阅读说明：本技术 一种高漂浮率的空心玻璃微珠的制备方法 (Preparation method of hollow glass beads with high floating rate ) 是由 许传华 刘亚辉 汪俊 汪光辉 柳雷 彭丽芬 于 2019-10-14 设计创作，主要内容包括：本发明公开了一种高漂浮率的空心玻璃微珠的制备方法,其生产工艺、步骤为：1)料浆的制备：准确称量基本原料各组份、稳定分散剂和表面活性剂；基本原料各组份为石英、硼砂、碳酸钙、碳酸钠、硫酸钠、磷酸钠；2)前驱物的制备；3)空心玻璃微珠的制备；4)表面改性。本发明方法制备的稳定分散料浆固相含量高且表面张力和粘度低,不仅显著降低了喷雾造粒能耗,而且制备的前驱物粒径跨度小且成分均匀,结合高温负压玻化工艺使空心玻璃微珠漂浮率高于96.5％且表面光洁度高,并采用低温循环风强化空心玻璃微珠。本发明原材料易得、空心玻璃微珠成球率高、工艺过程简单,能耗低、生产成本低且产品应用范围广。(The invention discloses a preparation method of hollow glass beads with high floating rate, which comprises the following steps: 1) preparing slurry: accurately weighing each component of the basic raw materials, the stable dispersing agent and the surfactant; the basic raw materials comprise quartz, borax, calcium carbonate, sodium sulfate and sodium phosphate; 2) preparing a precursor; 3) preparing hollow glass beads; 4) and (4) surface modification. The stable dispersion slurry prepared by the method has high solid phase content and low surface tension and viscosity, not only obviously reduces the energy consumption of spray granulation, but also has small particle size span and uniform components of the prepared precursor, combines a high-temperature negative pressure vitrification process to ensure that the floating rate of the hollow glass microspheres is higher than 96.5 percent and the surface smoothness is high, and adopts low-temperature circulating air to strengthen the hollow glass microspheres. The invention has the advantages of easily obtained raw materials, high balling rate of the hollow glass microspheres, simple process, low energy consumption, low production cost and wide application range of products.)

1. A preparation method of hollow glass beads with high floating rate is characterized in that the hollow glass beads with the floating rate of more than 96.5 percent in water are prepared by adopting the following processes and steps:

1) preparing slurry: accurately weighing each component of the basic raw materials, the stable dispersing agent and the surfactant, and metering a certain mass of water by adopting a flowmeter; mixing the components of the basic raw materials, the stable dispersing agent, the surfactant and water in a dispersing tank for 15-20 minutes, and conveying the mixture to a ball mill through a feeding pump to prepare slurry with the solid phase content of 55-65%;

the basic raw materials are a mixture of quartz, borax, calcium carbonate, sodium sulfate and sodium phosphate, and when the mass sum of all the components of the basic raw materials is calculated according to 100%, the contents of all the components are as follows: 60.30-61.15% of quartz, 14.00-14.90% of borax, 19.15-20.80% of calcium carbonate, 3.40-3.80% of sodium carbonate, 0.22-0.81% of sodium sulfate and 0.41-1.25% of sodium phosphate; the stabilizing dispersant is one or a mixture of more of sodium polyacrylate, sodium tripolyphosphate and polyethylene glycol according to any proportion, and the surfactant is a fluorocarbon surfactant or an organic silicon surfactant; the stable dispersing agent accounts for 0.1-0.5% of the mass of the slurry, and the surfactant accounts for 0.05-0.2% of the mass of the slurry;

2) preparation of the precursor: conveying the mixed slurry prepared in the step 1) to spray granulation equipment through a feeding pump, and performing spray granulation under the conditions that the inlet temperature is 280-425 ℃, the outlet temperature is 100-155 ℃ and the centrifugal speed is 10000-16500 rpm, wherein powder collected by cyclone is a high-fluidity solid ball-hollow glass microsphere precursor;

3) preparing hollow glass beads: conveying the hollow glass bead precursor prepared in the step 2) to sintering equipment through powder conveying equipment, completing the sintering process under the synergistic action of a negative pressure system, a multi-component gas distribution system and a heating system, then conveying the hollow glass bead precursor to a cooling tower through gas flow, completing the strengthening process through room-temperature circulating air, and collecting hollow glass bead products through collecting equipment;

4) surface modification: finishing the coating process of the hollow glass bead product collected in the step 3) and a surface modifier by dry continuous powder surface modification equipment to prepare surface modified hollow glass beads; the surface modifier is a modifier which can form chemical bonding, hydrogen bonding or physical adsorption with silicon hydroxyl on the surface of the glass.

2. The method for preparing hollow glass microspheres with high floatation rate according to claim 1, wherein: the surface modifier adopted in the step 4) is liquid, the modification temperature is 100-120 ℃, and the rotating speed of the dry continuous powder surface modification equipment is 1450-1550 rpm.

3. The method for preparing hollow glass microspheres with high floatation rate according to claim 1, wherein: and 4) the surface modifier adopted in the step 4) is solid powder, the heating system is closed, modification is carried out at room temperature, and the rotating speed of the dry continuous powder surface modification equipment is 1450-1550 rpm.

4. The method for producing hollow glass microspheres of claim 1, 2 or 3, wherein: when the mass sum of all the components of the basic raw materials is calculated according to 100 percent, the content of all the components is as follows: 60.60-61.10% of quartz, 14.20-14.50% of borax, 20.30-20.75% of calcium carbonate, 3.45-3.80% of sodium carbonate, 0.24-0.26% of sodium sulfate and 0.42-0.48% of sodium phosphate; the stable dispersing agent accounts for 0.26-0.35% of the mass of the slurry, and the surfactant accounts for 0.08-0.12% of the mass of the slurry; in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal speed is 15700-16300 rpm, the inlet temperature is 285-295 ℃, and the outlet temperature is 105-115 ℃; the true density of the prepared hollow glass beads is 0.45-0.55 g/cm³Compressive strength>115Ma, flotation rate>96.5％。

5. The method for producing hollow glass microspheres of claim 1, 2 or 3, wherein: when the mass sum of all the components of the basic raw materials is calculated according to 100 percent, the content of all the components is as follows: 60.70-61.15% of quartz, 14.10-14.50% of borax, 19.85-20.35% of calcium carbonate, 3.45-3.80% of sodium carbonate, 0.36-0.53% of sodium sulfate and 0.60-0.78% of sodium phosphate; the stable dispersing agent accounts for 0.18-0.30% of the mass of the slurry, and the surfactant accounts for 0.06-0.16% of the mass of the slurry; in the step 2), the technological parameters of the spray granulation equipment are as follows: centrifugal rotation speed of 13000-14800 rpm, inlet temperature of 330-375 ℃ and outlet temperature of 135-150 ℃; the true density of the prepared hollow glass beads is 0.30-0.41 g/cm³Compressive strength of 27-55 Ma, floating rate>98.0％。

6. The method for producing hollow glass microspheres of claim 1, 2 or 3, wherein: when the mass sum of all the components of the basic raw materials is calculated according to 100 percent, the content of all the components is as follows: 60.35-60.60% of quartz, 14.45-14.75% of borax, 19.15-19.50% of calcium carbonate, 3.45-3.80% of sodium carbonate, 0.75-0.81% of sodium sulfate and 1.05-1.25% of sodium phosphate; the stable dispersant accounts for the mass of the slurry0.28-0.32% of the slurry, wherein the surfactant accounts for 0.16-0.2% of the mass of the slurry; in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal speed is 9500-10500 rpm, the inlet temperature is 400-425 ℃, and the outlet temperature is 145-155 ℃; the true density of the prepared hollow glass beads is 0.11-0.13 g/cm³Compressive strength>3Ma, flotation rate>97.5％。

Technical Field

The invention relates to an inorganic filler, in particular to a hollow glass bead which can be widely applied to the fields of petroleum, chemical industry, war industry, shipbuilding, automobiles, aerospace, building materials and the like, and is particularly suitable for the exploitation of coatings, glass fiber reinforced plastics and oil and gas fields, coatings of epoxy/unsaturated resins, nitriles, phenolic aldehyde, acrylic acid and the like, and products of printing ink, adhesives, sealants, emulsion explosives and the like.

Background

The hollow glass beads are hollow micron-sized spherical particles, have the excellent characteristics of low density, high strength, low heat conductivity coefficient, sound insulation, high melting point, strong stability, good fluidity and the like, are an excellent modified material due to a series of advantages, and endow a substrate with multiple functions, so the hollow glass beads are widely applied to industries such as petroleum, military industry, building materials, automobiles, plastics, paint, explosive and the like.

At present, the preparation technology of the hollow glass beads which have already realized industrialization mainly comprises a soft chemical method, a solid-phase powder method and a liquid-phase atomization method. The production method of the American 3M company is a solid-phase powder method, for example, the hollow glass microspheres prepared by the methods disclosed in patents US4391646, US3365315 and WO 2017/040900A 1 have high performance and good chemical stability, but the method has the disadvantages of complex process, low floating rate and high energy consumption; the production method of PQ company is a liquid phase atomization method, as described in patents US3794503 and US3796777, the process is simple, the energy consumption is low, the floating rate is high, but the raw materials are limited, and the prepared hollow glass microspheres have low strength and are easy to agglomerate; the performance of the hollow glass bead prepared by the soft chemical method is between that of a solid-phase powder method and that of a soft chemical method, the process is simple, but the defects of overlarge cost ratio of fuel, easy caking and the like exist. Related domestic enterprises and research institutions improve the process or formula in the aspects of surface modification and the like for improving the strength and the floating rate of the Hollow Glass Microspheres (HGMs), but still have the defects of high raw material cost, complex process, wide particle size distribution, low strength and the like.

In order to prepare the hollow glass bead with high strength and low density, Chinese patent CN 101704632B (ZL 200910185799.5) discloses a preparation method of the hollow glass bead with high strength and low density, which comprises the following raw materials in parts by weight: SiO 2₂70～80％，Na₂O 8～12％，CaO 5～9％，B₂O₃ 2～6％，SO₃ 0.2～0.5％，K₂O or Li₂0-5% of O, 0-5% of ZnO or BaO, and Al₂O₃0 to 3 percent. But the preparation method adopts SO₃As a foaming agent, the hollow glass microsphere has great harm to the environment and has safety risk, and the hollow glass microsphere prepared by the method has a single product, the crushing strength of the hollow microsphere is 16-23 MPa, and the application range is narrow.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the preparation method of the hollow glass microspheres with high floating rate, which has the advantages of easily obtained raw materials, high balling rate of the hollow glass microspheres, simple process, low energy consumption, low production cost and wide product application range. By optimizing the raw material formula, preparing stable dispersion slurry, controlling technological parameters of atomizing granulation equipment, and applying high-temperature negative pressure sintering and low-temperature circulating air strengthening technology, the floating rate and the strength of the hollow glass microspheres are improved, and the particle size distribution is controlled.

In order to achieve the above purpose, the preparation method of the hollow glass microsphere with high floating rate of the invention adopts the following processes and steps:

1) preparing slurry: accurately weighing each component of the basic raw materials, the stable dispersing agent and the surfactant, and metering a certain mass of water by adopting a flowmeter; mixing the components of the basic raw materials, the stable dispersing agent, the surfactant and water in a dispersing tank for 15-20 minutes, and conveying the mixture to a ball mill through a feeding pump to prepare slurry with the solid content of 55-65% and the particle size of less than or equal to 10 microns;

the basic raw materials are a mixture of quartz, borax, calcium carbonate, sodium sulfate and sodium phosphate, and when the mass sum of all the components of the basic raw materials is calculated according to 100%, the contents of all the components are as follows: 60.30-61.15% of quartz, 14.00-14.90% of borax, 19.15-20.80% of calcium carbonate, 3.40-3.80% of sodium carbonate, 0.22-0.81% of sodium sulfate and 0.41-1.25% of sodium phosphate; the stabilizing dispersant is one or a mixture of more of sodium polyacrylate, sodium tripolyphosphate and polyethylene glycol according to any proportion, and the surfactant is a fluorocarbon surfactant or an organic silicon surfactant; the stable dispersing agent accounts for 0.1-0.5% of the mass of the slurry, and the surfactant accounts for 0.05-0.2% of the mass of the slurry;

2) preparation of the precursor: conveying the mixed slurry prepared in the step 1) to spray granulation equipment through a feeding pump, and performing spray granulation under the conditions that the inlet temperature is 280-425 ℃, the outlet temperature is 100-155 ℃ and the centrifugal speed is 10000-16500 rpm, wherein powder collected by cyclone is a high-fluidity solid ball-hollow glass microsphere precursor;

in the step 2), the probability of collision and agglomeration of liquid drops atomized from the slurry is low in the drying process, and the performance of the slurry is regulated and controlled by combining a stable dispersing agent and a surfactant, so that the prepared hollow glass bead precursor is a solid sphere with good fluidity and narrow particle size distribution, the particle size is 1-100 mu m, and the water content is 3-5%.

3) Preparing hollow glass beads: conveying the hollow glass bead precursor prepared in the step 2) to sintering equipment through powder conveying equipment, finishing a sintering and vitrifying process under the synergistic action of a negative pressure system, a multi-component gas distribution system and a heating system, conveying the hollow glass bead precursor to a cooling tower through gas flow, finishing a strengthening process through room-temperature circulating air, and collecting hollow glass bead products through collecting equipment;

the method of the invention adopts room temperature air for quenching, effectively prevents glass from phase splitting and crystallization, and improves the strength of the hollow glass beads; according to the invention, through high-temperature negative-pressure vitrification and regulation and control of a multi-component gas distribution system on the mixing ratio of gases, the control of flame temperature, height and heat conduction coefficient is realized, so that the internal and external pressure of the spherical shell, the surface tension and viscosity of a glass liquid phase are regulated, the expansion rate, sphericity and uniformity of the spherical shell are further controlled, the generation of solid spheres is reduced, and the hollow glass beads with the floating rate of more than 96.5% and high surface smoothness are prepared.

4) Surface modification: finishing the coating process of the hollow glass bead product collected in the step 3) and a surface modifier by dry continuous powder surface modification equipment to prepare surface modified hollow glass beads; the surface modifier is a modifier which can form chemical bonding, hydrogen bonding or physical adsorption with silicon hydroxyl on the surface of the glass.

In the step 4), if the adopted surface modifier is liquid, the modification temperature is controlled between 100 and 120 ℃, and the rotating speed of the dry continuous powder surface modification equipment is 1450 to 1550 rpm; and if the adopted surface modifier is solid powder, closing the heating system, and modifying at room temperature, wherein the rotating speed of the dry continuous powder surface modification equipment is 1450-1550 rpm.

The surface modifier is preferably selected from silane coupling agent, oligomer and active nano-grade powder. The adding amount of the liquid surface modifier is 0.5-1.5% of the mass of the hollow glass beads, and the adding amount of the solid surface modifier is 1-3% of the mass of the hollow glass beads.

In order to produce the high-performance hollow glass microspheres with the compressive strength of more than 115MPa (up to 180MPa), the adopted basic raw material formula is preferably as follows: 60.60-61.10% of quartz, 14.20-14.50% of borax, 20.30-20.75% of calcium carbonate, 3.45-3.80% of sodium carbonate, 0.24-0.26% of sodium sulfate and 0.42-0.48% of sodium phosphate; the stable dispersing agent accounts for 0.26-0.35% of the mass of the slurry, and the surfactant accounts for 0.08-0.12% of the mass of the slurry; in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal speed is 15700-16300 rpm, the inlet temperature is 285-295 ℃, and the outlet temperature is 105-115 ℃; the true density of the prepared hollow glass beads is 0.45-0.55 g/cm³Compressive strength>115Ma, flotation rate>96.5％。

In order to produce the hollow glass beads with the medium and high compressive strength between 25 and 70MPa, the adopted basic raw material formula is preferably as follows: 60.70-61.15% of quartz, 14.10-14.50% of borax, 19.85-20.35% of calcium carbonate, 3.45-3.80% of sodium carbonate, 0.36-0.53% of sodium sulfate and 0.60-0.78% of sodium phosphate; the stable dispersant accounts for0.18-0.30% of the mass of the slurry, and the surfactant accounts for 0.06-0.16% of the mass of the slurry; in the step 2), the technological parameters of the spray granulation equipment are as follows: centrifugal rotation speed of 13000-14800 rpm, inlet temperature of 330-375 ℃ and outlet temperature of 135-150 ℃; the true density of the prepared hollow glass beads is 0.30-0.41 g/cm³Compressive strength of 27-55 Ma, floating rate>98.0％。

In some cases, the market needs hollow glass beads with compressive strength of only a few MPa, such as emulsion explosive and paint industries, and in order to reduce production cost, the adopted basic raw material formula is preferably as follows: 60.35-60.60% of quartz, 14.45-14.75% of borax, 19.15-19.50% of calcium carbonate, 3.45-3.80% of sodium carbonate, 0.75-0.81% of sodium sulfate and 1.05-1.25% of sodium phosphate; the stable dispersing agent accounts for 0.28-0.32% of the mass of the slurry, and the surfactant accounts for 0.16-0.2% of the mass of the slurry; in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal speed is 9500-10500 rpm, the inlet temperature is 400-425 ℃, and the outlet temperature is 145-155 ℃; the true density of the prepared hollow glass beads is 0.11-0.13 g/cm³Compressive strength>3Ma, flotation rate>97.5％。

According to the scheme, the prepared hollow glass bead has the true density of 0.11-0.55 g/cm³Compressive strength of 3-180 MPa, and floating rate>96.5%, the particle diameter is 2-150 μm.

After the technical scheme is adopted, the invention has the following beneficial effects:

(1) the raw materials are easily available and are not limited by solubility.

(2) The high solid content stable dispersion slurry prepared by adding the stable dispersant and the surfactant improves the matching degree of the surface tension and the viscosity of the slurry and the technological parameters of spray granulation equipment, reduces the granulation energy consumption, and the prepared solid spherical precursor has uniform components, good fluidity, narrow and controllable particle size distribution.

(3) The high-temperature negative-pressure vitrification process and the multi-component gas distribution process are adopted to realize the accurate control of three factors, namely temperature, atmosphere and pressure, in the sintering process, thereby realizing the adjustment of the pressure difference inside and outside the spherical shell, the surface tension and viscosity of the glass liquid phase, further controlling the expansion rate, the sphericity and the uniformity of the spherical shell, reducing the generation of solid spheres, and ensuring that the prepared hollow glass bead has the balling rate of more than or equal to 96.5 percent and high performance.

(4) The low-temperature circulating air strengthening process is adopted, so that the phase separation and crystallization of the glass are prevented, and the strength of the hollow glass beads is further improved.

(5) The dry surface modification process is adopted, the surface modifier is not limited by physical state, the selectivity is wide, drying is not needed, the process is simplified, the energy consumption is reduced, and meanwhile, the application range of the product is widened.

Detailed Description

To further describe the present invention, the following examples are provided to further illustrate the preparation method of hollow glass microspheres with high floatation rate. The invention is not limited to the examples.

The preparation method of the hollow glass bead with high floating rate comprises the following specific implementation processes:

(1) the raw materials, the surfactant and the stable dispersing agent are accurately weighed, a flowmeter is used for metering a certain mass of water, the water is mixed for 15-20 minutes through a dispersing tank, and then the mixture is conveyed to a ball mill through a feeding pump, so that slurry with the solid phase content of 55-65% is prepared.

(2) And conveying the slurry to spray granulation equipment through a feeding pump, and performing spray granulation under the conditions that the inlet temperature is 280-420 ℃, the outlet temperature is 100-150 ℃ and the centrifugal speed is 10000-16000 rpm, wherein the powder collected by cyclone is a high-fluidity solid ball, the particle size of the solid ball is 1-100 mu m, and the water content is 3-5%.

(3) The precursor particles are conveyed into sintering equipment through powder conveying equipment, the sintering process is completed under the synergistic effect of a negative pressure system, a multi-component gas distribution system and a heating system, then the precursor particles are conveyed into a cooling tower through gas flow, the strengthening process is completed through low-temperature circulating air, and hollow glass bead products are collected through collecting equipment.

(4) According to the application, the surface modifier is selected, and the surface modified hollow glass microspheres are prepared by dry continuous powder surface modification equipment. When the surface modifier is liquid, setting the modification temperature to be 100-120 ℃ and the rotation speed to be 1500 rpm; when the surface modifier is solid, the heating system is closed, modification is carried out at room temperature, and the set rotation speed is 1500 rpm.