Production method of bauxite for ceramic microbeads

Abstract

The invention discloses a production method of bauxite for ceramic microbeads, which comprises the following steps: calcining bauxite ore, and crushing the calcined bauxite ore to 300-400 meshes to obtain coarse bauxite; then putting the mixture into a ball mill for ball milling until D50 is 6-10 [mu] m to obtain fine bauxite; adding the mixture into a vertical grinder, adding a dispersing agent and aluminum oxide grinding balls at the same time, grinding the mixture, adding the ground mixture into a sorting machine, and sorting the mixture to obtain bauxite powder with the particle size of 2-4 microns; and finally, drying, crushing and screening after centrifugal dewatering, and winnowing to obtain the bauxite for the ceramic microbeads. The bauxite is subjected to multi-stage treatment through the steps of calcining, crushing, ball milling, grinding and the like, so that the purity and the uniformity of particle size distribution of the bauxite are improved, the physical and chemical properties of the bauxite are also improved, and the method is easy to popularize and implement, is more suitable for various industrial fields, meets the production requirements of downstream high-end products and has a wide application prospect. And particularly, the method has important significance on production of ceramic microbeads.

Description

Technical Field

[0001] The invention belongs to the technical field of bauxite processing, and in particular relates to a method for producing bauxite for ceramic microbeads. Background Art

[0002] Bauxite, or bauxite, is a general term for a variety of hydrous aluminum oxide ores with very different geological sources. With the advancement of science and technology and the development of industry, bauxite plays an increasingly important role in many industries, such as the ceramic industry and the abrasive industry. At the same time, the requirements for the particle size of bauxite are getting higher and higher. Bauxite powders with different particle sizes have various uses and can be used in grinding products, cosmetics, plastics, rubber, papermaking, environmental protection and other fields.

[0003] With the continuous expansion of the application fields of bauxite fine powder and the expansion of the market scale, its market prospects are becoming increasingly broad, especially in the building materials, ceramics, cosmetics, plastics, rubber and other industries. The demand for bauxite fine powder continues to grow, which has promoted the development of bauxite powder production.

[0004] The existing production process of bauxite fine powder generally includes raw material preparation, crushing process, grinding process, screening process, packaging and storage and other links. The selected bauxite raw material is initially crushed by a crusher, and then ground into fine powder that meets the requirements through a grinding process. The ground bauxite fine powder needs to be screened to remove particles that do not meet the requirements to ensure the quality and stability of the product. However, the existing production process has uneven particle distribution and low quality, which cannot meet the production needs of downstream high-end products. Therefore, a new production process is urgently needed. Summary of the invention

[0005] The object of the present invention is to provide a method for producing bauxite for ceramic microbeads.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A method for producing bauxite for ceramic microbeads comprises the following steps:

[0008] S1, calcining the bauxite ore and crushing it into 300-400 meshes to obtain crude bauxite;

[0009] S2, putting the coarse bauxite into a ball mill and grinding it until the D50 is 6-10 μm to obtain fine bauxite;

[0010] S3, adding fine bauxite into a vertical mill, adding a dispersant and alumina grinding balls, and adding the ground bauxite into a separator for separation to separate bauxite powder with a particle size of 2-4 μm;

[0011] S4. After centrifugal dehydration, the bauxite powder is dried, crushed, screened, and air-selected to obtain bauxite for ceramic microbeads.

[0012] Preferably, the mass content of aluminum in the bauxite is greater than 80%, and the mass content of iron is less than 2%. The calcination temperature in S1 is 1400-1600°C. The calcination of the bauxite can remove impurities and crystal water, increase the content of alumina, improve physical and chemical properties, promote physical and chemical reactions, and optimize the production process. It is helpful to improve the quality and performance of bauxite clinker, making it more suitable for use in various industrial fields.

[0013] Preferably, in order to reduce the introduction of impurities during ball milling, in S2, the grinding balls in the ball mill are alumina grinding balls.

[0014] During the ball milling process, the volume and different proportions of the grinding balls have a significant impact on the grinding effect. In order to achieve a better grinding effect, the alumina grinding balls account for 40-50% of the volume of the ball mill; in order to further ensure the grinding effect, the alumina grinding balls are composed of large balls, medium balls and small balls. The number of large balls accounts for 20-30% of the total number of alumina grinding balls, the number of medium balls accounts for 30-40% of the total number of alumina grinding balls, and the number of small balls accounts for 30-40% of the total number of alumina grinding balls. The diameter of the large ball is 60-120mm, the diameter of the medium ball is 40-60mm, and the diameter of the small ball is 5-20mm. The large ball is used to crush larger particles, and the small ball can further reduce the particle size. The reasonable design of large, medium and small balls can maximize the contact area, accelerate ball milling, and ensure the ball milling effect.

[0015] Preferably, the diameter of the large ball is 90-110 mm, the diameter of the medium ball is 50-60 mm, and the diameter of the small ball is 10-20 mm.

[0016] Preferably, in S3, water is added to the fine bauxite in a vertical mill to prepare a fine bauxite suspension, wherein the mass ratio of the fine bauxite to water is 1:(1.2-2.5);

[0017] 0.2-0.3g of dispersant is added to every 1 liter of fine bauxite suspension, and the dispersant is composed of the following raw materials in parts by weight: 2-5 parts of EDTA, 0.5-1.5 parts of DA dispersant, and 1-3 parts of maleic anhydride. The dispersant is mainly used to separate particles in the suspension to prevent agglomeration and affect the grinding effect; wherein, EDTA combines with metal ions such as aluminum and iron to form a protective film to prevent agglomeration between particles, and EDTA molecules carry negative charges after ionization in water, and these negative charges can interact with the positive charges on the surface of bauxite particles, increase the repulsive force between particles, and help disperse the particles. DA dispersant can change the potential of the bauxite surface, improve the particle morphology, and weaken the interaction force between particles, so that it is easier to be ground; maleic anhydride molecules can interact with the surface of bauxite particles, thereby changing the properties of the particle surface and reducing the adhesion and agglomeration between particles. The combination of the three can achieve a better effect of dispersing bauxite particles and improve the grinding effect.

[0018] Preferably, in S3, the diameter of the alumina grinding balls is 2-3 μm, and the alumina grinding balls occupy 30-40% of the volume of the vertical mill; the grinding temperature of the vertical mill is 20-28° C., and the rotation speed is 450-550 r / min.

[0019] Preferably, in order to make the grinding more uniform, in S3, the vertical grinding machine is subjected to forward rotation grinding for 7-9 hours and then reverse rotation grinding for 6-8 hours.

[0020] Preferably, in order to remove the dispersant and improve the quality of the bauxite powder, after the bauxite powder is sorted out in S3, it is washed with water three times, each time for 30-60 minutes, and the mass ratio of the bauxite powder to water during the washing is 1: (3-4);

[0021] Preferably, in S3, a flocculant is added to the washed bauxite powder to accelerate the coagulation of the bauxite powder; the flocculant is composed of the following raw materials in parts by weight: 2-3 parts of polyacrylamide and 1-2 parts of polyaluminium chloride; 0.03-0.08g of flocculant is added per ton of bauxite powder. Both polyacrylamide and polyaluminium chloride are flocculants with good flocculation effects, and both can be removed in the later drying process to reduce impurities in the bauxite.

[0022] Preferably, in S4, during centrifugal dehydration, the centrifugal speed is 1500-2500r / min; the drying temperature is 180-230°C; the screening screen is 1500-1800 mesh; the ceramic microbeads are heated to 130-160°C before air selection; the ceramic microbeads obtained by air selection have a bauxite particle size of 2.7-3μm.

[0023] Preferably, the method further comprises S5, mixing the ceramic micro-beads obtained after air selection with bauxite at a mixing speed of 80-150 r / min and a mixing time of 8-9 h. After mixing, the ceramic micro-beads with bauxite are more uniform.

[0024] The production method of the present invention has a simple process. First, the bauxite ore is calcined to increase the content of aluminum oxide and improve the physical and chemical properties of the bauxite. Then, the alumina grinding balls are used for ball milling, so that the impurities in the bauxite can be more effectively removed and the purity can be improved. Then, the ground bauxite is ground together with water and a dispersant to better disperse the bauxite. Finally, the bauxite is further processed by centrifugal dehydration, drying, screening and the like to obtain bauxite for ceramic microbeads with uniform particle size distribution.

[0025] The present invention performs multi-stage treatment on bauxite through calcination, crushing, ball milling, grinding and other steps, thereby improving the purity of bauxite and the uniformity of particle size distribution, and also improving its physical and chemical properties, effectively solving the problems of uneven particle distribution and low quality in the existing production process, with low cost and easy promotion and implementation, making it more suitable for use in various industrial fields and meeting the production needs of downstream high-end products, especially for the production of ceramic microbeads, which is of great significance. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with embodiments, but the protection scope of the present invention is not limited thereto.

[0027] In the following examples, the mass content of aluminum in the bauxite ore is greater than 80%, and the mass content of iron is less than 2%. The separator is an automatic diamond powder separator, which adopts the water washing and sedimentation principle.

[0028] Example 1

[0029] A method for producing bauxite for ceramic microbeads comprises the following steps:

[0030] S1, calcining the bauxite ore and crushing it into 300-400 meshes to obtain crude bauxite;

[0031] S2. Put the coarse bauxite into a ball mill and grind it until D50 is 6-10 μm to obtain fine bauxite; the grinding balls in the ball mill are alumina grinding balls, which account for 40% of the volume of the ball mill. The alumina grinding balls are composed of large balls, medium balls and small balls, the number of large balls accounts for 30% of the total number of alumina grinding balls, the number of medium balls accounts for 30% of the total number of alumina grinding balls, and the number of small balls accounts for 40% of the total number of alumina grinding balls. The diameter of the large balls is 60 mm, the diameter of the medium balls is 40 mm, and the diameter of the small balls is 5 mm;

[0032] S3, add fine bauxite into a vertical mill, add water to make a fine bauxite suspension, the mass ratio of the fine bauxite to water is 1:2.5, add dispersant and alumina grinding balls at the same time, add the ground and add to a separator for separation, and separate out bauxite powder with a particle size of 2-4 μm; add 0.2 g of dispersant to every 1 liter of fine bauxite suspension, the dispersant is composed of the following raw materials in parts by weight: EDTA 2 parts, DA dispersant 0.5 parts, maleic anhydride 3 parts; the diameter of the alumina grinding ball is 3μm, and the alumina grinding ball occupies 30% of the volume of the vertical mill; the grinding temperature of the vertical mill is 25℃, and the rotation speed is 450r / min; the vertical mill rotates forward for 7h and then rotates backward for 8h; after the bauxite powder is sorted out, it is washed with water three times, each time for 30min, and the mass ratio of bauxite powder to water is 1:4 during the washing; a flocculant is added to the washed bauxite powder to accelerate the coagulation of the bauxite powder; the flocculant is composed of the following raw materials in parts by weight: 2 parts of polyacrylamide and 2 parts of polyaluminium chloride; 0.03g of flocculant is added to each ton of bauxite powder;

[0033] S4, drying, crushing, screening and air selection of bauxite powder after centrifugal dehydration to obtain bauxite for ceramic microbeads; during centrifugal dehydration, the centrifugal speed is 2500r / min; the drying temperature is 230°C; the sieve for screening is 1600 mesh; the bauxite for ceramic microbeads is heated to 160°C before air selection; the particle size of the bauxite for ceramic microbeads obtained by air selection is 2.7-3μm;

[0034] S5, mixing the ceramic microbeads obtained after air selection with 2 tons of bauxite at a mixing speed of 150 r / min for 9 hours.

[0035] Example 2

[0036] A method for producing bauxite for ceramic microbeads comprises the following steps:

[0037] S1, calcining the bauxite ore and crushing it into 300-400 mesh to obtain crude bauxite;

[0038] S2. Put the coarse bauxite into a ball mill and grind it until D50 is 6-10 μm to obtain fine bauxite; the grinding balls in the ball mill are alumina grinding balls, which account for 50% of the volume of the ball mill. The alumina grinding balls are composed of large balls, medium balls and small balls, the number of large balls accounts for 20% of the total number of alumina grinding balls, the number of medium balls accounts for 40% of the total number of alumina grinding balls, and the number of small balls accounts for 40% of the total number of alumina grinding balls. The diameter of the large balls is 120 mm, the diameter of the medium balls is 60 mm, and the diameter of the small balls is 20 mm;

[0039] S3, add fine bauxite into a vertical mill, add water to make a fine bauxite suspension, the mass ratio of the fine bauxite to water is 1:2, add dispersant and alumina grinding balls at the same time, add the ground and add to a separator for separation, and separate out bauxite powder with a particle size of 2-4 μm; add 0.25 g of dispersant to every 1 liter of fine bauxite suspension, the dispersant is composed of the following raw materials in parts by weight: EDTA 4 parts, DA dispersant 1.5 parts, maleic anhydride 1 part; the diameter of the alumina grinding ball is 2μm, and the alumina grinding ball occupies 35% of the volume of the vertical mill; the grinding temperature of the vertical mill is 28°C, and the rotation speed is 550r / min; the vertical mill rotates forward for 9 hours and then rotates reversely for 6 hours; after the bauxite powder is sorted out, it is washed with water three times, each time for 60 minutes, and the mass ratio of bauxite powder to water during washing is 1:3; flocculant is added to the washed bauxite powder to accelerate the coagulation of the bauxite powder; the flocculant is composed of the following raw materials in parts by weight: 3 parts of polyacrylamide and 1 part of polyaluminium chloride; 0.08g of flocculant is added per ton of bauxite powder;

[0040] S4, drying, crushing, screening and air selection of bauxite powder after centrifugal dehydration to obtain bauxite for ceramic microbeads; during centrifugal dehydration, the centrifugal speed is 1500r / min; the drying temperature is 180°C; the sieve for screening is 1800 mesh; the bauxite for ceramic microbeads is heated to 130°C before air selection; the particle size of the bauxite for ceramic microbeads obtained by air selection is 2.7-3μm;

[0041] S5, mixing the ceramic microbeads obtained after air selection with 3 tons of bauxite at a mixing speed of 80 r / min and a mixing time of 8 h.

[0042] Example 3

[0043] A method for producing bauxite for ceramic microbeads comprises the following steps:

[0044] S1, calcining the bauxite ore and crushing it into 300-400 meshes to obtain crude bauxite;

[0045] S2, putting the coarse bauxite into a ball mill and grinding it until D50 is 6-10 μm to obtain fine bauxite; the grinding balls in the ball mill are alumina grinding balls, the alumina grinding balls account for 45% of the volume of the ball mill, the alumina grinding balls are composed of large balls, medium balls and small balls, the number of large balls accounts for 25% of the total number of alumina grinding balls, the number of medium balls accounts for 35% of the total number of alumina grinding balls, the number of small balls accounts for 40% of the total number of alumina grinding balls, the diameter of the large balls is 100 mm, the diameter of the medium balls is 50 mm, and the diameter of the small balls is 10 mm;

[0046] S3, add fine bauxite into a vertical mill, add water to make a fine bauxite suspension, the mass ratio of the fine bauxite to water is 1:1.2, add dispersant and alumina grinding balls at the same time, add the ground and add to a separator for separation, and separate out bauxite powder with a particle size of 2-4 μm; add 0.3 g of dispersant to every 1 liter of fine bauxite suspension, the dispersant is composed of the following raw materials in parts by weight: EDTA 5 parts, DA dispersant 1 part, maleic anhydride 2 parts; the diameter of the alumina grinding ball is 2μm, and the alumina grinding ball occupies 40% of the volume of the vertical mill; the grinding temperature of the vertical mill is 20℃, and the rotation speed is 500r / min; the vertical mill is forward rotating for 8h and then reverse rotating for 7h; after the bauxite powder is sorted out, it is washed with water three times, each time for 40min, and the mass ratio of bauxite powder to water is 1:3.5 during the washing; a flocculant is added to the washed bauxite powder to accelerate the coagulation of the bauxite powder; the flocculant is composed of the following raw materials in parts by weight: 2.5 parts of polyacrylamide and 1 part of polyaluminium chloride; 0.035g of flocculant is added per ton of bauxite powder;

[0047] S4, drying, crushing, screening and air selection of bauxite powder after centrifugal dehydration to obtain bauxite for ceramic microbeads; during centrifugal dehydration, the centrifugal speed is 2000r / min; the drying temperature is 1200℃; the sieve for screening is 1500 mesh; the bauxite for ceramic microbeads is heated to 140℃ before air selection; the particle size of bauxite for ceramic microbeads obtained by air selection is 2.7-3μm;

[0048] S5, mixing the ceramic microbeads obtained after air selection with 2.5 tons of bauxite at a mixing speed of 100 r / min for 8.5 h.

[0049] Example 4

[0050] A method for producing bauxite for ceramic microbeads comprises the following steps:

[0051] S1, calcining the bauxite ore and crushing it into 300-400 meshes to obtain crude bauxite;

[0052] S2. Put the coarse bauxite into a ball mill and grind it until D50 is 6-10 μm to obtain fine bauxite; the grinding balls in the ball mill are alumina grinding balls, which account for 43% of the volume of the ball mill. The alumina grinding balls are composed of large balls, medium balls and small balls, the number of large balls accounts for 28% of the total number of alumina grinding balls, the number of medium balls accounts for 35% of the total number of alumina grinding balls, and the number of small balls accounts for 37% of the total number of alumina grinding balls. The diameter of the large balls is 110 mm, the diameter of the medium balls is 55 mm, and the diameter of the small balls is 15 mm;

[0053] S3, add fine bauxite into a vertical mill, add water to make a fine bauxite suspension, the mass ratio of the fine bauxite to water is 1:1.8, add dispersant and alumina grinding balls at the same time, add the ground and add to a separator for separation, and separate out bauxite powder with a particle size of 2-4 μm; add 0.23 g of dispersant to every 1 liter of fine bauxite suspension, the dispersant is composed of the following raw materials in parts by weight: EDTA 3 parts, DA dispersant 0.8 parts, maleic anhydride 2 parts; the diameter of the alumina grinding ball is 3μm, and the alumina grinding ball occupies 33% of the volume of the vertical mill; the grinding temperature of the vertical mill is 202℃, and the rotation speed is 490r / min; the vertical mill is forward rotating for 7.5h and then reverse rotating for 6.5h; after the bauxite powder is sorted out, it is washed with water three times, each time for 50min, and the mass ratio of bauxite powder to water during washing is 1:(4; flocculant is added to the washed bauxite powder to accelerate the coagulation of the bauxite powder; the flocculant is composed of the following raw materials in parts by weight: 3 parts of polyacrylamide and 2 parts of polyaluminium chloride; 0.04g of flocculant is added per ton of bauxite powder;

[0054] S4, drying, crushing, screening and air selection of bauxite powder after centrifugal dehydration to obtain bauxite for ceramic microbeads; during centrifugal dehydration, the centrifugal speed is 1800r / min; the drying temperature is 210°C; the sieve for screening is 1700 mesh; the bauxite for ceramic microbeads is heated to 150°C before air selection; the particle size of the bauxite for ceramic microbeads obtained by air selection is 2.7-3μm;

[0055] S5, mixing the ceramic microbeads obtained after air separation with 2.8 tons of bauxite at a mixing speed of 120 r / min for 8 hours.

[0056] Example 5

[0057] A method for producing bauxite for ceramic microbeads comprises the following steps:

[0058] S1, calcining the bauxite ore and crushing it into 300-400 mesh to obtain crude bauxite;

[0059] S2. Put the coarse bauxite into a ball mill and grind it until D50 is 6-10 μm to obtain fine bauxite; the grinding balls in the ball mill are alumina grinding balls, which account for 48% of the volume of the ball mill. The alumina grinding balls are composed of large balls, medium balls and small balls. The number of large balls accounts for 21% of the total number of alumina grinding balls, the number of medium balls accounts for 39% of the total number of alumina grinding balls, and the number of small balls accounts for 40% of the total number of alumina grinding balls. The diameter of the large balls is 90 mm, the diameter of the medium balls is 45 mm, and the diameter of the small balls is 20 mm;

[0060] S3, add fine bauxite into a vertical mill, add water to make a fine bauxite suspension, the mass ratio of the fine bauxite to water is 1:2.2, add dispersant and alumina grinding balls at the same time, add the ground and add to a separator for separation, and separate out bauxite powder with a particle size of 2-4 μm; add 0.27 g of dispersant to every 1 liter of fine bauxite suspension, the dispersant is composed of the following raw materials in parts by weight: EDTA 2 parts, DA dispersant 1.2 parts, maleic anhydride 3 parts; the diameter of the alumina grinding ball is 3μm, and the alumina grinding ball occupies 38% of the volume of the vertical mill; the grinding temperature of the vertical mill is 26°C, and the rotation speed is 520r / min; the vertical mill is forward rotating for 8.5h and then reverse rotating for 7.5h; after the bauxite powder is sorted out, it is washed with water three times, each time for 45min, and the mass ratio of bauxite powder to water is 1:3 during the washing; a flocculant is added to the washed bauxite powder to accelerate the coagulation of the bauxite powder; the flocculant is composed of the following raw materials in parts by weight: 2 parts of polyacrylamide and 1.5 parts of polyaluminium chloride; 0.06g of flocculant is added per ton of bauxite powder;

[0061] S4, drying, crushing, screening and air selection of bauxite powder after centrifugal dehydration to obtain bauxite for ceramic microbeads; during centrifugal dehydration, the centrifugal speed is 2200r / min; the drying temperature is 220°C; the sieve for screening is 1600 mesh; the bauxite for ceramic microbeads is heated to 135°C before air selection; the particle size of the bauxite for ceramic microbeads obtained by air selection is 2.7-3μm;

[0062] S5, the ceramic microbeads obtained after air selection are mixed with 2.3 tons of bauxite at a mixing speed of 90 r / min and a mixing time of 9 hours.

[0063] Example 6

[0064] A method for producing bauxite for ceramic microbeads comprises the following steps:

[0065] S1, calcining the bauxite ore and crushing it into 300-400 mesh to obtain crude bauxite;

[0066] S2. Put the coarse bauxite into a ball mill and grind it until D50 is 6-10 μm to obtain fine bauxite; the grinding balls in the ball mill are alumina grinding balls, which account for 42% of the volume of the ball mill. The alumina grinding balls are composed of large balls, medium balls and small balls, the number of large balls accounts for 30% of the total number of alumina grinding balls, the number of medium balls accounts for 34% of the total number of alumina grinding balls, and the number of small balls accounts for 36% of the total number of alumina grinding balls. The diameter of the large balls is 80 mm, the diameter of the medium balls is 40 mm, and the diameter of the small balls is 5 mm;

[0067] S3, add fine bauxite into a vertical mill, add water to make a fine bauxite suspension, the mass ratio of the fine bauxite to water is 1:2.3, add dispersant and alumina grinding balls at the same time, add the ground and add to a separator for separation, and separate out bauxite powder with a particle size of 2-4 μm; add 0.24 g of dispersant to every 1 liter of fine bauxite suspension, the dispersant is composed of the following raw materials in parts by weight: EDTA 4 parts, DA dispersant 1.1 parts, maleic anhydride 1 part; the diameter of the alumina grinding ball is 2μm, and the alumina grinding ball occupies 36% of the volume of the vertical mill; the grinding temperature of the vertical mill is 24°C, and the rotation speed is 540r / min; the vertical mill is forward rotating for 9h and then reverse rotating for 7.5h; after the bauxite powder is sorted out, it is washed with water three times, each time for 55min, and the mass ratio of bauxite powder to water is 1:4 during washing; flocculant is added to the washed bauxite powder to accelerate the coagulation of the bauxite powder; the flocculant is composed of the following raw materials in parts by weight: 3 parts of polyacrylamide and 1.8 parts of polyaluminium chloride; 0.07g of flocculant is added per ton of bauxite powder;

[0068] S4, drying, crushing, screening and air selection of bauxite powder after centrifugal dehydration to obtain bauxite for ceramic microbeads; during centrifugal dehydration, the centrifugal speed is 2100r / min; the drying temperature is 190°C; the sieve for screening is 1800 mesh; the bauxite for ceramic microbeads is heated to 155°C before air selection; the particle size of the bauxite for ceramic microbeads obtained by air selection is 2.7-3μm;

[0069] S5, mixing the ceramic microbeads obtained after air selection with 2.2 tons of bauxite at a mixing speed of 130 r / min for 8 hours.

[0070] The particle size of the products in Examples 1-6 was tested using a particle size detector, and the test results are shown in Table 1 below:

[0071] Table 1 Particle size results of products of Examples 1-6

[0072]

[0073]

[0074] As can be seen from Table 1, the product prepared by the method of the present invention has uniform particle size distribution and high quality, is suitable for use in various industrial fields, and meets the production needs of downstream high-end products, especially for the production of ceramic microbeads.

Claims

1. A method for producing bauxite for ceramic microspheres, characterized in that: The following steps are involved: S1, calcining the bauxite ore and crushing it into 300-400 mesh to obtain crude bauxite; S2, putting the coarse bauxite into a ball mill and grinding it until the D50 is 6-10 μm to obtain fine bauxite; S3, adding fine bauxite into a vertical mill, adding a dispersant and alumina grinding balls, and adding the ground bauxite into a separator for separation to separate bauxite powder with a particle size of 2-4 μm; S4. After centrifugal dehydration, the bauxite powder is dried, crushed, screened, and air-selected to obtain bauxite for ceramic microbeads.

2. The method for producing bauxite for ceramic microspheres according to claim 1, characterized in that: The mass content of aluminum in the bauxite ore is greater than 80%, and the mass content of iron is less than 2%.

3. The method for producing bauxite for ceramic microspheres according to claim 1, characterized in that: In S2, the grinding balls in the ball mill are alumina grinding balls, which account for 40-50% of the volume of the ball mill. The alumina grinding balls are composed of large balls, medium balls and small balls. The number of large balls accounts for 20-30% of the total number of alumina grinding balls, the number of medium balls accounts for 30-40% of the total number of alumina grinding balls, and the number of small balls accounts for 30-40% of the total number of alumina grinding balls. The diameter of the large balls is 60-120mm, the diameter of the medium balls is 40-60mm, and the diameter of the small balls is 5-20mm.

4. The method for producing bauxite for ceramic microspheres according to claim 1, characterized in that: In S3, fine bauxite is added into a vertical mill and then water is added to prepare a fine bauxite suspension, wherein the mass ratio of the fine bauxite to water is 1:(1.2-2.5); 0.2-0.3 g of a dispersant is added to every liter of fine bauxite suspension, wherein the dispersant is composed of the following raw materials in parts by weight: 2-5 parts of EDTA, 0.5-1.5 parts of DA dispersant, and 1-3 parts of maleic anhydride.

5. The method for producing bauxite for ceramic microspheres according to claim 4, characterized in that: In S3, the diameter of the alumina grinding balls is 2-3 μm, and the alumina grinding balls occupy 30-40% of the volume of the vertical mill; the grinding temperature of the vertical mill is 20-28° C., and the rotation speed is 450-550 r / min.

6. The method for producing bauxite for ceramic microspheres according to claim 5, characterized in that: In S3, the vertical grinding machine is subjected to forward rotation grinding for 7-9 hours and then reverse rotation grinding for 6-8 hours.

7. The method for producing bauxite for ceramic microspheres according to claim 1, characterized in that: After the bauxite powder is separated out in S3, it is washed with water for three times, each time for 30-60 minutes. During the washing, the mass ratio of the bauxite powder to water is 1: (3-4).

8. The method for producing bauxite for ceramic microspheres according to claim 7, characterized in that: In S3, a flocculant is added to the washed bauxite powder to accelerate the coagulation of the bauxite powder; the flocculant is composed of the following raw materials in parts by weight: 2-3 parts of polyacrylamide and 1-2 parts of polyaluminium chloride; 0.03-0.08 g of the flocculant is added per ton of bauxite powder.

9. The method for producing bauxite for ceramic microspheres according to claim 1, characterized in that: In S4, during centrifugal dehydration, the centrifugal speed is 1500-2500r / min; the drying temperature is 180-230°C; the screening screen is 1500-1800 mesh; the ceramic microbeads are heated to 130-160°C before air selection; the ceramic microbeads are obtained by air selection. The particle size of the bauxite is 2.7-3μm.

10. The method for producing bauxite for ceramic microspheres according to claim 1, characterized in that: The process further comprises S5, wherein the ceramic microbeads obtained after air selection are mixed with 2-3 tons of bauxite at a mixing speed of 80-150 r / min and a mixing time of 8-9 h.

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