Method for preparing superfine silicon dioxide with ultralow energy consumption

Abstract

The invention belongs to the technical field of silicon oxide, and provides a method for preparing superfine silicon dioxide with ultralow energy consumption. The method comprises the following steps: crushing quartz ore to obtain quartz particles, adding a grinding aid material A and a grinding aid material B into the quartz particles to obtain a quartz particle mixture, and sequentially carrying out ball milling and grading on the quartz particle mixture to obtain superfine silicon dioxide, the types of the grinding aid material A and the grinding aid material B are defined. According to the invention, the grinding aid material is added by spraying before ball milling, and the high molecular weight cellulose dispersant and the low molecular weight anion dispersant are used as the grinding aid material together, so that the friction among quartz particles is improved, the adsorption agglomeration between new interfaces generated in the ball milling process is prevented, and the ball milling efficiency is improved; extending the path of an air conveying system after grading, and then collecting to ensure that the moisture content of a final product reaches the standard; compared with the traditional process, the method for preparing the superfine silicon dioxide has the advantage that the energy consumption is reduced by more than 25%.

Description

Technical Field

[0001] The invention relates to the technical field of silicon oxide, and in particular to a method for preparing ultrafine silicon dioxide with ultra-low energy consumption. Background Art

[0002] Quartz ore is a non-metallic mineral widely found in nature, and its main component is silicon dioxide. Silica powder is a silicon dioxide powder with controllable particle size obtained by crushing, grinding and grading quartz ore. It is widely used in ink, coating, plastic, ceramics, construction, papermaking and other industries. Silica powder has high strength, wear resistance, high adhesion, corrosion resistance, anti-aging, radiation protection and good hiding power. Using modified silica powder as a filler for coatings can greatly reduce the amount of titanium dioxide. Since silica powder itself is bright white, has low oil absorption and high hardness, high-purity silica powder can be added to powder coatings to prepare high-quality white and soft light-colored powder coatings, while improving the toughness, durability and weather resistance of the powder coatings, and maintaining the surface smoothness and gloss of the powder coatings. In addition, the surface-treated silica powder has fine particles and is a low-cost, high-efficiency multifunctional filler, which is widely used in anti-corrosion coatings, floor paints and ink coatings.

[0003] At present, the processing technology of quartz ore is mainly divided into two categories: dry grinding and wet grinding. Since the grinding medium is air, dry grinding has a certain grinding limit. When the fineness exceeds 3000 mesh, a large amount of energy is lost in the form of heat, the grinding efficiency is low, and the energy consumption is high. Therefore, dry grinding is currently mainly used to produce silicon dioxide with a fineness of less than 3000 mesh. The grinding medium of the wet grinding process is water. During the grinding process, the energy loss is relatively small, and the grinding efficiency is higher than that of dry grinding. It is mainly used to produce ultrafine silicon dioxide with a fineness of more than 3000 mesh. Wet grinding needs to take into account the viscosity of the slurry and other issues. The low solid content of the material leads to high drying costs in the later stage, and the slurry produced by wet grinding needs to be processed. In the actual production process, the energy consumption and production costs are high.

[0004] Therefore, effectively reducing the energy consumption and production cost of ultrafine silica above 3000 mesh has become one of the key issues that the industry is most concerned about. Research on ultra-low energy consumption production methods of ultrafine silica has important economic value and significance. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing ultrafine silicon dioxide with ultra-low energy consumption in view of the deficiencies in the prior art.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing ultrafine silicon dioxide with ultra-low energy consumption, comprising the following steps:

[0008] (1) crushing quartz ore to obtain quartz particles;

[0009] (2) adding grinding aid material A and grinding aid material B to the quartz particles to obtain a quartz particle mixture;

[0010] (3) ball milling and classifying the quartz particle mixture in sequence to obtain ultrafine silicon dioxide;

[0011] The grinding aid material A comprises a high molecular weight cellulose dispersant and water;

[0012] The grinding aid material B comprises a low molecular weight anionic dispersant and water.

[0013] Preferably, the high molecular weight cellulose dispersant comprises lignocellulose and / or sodium carboxymethyl cellulose, and the molecular weight of the high molecular weight cellulose dispersant is 30000 to 700000 Da;

[0014] The low molecular weight anionic dispersant comprises sodium polyacrylate and / or a silane coupling agent, and the molecular weight of the low molecular weight anionic dispersant is 200-10000 Da.

[0015] Preferably, the total mass of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 2-8‰ of the mass of the quartz particles, and the mass ratio of the high molecular weight cellulose dispersant to the low molecular weight anionic dispersant is 1:5-10.

[0016] Preferably, in the grinding aid material A, the mass ratio of the high molecular weight cellulose dispersant to water is 1:8-12;

[0017] In the grinding aid material B, the mass ratio of the low molecular weight anionic dispersant to water is 1:5-8.

[0018] Preferably, the adding in step (2) is carried out by spraying, the spraying pressure is 1 to 3 bar, and the spraying time is 3 to 8 minutes.

[0019] Preferably, the ball milling time in step (3) is 20 to 40 min, the ball milling speed is 15 to 45 r / min, and the ball-to-material ratio is 1:3 to 8.

[0020] Preferably, the ball milling medium used in the ball milling in step (3) is alumina ceramic balls, the ball milling medium filling rate is 30-35%, and the diameter of the alumina ceramic balls is 1-60 mm.

[0021] Preferably, the ball milling in step (3) adopts a double-chamber ball mill, the diameter of the alumina ceramic balls in the front chamber is 30-60 mm, and the diameter of the alumina ceramic balls in the rear chamber is 1-30 mm.

[0022] Preferably, in the front chamber, the mass ratio of alumina ceramic balls with a diameter of 30 to 40 mm, alumina ceramic balls with a diameter of 40 to 50 mm, and alumina ceramic balls with a diameter of 50 to 60 mm is 1 to 3:2 to 4:3 to 7;

[0023] In the rear chamber, the mass ratio of alumina ceramic balls with a diameter of 0 to 10 mm, alumina ceramic balls with a diameter of 10 to 20 mm, and alumina ceramic balls with a diameter of 20 to 30 mm is 3 to 7:2 to 4:1 to 2.

[0024] The beneficial effects of the present invention include the following:

[0025] 1) The present invention adopts a high molecular weight cellulose dispersant and a low molecular weight anionic dispersant as grinding aid materials. The high molecular weight cellulose dispersant increases the viscosity of the quartz particles, which can increase the friction between the quartz particles during the ball milling process, thereby improving the ball milling efficiency; the low molecular weight anionic dispersant improves the interfacial wetting performance, thereby preventing the problem of reduced ball milling efficiency caused by adsorption and agglomeration between new interfaces generated during the ball milling process.

[0026] 2) Before ball milling, the quartz particles of the present invention are added with grinding aids by spraying to improve the ball milling efficiency; after classification, the path of the wind conveying system is extended before collection, so that the time of the material in the wind conveying system is prolonged, and the material is further dried to ensure that the moisture content of the final product ultrafine silicon dioxide meets the standard without an additional drying process.

[0027] 3) Compared with the traditional production process, the method for preparing ultrafine silicon dioxide of the present invention reduces energy consumption by more than 25%. DETAILED DESCRIPTION

[0028] The present invention provides a method for preparing ultrafine silicon dioxide with ultra-low energy consumption, comprising the following steps:

[0029] (1) crushing quartz ore to obtain quartz particles;

[0030] (2) adding grinding aid material A and grinding aid material B to the quartz particles to obtain a quartz particle mixture;

[0031] (3) ball milling and classifying the quartz particle mixture in sequence to obtain ultrafine silicon dioxide;

[0032] The grinding aid material A comprises a high molecular weight cellulose dispersant and water;

[0033] The grinding aid material B comprises a low molecular weight anionic dispersant and water.

[0034] In the present invention, the mass content of silicon dioxide in the quartz ore in step (1) is preferably ≥95%, more preferably ≥98%; the diameter of the quartz particles is preferably 5 to 20 mm, more preferably 10 to 15 mm; and the crushing is preferably carried out by two-stage jaw crushing.

[0035] In the present invention, the high molecular weight cellulose dispersant preferably comprises lignocellulose and / or sodium carboxymethyl cellulose, and the molecular weight of the high molecular weight cellulose dispersant is preferably 30000 to 700000 Da, more preferably 60000 to 500000 Da, and more preferably 90000 to 300000 Da;

[0036] The low molecular weight anionic dispersant preferably comprises sodium polyacrylate and / or a silane coupling agent. The molecular weight of the low molecular weight anionic dispersant is preferably 200 to 10000 Da, more preferably 400 to 5000 Da, and even more preferably 1000 to 3000 Da.

[0037] In the present invention, the silane coupling agent is preferably silane coupling agent KH-560. High molecular weight cellulose dispersants can significantly increase the viscosity of quartz particles, increase the friction between quartz particles during ball milling, and thus improve the ball milling efficiency; low molecular weight anionic dispersants can improve the interfacial wetting properties, and prevent the ball milling efficiency from being reduced due to adsorption and agglomeration between new interfaces generated during ball milling.

[0038] In the present invention, the total mass of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is preferably 2-8‰ of the mass of the quartz particles, more preferably 4-7‰, and more preferably 5-6‰; the mass ratio of the high molecular weight cellulose dispersant to the low molecular weight anionic dispersant is preferably 1:5-10, more preferably 1:6-9, and more preferably 1:7-8. The amount of the high molecular weight cellulose dispersant must be within an appropriate range. If the amount is too high, the viscosity of the quartz particles will increase significantly, which will reduce the ball milling efficiency and fail to play a grinding aid role; if the amount is too low, the viscosity of the quartz particles is too low, which reduces the probability of friction between the quartz particles, thereby reducing the ball milling efficiency.

[0039] In the present invention, in the grinding aid material A, the mass ratio of the high molecular weight cellulose dispersant to water is preferably 1:8-12, more preferably 1:9-11, and more preferably 1:10;

[0040] In the grinding aid material B, the mass ratio of the low molecular weight anionic dispersant to water is preferably 1:5-8, and more preferably 1:6-7. By mixing with water, the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant are more fully dispersed in the quartz particles, which has a better grinding aid effect; at the same time, water itself has a wetting effect on the quartz particles, which can increase the viscosity of the quartz particle mixture. The mass ratio of the high molecular weight cellulose dispersant, the low molecular weight anionic dispersant and water must be controlled within an appropriate range. If the amount of water is too high, the moisture content in the quartz particle mixture will be too high, affecting the moisture content of the final product (ultrafine silica).

[0041] In the present invention, the addition in step (2) is preferably carried out by spraying, the spraying pressure is preferably 1 to 3 bar, more preferably 2 bar, and the spraying time is preferably 3 to 8 min, more preferably 4 to 7 min, and more preferably 5 to 6 min.

[0042] In the present invention, step (2) is preferably carried out in a spiral reamer conveying system to obtain a quartz particle mixture; grinding aid material A and grinding aid material B are preferably added at the front end of the spiral reamer conveying system, and the spiral reamer conveying system is preferably distributed in a zigzag pattern. The length of the spiral reamer conveying system is preferably 15 to 25 meters, and more preferably 20 meters. Extending the conveying path of the spiral reamer conveying system is conducive to the full contact and uniform dispersion of the grinding aid material A and the grinding aid material B with the quartz particles, so that it is easier to quickly infiltrate the newly generated interface during the ball milling process, thereby improving the ball milling efficiency.

[0043] In the present invention, the ball milling time in step (3) is preferably 20 to 40 min, more preferably 25 to 35 min, and more preferably 30 min; the ball milling speed is preferably 15 to 45 r / min, more preferably 20 to 30 r / min, and more preferably 26 r / min; the ball-to-material ratio is preferably 1:3 to 8, more preferably 1:4 to 7, and more preferably 1:5 to 6.

[0044] In the present invention, the ball milling medium used in the ball milling in step (3) is preferably alumina ceramic balls, and the ball milling medium filling rate is preferably 30-35%, further preferably 31-34%, and more preferably 32-33%; the diameter of the alumina ceramic balls is preferably 1-60 mm, further preferably 10-50 mm, and more preferably 20-40 mm.

[0045] In the present invention, the ball milling in step (3) is preferably carried out using a double-chamber ball mill, and the diameter of the alumina ceramic balls in the front chamber is preferably 30 to 60 mm, and more preferably 40 to 50 mm; the diameter of the alumina ceramic balls in the rear chamber is preferably 1 to 30 mm, and more preferably 10 to 20 mm.

[0046] In the present invention, in the front chamber, the mass ratio of alumina ceramic balls with a diameter of 30 to 40 mm (including 30 mm and 40 mm), alumina ceramic balls with a diameter of 40 to 50 mm (excluding 40 mm and including 50 mm), and alumina ceramic balls with a diameter of 50 to 60 mm (excluding 50 mm and including 60 mm) is preferably 1 to 3: 2 to 4: 3 to 7, more preferably 1.5 to 2.5: 2.5 to 3.5: 4 to 6, and more preferably 2: 3: 5;

[0047] In the rear chamber, the mass ratio of alumina ceramic balls with a diameter of 0-10mm (excluding 0mm and including 10mm), alumina ceramic balls with a diameter of 10-20mm (excluding 10mm and including 20mm), and alumina ceramic balls with a diameter of 20-30mm (excluding 20mm and including 30mm) is preferably 3-7:2-4:1-2, and more preferably 4-5:3:1.5.

[0048] In the present invention, the grading preferably uses a 6-head grading machine, and after the grading is completed, it is preferably transported to the collection device by a wind conveying system; the length of the wind conveying system is preferably 10 to 20 meters, and more preferably 15 meters. Extending the path of the wind conveying system prolongs the time that the qualified products after grading stay in the wind conveying system, and using the wind of the wind conveying system to further dry the materials, thereby reducing the moisture content in the final product ultrafine silica.

[0049] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0050] Example 1

[0051] In this embodiment, the grinding aid material A is a high molecular weight cellulose dispersant and water in a mass ratio of 1:8, and the high molecular weight cellulose dispersant is lignocellulose (the molecular weight of lignocellulose is 90,000 Da) and sodium carboxymethyl cellulose (the molecular weight of sodium carboxymethyl cellulose is 120,000 Da) in a mass ratio of 1:1; the grinding aid material B is a low molecular weight anionic dispersant and water in a mass ratio of 1:5, and the low molecular weight anionic dispersant is sodium polyacrylate (the molecular weight of sodium polyacrylate is 1000 Da) and silane coupling agent KH-560 (the molecular weight of silane coupling agent KH-560 is 236 Da) in a mass ratio of 1:1; the total mass of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 2‰ of the mass of the quartz particles; the mass ratio of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 1:9.

[0052] The quartz ore with a silicon dioxide mass content of ≥95% is washed, dried naturally, and crushed by two stages to obtain quartz particles with a diameter of 10 mm. The quartz particles are placed in a spiral reamer conveying system with a length of 20 m and a conveying speed of 1 m / min (the spiral reamer conveying system is in a zigzag distribution), and grinding aids A and B are added at the front end of the spiral reamer conveying system by spraying (the spraying pressure is 2 bar and the spraying time is 5 min) to obtain a quartz particle mixture. The quartz particle mixture is placed in a 2.4m×8m double-bin ball mill, and ball milled for 30 minutes at a speed of 26r / min and a ball-to-material ratio of 1:5. The ball milling medium filling rate is 30%, and the ball milling medium is alumina ceramic balls. The mass ratio of alumina ceramic balls with a diameter of 30-40mm, alumina ceramic balls with a diameter of 40-50mm, and alumina ceramic balls with a diameter of 50-60mm in the front bin is 1:2:3, and the mass ratio of alumina ceramic balls with a diameter of 0-10mm, alumina ceramic balls with a diameter of 10-20mm, and alumina ceramic balls with a diameter of 20-30mm in the rear bin is 3:2:1. After ball milling, a 6-head classifier is used for classification, and the ball is sent to the collection device through a wind conveying system with a length of 15m.

[0053] Example 2

[0054] In this embodiment, the grinding aid material A is a high molecular weight cellulose dispersant and water in a mass ratio of 1:10, and the high molecular weight cellulose dispersant is lignocellulose (the molecular weight of lignocellulose is 70,000 Da) and sodium carboxymethyl cellulose (the molecular weight of sodium carboxymethyl cellulose is 300,000 Da) in a mass ratio of 1:1; the grinding aid material B is a low molecular weight anionic dispersant and water in a mass ratio of 1:7, and the low molecular weight anionic dispersant is sodium polyacrylate (the molecular weight of sodium polyacrylate is 3,000 Da) and silane coupling agent KH-560 (the molecular weight of silane coupling agent KH-560 is 236 Da) in a mass ratio of 1:1; the total mass of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 4‰ of the mass of the quartz particles; the mass ratio of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 1:7.

[0055] The quartz ore with a silicon dioxide mass content of ≥95% is washed, dried naturally, and crushed by two stages to obtain quartz particles with a diameter of 20 mm. The quartz particles are placed in a spiral reamer conveying system with a length of 20 m and a conveying speed of 1 m / min (the spiral reamer conveying system is in a zigzag distribution), and grinding aids A and B are added at the front end of the spiral reamer conveying system by spraying (the spraying pressure is 2 bar and the spraying time is 5 min) to obtain a quartz particle mixture. The quartz particle mixture is placed in a 2.4m×8m double-bin ball mill, and ball milled for 30 minutes at a speed of 26r / min and a ball-to-material ratio of 1:6. The ball milling medium filling rate is 33%. The ball milling medium is alumina ceramic balls. The mass ratio of alumina ceramic balls with a diameter of 30-40mm, alumina ceramic balls with a diameter of 40-50mm, and alumina ceramic balls with a diameter of 50-60mm in the front bin is 1:3:5, and the mass ratio of alumina ceramic balls with a diameter of 0-10mm, alumina ceramic balls with a diameter of 10-20mm, and alumina ceramic balls with a diameter of 20-30mm in the rear bin is 5:3:1. After ball milling, a 6-head classifier is used for classification, and the ball is sent to a collection device through a wind conveying system with a length of 15m.

[0056] Example 3

[0057] In this embodiment, the grinding aid material A is a high molecular weight cellulose dispersant and water in a mass ratio of 1:12, and the high molecular weight cellulose dispersant is lignocellulose (the molecular weight of lignocellulose is 60,000 Da) and sodium carboxymethyl cellulose (the molecular weight of sodium carboxymethyl cellulose is 100,000 Da) in a mass ratio of 1:1; the grinding aid material B is a low molecular weight anionic dispersant and water in a mass ratio of 1:8, and the low molecular weight anionic dispersant is sodium polyacrylate (the molecular weight of sodium polyacrylate is 1000 Da) and silane coupling agent KH-560 (the molecular weight of silane coupling agent KH-560 is 236 Da) in a mass ratio of 1:1; the total mass of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 8‰ of the mass of the quartz particles; the mass ratio of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 1:9.

[0058] The quartz ore with a silicon dioxide mass content of ≥95% is washed, dried naturally, and crushed by two stages to obtain quartz particles with a diameter of 5 mm. The quartz particles are placed in a spiral reamer conveying system with a length of 20 m and a conveying speed of 1 m / min (the spiral reamer conveying system is in a zigzag distribution), and grinding aids A and B are added at the front end of the spiral reamer conveying system by spraying (the spraying pressure is 2 bar and the spraying time is 5 min) to obtain a quartz particle mixture. The quartz particle mixture is placed in a 2.4m×8m double-bin ball mill, and ball milled for 30 minutes at a speed of 26r / min and a ball-to-material ratio of 1:5. The ball milling medium filling rate is 35%, and the ball milling medium is alumina ceramic balls. The mass ratio of alumina ceramic balls with a diameter of 30-40mm, alumina ceramic balls with a diameter of 40-50mm, and alumina ceramic balls with a diameter of 50-60mm in the front bin is 1:4:7, and the mass ratio of alumina ceramic balls with a diameter of 0-10mm, alumina ceramic balls with a diameter of 10-20mm, and alumina ceramic balls with a diameter of 20-30mm in the rear bin is 7:4:1. After ball milling, a 6-head classifier is used for classification, and the ball is sent to the collection device through a wind conveying system with a length of 15m.

[0059] Example 4

[0060] In this embodiment, the grinding aid material A is a high molecular weight cellulose dispersant and water in a mass ratio of 1:11, and the high molecular weight cellulose dispersant is lignocellulose (the molecular weight of lignocellulose is 30,000 Da) and sodium carboxymethyl cellulose (the molecular weight of sodium carboxymethyl cellulose is 500,000 Da) in a mass ratio of 1:1; the grinding aid material B is a low molecular weight anionic dispersant and water in a mass ratio of 1:6, and the low molecular weight anionic dispersant is sodium polyacrylate (the molecular weight of sodium polyacrylate is 5,000 Da) and silane coupling agent KH-560 (the molecular weight of silane coupling agent KH-560 is 236 Da) in a mass ratio of 1:1; the total mass of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 5‰ of the mass of the quartz particles; the mass ratio of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 1:10.

[0061] The quartz ore with a silicon dioxide mass content of ≥98% is washed, dried naturally, and crushed by two stages to obtain quartz particles with a diameter of 15 mm. The quartz particles are placed in a spiral reamer conveying system with a length of 20 m and a conveying speed of 1 m / min (the spiral reamer conveying system is in a zigzag distribution), and grinding aid materials A and grinding aid materials B are added at the front end of the spiral reamer conveying system by spraying (the spraying pressure is 1 bar and the spraying time is 8 minutes) to obtain a quartz particle mixture. The quartz particle mixture is placed in a 2.4m×8m double-bin ball mill, and milled for 35 minutes at a speed of 15r / min and a ball-to-material ratio of 1:3. The ball milling medium filling rate is 31%. The ball milling medium is alumina ceramic balls. The mass ratio of alumina ceramic balls with a diameter of 30-40mm, alumina ceramic balls with a diameter of 40-50mm, and alumina ceramic balls with a diameter of 50-60mm in the front bin is 1:2:3, and the mass ratio of alumina ceramic balls with a diameter of 0-10mm, alumina ceramic balls with a diameter of 10-20mm, and alumina ceramic balls with a diameter of 20-30mm in the rear bin is 3:2:1. After ball milling, a 6-head classifier is used for classification, and the ball is sent to the collection device through a wind conveying system with a length of 15m.

[0062] Example 5

[0063] In this embodiment, the grinding aid material A is a high molecular weight cellulose dispersant and water in a mass ratio of 1:9, and the high molecular weight cellulose dispersant is lignocellulose (the molecular weight of lignocellulose is 60,000 Da) and sodium carboxymethyl cellulose (the molecular weight of sodium carboxymethyl cellulose is 100,000 Da) in a mass ratio of 1:1; the grinding aid material B is a low molecular weight anionic dispersant and water in a mass ratio of 1:7, and the low molecular weight anionic dispersant is sodium polyacrylate (the molecular weight of sodium polyacrylate is 400 Da) and silane coupling agent KH-560 (the molecular weight of silane coupling agent KH-560 is 236 Da) in a mass ratio of 1:1; the total mass of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 7‰ of the mass of the quartz particles; the mass ratio of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 1:5.

[0064] The quartz ore with a silicon dioxide mass content of ≥95% is washed, dried naturally, and crushed by two stages to obtain quartz particles with a diameter of 10 mm. The quartz particles are placed in a spiral reamer conveying system with a length of 20 m and a conveying speed of 1 m / min (the spiral reamer conveying system is in a zigzag distribution), and grinding aids A and B are added at the front end of the spiral reamer conveying system by spraying (the spraying pressure is 3 bar and the spraying time is 3 min) to obtain a quartz particle mixture. The quartz particle mixture is placed in a 2.4m×8m double-bin ball mill, and ball milled for 25 minutes at a speed of 45r / min and a ball-to-material ratio of 1:8. The ball milling medium filling rate is 34%, and the ball milling medium is alumina ceramic balls. The mass ratio of alumina ceramic balls with a diameter of 30-40mm, alumina ceramic balls with a diameter of 40-50mm, and alumina ceramic balls with a diameter of 50-60mm in the front bin is 1:2:3, and the mass ratio of alumina ceramic balls with a diameter of 0-10mm, alumina ceramic balls with a diameter of 10-20mm, and alumina ceramic balls with a diameter of 20-30mm in the rear bin is 3:2:1. After ball milling, a 6-head classifier is used for classification, and the ball is sent to the collection device through a wind conveying system with a length of 15m.

[0065] Comparative Example 1

[0066] The quartz ore with a silicon dioxide mass content of ≥95% is washed, dried naturally, and crushed by two stages to obtain quartz particles with a diameter of 10 mm. The quartz particles are mixed with sodium polyacrylate (the molecular weight of sodium polyacrylate is 300Da, and the mass of sodium polyacrylate is 2‰ of the mass of the quartz particles), added to a 2.4m×8m double-bin ball mill, and milled for 30 minutes at a speed of 26r / min and a ball-to-material ratio of 1:5. The ball milling medium filling rate is 35%, and the ball milling medium is alumina ceramic balls. The mass ratio of alumina ceramic balls with a diameter of 30-40mm, alumina ceramic balls with a diameter of 40-50mm, and alumina ceramic balls with a diameter of 50-60mm in the front bin is 1:2:3, and the mass ratio of alumina ceramic balls with a diameter of 0-10mm, alumina ceramic balls with a diameter of 10-20mm, and alumina ceramic balls with a diameter of 20-30mm in the rear bin is 3:2:1. After ball milling, a 6-head classifier is used for classification and then the materials are sent to the collection device through a 15m long wind conveying system.

[0067] Comparative Example 2

[0068] The quartz ore with a silicon dioxide mass content of ≥95% is washed, dried naturally, and crushed by two stages to obtain quartz particles with a diameter of 10 mm. The quartz particles are mixed with sodium dodecyl sulfate (the mass of sodium dodecyl sulfate is 2‰ of the mass of the quartz particles), added to a 2.4m×8m double-bin ball mill, and milled for 30 minutes at a speed of 26r / min and a ball-to-material ratio of 1:5. The ball milling medium filling rate is 35%, and the ball milling medium is alumina ceramic balls. The mass ratio of alumina ceramic balls with a diameter of 30-40mm, alumina ceramic balls with a diameter of 40-50mm, and alumina ceramic balls with a diameter of 50-60mm in the front bin is 1:2:3, and the mass ratio of alumina ceramic balls with a diameter of 0-10mm, alumina ceramic balls with a diameter of 10-20mm, and alumina ceramic balls with a diameter of 20-30mm in the rear bin is 3:2:1. After ball milling, a 6-head classifier is used for classification and then the materials are sent to the collection device through a 15m long wind conveying system.

[0069] The performance test and energy consumption record were performed on the ultrafine silicon dioxide of Examples 1 to 5 and Comparative Examples 1 to 2. The performance test results and energy consumption comparison results are shown in Table 1.

[0070] Test the D of ultrafine silica according to GB / T19077-2016 50 and D 97 , the whiteness, oil absorption and moisture of ultrafine silica were tested according to SJ / T10675-2002.

[0071] Table 1 Performance test and energy consumption comparison results

[0072]

[0073]

[0074] It can be seen from Table 1 that the various properties of the ultrafine silicon dioxide prepared by the method of the present invention are equal to those of the ultrafine silicon dioxide produced by the traditional process, and the unit energy consumption of the present invention is reduced by more than 25% compared with the traditional process.

[0075] The above is only a preferred embodiment of the present invention. 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 present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing ultra-fine silicon dioxide with ultra-low energy consumption, characterized in that: The following steps are included: (1) crushing quartz ore to obtain quartz particles; (2) adding grinding aid material A and grinding aid material B to the quartz particles to obtain a quartz particle mixture; (3) ball milling and classifying the quartz particle mixture in sequence to obtain ultrafine silicon dioxide; The grinding aid material A comprises a high molecular weight cellulose dispersant and water; The grinding aid material B comprises a low molecular weight anionic dispersant and water.

2. The method for preparing ultrafine silicon dioxide with ultra-low energy consumption according to claim 1, characterized in that: The high molecular weight cellulose dispersant comprises lignocellulose and / or sodium carboxymethyl cellulose, and the molecular weight of the high molecular weight cellulose dispersant is 30000 to 700000 Da; The low molecular weight anionic dispersant comprises sodium polyacrylate and / or a silane coupling agent, and the molecular weight of the low molecular weight anionic dispersant is 200 to 10000 Da.

3. The method for preparing ultrafine silicon dioxide with ultra-low energy consumption according to claim 1 or 2, characterized in that: The total mass of the high molecular weight cellulose dispersant and the low molecular weight anionic dispersant is 2-8‰ of the mass of the quartz particles, and the mass ratio of the high molecular weight cellulose dispersant to the low molecular weight anionic dispersant is 1:5-10.

4. The method for preparing ultrafine silicon dioxide with ultra-low energy consumption according to claim 3, characterized in that: In the grinding aid material A, the mass ratio of the high molecular weight cellulose dispersant to water is 1:8-12; In the grinding aid material B, the mass ratio of the low molecular weight anionic dispersant to water is 1:5-8.

5. The method for preparing ultrafine silicon dioxide with ultra-low energy consumption according to claim 4, characterized in that: The addition in step (2) is carried out by spraying, the pressure of the spraying is 1 to 3 bar, and the spraying time is 3 to 8 minutes.

6. The method for preparing ultrafine silicon dioxide with ultra-low energy consumption according to claim 4 or 5, characterized in that: The ball milling time in step (3) is 20 to 40 minutes, the ball milling speed is 15 to 45 r / min, and the ball-to-material ratio is 1:3 to 8.

7. The method for preparing ultrafine silicon dioxide with ultra-low energy consumption according to claim 6, characterized in that: The ball milling medium used in the ball milling in step (3) is alumina ceramic balls, the ball milling medium filling rate is 30-35%, and the diameter of the alumina ceramic balls is 1-60 mm.

8. The method for preparing ultrafine silicon dioxide with ultra-low energy consumption according to claim 7, characterized in that: The ball milling in step (3) adopts a double-chamber ball mill, the diameter of the alumina ceramic balls in the front chamber is 30-60 mm, and the diameter of the alumina ceramic balls in the rear chamber is 1-30 mm.

9. The method for preparing ultrafine silicon dioxide with ultra-low energy consumption according to claim 8, characterized in that: In the front chamber, the mass ratio of alumina ceramic balls with a diameter of 30 to 40 mm, alumina ceramic balls with a diameter of 40 to 50 mm, and alumina ceramic balls with a diameter of 50 to 60 mm is 1 to 3:2 to 4:3 to 7; In the rear chamber, the mass ratio of alumina ceramic balls with a diameter of 0 to 10 mm, alumina ceramic balls with a diameter of 10 to 20 mm, and alumina ceramic balls with a diameter of 20 to 30 mm is 3 to 7:2 to 4:1 to 2.

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