Expanded porous porcelainized aggregate acoustic board as well as preparation method and application thereof

Abstract

The invention discloses an expanded porous porcelainized aggregate acoustic board and a preparation method and application thereof.The preparation method comprises the following steps that phosphorus mud, waste incineration fly ash and steel slag are dried and subjected to ball milling, and then powder is obtained; uniformly mixing the powder of each raw material with the expanding agent in proportion, adding water, mixing and granulating to prepare an aggregate biscuit; and stacking the aggregate biscuit in a mold to form a plate shape, then drying the plate shape along with the mold, preheating at 400-500 DEG C, heating to 1100-1200 DEG C, sintering, and quenching after sintering to obtain the expanded porous porcelainized aggregate acoustic board. The aggregate acoustic board prepared by the invention has the excellent performances of high porosity, light weight, high compressive strength, good fire resistance and the like, and can simultaneously realize low carbon emission and solid waste resource utilization in the preparation process.

Description

Technical Field

[0001] The invention belongs to the technical field of sound-absorbing panels and solid waste resource utilization, and in particular relates to an expanded porous porcelain aggregate sound-absorbing panel and a preparation method and application thereof. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the rapid development of rail transit, while driving high-quality economic development and facilitating people's lives, the noise problem it brings should not be underestimated. The types of sound-absorbing panels currently used in engineering projects mainly include fiber cement sound-absorbing panels, lightweight aggregate cement sound-absorbing panels, etc. Among them, lightweight aggregate cement sound-absorbing panels are mainly prepared by adding lightweight aggregates such as ceramsite to porous cement-based sound-absorbing materials, but in the process of cement production, fuel combustion and raw material carbonate decomposition will lead to a large amount of carbon emissions, which does not meet the requirements of green and low-carbon development.

[0004] Phosphorus mud is an important by-product produced when phosphorus is produced using phosphate rock as the main raw material. Its main components are SiO2, CaO, Fe2O3, Al2O3, etc. In addition, it also contains harmful elements such as heavy metals. The mainstream treatment methods include physical methods to recover phosphorus, mainly including phosphorus evaporation, filtration, extraction, etc. Among them, ① Phosphorus evaporation is to heat phosphorus mud and use the physical changes of elemental phosphorus with temperature to separate it from water and impurities, and then condense and recover phosphorus vapor. ② Filtration method is to dissolve phosphorus mud containing about 60% phosphorus in hot water at 70-80℃, while keeping it warm. The molten phosphorus mud is vacuum filtered through a suction filter tank with two layers of tussah silk as filter cloth. Impurities are trapped on the filter cloth and the finished yellow phosphorus is filtered out. ③ Solvent extraction method is to extract yellow phosphorus from phosphorus mud by using the properties that yellow phosphorus is insoluble in water, slightly soluble in benzene and chloroform, and easily soluble in carbon disulfide. The above treatment methods of phosphate sludge all use physical methods to recover phosphorus in the phosphate sludge, but the treatment of the phosphate sludge is incomplete. A large amount of toxic heavy metals contained in the phosphate sludge enter the environment and are enriched in the soil and plants, eventually endangering human health. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an expanded porous porcelain aggregate sound-absorbing board and a preparation method and application thereof. The aggregate sound-absorbing board prepared by the present invention has excellent properties such as high porosity, light weight, high compressive strength, and good fire resistance. During the preparation process, low carbon emissions and solid waste resource utilization can be achieved at the same time.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, the present invention provides an expanded porous vitrified aggregate sound-absorbing board, the materials of which include the following components by weight: 35-60 parts of phosphorus mud, 10-25 parts of waste incineration fly ash, 10-55 parts of steel slag, and 0.4-1 part of an expansion agent.

[0008] In some embodiments, phosphorus mud, waste incineration fly ash, steel slag and expansion agent are all powders, and the particle size of the powders is 80-100 mesh.

[0009] In some embodiments, the expanded porous ceramic aggregate sound-absorbing board includes the following components by weight: 35-60 parts of phosphorus mud, 15-25 parts of waste incineration fly ash, 20-40 parts of steel slag, and 0.4-1 part of expansion agent.

[0010] In a second aspect, the present invention provides a method for preparing the expanded porous ceramic aggregate sound-absorbing board, comprising the following steps:

[0011] The phosphorus mud, waste incineration fly ash and steel slag are dried and ball-milled to obtain powder, wherein SiO2 accounts for 53%-79% and Al2O3 accounts for 15-25%, where % is mass percentage;

[0012] The powder of each raw material is mixed evenly with the expansion agent according to the proportion, and water is added to mix and granulate to obtain the aggregate blank;

[0013] The aggregate blanks are piled in a mold to form a plate shape, and then dried together with the mold, preheated at 400-500°C, heated to 1100-1200°C for sintering, and rapidly cooled after sintering to obtain an expanded porous porcelain aggregate sound-absorbing board.

[0014] The existing method for preparing aggregate sound-absorbing panels is to use solid waste and dispersants, gelling agents, foaming agents, etc. This technology has poor adaptability and has high restrictions on the components of solid waste raw materials. There is currently no relevant research on the preparation of sound-absorbing panels from phosphate mud and fly ash.

[0015] The mechanism of porous expansion of the prepared porcelain aggregate sound-absorbing board is as follows: the SiO2 content in the phosphate mud raw material is between 30% and 40%, and the Fe2O3 content is between 10% and 25%. Fe2O3 reacts with waste incineration fly ash, steel slag and C in the added expansion agent to release gases such as CO and CO2, which are wrapped by the generated liquid phase during the rapid heating stage and form a honeycomb porous structure after cooling, causing the aggregate sound-absorbing board to expand.

[0016] The temperature of the aggregate sound-absorbing board is lowered by rapid cooling, and a glass phase is formed on the surface of the sound-absorbing board during the temperature drop process, thereby obtaining better compressive strength.

[0017] The main components of waste incineration fly ash are SiO2, CaO, Al2O3 and Fe2O3, which are scientifically mixed with steel slag and mainly serve as the skeleton of aggregate sound-absorbing panels.

[0018] The role of steel slag is that the main components of steel slag are calcium oxide, magnesium oxide, etc., which can be used to lower the melting point and reduce energy consumption. In addition, steel slag and incineration fly ash are reasonably proportioned to serve as the skeleton of the aggregate sound-absorbing board.

[0019] During the high-temperature firing process, phosphorus mud, waste incineration fly ash and steel slag are scientifically proportioned to make SiO2 account for about 53%-79% and Al2O3 account for about 15-25%. The expansion agent is added. During the high-temperature firing process, the C in the raw materials reacts with Fe2O3 to release CO2 gas, which is wrapped by the glass phase and causes the sound-absorbing board to expand. The sound-absorbing board is fired at a high temperature of 1100-1200℃ and has high compressive strength.

[0020] In some embodiments, the particle size of the powder after ball milling is 80-100 mesh.

[0021] Preferably, the process conditions for ball milling are as follows: the ball mill speed is 220 to 300 r / min, the turning speed is set at 5 to 8 times / min, and the ball milling time is 30 to 50 min.

[0022] In some embodiments, the aggregate blank has a particle size of 0.5-1 cm.

[0023] In some embodiments, the expansion agent is a silicon carbide expansion agent.

[0024] In some embodiments, the preheating time at 400-500° C. is 20-35 min.

[0025] Preferably, the preheating program heating rate is 5-10℃ / min. The preheating has two main functions: on the one hand, it is to reduce the cracking of the green embryo due to the sudden temperature change caused by the temperature difference between the surface and the inside of the green embryo; on the other hand, it is to reduce the phenomenon of large pores caused by excessive gas in the green embryo. If the preheating rate is too high, the green embryo may crack, and if the preheating rate is too low, the firing time will be extended and the efficiency will be reduced.

[0026] In some embodiments, the sintering program heating rate is 10-20°C / min; the sintering holding time is 15-40min. Too high a sintering heating rate may cause the sound absorbing board to crack, while too low a heating rate may cause the internal reaction to be too slow and the expansion of the green embryo to be reduced.

[0027] In some embodiments, the rapid cooling method is: after the firing is completed, the prepared expanded porous ceramic aggregate sound-absorbing board is directly taken out from the high-temperature furnace after being kept warm for 15-40 minutes, and cooled to room temperature.

[0028] In a third aspect, the present invention provides an expanded porous ceramic aggregate sound-absorbing board prepared by the preparation method.

[0029] In some embodiments, the expanded porous ceramic aggregate sound-absorbing board has a porosity of 35-50% and a surface density of 10-35 kg / m 2 , the sound absorption coefficient is 0.6-0.9, and the expansion multiple is 0.5-3.

[0030] Porosity is the percentage of pore volume in a bulk material to the total volume of the material in its natural state.

[0031] Areal density is the mass per unit area of ​​an object with a specified thickness of 8-12 mm.

[0032] The sound absorption coefficient is a quantity that indicates the performance of a sound-absorbing material or structure. Different materials have different sound absorption capabilities. When the sound absorption coefficient is 0, it means that the sound is fully reflected and the material does not absorb sound; when the sound absorption coefficient is 1, it means that the material absorbs all sound energy and there is no reflection. The sound absorption coefficient of general materials is between 0 and 1. The larger the sound absorption coefficient, the better the sound absorption performance of the material.

[0033] In a fourth aspect, the present invention provides the use of the expanded porous ceramic aggregate sound-absorbing board in sound insulation and noise reduction in subways, tunnels or highways.

[0034] The beneficial effects achieved by one or more embodiments of the present invention are as follows:

[0035] (1) The raw materials of the expanded porous porcelain aggregate sound-absorbing board prepared by the present invention are all from solid waste, which can greatly absorb solid waste, realize the high-value resource utilization of solid waste, and greatly save natural resources.

[0036] (2) The present invention utilizes steel slag as an alkali activator. During the high-temperature firing process, pollutants such as heavy metals in phosphorus mud and waste incineration fly ash are fixed in the sound-absorbing board, thereby achieving harmless solid waste treatment.

[0037] (3) Compared with cement-based sound-absorbing materials, the expanded porous ceramic aggregate sound-absorbing board prepared by the present invention has higher porosity (35% to 50%) and compressive strength. The porous characteristics of the sound-absorbing board inside improve the sound absorption performance in medium and low frequency environments, and the carbon emissions during the preparation process are much lower than those of cement-based sound-absorbing materials, which has significant carbon emission reduction significance. DETAILED DESCRIPTION

[0038] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0039] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0040] Example 1

[0041] A method for preparing an expanded porous porcelain aggregate sound-absorbing board, the specific steps are as follows:

[0042] (1) 40 parts by weight of phosphorus mud, 10 parts by weight of waste incineration fly ash, and 50 parts by weight of steel slag were dried at 100° C. for 12 hours to reduce the moisture content in the raw materials to less than 0.5%.

[0043] (2) The ball mill is set to rotate at 220 r / min and the turning speed is set at 7 times / min. The dried raw material is placed in the ball mill and ball-milled for 35 min. The raw material is then filtered and sieved to obtain a powder of 80-100 mesh.

[0044] (3) The powder is mixed evenly with 0.4 parts by mass of a silicon carbide expansion agent to obtain a mixed material.

[0045] (4) Add water to the above mixed material with a water-cement ratio of 0.5:1, and granulate to obtain a porcelain aggregate blank. The particle size of the porcelain aggregate blank is 0.5 cm.

[0046] (5) The aggregate blanks are tightly stacked in a 600*600*8mm aluminum silicate fiber mold to form a plate-shaped aggregate blank.

[0047] (6) Drying the plate-shaped aggregate embryo together with the aluminum silicate fiber mold at 100° C. for 6 hours.

[0048] (7) The dried plate-shaped aggregate blank and the mold are placed in a high-temperature furnace, heated to 400°C at a heating rate of 5°C / min for preheating, and kept at this temperature for 25 minutes. Then, the temperature is raised to 1100°C at a rate of 10°C / min for sintering, and kept at this temperature for 30 minutes.

[0049] (8) After the high-temperature firing is completed, the sintered plate is placed at room temperature for rapid cooling to obtain an expanded porous ceramic aggregate sound-absorbing plate with a size of 600*600*8mm.

[0050] The sound absorption coefficient was tested using an AWA 6128 standing wave tube sound absorption coefficient tester in accordance with the "Standing Wave Tube Sound Absorption Coefficient and Acoustic Impedance Measurement Specification" (GBJ 88-85).

[0051] The expansion multiple of the ceramic aggregate sound-absorbing board prepared in this embodiment is 1.7, the porosity is 36.1%, and the surface density (thickness is 8 mm) is 11.6 kg / m 2, sound absorption coefficient is 0.75 and compressive strength is 5.1MPa.

[0052] Example 2

[0053] A method for preparing an expanded porous porcelain aggregate sound-absorbing board, the specific steps are as follows:

[0054] (1) 55 parts by weight of phosphorus mud, 15 parts by weight of waste incineration fly ash, and 29 parts by weight of steel slag were dried at 110° C. for 6 hours to reduce the moisture content in the raw materials to less than 0.5%.

[0055] (2) The ball mill is set to rotate at 250 r / min and the turning speed is set at 7 times / min. The dried raw material is placed in the ball mill and ball-milled for 40 min. The raw material is then filtered and sieved to obtain a powder of 80-100 mesh.

[0056] (3) The powder is mixed evenly with 1 part by mass of a silicon carbide expansion agent to obtain a mixed material.

[0057] (4) Add water to the above mixed material with a water-cement ratio of 0.8:1, and granulate to obtain a porcelain aggregate blank.

[0058] (5) The aggregate blanks are tightly stacked in a 600*600*8mm aluminum silicate fiber mold to form a plate-shaped aggregate blank.

[0059] (6) Drying the plate-shaped aggregate embryo together with the aluminum silicate fiber mold at 110° C. for 6 hours.

[0060] (7) The dried plate-shaped aggregate blank and the mold are placed in a high-temperature furnace, heated to 500°C at a heating rate of 10°C / min for preheating, and kept at this temperature for 30 minutes. Then, the temperature is increased to 1180°C at a rate of 20°C / min for sintering, and kept at this temperature for 30 minutes.

[0061] (8) After the high-temperature firing is completed, the sintered plate is placed at room temperature for rapid cooling to obtain an expanded porous ceramic aggregate sound-absorbing plate.

[0062] The expansion multiple of the ceramic aggregate sound-absorbing board prepared in this embodiment is 2.7, the porosity is 47.3%, and the surface density (thickness is 1.2 cm) is 30.4 kg / m 2 , the sound absorption coefficient is 0.83 and the compressive strength is 7.4MPa.

[0063] Example 3

[0064] A method for preparing an expanded porous porcelain aggregate sound-absorbing board, the specific steps are as follows:

[0065] (1) 47 parts by weight of phosphorus mud, 22 parts by weight of waste incineration fly ash, and 31 parts by weight of steel slag were dried at 105° C. for 8 hours to reduce the moisture content in the raw materials to less than 0.5%.

[0066] (2) The ball mill is set to rotate at 300 r / min and the turning speed is set at 8 times / min. The dried raw material is placed in the ball mill and ball-milled for 40 min. The raw material is then filtered and sieved to obtain a powder of 80-100 mesh.

[0067] (3) The powder is mixed evenly with 0.8 parts by mass of a silicon carbide expansion agent to obtain a mixed material.

[0068] (4) Add water to the above mixed material and granulate it to obtain a porcelain aggregate blank.

[0069] (5) The aggregate blanks are tightly stacked in a 600*600*8mm aluminum silicate fiber mold to form a plate-shaped aggregate blank.

[0070] (6) Drying the plate-shaped aggregate embryo together with the aluminum silicate fiber mold at 105° C. for 6 hours.

[0071] (7) The dried plate-shaped aggregate blank and the mold are placed in a high-temperature furnace, heated to 450°C at a heating rate of 10°C / min for preheating, and kept at this temperature for 30 minutes. Then, the temperature is raised to 1150°C at a rate of 15°C / min for sintering, and kept at this temperature for 35 minutes.

[0072] (8) After the high-temperature firing is completed, the sintered plate is placed at room temperature for rapid cooling to obtain an expanded porous ceramic aggregate sound-absorbing plate.

[0073] The expansion multiple of the ceramic aggregate sound-absorbing board prepared in this embodiment is 2.1, the porosity is 39.4%, and the surface density (thickness is 1 cm) is 25.8 kg / m 2 , the sound absorption coefficient is 0.79 and the compressive strength is 6.7MPa.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An expanded porous porcelain aggregate sound-absorbing board, characterized in that: The materials include the following components by weight: 35-60 parts of phosphorus mud, 10-25 parts of waste incineration fly ash, 10-55 parts of steel slag, and 0.4-1 part of expansion agent.

2. The expanded porous porcelain aggregate sound-absorbing board according to claim 1, characterized in that: The materials include the following components by weight: 35-60 parts of phosphorus mud, 15-25 parts of waste incineration fly ash, 20-40 parts of steel slag, and 0.4-1 part of expansion agent.

3. The method for preparing the expanded porous porcelain aggregate sound-absorbing board according to claim 1 or 2, characterized in that: The steps include: The phosphorus mud, waste incineration fly ash and steel slag are dried and ball-milled to obtain powder, in which SiO2 accounts for 53%-79% and Al2O3 accounts for 15-25%, where % is the mass percentage; The powder of each raw material is mixed evenly with the expansion agent according to the proportion, and water is added to mix and granulate to obtain the aggregate blank; The aggregate blanks are piled in a mold to form a plate shape, and then dried together with the mold, preheated at 400-500°C, heated to 1100-1200°C for sintering, and rapidly cooled after sintering to obtain an expanded porous porcelain aggregate sound-absorbing board.

4. The method for preparing the expanded porous porcelain aggregate sound-absorbing board according to claim 3, characterized in that: The particle size of the powder after ball milling is 80-100 mesh; Preferably, the process conditions for ball milling are as follows: the ball mill speed is 220 to 300 r / min, the turning speed is set at 5 to 8 times / min, and the ball milling time is 30 to 50 min.

5. The method for preparing the expanded porous porcelain aggregate sound-absorbing board according to claim 3, characterized in that: The particle size of the aggregate blank is 0.5-1 cm.

6. The method for preparing the expanded porous porcelain aggregate sound-absorbing board according to claim 3, characterized in that: The holding time for preheating at 400-500℃ is 20-35min; Preferably, the preheating program heating rate is 5-10°C / min.

7. The method for preparing the expanded porous porcelain aggregate sound-absorbing board according to claim 3, characterized in that: The program heating rate of sintering is 10-20℃ / min; the holding time of sintering is 15-40min; Alternatively, the rapid cooling method is: after the firing is completed, the prepared expanded porous porcelain aggregate sound-absorbing board is directly taken out from the high-temperature furnace after being kept warm for 15-40 minutes, and cooled to room temperature.

8. An expanded porous porcelain aggregate sound-absorbing board, characterized in that: Prepared by the preparation method described in any one of claims 3-7.

9. The expanded porous porcelain aggregate sound-absorbing board according to claim 8, characterized in that: The expanded porous porcelain aggregate sound-absorbing board has a porosity of 35-50% and a surface density of 10-35 kg / m 2 , the sound absorption coefficient is 0.6-0.9, and the expansion multiple is 0.5-3.

10. Use of the expanded porous vitrified aggregate sound-absorbing board according to claim 8 or 9 in sound insulation and noise reduction in subways, tunnels or highways.