle lining plate bottom plate 1 is 37, the involute equation base circle diameter is 25mm, the single block lining plate bottom plate 1 length L=300mm, the minimum thickness a of the lining plate bottom plate 1 is 25mm;Grinding medium lifting flow guide strip 3 width c=25mm, height h=30mm;Grinding medium filling rate 37%, material ball weight ratio 4.5%; mill speed 20r / min, feed particle size 76μm, product particle size distribution as shown in Figure 7 ;

[0043] Specific embodiment three, ball mill Φ3.0x14m, the number of each unit circle lining plate bottom plate 1 is 45, the involute equation base circle diameter is 30mm, the single block lining plate bottom plate 1 length L=350mm, the minimum thickness a of the lining plate bottom plate 1 is 30mm;Grinding medium lifting flow guide strip 3 width c=25mm, height h=30mm;Grinding medium filling rate 38%, material ball weight ratio 4%; mill speed 18r / min, feed particle size 76μm, product particle size distribution as shown in Figure 8 ;

[0044] Specific embodiment four, ball mill Φ1.5x7.5m, the number of each unit circle lining plate bottom plate 1 is 22, the involute equation base circle diameter is 20mm, the single block lining plate bottom plate 1 length L=200mm, the minimum thickness a of the lining plate bottom plate 1 is 20mm;Grinding medium lifting flow guide strip 3 width c=20mm, height h=25mm;Grinding medium filling rate 38%, material ball weight ratio 4%; mill speed 26r / min, feed particle size 76μm. Product particle size distribution as shown in Figure 9 .

[0045] Because the grinding medium lifting flow guide strip 3 has the lifting effect on the grinding medium, the interaction force between them is large, so the grinding medium lifting flow guide strip 3 is easy to wear, therefore, the surface of the grinding medium lifting flow guide strip 3 is provided with a hard alloy surfacing wear-resistant layer 4, and the thickness of the wear-resistant layer 4 is 2mm.

[0046] The middle part of the lining plate bottom plate 1 is provided with a mounting hole 5, the mounting hole 5 is located at the middle position of the intersection line of the two grinding working surfaces 2, and the bolt is inserted into the mounting hole 5 to sequentially fix the lining plate bottom plate 1 on the inner wall of the ball mill.

[0047] A manufacturing method of a lining plate of a superfine powder ball mill, based on a lining plate of a superfine powder ball mill, comprising the following steps:

[0048] Step one, the lining plate bottom plate 1 is made of high manganese steel, alloy steel, nodular cast iron, high chromium steel or high chromium cast iron, a groove is milled on the top of the lining plate bottom plate 1 and polished to form a grinding working surface 2;

[0049] Step two, a mounting hole 5 is formed in the middle of the intersection line of the grinding working surface 2;

[0050] Step 3: Weld the grinding medium lifting guide strip 3 at the corresponding position of the grinding working surface 2;

[0051] Step 4: Preheat the liner base plate 1 at a temperature of 400-500°C for 2 hours, bake the welding rod at 300°C for at least 1 hour or more, and after baking, weld the grinding medium lifting guide bar 3 with welding rods to form a wear-resistant layer 4 with a thickness of about 2 mm. After welding, slowly cool it down to ensure that the wear-resistant layer 4 is firmly welded to avoid cracks.

[0052] Working principle: After the material enters the ball mill, the grinding medium and the material rotate and mix in the ball mill. The smooth grinding working surface 2 facilitates full contact between the material and the grinding medium, increasing the grinding area; the grinding working surface 2 is a groove structure, and there is always material between the grinding medium and the liner bottom plate 1. Each grinding medium grinds and impacts within a certain angle range to avoid direct metal contact, which can further improve the grinding and impact efficiency; the grinding medium lifting guide bar 3 will lift the grinding medium, and at the same time, the grinding medium slides down along the grinding medium lifting guide bar 3 and moves toward the grinding head as a whole. The upper grinding medium is filled down, thereby promoting the self-circulation of the grinding medium and enhancing the grinding effect.

[0053] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0054] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A liner for a ball mill for preparing ultrafine powders, comprising a liner bottom plate (1), characterized in that: The liner bottom plate (1) is fixed to the inner side wall of the ball mill cylinder by bolts. The top surface of the liner bottom plate (1) is a grinding working surface (2). Each liner bottom plate (1) is provided with 2 to 4 grinding working surfaces (2). The grinding working surfaces (2) are involute arc-shaped curved surfaces. The involute direction is consistent with the material flow direction in the ball mill. Each grinding working surface (2) is provided with a grinding medium lifting guide strip (3). The grinding medium lifting guide strip (3) is an involute boss cast on the grinding working surface (2) along the axial direction of the ball mill.

2. The liner of a ball mill for preparing ultrafine powder according to claim 1, characterized in that: The outer diameter of the lining bottom plate (1) is equal to the inner diameter of the cylinder of the ball mill, the minimum thickness of the lining bottom plate (1) is 20 to 50 mm, and the length of the lining bottom plate (1) is 150 to 600 mm.

3. The liner of a ball mill for preparing ultrafine powder according to claim 2, characterized in that: A mounting hole (5) is provided in the middle of the lining plate bottom plate (1), and the mounting hole (5) is located in the middle of the intersection line of the two grinding working surfaces (2).

4. The liner of a ball mill for preparing ultrafine powder according to claim 3, characterized in that: The involute base circle diameter of the grinding working surface (2) is 2 to 5 times the maximum diameter of the grinding medium microspheres.

5. The liner of a ball mill for preparing ultrafine powder according to claim 4, characterized in that: The grinding working surface (2) is a smooth surface, and the surface hardness of the grinding working surface (2) is HRC ≥ 55.

6. The liner of a ball mill for preparing ultrafine powder according to claim 5, characterized in that: The grinding medium lifting guide strip (3) has a width of 20 to 50 mm and a height of 10 to 40 mm.

7. The liner of a ball mill for preparing ultrafine powder according to claim 6, characterized in that: The lower end point of the grinding medium lifting guide strip (3) is located at one-fifth of the distance from the lower edge of the grinding working surface (2), and the opening direction of the grinding medium lifting guide strip (3) is consistent with the rotation direction of the ball mill.

8. The liner of a ball mill for preparing ultrafine powder according to claim 7, characterized in that: The surface of the grinding medium lifting guide strip (3) is provided with a hard alloy surfacing wear-resistant layer (4), and the thickness of the wear-resistant layer (4) is 2 mm.

9. A method for manufacturing a liner for a ball mill for preparing ultrafine powders, based on the liner for a ball mill for preparing ultrafine powders according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: The liner base plate (1) is made of high manganese steel, alloy steel, ductile iron, high chromium steel or high chromium cast iron, and a groove is milled on the top of the liner base plate (1) and polished to form a grinding working surface (2); Step 2: Open a mounting hole (5) in the middle of the intersection line of the grinding working surface (2); Step 3: Welding the grinding medium lifting guide strip (3) at the corresponding position of the grinding working surface (2); Step 4: The lining base plate (1) is preheated at a temperature of 400-500°C for 2 hours, and the welding rod is baked at 300°C for at least 1 hour or more. After baking, the welding rod is used to perform overlay welding on the grinding medium lifting guide bar (3) to form a wear-resistant layer (4) with a thickness of 2 mm. After welding, the temperature is slowly lowered.

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