Microporous foamed glass prepared by taking waste glass as main raw material
阅读说明：本技术 一种以废玻璃为主要原料制备的微孔发泡玻璃 (Microporous foamed glass prepared by taking waste glass as main raw material ) 是由 王冰星 彭丽芬 柳雷 于 2021-01-27 设计创作，主要内容包括：本发明公开了一种以废玻璃为主要原料制备的微孔发泡玻璃,基础原料中各组份质量百分含量为：废玻璃62.8～77.0％,钠长石7.3～16.8％,空心玻璃微珠4.0～11.8％,硝酸钠0.1～0.3％,碳酸钙0.01～0.12％,硼砂0.6～3.0％,硼酸3.1～9.5％,萤石0.25～1.2％；所述的空心玻璃微珠的真密度为0.15～0.18g/cm～3,粒径为10～85μm。先制备坯料,坯料在高温炉内以5～8℃/min升温至780～860℃,保温30～50min,然后随炉冷却,制得微孔发泡玻璃。本发明采用空心玻璃微珠作为物理发泡剂,有效避免了发泡过程中异常孔洞的产生,制备的微孔发泡玻璃容重低,闭气孔率≥91％且孔径<80μm,显著提升了材料的抗压强度和保温隔热性能。(The invention discloses microporous foamed glass prepared by taking waste glass as a main raw material, which comprises the following components in percentage by mass: 62.8-77.0% of waste glass, 7.3-16.8% of albite, 4.0-11.8% of hollow glass beads, 0.1-0.3% of sodium nitrate, 0.01-0.12% of calcium carbonate, 0.6-3.0% of borax, 3.1-9.5% of boric acid and 0.25-1.2% of fluorite; the vacuum density of the hollow glass beads is 0.15-0.18 g/cm 3 The particle size is 10 to 85 μm. Firstly, preparing a blank, heating the blank to 780-860 ℃ at a speed of 5-8 ℃/min in a high-temperature furnace, preserving heat for 30-50 min, and then cooling along with the furnace to obtain the microporous foamed glass. The invention adopts the hollow glass beads as the physical foaming agent, effectively avoids the generation of abnormal holes in the foaming process, and the prepared microporous foamed glass has low volume weight, the closed porosity is more than or equal to 91 percent and the aperture<80 μm, and remarkably improves the compressive strength and the heat-insulating property of the material.)
1. The microporous foamed glass prepared by taking waste glass as a main raw material is characterized in that the basic raw material comprises the following components in percentage by mass: 62.8 to 77.0 percent of waste glass,7.3-16.8% of albite, 4.0-11.8% of hollow glass beads, 0.1-0.3% of sodium nitrate, 0.01-0.12% of calcium carbonate, 0.6-3.0% of borax, 3.1-9.5% of boric acid and 0.25-1.2% of fluorite; the vacuum density of the hollow glass beads is 0.15-0.18 g/cm3The particle size is 10-85 μm;
the preparation process comprises the following steps:
(1) preparing a blank: putting waste glass, albite, cosolvent, sodium nitrate, calcium carbonate and water into a ball mill for ball milling to obtain uniformly mixed slurry, dehydrating and drying, scattering the dried material to obtain a mixture, putting the mixture, hollow glass beads and a binder accounting for 3.5-6.7% of the total mass of the basic raw materials into a stirring tank, and mixing to obtain a blank;
(2) high-temperature foaming: and (2) filling the blank prepared in the step (1) into a mold paved with ceramic fiber paper for compression molding, heating to 780-860 ℃ at a speed of 5-8 ℃/min in a high-temperature furnace, preserving heat for 30-50 min, and then cooling along with the furnace to obtain the microporous foamed glass.
2. The microporous foamed glass prepared by using waste glass as a main raw material according to claim 1, wherein the base raw material comprises the following components in percentage by mass: 65.0-76.5% of waste glass, 7.3-15.5% of albite, 4.8-11.8% of hollow glass beads, 0.15-0.25% of sodium nitrate, 0.01-0.08% of calcium carbonate, 0.6-2.2% of borax, 3.4-8.5% of boric acid and 0.26-1.0% of fluorite.
3. The microcellular foamed glass produced from waste glass as a main raw material according to claim 1, wherein: the amount of the binder put into the stirring tank in the step (1) accounts for 4.5-6.5% of the total mass of the basic raw materials.
4. A microcellular foamed glass produced from waste glass as defined in claim 1, 2 or 3, wherein: the ball milling takes zirconia balls as a grinding medium, wherein the mass ratio of grinding balls to raw materials to water is (2.3-2.9): 1: (0.35-0.4).
5. The microcellular foamed glass produced from waste glass as a main raw material according to claim 4, wherein: the scattering adopts an airflow crusher, and the particle size of the mixture prepared after scattering is less than or equal to 100 mu m.
6. The fine pore foamed glass produced by using waste glass as a main raw material according to claim 5, wherein the binder comprises the following material components in mass content: 1.1-1.5% of beta-cyclodextrin, 3.3-4.1% of glycerol, 3.4-4.3% of sodium polymethylcellulose, 1.4-1.8% of polyethylene glycol and 88.3-90.8% of water, wherein the sum of the mass of the above materials is 100%.
7. The microcellular foamed glass produced from waste glass as a main raw material according to claim 6, wherein: the volume weight of the prepared microporous foamed glass is 180-230 kg/m3The heat conductivity coefficient is 0.053-0.062W/(m.k), the volume water absorption is less than or equal to 0.43%, the closed pore rate is more than or equal to 90%, and the pore diameter<0.8mm and the compressive strength of 0.90-1.25 MPa.
Technical Field
The invention belongs to the technical field of comprehensive utilization of waste glass, and particularly relates to foamed glass prepared by using waste glass as a main raw material, which can be widely applied to the fields of chemical engineering, environmental protection, buildings, underground engineering, national defense war industry and the like, and is particularly suitable for fire prevention engineering, waterproof engineering, building heat preservation, energy conservation and the like.
Background
The waste glass is leftover materials in the household building industry or broken glass in daily life, and the glass is difficult to degrade and sharp in mouth, so that the glass can only be subjected to landfill treatment in the past, precious land resources are occupied, and the environmental burden is increased. Millions of tons of waste glass generated every year in China are valuable resources, and researches show that the foam glass can be prepared from the waste glass and other main raw materials. In the building material family, the foam glass has excellent physical and chemical properties, and simultaneously has the characteristics of easy machining, construction and installation, and is widely applied to the fields of chemical industry, environmental protection, buildings, underground engineering, national defense war industry and the like.
The foam glass is foam glass for sealing air holes, has the excellent characteristics of small heat conductivity coefficient, low volume weight, high compressive strength, low water absorption, corrosion resistance, good chemical stability and the like, can be widely applied to the fields of chemical engineering, environmental protection, buildings, underground engineering, military products and the like to achieve the effects of water resistance, heat insulation, heat preservation, sound insulation and the like, and is called as an environment-friendly heat-insulating material.
With the development of industry in China, energy shortage and waste become one of the major bottlenecks in the development of socioeconomic industry. Meanwhile, China is in the stage of urbanization and industrialization development, and the total amount of newly constructed buildings is about 20 hundred million m every year2The energy consumption is about 4 times of that of developed countries, and the building energy consumption always occupies the first of the total energy consumption of the countries, so that the building energy conservation becomes the most important carrier for building the conservation-oriented society. The foamed glass has the functions of energy conservation, fire prevention, water prevention, environmental protection and the likeThe novel building material of the body can be widely popularized and applied.
Currently, foaming agents used for preparing foamed glass are classified into two main categories according to different foaming principles: one is a decomposition type foaming agent which generates gas such as carbonate, nitrate, sulfate, manganese dioxide and the like through decomposition reaction under the high-temperature condition; one is an oxidative blowing agent which undergoes an oxidation reaction with an oxygen-containing component to produce a gas, such as carbon black, sodium nitrate, and the like. In the high-temperature foaming process of the foamed glass, due to the problems of matching of the mixing amount, granularity, distribution and the like of the foaming agent with a thermal regulation, liquid phase viscosity, surface tension and the like, the product often has the defects of uneven structure of communicating holes and cells, large pore diameter difference and the like, and the defects can not be eliminated, so that the water absorption rate and the heat conductivity coefficient of the product are increased, the heat preservation and insulation effect is influenced, and the yield of the product is directly low. Therefore, the generation of non-uniform pore diameter and abnormal pores in the foamed glass is a problem to be solved.
In order to improve the physical and chemical properties of the foamed glass, the 'high-strength uniform foamed glass preparation' published in 7 months in 2015 of Chinese journal is prepared by using glass powder ground by waste glass as a main raw material and calcium carbonate as a foaming agent and foaming a melt by using gas generated by high-temperature decomposition of the calcium carbonate. However, research results show that the prepared foam glass has large internal pore diameter, low total porosity and poor heat insulation effect although the compressive strength is high, and particularly under the condition of high compressive strength, the prepared foam glass has the fatal defects of large volume density and low total porosity, and can not meet the performance index requirements of the microporous foam glass required by the market.
Disclosure of Invention
The invention aims to provide microporous foamed glass prepared by taking waste glass as a main raw material, aiming at the defects of low strength, high water absorption and high heat conductivity coefficient caused by the defects of large and uneven pore diameter, low porosity, abnormal pores and the like of the foamed glass in the prior art.
In order to achieve the purpose, the invention provides the microporous foamed glass prepared by taking the waste glass as the main raw material, and the mass percentage of each component in the basic raw material is: 62.8-77.0% of waste glass, 7.3-16.8% of albite, 4.0-11.8% of hollow glass beads, 0.1-0.3% of sodium nitrate, 0.01-0.12% of calcium carbonate, 0.6-3.0% of borax, 3.1-9.5% of boric acid and 0.25-1.2% of fluorite; the vacuum density of the hollow glass beads is 0.15-0.18 g/cm3The particle size is 10 to 85 μm. The preparation process comprises the following steps:
(1) preparing a blank: putting waste glass, albite, cosolvent, sodium nitrate, calcium carbonate and water into a ball mill for ball milling to obtain uniformly mixed slurry, dehydrating and drying, scattering the dried material to obtain a mixture, putting the mixture, hollow glass beads and a binder accounting for 3.5-6.7% of the total mass of the basic raw materials into a stirring tank, and mixing to obtain a blank; the amount of the adhesive put into the stirring tank is preferably 4.5-6.5% of the total mass of the basic raw materials.
(2) High-temperature foaming: and (2) filling the blank prepared in the step (1) into a mold paved with ceramic fiber paper for compression molding, heating to 780-860 ℃ at a speed of 5-8 ℃/min in a high-temperature furnace, preserving heat for 30-50 min, and then cooling along with the furnace to obtain the microporous foamed glass.
The basic raw materials of the microporous foamed glass of the invention preferably comprise the following components in percentage by mass: 65.0-76.5% of waste glass, 7.3-15.5% of albite, 4.8-11.8% of hollow glass beads, 0.15-0.25% of sodium nitrate, 0.01-0.08% of calcium carbonate, 0.6-2.2% of borax, 3.4-8.5% of boric acid and 0.26-1.0% of fluorite.
In order to prevent impurities from being mixed, zirconia balls are used as grinding media in the ball milling, wherein the mass ratio of grinding beads to raw materials to water is (2.3-2.9): 1: (0.35 to 0.4) is preferable.
The scattering is generally carried out by adopting an airflow crusher, and the grain diameter of the mixture prepared after scattering is preferably less than or equal to 100 mu m.
The adhesive comprises the following components in percentage by mass: 1.1-1.5% of beta-cyclodextrin, 3.3-4.1% of glycerol, 3.4-4.3% of sodium polymethylcellulose, 1.4-1.8% of polyethylene glycol and 88.3-90.8% of water, wherein the sum of the mass of the above materials is 100%. The optimal mixture ratio is as follows: 1.3% of beta-cyclodextrin, 3.7% of glycerol, 3.8% of sodium polymethylcellulose, 1.6% of polyethylene glycol and 89.6% of water.
The technical performance of the microporous foamed glass prepared by comprehensively optimizing the technical scheme is as follows: the bulk density is 180-230 kg/m3The heat conductivity coefficient is 0.053-0.062W/(m.k), the volume water absorption is less than or equal to 0.43%, the closed pore rate is more than or equal to 90%, and the pore diameter<0.8mm, compressive strength of 0.90-1.25 MPa
According to the invention, the mixture of hollow glass beads, sodium nitrate and calcium carbonate is used as a foaming agent, and 3 foaming materials play a synergistic effect, so that the volume weight is reduced, the closed porosity is improved, the heat conductivity coefficient is reduced, and the pore diameter of micropores is reduced; the invention adopts the mixture of borax, boric acid and fluorite as a cosolvent.
Compared with the prior art, the microporous foamed glass prepared by taking the waste glass as the main raw material has the following beneficial effects:
(1) the microporous foamed glass takes the solid waste glass as a basic raw material, so that the raw material is easy to obtain and low in price, and the ore resource is saved, so that the production cost of the foamed glass is reduced, and the high added value utilization of the waste glass is realized.
(2) According to the microporous foamed glass, the hollow glass beads are used as the physical foaming agent, in the high-temperature foaming process, gas in the hollow glass bead spherical shell is subjected to thermal expansion and is always coated in the spherical shell, so that the generation of intercommunicating pores is avoided, the cell structure is regular, the closed cell rate is improved, the stress concentration is effectively avoided, and the strength of the microporous foamed glass is improved.
(3) The invention adopts the hollow glass beads as spherical micron-sized hollow particles, thereby hindering heat convection, prolonging the heat conduction path, having the efficient reflection function of the cell wall curve to the heat radiation and the like, and obviously reducing the heat conductivity coefficient of the microporous foam glass.
(4) The invention introduces trace chemical foaming agent, preferably sodium nitrate and calcium carbonate, adjusts the volume weight of the microporous foamed glass, and finally prepares the high-efficiency heat-insulation fireproof foamed glass with high closed porosity, low thermal conductivity, low water absorption and micron-sized pores.
Detailed Description
In order to describe the present invention, the following will explain in detail a microcellular foamed glass prepared from waste glass as a main raw material in accordance with the present invention with reference to examples. The invention is not limited to the examples.
Example 1
The foaming glass comprises the following raw materials in percentage by mass: 71.3% of waste glass, 8.6% of albite, 10.29% of hollow glass beads, 0.21% of sodium nitrate, 1.54% of borax, 7.2% of boric acid and 0.86% of fluorite. Wherein the vacuum density of the hollow glass beads is 0.15g/cm3。
(1) Weighing waste glass, albite, sodium nitrate, borax, boric acid and fluorite according to a ratio, putting zirconium oxide grinding beads, raw materials and water into a ball milling tank according to a mass ratio of 2.6:1:0.35, and grinding for 60min to obtain uniform slurry; placing the slurry in a forced air drying oven, and drying at 110 deg.C for 100 min; and (3) scattering the dried material by using an airflow crusher, and then placing the scattered material, the hollow glass beads and a binder accounting for 5% of the total mass of the raw materials in a stirring tank for mixing for 25min to obtain a blank.
(2) And putting the prepared blank into a refractory material grinding tool paved with ceramic fiber paper, pressing and forming, putting into a high-temperature furnace, heating from room temperature to a foaming temperature of 800 ℃ at a heating rate of 5 ℃/min, preserving heat for 40min, cooling along with the furnace, demolding and cutting to obtain the microporous foamed glass.
Example 2
The foaming glass comprises the following raw materials in percentage by mass: 68.5 percent of waste glass, 15.1 percent of albite, 11.76 percent of hollow glass beads, 0.18 percent of sodium nitrate, 0.06 percent of calcium carbonate, 0.66 percent of borax, 3.45 percent of boric acid and 0.29 percent of fluorite. Wherein the hollow glass micro-bead has a true density of 0.18g/cm3。
(1) Weighing waste glass, albite, sodium nitrate, calcium carbonate, borax, boric acid and fluorite according to the proportion, putting zirconium oxide grinding beads, raw materials and water into a ball milling tank according to the mass ratio of 2.3:1:0.4, and grinding for 110min to prepare uniform slurry; placing the slurry in a forced air drying oven, and drying at 110 deg.C for 130 min; and (3) scattering the dried material by using an airflow crusher, and then placing the scattered material, the hollow glass beads and a binder accounting for 4.7% of the total mass of the raw materials in a stirring tank for mixing for 30min to obtain a blank.
(2) And putting the prepared blank into a refractory material grinding tool paved with ceramic fiber paper, pressing and forming, putting into a high-temperature furnace, heating from room temperature to a foaming temperature of 860 ℃ at a heating rate of 7 ℃/min, preserving heat for 30min, cooling along with the furnace, demolding, and cutting to obtain the foamed glass.
Example 3
The foaming glass comprises the following raw materials in percentage by mass: 76.5 percent of waste glass, 7.3 percent of albite, 4.86 percent of hollow glass beads, 0.11 percent of sodium nitrate, 0.03 percent of calcium carbonate, 2.01 percent of borax, 8.28 percent of boric acid and 0.91 percent of fluorite. Wherein the vacuum density of the hollow glass beads is 0.15g/cm3。
(1) Weighing waste glass, albite, sodium nitrate, calcium carbonate borax, boric acid and fluorite according to a ratio, putting zirconium oxide grinding beads, raw materials and water into a ball milling tank according to a mass ratio of 2.5:1:0.4, and grinding for 90min to prepare uniformly ground slurry; placing the slurry in a forced air drying oven, and drying at 110 deg.C for 100 min; and (3) scattering the dried material by using an airflow crusher, and then placing the scattered material, the hollow glass beads and a binder accounting for 6.2% of the total mass of the raw materials in a stirring tank for mixing for 30min to obtain a blank.
(2) And putting the prepared blank into a refractory material grinding tool paved with ceramic fiber paper, pressing and forming, putting into a high-temperature furnace, heating from room temperature to foaming temperature of 780 ℃ at the heating rate of 6 ℃/min, preserving heat for 50min, cooling along with the furnace, demoulding and cutting to obtain the foamed glass.
Examples 4 to 8
The foaming glass comprises the following raw materials in percentage by mass: see table 2.
(1) Weighing waste glass, albite, sodium nitrate, calcium carbonate, borax, boric acid and fluorite according to the proportion, putting zirconium oxide grinding beads, raw materials and water into a ball milling tank according to the mass ratio of 2.5:1:0.35, and grinding for 90min to prepare uniform slurry; placing the slurry in a forced air drying oven, and drying at 110 deg.C for 120 min; and (3) scattering the dried material by using an airflow crusher, and then placing the scattered material, the hollow glass beads and a binder accounting for 5.2% of the total mass of the raw materials in a stirring tank for mixing for 30min to obtain a blank.
(2) And putting the prepared blank into a refractory material grinding tool paved with ceramic fiber paper, pressing and forming, putting into a high-temperature furnace, heating from room temperature to a foaming temperature of 850 ℃ at a heating rate of 7 ℃/min, preserving heat for 35min, cooling along with the furnace, demolding, and cutting to obtain the foamed glass.
In the above embodiment, the adopted binder comprises the following material components in percentage by mass: 1.3 percent of beta- (3) cyclodextrin, 3.7 percent of glycerin, 3.8 percent of sodium polymethylcellulose, 1.6 percent of polyethylene glycol and 89.6 percent of water.
The upper and lower limit values and interval values of the raw materials, additives and process parameters related to the invention can all realize the invention, and are not listed.
The performance test method of the microporous foamed glass prepared in the embodiment is as follows: the test method of the compressive strength and the volume water absorption refers to JC/T647-2014 foam glass heat insulation products; the heat conductivity coefficient test method refers to GB/T10294-2008 heat insulation material steady-state thermal resistance and related characteristic determination-protective hot plate method; the volume weight and closed cell fraction are calculated by the following formula:
1) volume weight Db：
2) Apparent porosity Pa:
3) true porosity Pt:
4) closed cell ratio Pc: pc＝Pt-Pa
In the formula D1Density (g/cm) of the test solution at temperature3)；DtTrue density (g/cm) of the sample3)；M1-sample mass (g), oven-dried at 110 ℃ to constant weight; m2The apparent mass (g) of the saturated sample, the sample being placed in a beaker or other clean vessel, the immersion liquid (distilled water) being injected slowly until the sample is immersed, left to stand in air for 30min,placing the saturated sample on a lifting hook of a balance, and weighing the mass; m3The weight (g) of the sample was immediately weighed by using a towel saturated with immersion liquid to remove the liquid bead hanging on the surface of the saturated sample.
The properties of the microcellular foamed glass prepared in examples 1 to 3 are shown in Table 1.
The properties of the microcellular foamed glass prepared in examples 4 to 8 are shown in Table 3.
The hollow glass beads used in the invention are produced by New Material science and technology Limited of Middling Steel group Maanshan Ministry, and have a true density of 0.15-0.18 g/cm3The particle size is 10 to 85 μm.
TABLE 1 Performance of microcellular foamed glass prepared in examples 1 to 3
Table 2 examples 4 to 8 of examples 4 to 8 are based on the mass% of each component
TABLE 3 Performance of microcellular foamed glass prepared in examples 4 to 8
As can be seen from tables 1 and 3, the microcellular foamed glass prepared by the technical scheme provided by the invention has excellent physical properties, and the volume weight is lower than 221kg/m3The high-strength heat-insulating material has the advantages of high compressive strength, low heat conductivity coefficient, good heat-insulating effect, high closed pore rate of over 91.9 percent, low volume water absorption, small and uniform pore diameter of micropores and unexpected technical effect.