阅读说明：本技术 基于前驱物法制备空心玻璃微珠的产业化方法 (Industrialization method for preparing hollow glass beads based on precursor method ) 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：本发明公开了一种基于前驱物法制备空心玻璃微珠的产业化方法,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％,并采用低温循环风强化空心玻璃微珠。本发明采用干法表面改性,无需再干燥,简化工艺过程的同时拓宽了空心玻璃微珠的应用领域,解决了空心玻璃微珠应用领域窄的问题。(The invention discloses an industrialization method for preparing hollow glass beads based on a precursor method, 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 percent, and adopts low-temperature circulating air to strengthen the hollow glass microspheres. The invention adopts dry surface modification without drying, simplifies the process, widens the application field of the hollow glass beads and solves the problem of narrow application field of the hollow glass beads.)

1. An industrialization method for preparing hollow glass beads based on a precursor method is characterized 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; wherein the mass sum of all the components of the basic raw material is calculated according to 100 percent, and the content of all the components is as follows: 59.10-61.55% of quartz, 13.50-15.30% of borax, 18.75-21.25% of calcium carbonate, 3.10-3.90% of sodium carbonate, 0.22-0.82% of sodium sulfate and 0.40-1.25% 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; mixing and ball-milling water accounting for 37-45% of the total mass of the basic raw materials, a certain amount of stable dispersing agent and surfactant to prepare slurry with high solid phase content and stable dispersion; 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 to prepare a hollow glass bead precursor, namely a solid ball with the particle size of 1-100 mu m and the water content of 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 to complete vitrification, conveying the precursor to a cooling tower through air flow, completing a strengthening process through low-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 industrial method for preparing hollow glass microspheres based on the precursor method according to claim 1, wherein: in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal speed is 9500-16500 rpm, the inlet temperature is 280-425 ℃, and the outlet temperature is 100-155 ℃.

3. the industrial method for preparing hollow glass microspheres based on the precursor method according to claim 2, wherein: in the step 3), the sintering equipment is composed of a negative pressure system, a multi-component gas distribution system and a heating system; the low-temperature circulating air strengthening refers to quenching by adopting room-temperature air.

4. The industrial method for preparing hollow glass microspheres based on the precursor method according to 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: 60.10-61.25% of quartz, 13.80-14.60% of borax, 20.00-21.25% of calcium carbonate, 3.22-3.90% of sodium carbonate, 0.22-0.28% of sodium sulfate and 0.40-0.50% of sodium phosphate; the stable dispersing agent accounts for 0.20-0.4% of the mass of the slurry, and the surfactant accounts for 0.08-0.12% of the mass of the slurry.

5. The industrial method for preparing hollow glass microspheres based on the precursor method according to 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: 60.10-61.25% of quartz, 13.80-14.60% of borax, 19.65-20.50% of calcium carbonate, 3.22-3.90% of sodium carbonate, 0.34-0.55% of sodium sulfate and 0.60-0.80% of sodium phosphate; the stable dispersing agent accounts for 0.15-0.32% of the mass of the slurry, and the surfactant accounts for 0.05-0.17% of the mass of the slurry.

6. The industrial method for preparing hollow glass microspheres based on the precursor method according to 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: 59.10-60.80% of quartz, 14.25-15.30% of borax, 18.75-19.90% of calcium carbonate, 3.22-3.90% of sodium carbonate, 0.70-0.82% of sodium sulfate and 0.90-1.25% of sodium phosphate; the stable dispersing agent accounts for 0.22-0.4% of the mass of the slurry, and the surfactant accounts for 0.15-0.2% of the mass of the slurry.

7. the industrial method for preparing hollow glass microspheres based on the precursor method according to claim 4, wherein: in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal speed is 15500-16500 rpm, the inlet temperature is 280-300 ℃, and the outlet temperature is 100-120 ℃.

8. the industrial method for preparing hollow glass microspheres based on the precursor method according to claim 5, wherein: in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal speed is 13000-15000 rpm, the inlet temperature is 330-375 ℃, and the outlet temperature is 130-150 ℃.

9. The industrial method for preparing hollow glass microspheres based on the precursor method according to claim 6, wherein the method comprises the following steps: in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal rotation speed is 9500-10500 rpm, the inlet temperature is 400-425 ℃, and the outlet temperature is 145-155 ℃.

Technical Field

The invention belongs to the technical field of hollow glass bead preparation, and particularly relates to a method for preparing hollow glass beads by adopting a precursor method.

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.

disclosure of Invention

aiming at the defects in the prior art, the invention provides the industrialization method for preparing the hollow glass microspheres based on the precursor method, 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 of the present invention, the industrialization method for preparing hollow glass beads based on the precursor method 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; wherein the mass sum of all the components of the basic raw material is calculated according to 100 percent, and the content of all the components is as follows: 59.10-61.55% of quartz, 13.50-15.30% of borax, 18.75-21.25% of calcium carbonate, 3.10-3.90% of sodium carbonate, 0.22-0.82% of sodium sulfate and 0.40-1.25% 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; mixing and ball-milling water accounting for 37-45% of the total mass of the basic raw materials, a certain amount of stable dispersing agent and surfactant to prepare slurry with high solid phase content and stable dispersion; 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;

The solid phase content of the prepared stably dispersed slurry is 55-65%, and the particle size is less than or equal to 10 microns.

2) Preparation of the precursor: conveying the mixed slurry prepared in the step 1) to spray granulation equipment through a feeding pump to prepare a hollow glass bead precursor, namely a solid ball with the particle size of 1-100 mu m and the water content of 3-5%;

The adopted spray granulation equipment has the following technological parameters: the centrifugal speed is 9500-16500 rpm, the inlet temperature is 280-425 ℃, and the outlet temperature is 100-155 ℃. 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 slurry performance 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, and the particle size adjustable range of the hollow glass bead precursor is 1-100 mu m.

3) Preparing hollow glass beads: conveying the hollow glass bead precursor prepared in the step 2) to sintering equipment through powder conveying equipment to complete vitrification, conveying the precursor to a cooling tower through air flow, completing a strengthening process through low-temperature circulating air, and collecting hollow glass bead products through collecting equipment;

The sintering equipment is mainly composed of a negative pressure system, a multi-component gas distribution system and a heating system; the low-temperature circulating air strengthening means that after the hollow glass beads are solidified in the cooling stage of the sintering equipment, room-temperature air is adopted for quenching, so that the phase separation and crystallization of glass are prevented, and the strength of the hollow glass beads is improved.

the vitrification of the hollow glass bead precursor in the sintering equipment refers to high-temperature negative-pressure vitrification, and the control of flame temperature, height and heat conduction coefficient is realized by combining the regulation and control of a multi-component gas distribution system on the mixing ratio of gases, so that the internal and external pressure of the spherical shell, the surface tension and viscosity of the glass liquid phase are regulated, the expansion rate, the sphericity and the uniformity of the spherical shell are further controlled, the generation of solid spheres is reduced, and the hollow glass bead with the floating rate of more than 96% and high surface smoothness is 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.

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 beads with the compressive strength of more than 115MPa, the adopted raw material formula is preferably as follows: 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: 60.10-61.25% of quartz, 13.80-14.60% of borax, 20.00-21.25% of calcium carbonate, 3.22-3.90% of sodium carbonate, 0.22-0.28% of sodium sulfate and 0.40-0.50% of sodium phosphate; the stable dispersing agent accounts for 0.20-0.4% of the mass of the slurry, and the surfactant accounts for 0.08-0.12% of the mass of the slurry. Under the condition of the mixture ratio of the raw material components, in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal speed is 15500-16500 rpm, the inlet temperature is 280-300 ℃, and the outlet temperature is 100-120 ℃.

In order to produce the hollow glass beads with the medium and high compressive strength between 25 and 70MPa, the adopted raw material formula is preferably as follows: 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: 60.10-61.25% of quartz, 13.80-14.60% of borax, 19.65-20.50% of calcium carbonate, 3.22-3.90% of sodium carbonate, 0.34-0.55% of sodium sulfate and 0.60-0.80% of sodium phosphate; the stable dispersing agent accounts for 0.15-0.32% of the mass of the slurry, and the surfactant accounts for 0.05-0.17% of the mass of the slurry. Under the condition of the mixture ratio of the raw material components, in the step 2), the technological parameters of the spray granulation equipment are as follows: the centrifugal speed is 13000-15000 rpm, the inlet temperature is 330-375 ℃, and the outlet temperature is 130-150 ℃.

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 the production cost, the mass sum of all the components of the basic raw materials is 100%, and the content of all the components is as follows: 59.10-60.80% of quartz, 14.25-15.30% of borax, 18.75-19.90% of calcium carbonate, 3.22-3.90% of sodium carbonate, 0.70-0.82% of sodium sulfate and 0.90-1.25% of sodium phosphate; the stable dispersing agent accounts for 0.22-0.4% of the mass of the slurry, and the surfactant accounts for 0.15-0.2% of the mass of the slurry. In this case, the process parameters of the spray granulation equipment in the step 2) are as follows: the centrifugal rotation speed is 9500-10500 rpm, the inlet temperature is 400-425 ℃, and the outlet temperature is 145-155 ℃.

according to the scheme, the true density of the prepared hollow glass bead is 0.12-0.6 g/cm³Compressive strength of 3-180 MPa, and floating rate>96% and 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 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 industrial method for preparing hollow glass microspheres based on the precursor method. The invention is not limited to the examples.

The specific implementation process of the industrialization method for preparing the hollow glass beads based on the precursor method is as follows:

(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.