Production system of high-aluminum ballstone
After the dry press is formed, the cold isostatic pressure treatment is performed, combined with the sintering unit, and the problems of inconsistent density and high wear of traditional high-aluminum balls are solved, and high-efficiency and low-energy production of high-aluminum balls are achieved.
Patent Information
- Application Number
- CN202323459788.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-18
- Publication Date
- 2024-12-06
- Estimated Expiration
- 2033-12-18
AI Technical Summary
In the traditional preparation method of high alumina sphere, the ball ball method leads to inconsistent density, the dry pressure method leads to low spherical shape and high wear, the isostatic pressure method is low production efficiency, and the firing temperature of high alumina sphere is too high, and the wear and High damage rate.
After molding by dry press, cold isostatic pressure is performed, combined with the sintering unit, the density and spherical shape are improved through two molding processes, and the firing temperature and energy consumption are reduced.
The density and sphericality of high-aluminum spherical stones are improved, the wear and crushing rate is reduced, the forming efficiency is improved, and the firing temperature and energy consumption are reduced.
Smart Images
Figure CN222115503U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of grinding media, in particular to a production system of high-aluminum ball stone. Background Art
[0002] Ball stone is a grinding medium widely used in the crushing and grinding industries. Traditional ball stone is generally flint ball stone. With the development of technology, alumina ball stone, ordinary porcelain ball stone, talc porcelain ball stone, zirconium aluminum porcelain ball stone, etc. have gradually appeared. Among them, alumina ball stone has high density and high hardness, so it is widely used. At present, the preparation method of alumina ball stone is: various raw materials are mixed and ball milled to make slurry, the slurry is spray dried to make powder, the powder is formed into a green body, and the green body is sintered. There are two common powder forming processes: dry pressing method and balling method. The balling method is to roll and bond the powder to form a sphere. This sphere has high sphericity, but the difference between different layers in the balling process is large, and the density consistency is poor. As a result, although the overall wear of the finished ball stone is relatively low, the ball breakage rate during the grinding process is high. The dry pressing method is generally formed by a dry press or an isostatic press. The disadvantage of the dry press is that the pressure uniformity is low, resulting in low sphericity of the resulting green body, high wear of the finished product, and limited by the equipment, the molding pressure is relatively low (≤100MPa). Although the isostatic press applies pressure more evenly and at high pressure, its overall molding time is longer, resulting in low production efficiency.
[0003] On the other hand, in some specific industries, in order to avoid introducing too many impurities during the grinding process, extremely high requirements are often placed on grinding media. For example, for some high-purity alumina products, the proportion of Al2O3 in alumina balls is required to reach more than 95wt%, or even higher. Due to the extremely high Al2O3 content of this high-alumina ball, the use of a dry press to form it often leads to insufficient density, excessively high sintering temperature, and poor sphericity, resulting in poor bonding of the raw materials in the ball and high wear. Although high-alumina balls can also be produced by isostatic pressing, the holding time is often more than 5 minutes, coupled with the time for the previous vacuuming and subsequent pressure recovery, which greatly reduces the molding efficiency. Although high-alumina balls can be produced normally by the ball forming method, there are also problems with high wear of the finished product and high firing temperature. Utility Model Content
[0004] The technical problem to be solved by the utility model is to provide a production system of high-aluminum ball stone, which is applicable to the production of ball stone with high Al2O3 content and has low sintering temperature. The prepared ball stone has low wear and low breakage rate.
[0005] In order to solve the above problems, the utility model provides a production system of high-alumina ball stone, which comprises:
[0006] A powder supply unit for providing powder for the ball stone blank;
[0007] A molding unit for pressing the powder into a rough blank;
[0008] an isostatic pressing unit for isostatically pressing the rough blank to obtain a fine blank; and
[0009] A firing unit is used for firing the refined blank.
[0010] As an improvement of the above technical solution, the molding unit is a dry press, and the first mold thereof in contact with the powder is made of metal or ceramic material.
[0011] As an improvement of the above technical solution, the isostatic pressing unit is a cold isostatic pressing machine, and the second mold in contact with the rough blank is made of polyurethane or rubber;
[0012] The Shore hardness of the second mold is ≤70HA.
[0013] As an improvement of the above technical solution, the molding pressure of the molding unit is 10-80MPa, and the holding time is 2-10s;
[0014] The processing pressure of the isostatic pressing unit is 150-250 MPa, and the processing time is 1-20 seconds.
[0015] As an improvement of the above technical solution, the molding pressure of the molding unit is 20-50 MPa, and the molding time is 2-4 s;
[0016] The processing pressure of the isostatic pressing unit is 150-200 MPa, and the processing time is 2-8 s.
[0017] As an improvement of the above technical solution, the powder providing unit includes:
[0018] A ball mill unit for grinding the raw material mixture to obtain a slurry; and
[0019] The slurry is spray dried to obtain a spray unit of powder.
[0020] As an improvement of the above technical solution, the powder providing unit further includes:
[0021] A homogenizing unit for homogenizing the slurry is arranged between the ball milling unit and the spraying unit.
[0022] As an improvement of the above technical solution, the powder supply unit further includes: an aging unit for aging the powder, which is arranged between the spray unit and the molding unit.
[0023] As an improvement of the above technical solution, the ball milling unit comprises:
[0024] A first ball milling unit for ball milling the raw material mixture to a first particle size to obtain a coarse slurry; and
[0025] a second ball milling unit for ball milling the coarse slurry to a second particle size;
[0026] The first particle size is larger than the second particle size.
[0027] As an improvement of the above technical solution, the ball milling unit further includes: an iron removal unit for screening the coarse slurry to remove iron; the iron removal unit is arranged between the first ball milling unit and the second ball milling unit.
[0028] The implementation of this utility model has the following beneficial effects:
[0029] In the production system of the high-aluminum ball stone of the utility model, the powder is first pressed into a rough blank, then isostatically pressed into a refined blank, and then sintered. This two-step forming process of pressing and isostatically pressed densification effectively improves the density, density uniformity and sphericity of the refined blank, reduces the subsequent required sintering temperature, reduces energy consumption, and improves forming efficiency. At the same time, it also makes the wear of the finished high-aluminum ball stone lower and the breakage rate lower. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 This is a schematic diagram of the composition of a production system of high-alumina ball stone in one embodiment of the utility model;
[0031] Figure 2 It is a schematic diagram of the composition of a powder supply unit in one embodiment of the utility model;
[0032] Figure 3 It is a schematic diagram of the composition of the ball mill unit in one embodiment of the utility model. DETAILED DESCRIPTION
[0033] In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model is further described in detail below.
[0034] See also Figure 1 , this embodiment provides a production system for high-aluminum spheroidite, which includes: a powder supply unit 1 for providing powder for spheroidite blanks, a molding unit 2 for pressing the powder into a rough blank, an isostatic pressing unit 3 for isostatically pressing the rough blank to obtain a refined blank, and a sintering unit 4 for sintering the refined blank. Based on the above production system, high-aluminum spheroidite with a high Al2O3 content (≥95wt%) can be obtained by sintering at a relatively low sintering temperature (≤1650°C). And because the subsequent isostatic pressing treatment effectively improves the sphericity and uniformity of the refined blank, the wear of the high-aluminum spheroidite product is greatly reduced, and the breakage rate is reduced. In addition, by combining the molding unit 2 with the isostatic pressing treatment unit 3, the molding efficiency can also be effectively improved.
[0035] Specifically, the molding unit 2 can be a dry press commonly seen in the art, such as an automatic hydraulic press produced by Foshan Henglitai Machinery Co., Ltd., but is not limited thereto. Preferably, in one embodiment, the molding unit 2 is a dry press, and is provided with a first mold, the first mold is in contact with the powder, and the first mold is made of metal or ceramic. It should be noted that in the conventional ball stone dry pressing molding process, considering the sphericity factor, a layer of soft mold core (such as polyurethane, etc.) is often attached to the inside of the mold, but the role of pressing in this embodiment is only to form a rough blank, and the sphericity can be optimized by isostatic pressing treatment later, so the first mold of the dry press in this embodiment directly uses a hard material (such as metal or ceramic), which is easy to clean and can shorten the molding time. Specifically, in this embodiment, the molding pressure of the molding unit 2 is 10-80 MPa, and exemplary ones are 12 MPa, 18 MPa, 24 MPa, 30 MPa, 36 MPa, 42 MPa, 48 MPa, 54 MPa, 60 MPa, 66 MPa, 72 MPa or 78 MPa, but not limited thereto. Preferably, it is 20-80 MPa, and more preferably, it is 20-50 MPa. The holding time of the molding unit 2 is 2-10 s, and exemplary ones are 2.5 s, 3 s, 3.5 s, 4 s, 4.5 s, 5 s, 5.5 s, 6 s, 6.5 s, 7 s, 7.5 s, 8 s, 8.5 s, 9 s or 9.5 s, but not limited thereto; preferably, it is 2-5 s, and more preferably, it is 2-4 s.
[0036] Specifically, the isostatic pressing unit 3 is a common cold isostatic press or hot isostatic press in the art, preferably a cold isostatic press. The second mold in contact with the rough blank by the cold isostatic press is made of polyurethane or rubber material, with a Shore hardness of ≤70HA. This second mold material is relatively soft and can effectively cover the rough blank, making the pressure applied by isostatic pressing more uniform, effectively improving the sphericity of the refined blank, and improving the various properties of the finished high-aluminum ball stone. At the same time, the isostatic pressing process also densifies the rough blank and reduces the firing temperature.
[0037] Specifically, the treatment pressure of the isostatic pressing unit 3 in this embodiment is 150-250 MPa, and is exemplarily 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, 230 MPa or 240 MPa, but not limited thereto. Preferably, it is 150-200 MPa. The isostatic pressing treatment time is 1-20 s, and is exemplarily 2.5 s, 4 s, 5.5 s, 7 s, 8.5 s, 9 s, 10 s, 10.5 s, 12 s, 14 s, 16 s or 18 s, but not limited thereto. Preferably, it is 2-10 s, and more preferably, it is 2-8 s.
[0038] Specifically, the firing unit 4 in the present embodiment can be a roller kiln, tunnel kiln or shuttle kiln commonly used in the art, but is not limited thereto. A tunnel kiln is preferred. More preferably, the firing unit 4 in the present embodiment is a tunnel kiln for firing ceramic rollers. That is, the high-alumina ball stone in the present embodiment can be fired together with the ceramic rollers, greatly reducing the firing energy consumption. Specifically, since the present embodiment adopts a forming process of dry pressing-isostatic pressing densification treatment, the density of the high-alumina ball stone blank is greatly improved, so the firing temperature is also reduced accordingly, and therefore it can be fired together with the ceramic rollers. In addition, it should be noted that ceramic rollers generally adopt a hanging firing mode, and the lengths of different ceramic rollers are inconsistent, so it is often difficult to fully utilize part of the kiln space. The present embodiment fires the two together, fully utilizing the kiln space and effectively reducing the average firing energy consumption of the two.
[0039] Specifically, the powder providing unit 1 may adopt a wet powder making process or a dry powder making process. The wet powder making process is a process of ball milling slurry making-spray powder making. Based on this process, the powder providing unit 1 includes: a ball mill for mixing raw materials and ball milling to obtain slurry and a spray drying tower for spray drying the slurry to obtain powder, but is not limited to this. The dry powder making process is a process of dry grinding raw materials and adding water to make powder. Based on this process, the powder providing unit 1 includes: a grinding unit (such as a vertical mill, etc.) for grinding the raw materials into fine powder and a granulating unit (such as a disc granulator, a roller granulator, a tower granulator, etc.) for adding water to the fine powder for granulation. It may also include a drying unit (such as a fluidized bed, etc.) for drying and shaping the powder obtained by the granulation unit.
[0040] Preferably, see Figure 2 In one embodiment, the powder providing unit 1 adopts a wet powder making process, that is, it includes a ball milling unit 11 for mixing and grinding raw materials to obtain a slurry and a spray unit 12 for spray drying the slurry to obtain a powder. Specifically, the ball milling unit 11 is a common single ball mill or a continuous ball mill in the art, but is not limited thereto. The spray unit 12 can be a common spray drying tower in the art, but is not limited thereto.
[0041] Preferably, in one embodiment, the powder supply unit 1 further includes a homogenizing unit 13 for homogenizing the slurry, which is disposed between the ball mill unit 11 and the spray unit 12. The homogenizing unit 13 is a slurry tank with a stirring device commonly used in the art, and the uniformity of the high-alumina ball stone can be effectively improved by stirring and homogenizing the slurry in the slurry tank for 6 to 10 hours, thereby improving the yield rate.
[0042] Preferably, in one embodiment, the powder supply unit 1 further comprises: an aging unit 14 for aging the powder, which is arranged between the spray unit 12 and the molding unit 2. Specifically, the aging unit 14 can be a common aging silo in the art, and the gradation and moisture of the powder can be uniformed by aging, which is beneficial to improve the uniformity of the fine blank after molding.
[0043] Preferably, see Figure 3 In one embodiment, the ball milling unit 11 includes: a first ball milling unit 111 for ball milling the raw material mixture to a first particle size to obtain a coarse slurry and a second ball milling unit 112 for ball milling the coarse slurry to a second particle size. Specifically, the first particle size is 10 to 16 μm, and the ball milling time of the first ball milling unit 111 is 18 to 24 hours. The second particle size is 3 to 6 μm, and the ball milling time of the second ball milling unit 112 is 25 to 35 hours. Since high-alumina ball stone has high requirements on the fineness of particles in the slurry, the use of two-stage ball milling can speed up the ball milling efficiency.
[0044] Preferably, in one embodiment, the ball mill unit 11 further includes an iron removal unit 113 for removing iron from the coarse slurry by screening. The iron removal unit 113 is disposed between the first ball mill unit 111 and the second ball mill unit 112. The iron removal unit 113 may be a strong magnetic iron removal machine commonly used in the art, but is not limited thereto.
[0045] Based on the high-aluminum ball stone production system in this embodiment, the production method of high-aluminum ball stone is as follows: the raw material is ball-milled for 18 to 24 hours by the first ball milling unit 111 to obtain a coarse slurry with a particle size of 10 to 16 μm; the coarse slurry is deironed by the deironing unit 113; the deironed coarse slurry is ball-milled by the second ball milling unit for 25 to 35 hours to obtain a slurry with a particle size of 3 to 6 μm. The slurry is stirred and homogenized in the homogenization unit 13 for 6 to 10 hours and then passed into the spray unit 12 for spray drying to obtain a powder with a moisture content of ≤2wt%, and the powder is aged in the aging unit 14 for 10 to 20 hours. Then, the molding unit 2 is used to press and form a rough blank, and the rough blank is densified by the isostatic pressing unit 3 to obtain a fine blank, and the fine blank is fired in the firing unit 4 to obtain a high-aluminum ball stone finished product.
[0046] In summary, the production system of high-aluminum spheroidal stone based on the above embodiment first presses the powder into a rough blank, then isostatically presses it into a refined blank, and then sintered. This two-molding process of pressing and isostatically pressing effectively improves the density, density uniformity and sphericity of the refined blank, reduces the subsequent required sintering temperature, and reduces energy consumption. At the same time, it also makes the wear of the finished high-aluminum spheroidal stone lower and the breakage rate lower.
[0047] The above is a preferred embodiment of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications are also considered to be within the scope of protection of the utility model.
Claims
1. A production system of high-alumina ball stone, characterized in that: include: A powder supply unit for providing powder for the ball stone blank; A molding unit for pressing the powder into a rough blank; An isostatic pressing unit for isostatically pressing the rough blank to obtain a fine blank; and A firing unit is used for firing the refined blank.
2. The production system of high-alumina ball stone according to claim 1, characterized in that: The molding unit is a dry press, and the first mold in contact with the powder is made of metal or ceramic material.
3. The production system of high-alumina ball stone according to claim 1, characterized in that: The isostatic pressing unit is a cold isostatic press, and the second mold in contact with the rough blank is made of polyurethane or rubber; The Shore hardness of the second mold is ≤70HA.
4. The production system of high-alumina ball stone according to claim 1, characterized in that: The molding pressure of the molding unit is 10-80 MPa, and the holding time is 2-10 s; The processing pressure of the isostatic pressing unit is 150-250 MPa, and the processing time is 1-20 seconds.
5. The production system of high-alumina ball stone according to claim 1, characterized in that: The molding pressure of the molding unit is 20-50 MPa, and the molding time is 2-4 s; The processing pressure of the isostatic pressing unit is 150-200 MPa, and the processing time is 2-8 s.
6. The production system of high-alumina ball stone according to claim 1, characterized in that: The powder supply unit comprises: A ball mill unit for grinding the raw material mixture to obtain a slurry; and The slurry is spray dried to obtain a spray unit of powder.
7. The production system of high-alumina ball stone according to claim 6, characterized in that: The powder material providing unit also includes: A homogenizing unit for homogenizing the slurry is arranged between the ball milling unit and the spraying unit.
8. The production system of high-alumina ball stone according to claim 6, characterized in that: The powder supply unit further includes: an aging unit for aging the powder, which is arranged between the spray unit and the molding unit.
9. The production system of high-alumina ball stone according to claim 6, characterized in that: The ball milling unit comprises: A first ball milling unit for ball milling the raw material mixture to a first particle size to obtain a coarse slurry; and a second ball milling unit for ball milling the coarse slurry to a second particle size; The first particle size is larger than the second particle size.
10. The production system of high-alumina ball stone according to claim 9, characterized in that: The ball milling unit further comprises: an iron removal unit for removing iron from the coarse slurry through screening; the iron removal unit is arranged between the first ball milling unit and the second ball milling unit.