WO2021073060A1

WO2021073060A1 - Method for preparing hollow glass microbeads with high floatation rate

Info

Publication number: WO2021073060A1
Application number: PCT/CN2020/084454
Authority: WO
Inventors: 许传华; 刘亚辉; 汪俊; 汪光辉; 柳雷; 彭丽芬
Original assignee: 中钢集团马鞍山矿山研究总院股份有限公司; 中钢集团马鞍山矿院新材料科技有限公司
Priority date: 2019-10-14
Filing date: 2020-04-13
Publication date: 2021-04-22
Also published as: CN110590166B; CN110590166A; DE112020000050T5

Abstract

Disclosed is a method for preparing hollow glass microbeads with a high floatation rate, and the production process and steps thereof comprising: 1) preparation of a slurry: accurately weighing the components of basic raw materials, a stable dispersant and a surfactant, wherein the components of the basic raw materials are quartz, borax, calcium carbonate, sodium carbonate, sodium sulfate, and sodium phosphate; 2) preparation of a precursor; 3) preparation of hollow glass microbeads; and 4) surface modification. The stably dispersed slurry prepared by the method of the present invention has a high solid phase content, and low surface tension and viscosity, such that the energy consumption of spray granulation is not only significantly decreased, but also the prepared precursor has a small particle size span and uniform composition. In combination with a high-temperature negative-pressure vitrification process, the hollow glass microbeads are enabled to have a floatation rate of higher than 96.5% and a high surface finish, and furthermore, the hollow glass microbeads are strengthened by using low-temperature circulating wind. The raw materials of the present invention are easily available, the conglomeration rate of the hollow glass microbeads is high, and the present invention is simple in technological process, and low in energy consumption and production cost, and the product has a wide range of application.

Description

Method for preparing hollow glass microbeads with high floating rate

Technical field

The invention relates to inorganic fillers, in particular to a hollow glass microsphere, which can be widely used in the fields of petroleum, chemical industry, military industry, shipbuilding, automobile, aerospace, building materials, etc., and is especially suitable for coatings, glass fiber reinforced plastics, oil and gas field mining, and epoxy/ Unsaturated resins, nitrile, phenolic, acrylic and other coatings, as well as inks, adhesives, sealants, emulsion explosives and other products.

Background technique

Hollow glass beads are hollow micron-sized spherical particles, which have excellent characteristics such as low density, high strength, low thermal conductivity, sound insulation, high melting point, strong stability, and good fluidity. It is precisely because of this series of advantages. Make it an excellent modified material, endow the substrate with multiple functions, so it is widely used in petroleum, military, building materials, automobiles, plastics, paint, explosives and other industries.

At present, the industrialized hollow glass microbead preparation technologies mainly include soft chemical method, solid phase powder method and liquid phase atomization method. The production method of 3M Company in the United States is a solid phase powder method, as described in patents US4391646, US3365315, WO2017/040900 A1, the hollow glass beads prepared have high performance and good chemical stability, but the process is complex, the floating rate is low, and energy consumption High; PQ’s production method is a liquid phase atomization method, as described in patents US3794503 and US3796777. The process is simple, low energy consumption, high floating rate, but the raw materials are limited, and the hollow glass beads prepared are low in strength and easy Agglomeration; the properties of hollow glass beads prepared by soft chemical method are between the solid phase powder method and the soft chemical method, and the process is simple, but there are disadvantages such as excessive fuel cost and easy agglomeration. In order to improve the strength and floating rate of hollow glass microspheres (HGMs), relevant domestic enterprises and research institutions have made improvements in process or formulation in terms of surface modification. However, there are still high raw material costs, complex processes, wide particle size distribution, and Disadvantages such as low strength.

In order to prepare high-strength and low-density hollow glass beads, Chinese Patent CN 101704632 B (ZL 200910185799.5) discloses a method for preparing high-strength and low-density hollow glass beads. The raw material composition of the hollow glass beads is SiO. ₂ 70～80%, Na ₂ O 8～12%, CaO 5～9%, B ₂ O ₃ 2～6%, SO ₃ 0.2～0.5%, K ₂ O or Li ₂ O 0～5%, ZnO or BaO 0～5%, Al ₂ O ₃ 0～3%. However, this preparation method uses SO ₃ as a foaming agent, which is harmful to the environment and has safety risks. Moreover, the hollow glass microspheres prepared by this method have a single product, the crushing strength of the hollow microspheres is 16 to 23 MPa, and the application range is narrow. .

Summary of the invention

The purpose of the present invention is to address the above-mentioned defects in the prior art, and provide a high-floating material with easily available raw materials, high spheroidization rate of hollow glass beads, simple process, low energy consumption, low production cost and wide product application range. The method of preparing hollow glass microspheres with high efficiency. By optimizing the formulation of raw materials, the preparation of stable dispersion slurry, the control of the process parameters of the atomized granulation equipment, the application of high-temperature negative pressure sintering and low-temperature circulating air strengthening technology, the floating rate and strength of the hollow glass beads are improved, and the particle size The distribution is controlled.

In order to achieve the above-mentioned object of the present invention, a method for preparing hollow glass beads with a high floating rate of the present invention adopts the following processes and steps:

1) Preparation of slurry: accurately weigh the components of the basic raw materials, stable dispersant and surfactant, and use a flow meter to measure a certain quality of water; combine the components of the basic raw materials, stabilized dispersant, surfactant and water After mixing for 15-20 minutes in the dispersion tank, it is transported to the ball mill by the feed pump to prepare a slurry with a solid content of 55-65%, with a particle size of ≤10μm;

The basic raw material is a mixture of quartz, borax, calcium carbonate, sodium carbonate, sodium sulfate, and sodium phosphate. When the total mass of each component of the basic raw material is calculated as 100%, the content of each component is: 60.30-61.15% of quartz, borax 14.00～14.90%, calcium carbonate 19.15～20.80%, sodium carbonate 3.40～3.80%, sodium sulfate 0.22～0.81%, sodium phosphate 0.41～1.25%; the stable dispersant is sodium polyacrylate, sodium tripolyphosphate, poly One or more of the ethylene glycol is mixed in any proportion, the surfactant is a fluorocarbon surfactant or a silicone surfactant; the stable dispersant accounts for 0.1 to 0.5% of the mass of the slurry, Said surfactant accounts for 0.05-0.2% of the mass of the slurry;

2) Preparation of precursors: the mixed slurry prepared in step 1) is transported to the spray granulation equipment through a feeding pump, and carried out under the conditions of an inlet temperature of 280-425°C, an outlet temperature of 100-155°C, and a centrifugal speed of 10000-16500 rpm Spray granulation, the powder collected by the cyclone is a high-fluidity solid ball-the precursor of hollow glass beads;

In step 2), the droplets atomized by the slurry have a low probability of collision and agglomeration during the drying process. Combining the regulation of the slurry performance with a stable dispersant and a surfactant, the hollow glass microbead precursor is made to flow. Solid spheres with good properties and narrow particle size distribution, with a particle size of 1-100 μm and a moisture content of 3 to 5%.

3) Preparation of hollow glass microbeads: the precursor of the hollow glass microbeads prepared in step 2) is transported to the sintering equipment through the powder feeding equipment, and the sintering is completed under the synergistic effect of the negative pressure system, the multi-group distribution gas system, and the heating system The vitrification process is then transported to the cooling tower by air flow, and the strengthening process is completed by circulating air at room temperature, and the hollow glass microbead products are collected through the collection equipment;

The method of the present invention adopts room temperature air for quenching, effectively prevents phase separation and crystallization of the glass, and improves the strength of hollow glass beads; the present invention realizes the control of the mixing ratio of each gas through the high-temperature negative pressure vitrification combined with the multi-group distribution gas system. The flame temperature, height and thermal conductivity are controlled to adjust the internal and external pressure of the spherical shell, as well as the surface tension and viscosity of the glass liquid phase, thereby controlling the expansion rate, sphericity and uniformity of the spherical shell, reducing the production of solid balls and preparing floats. Hollow glass beads with a rate of >96.5% and a high surface finish.

4) Surface modification: the hollow glass microbeads collected in step 3) and the surface modifier are passed through a dry continuous powder surface modification equipment to complete the coating process to obtain surface modified hollow glass microbeads; Surface modifiers refer to modifiers that can form chemical bonds, hydrogen bonds or physical adsorption with the silanol groups on the glass surface.

In step 4), if the surface modifier used is liquid, the modification temperature is controlled between 100 and 120°C, and the rotating speed of the dry continuous powder surface modification equipment is 1450 rpm to 1550 rpm; if the surface is used If the modifier is a solid powder, the heating system is turned off and the modification is carried out at room temperature. The rotating speed of the dry continuous powder surface modification equipment is 1450-1550 rpm.

The surface modifiers are preferably silane coupling agents, oligomers, and active nano-level powders. The addition amount of the liquid surface modifier is 0.5 to 1.5% of the mass of the hollow glass microspheres, and the addition amount of the solid surface modifier is 1 to 3% of the mass of the hollow glass microspheres.

In order to produce high-performance hollow glass beads with a compressive strength greater than 115MPa (up to 180MPa), the basic raw material formula used is preferably: quartz 60.60～61.10%, borax 14.20～14.50%, calcium carbonate 20.30～20.75%, sodium carbonate 3.45 to 3.80%, sodium sulfate 0.24 to 0.26%, sodium phosphate 0.42 to 0.48%; the stable dispersant accounts for 0.26 to 0.35% of the mass of the slurry, and the surfactant accounts for 0.08 to 0.12% of the mass of the slurry In step 2), the process parameters of the spray granulation equipment are: centrifugal speed 15700-16300rpm, inlet temperature 285-295°C, outlet temperature 105-115°C; the true density of the prepared hollow glass beads is 0.45-0.55g /cm ³ , compressive strength>115Ma, floating rate>96.5%.

In order to produce hollow glass beads with medium and high compressive strength between 25 and 70 MPa, the basic raw material formula used is preferably: quartz 60.70-61.15%, borax 14.10-14.50%, calcium carbonate 19.85-20.35%, carbonic acid Sodium 3.45～3.80%, sodium sulfate 0.36～0.53%, sodium phosphate 0.60～0.78%; the stabilizing dispersant accounts for 0.18～0.30% of the mass of the slurry, and the said surfactant accounts for 0.06～0.16 of the mass of the slurry %; In step 2), the process parameters of the spray granulation equipment are: centrifugal speed 13000-14800rpm, inlet temperature 330-375°C, outlet temperature 135-150°C; the true density of the prepared hollow glass beads is 0.30-0.41 g/cm ³ , compressive strength 27～55Ma, floating rate>98.0%.

In some cases, the market requires hollow glass beads with a compressive strength of only a few MPa, such as emulsion explosives and paint industries. In order to reduce production costs, the basic raw material formula used is preferably 60.35-60.60% quartz and 14.45- borax. 14.75%, calcium carbonate 19.15-19.50%, sodium carbonate 3.45-3.80%, sodium sulfate 0.75-0.81%, sodium phosphate 1.05-1.25%; the stabilizing dispersant accounts for 0.28-0.32% of the mass of the slurry. Surfactant accounts for 0.16-0.2% of the mass of the slurry; in step 2), the spray granulation equipment process parameters are: centrifugal speed 9500-10500rpm, inlet temperature 400-425°C, outlet temperature 145-155°C; prepared The true density of the hollow glass beads is 0.11～0.13g/cm ³ , the compressive strength>3Ma, and the floating rate>97.5%.

According to the above scheme, the prepared hollow glass beads have a true density of 0.11 to 0.55 g/cm ³ , a compressive strength of 3 to 180 MPa, a floating rate of >96.5%, and a particle size of 2 to 150 μm.

After adopting the above technical scheme, the present invention has the following beneficial effects:

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

(2) Stable dispersion slurry with high solid content prepared by adding stable dispersant and surfactant, while improving the matching degree of slurry surface tension and viscosity with the process parameters of spray granulation equipment, not only reduces the energy consumption of granulation, but also Moreover, the prepared solid spherical precursor has uniform composition, good fluidity, narrow and controllable particle size distribution.

(3) Adopt high-temperature negative pressure vitrification process and multi-group gas distribution process to realize the precise control of the three elements of the sintering process-temperature, atmosphere, and pressure, so as to achieve the control of the pressure difference between the inside and outside of the spherical shell, the surface tension and viscosity of the liquid Adjust to control the expansion rate, sphericity and uniformity of the spherical shell, reduce the generation of solid spheres, and the prepared hollow glass microbeads have a sphericity rate of ≥96.5% and high performance.

(4) The use of low-temperature circulating wind strengthening technology prevents the glass from phase separation and crystallization, and further improves the strength of the hollow glass beads.

(5) Adopting dry surface modification process, the surface modifier is not limited by the physical state, has wide selectivity, does not need to be dried, simplifies the process, reduces energy consumption, and at the same time broadens the product application range.

Detailed ways

In order to further describe the present invention, the method for preparing a hollow glass microbead with a high floating rate of the present invention will be further described below in conjunction with examples. However, the present invention is not limited to the embodiment.

The specific implementation process of the method for preparing hollow glass microspheres with high floating rate of the present invention is as follows:

(1) Accurately weigh the raw materials, surfactants and stabilizing dispersants, and use a flow meter to measure a certain quality of water. After mixing for 15-20 minutes in the dispersion tank, it will be transported to the ball mill by the feeding pump to obtain a solid content of 55. ~65% slurry.

(2) The slurry is transported to the spray granulation equipment by the feeding pump, and the spray granulation is carried out under the conditions of inlet temperature of 280～420℃, outlet temperature of 100～150℃ and centrifugal rotation speed of 10000～16000rpm. The powder collected by the cyclone is High-fluidity solid ball, the particle size of the solid ball is 1-100 μm, and the water content is 3 to 5%.

(3) The precursor particles are transported to the sintering equipment through the powder feeding equipment, and the sintering process is completed under the synergy of the negative pressure system, the multi-group distribution air system, and the heating system, and then transported to the cooling tower through the airflow to complete the low-temperature circulating air. Strengthen the process and collect hollow glass microbead products through collection equipment.

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

The preparation processes of Examples 1 to 4 are the same, and the parameters in the preparation process are shown in Table 1. The upper and lower limit values and interval values of the additives involved in the present invention can all realize the present invention, and the upper and lower limit values and interval values of the process parameters of the present invention (such as spray granulation process parameters, modified process parameters, etc.) can be realized. The embodiments of the present invention are not listed here.

Table 1 The preparation process parameters of Examples 1 to 4 and the properties of the hollow glass beads prepared

Note: Strength refers to the pressure applied when the survival rate of hollow glass beads is 80%.

Claims

A method for preparing hollow glass beads with a high floating rate, which is characterized in that the hollow glass beads with a floating rate in water >96.5% are prepared by adopting the following processes and steps:

1) Preparation of slurry: accurately weigh the components of the basic raw materials, stable dispersant and surfactant, and use a flow meter to measure a certain quality of water; combine the components of the basic raw materials, stabilized dispersant, surfactant and water After mixing in a dispersion tank for 15-20 minutes, it is transported to a ball mill by a feed pump to prepare a slurry with a solid content of 55-65%;

The basic raw material is a mixture of quartz, borax, calcium carbonate, sodium carbonate, sodium sulfate, and sodium phosphate. When the total mass of each component of the basic raw material is calculated as 100%, the content of each component is: 60.30-61.15% of quartz, borax 14.00～14.90%, calcium carbonate 19.15～20.80%, sodium carbonate 3.40～3.80%, sodium sulfate 0.22～0.81%, sodium phosphate 0.41～1.25%; the stable dispersant is sodium polyacrylate, sodium tripolyphosphate, poly One or more of the ethylene glycol is mixed in any proportion, the surfactant is a fluorocarbon surfactant or a silicone surfactant; the stable dispersant accounts for 0.1 to 0.5% of the mass of the slurry, Said surfactant accounts for 0.05-0.2% of the mass of the slurry;

2) Precursor preparation: the mixed slurry prepared in step 1) is transported to the spray granulation equipment through a feeding pump, under the conditions of an inlet temperature of 280-425°C, an outlet temperature of 100-155°C and a centrifugal speed of 10000-16500rpm Spray granulation, the powder collected by the cyclone is a high-fluidity solid ball-the precursor of hollow glass beads;

3) Preparation of hollow glass microbeads: the precursor of the hollow glass microbeads prepared in step 2) is transported to the sintering equipment through the powder feeding equipment, and the sintering is completed under the synergistic effect of the negative pressure system, the multi-group distribution gas system, and the heating system The process is then conveyed to the cooling tower by airflow, and the strengthening process is completed by circulating air at room temperature, and the hollow glass microbead products are collected through the collection equipment;

4) Surface modification: the hollow glass microbeads collected in step 3) and the surface modifier are passed through a dry continuous powder surface modification equipment to complete the coating process to obtain surface modified hollow glass microbeads; Surface modifiers refer to modifiers that can form chemical bonds, hydrogen bonds or physical adsorption with the silanol on the glass surface.
The method for preparing hollow glass beads with high floating rate according to claim 1, characterized in that the surface modifier used in step 4) is liquid, the modification temperature is 100-120°C, and the dry method The rotating speed of the continuous powder surface modification equipment is 1450 rpm to 1550 rpm.
The method for preparing hollow glass beads with high floating rate according to claim 1, wherein the surface modifier used in step 4) is solid powder, the heating system is turned off, and the modification is carried out at room temperature. , The rotating speed of dry continuous powder surface modification equipment is 1450-1550rpm.
The method for preparing hollow glass beads with high floating rate according to claim 1, 2 or 3, characterized in that: when the total mass of each component of the basic raw material is calculated at 100%, the content of each component is: 60.60 quartz ～61.10%, borax 14.20～14.50%, calcium carbonate 20.30～20.75%, sodium carbonate 3.45～3.80%, sodium sulfate 0.24～0.26%, sodium phosphate 0.42～0.48%; the stable dispersant accounts for 0.26 of the mass of the slurry ~0.35%, the surfactant accounts for 0.08~0.12% of the mass of the slurry; in step 2), the process parameters of the spray granulation equipment are: centrifugal speed 15700-16300rpm, inlet temperature 285-295°C, outlet temperature 105 ～115℃; the true density of the prepared hollow glass beads is 0.45～0.55g/cm 3 , the compressive strength>115Ma, and the floating rate>96.5%.
The method for preparing hollow glass beads with high floating rate according to claim 1, 2 or 3, characterized in that: when the total mass of each component of the basic raw material is calculated at 100%, the content of each component is: 60.70 quartz ～61.15%, borax 14.10～14.50%, calcium carbonate 19.85～20.35%, sodium carbonate 3.45～3.80%, sodium sulfate 0.36～0.53%, sodium phosphate 0.60～0.78%; the stabilizing dispersant accounts for 0.18 of the mass of the slurry ～0.30%, the surfactant accounts for 0.06～0.16% of the mass of the slurry; in step 2), the process parameters of the spray granulation equipment are: centrifugal speed 13000～14800rpm, inlet temperature 330～375℃, outlet temperature 135 ～150℃; The true density of the prepared hollow glass beads is 0.30～0.41g/cm 3 , the compressive strength is 27～55Ma, and the floating rate is >98.0%.
The method for preparing hollow glass beads with high floating rate according to claim 1, 2 or 3, characterized in that: when the total mass of each component of the basic raw material is calculated at 100%, the content of each component is: 60.35 quartz ～60.60%, borax 14.45～14.75%, calcium carbonate 19.15～19.50%, sodium carbonate 3.45～3.80%, sodium sulfate 0.75～0.81%, sodium phosphate 1.05～1.25%; the stabilized dispersant accounts for 0.28 of the mass of the slurry ~0.32%, the surfactant accounts for 0.16~0.2% of the mass of the slurry; in step 2), the process parameters of the spray granulation equipment are: centrifugal speed 9500-10500rpm, inlet temperature 400-425°C, outlet temperature 145 ～155℃; the true density of the prepared hollow glass beads is 0.11～0.13g/cm 3 , the compressive strength>3Ma, and the floating rate>97.5%.