A process for producing aluminum silicate ceramic fiber by recycling hazardous waste fly ash

Abstract

The present invention relates to a process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash, which belongs to the technical field of resource utilization of solid waste, and includes the following steps: obtaining fly ash and additives, formulating a melting compounding scheme according to the material composition; determining the process formula according to the melting compounding scheme, and then desalting the fly ash; transporting the fly ash and additives to the weighing bin, inputting the process formula into the program, and the system adopts PLC control for automatic metering, batching, and unloading; then melting at high temperature at 2100-2800℃ to form a magma body; testing the composition of the magma body, and conducting acid leaching toxicity testing; spinning into fibers, and obtaining. In the high-temperature melting process, dioxins are effectively decomposed, and most of the heavy metals are solidified in the aluminum silicate ceramic fiber. The aluminum silicate ceramic fiber cotton formed by the acupuncture operation, drying, shaping, and cutting and rolling of the aluminum silicate ceramic fiber meets the GB / T 16400-2023 standard.

Description

Technical Field

[0001] The invention belongs to the technical field of resource utilization of solid waste, and specifically relates to a process for producing aluminum silicate ceramic fibers by resource utilization of hazardous waste fly ash. Background Art

[0002] At present, the main methods for harmless treatment of garbage fly ash at home and abroad include cement solidification, sintering solidification, melt solidification and agent stabilization. Among them, the melt solidification treatment technology is to mix the fly ash with additives and then melt it at a high temperature of 1000-1600℃. It can effectively decompose dioxins in fly ash, has a high volume reduction rate, and heavy metals form stable compounds during high-temperature melting. It is currently the most widely used fly ash treatment method. At present, high-temperature melted fly ash is often used to form mineral fibers, which can be used as building insulation materials, so that fly ash can be utilized as a resource. However, there are few reports on the technology of melting fly ash into aluminum silicate ceramic fibers through high-temperature melting technology. Summary of the invention

[0003] The purpose of the present invention is to provide a process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash, wherein fly ash and additives are compounded in a process, and then subjected to high-temperature melting treatment at 2100-2800°C in an electric arc furnace to obtain aluminum silicate ceramic fiber. In the high-temperature melting process, dioxins in the fly ash are effectively decomposed, heavy metals are solidified in the aluminum silicate ceramic fiber, and the magma body formed after high-temperature melting flows through a fiber forming system and is spun into fibers to form aluminum silicate ceramic fiber. The aluminum silicate ceramic fiber cotton formed by needle punching, drying, shaping, cutting and rolling of the aluminum silicate ceramic fiber meets the GB / T 16400-2023 standard.

[0004] The technical problem to be solved by the present invention is that the prior art often utilizes high-temperature melting of fly ash to form mineral fibers, but there are few reports on the technology of melting fly ash to form aluminum silicate ceramic fibers through high-temperature melting technology.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash comprises the following steps:

[0007] A1. Obtain fly ash and additive raw materials, and formulate a melting compounding plan based on the material components in the fly ash and additives;

[0008] Furthermore, in step A1, the additives are kaolin, slag, talc, coal gangue and dolomite.

[0009] Furthermore, the slag is blast furnace slag or waste incineration slag.

[0010] A2. Determine the process formula according to the melting compounding scheme, then desalt the fly ash and dry it;

[0011] Furthermore, in step A2, the process formula is: by weight, 25-50 parts of fly ash, 13-20 parts of kaolin, 8-15 parts of slag, 6-11 parts of talc, 20-35 parts of coal gangue and 1-6 parts of dolomite.

[0012] Furthermore, in step A2, the desalination pretreatment is to wash the fly ash with water through a multi-stage countercurrent water washing process.

[0013] A3. Use fully sealed conveying method to transport fly ash and additives to the weighing bin, input the process formula into the program, and the system uses PLC to control automatic metering, batching and unloading;

[0014] A4. The fly ash and additives are uniformly fed into the kiln through the sealed ash unloading system discharge port, melted at a high temperature of 2100-2800℃ to form a magma body, and the flue gas is treated;

[0015] A5. Conduct composition test on magma body and acid leaching toxicity test;

[0016] A6. When the composition of the magma body meets the fiber requirements, the magma body flows out through the outlet to the first roller of the spinning machine, and is spun into fibers to obtain aluminum silicate ceramic fibers.

[0017] Furthermore, in step A6, during the spinning and fiberizing process, the rotation speed is 7000-10000 r / min.

[0018] During the above operation, the present invention uses kaolin, slag, talc, coal gangue and dolomite as additives and mixes them with fly ash, and obtains aluminum silicate ceramic fiber by high-temperature melting at 2100-2800°C. The fly ash and the additives are reasonably matched to obtain a magma body with good fluidity and easy spin-forming. The magma body flows through the fiber-forming system and is spun into fibers to form aluminum silicate ceramic fibers. The aluminum silicate ceramic fiber cotton formed by cotton collection, needle punching, drying, shaping and cutting and rolling meets the GB / T 16400-2023 standard.

[0019] Beneficial effects of the present invention:

[0020] (1) In the technical scheme of the present invention, kaolin, slag, talc, coal gangue and dolomite are mixed with fly ash as additives, and aluminum silicate ceramic fibers are obtained by high-temperature melting at 2100-2800°C. A magma body with good fluidity and easy spin-forming is obtained by reasonable matching of fly ash and additives. The magma body flows through a fiber-forming system and is spun into fibers to form aluminum silicate ceramic fibers. The aluminum silicate ceramic fibers are subjected to cotton collection, needle punching, drying, shaping and cutting and rolling to form aluminum silicate ceramic fiber wool that meets the GB / T 16400-2023 standard.

[0021] (2) In the technical solution of the present invention, fly ash is mixed with additives and melted at high temperature to obtain aluminum silicate ceramic fibers. The fly ash is utilized as a resource, and the heavy metal leaching concentration of the obtained aluminum silicate ceramic fibers is much lower than the GB 5085.3-2007 standard. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] A process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash comprises the following steps:

[0025] A1. Obtain fly ash and kaolin, waste incineration slag, talc, coal gangue and dolomite raw materials, and formulate a melting compounding plan based on the material components in the fly ash and additives;

[0026] A2. Determine the process formula according to the melting compounding scheme (by weight, 30 parts of fly ash, 16 parts of kaolin, 10 parts of garbage incineration slag, 7 parts of talc, 35 parts of coal gangue and 2 parts of dolomite), then perform three-stage countercurrent water washing on the fly ash, and dry the last stage of water-washed fly ash;

[0027] A3. Use a fully sealed conveying method to transport fly ash, kaolin, waste incineration slag, talc, coal gangue and dolomite to the weighing bin, input the process formula into the program, and the system uses PLC to control automatic metering, batching and unloading;

[0028] A4. The obtained pellets are uniformly fed into the kiln through the sealed ash unloading system discharge port. There are three 700-type molybdenum electrodes in the kiln pool. The temperature is raised to 2100°C. The pellets are melted at high temperature to form magma, and the flue gas is treated at the same time.

[0029] A5. Conduct composition test on magma body and acid leaching toxicity test;

[0030] A6. When the composition of the magma meets the fiber requirements, the magma flows out through the outlet to the first roller of the spinning machine (rotation speed is 7000r / min). Under the action of high-speed centrifugal force, the magma forms a thin layer of slurry on the surface of the centrifugal roller and extends outward into fibrous cotton yarn, thus obtaining aluminum silicate ceramic fiber.

[0031] Example 2

[0032] A process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash comprises the following steps:

[0033] A1. Obtain fly ash and kaolin, blast furnace slag, talc, coal gangue and dolomite raw materials, and formulate a melting compounding plan based on the material components in the fly ash and additives;

[0034] A2, according to the melting compounding scheme, the process formula is determined (by weight, 35 parts of fly ash, 15 parts of kaolin, 9 parts of blast furnace slag, 11 parts of talc, 25 parts of coal gangue and 5 parts of dolomite), and then the fly ash is subjected to three-stage countercurrent washing, and the last stage of washed fly ash is dried;

[0035] A3. Use fully sealed conveying method to transport fly ash, kaolin, blast furnace slag, talc, coal gangue and dolomite to the weighing bin, input the process formula into the program, and the system uses PLC to control automatic measurement, batching and unloading;

[0036] A4. The obtained pellets are uniformly fed into the kiln through the sealed ash unloading system discharge port. There are three 700-type molybdenum electrodes in the kiln pool. The temperature is raised to 2300°C. The pellets are melted at high temperature to form magma, and the flue gas is treated at the same time.

[0037] A5. Conduct composition test on magma body and acid leaching toxicity test;

[0038] A6. When the composition of the magma meets the fiber requirements, the magma flows out through the outlet to the first roller of the spinning machine (rotation speed is 8000r / min). Under the action of high-speed centrifugal force, the magma forms a thin layer of slurry on the surface of the centrifugal roller and extends outward into fibrous cotton yarn, thus obtaining aluminum silicate ceramic fiber.

[0039] Example 3

[0040] A process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash comprises the following steps:

[0041] A1. Obtain fly ash and kaolin, waste incineration slag, talc, coal gangue and dolomite raw materials, and formulate a melting compounding plan based on the material components in the fly ash and additives;

[0042] A2. Determine the process formula according to the melting compounding scheme (by weight, 35 parts of fly ash, 14 parts of kaolin, 13 parts of garbage incineration slag, 8 parts of talc, 27 parts of coal gangue and 3 parts of dolomite), then perform three-stage countercurrent washing on the fly ash, and dry the last stage of washed fly ash;

[0043] A3. Use a fully sealed conveying method to transport fly ash, kaolin, waste incineration slag, talc, coal gangue and dolomite to the weighing bin, input the process formula into the program, and the system uses PLC to control automatic metering, batching and unloading;

[0044] A4. The obtained pellets are uniformly fed into the kiln through the sealed ash unloading system discharge port. There are three 700-type molybdenum electrodes in the kiln pool. The temperature is raised to 2500°C. The pellets are melted at high temperature to form magma, and the flue gas is treated at the same time.

[0045] A5. Conduct composition test on magma body and acid leaching toxicity test;

[0046] A6. When the composition of the magma meets the fiber requirements, the magma flows out through the outlet to the first roller of the spinning machine (rotation speed is 8000r / min). Under the action of high-speed centrifugal force, the magma forms a thin layer of slurry on the surface of the centrifugal roller and extends outward into fibrous cotton yarn, thus obtaining aluminum silicate ceramic fiber.

[0047] Example 4

[0048] A process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash comprises the following steps:

[0049] A1. Obtain fly ash and kaolin, waste incineration slag, talc, coal gangue and dolomite raw materials, and formulate a melting compounding plan based on the material components in the fly ash and additives;

[0050] A2. Determine the process formula according to the melting compounding scheme (by weight, 40 parts of fly ash, 13 parts of kaolin, 8 parts of garbage incineration slag, 8 parts of talc, 30 parts of coal gangue and 1 part of dolomite), then perform three-stage countercurrent washing on the fly ash, and dry the last stage of washed fly ash;

[0051] A3. Use a fully sealed conveying method to transport fly ash, kaolin, waste incineration slag, talc, coal gangue and dolomite to the weighing bin, input the process formula into the program, and the system uses PLC to control automatic metering, batching and unloading;

[0052] A4. The obtained pellets are uniformly fed into the kiln through the sealed ash unloading system discharge port. There are three 700-type molybdenum electrodes in the kiln pool. The temperature is raised to 2600°C. The pellets are melted at high temperature to form magma, and the flue gas is treated at the same time.

[0053] A5. Conduct composition test on magma body and acid leaching toxicity test;

[0054] A6. When the composition of the magma meets the fiber requirements, the magma flows out through the outlet to the first roller of the spinning machine (rotation speed is 9000r / min). Under the action of high-speed centrifugal force, the magma forms a thin layer of slurry on the surface of the centrifugal roller and extends outward into fibrous cotton yarn, thus obtaining aluminum silicate ceramic fiber.

[0055] Example 5

[0056] A process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash comprises the following steps:

[0057] A1. Obtain fly ash and kaolin, blast furnace slag, talc, coal gangue and dolomite raw materials, and formulate a melting compounding plan based on the material components in the fly ash and additives;

[0058] A2. Determine the process formula according to the melting compounding scheme (by weight, 50 parts of fly ash, 13 parts of kaolin, 8 parts of blast furnace slag, 6 parts of talc, 20 parts of coal gangue and 3 parts of dolomite), then perform three-stage countercurrent washing on the fly ash, and dry the last stage of washed fly ash;

[0059] A3. Use fully sealed conveying method to transport fly ash, kaolin, blast furnace slag, talc, coal gangue and dolomite to the weighing bin, input the process formula into the program, and the system uses PLC to control automatic measurement, batching and unloading;

[0060] A4. The obtained pellets are uniformly fed into the kiln through the sealed ash unloading system discharge port. There are three 700-type molybdenum electrodes in the kiln pool. The temperature is raised to 2800°C. The pellets are melted at high temperature to form magma, and the flue gas is treated at the same time.

[0061] A5. Conduct composition test on magma body and acid leaching toxicity test;

[0062] A6. When the composition of the magma meets the fiber requirements, the magma flows out through the outlet to the first roller of the spinning machine (rotation speed is 10000r / min). Under the action of high-speed centrifugal force, the magma forms a thin layer of slurry on the surface of the centrifugal roller and extends outward into fibrous cotton yarn, thus obtaining aluminum silicate ceramic fiber.

[0063] Comparative Example 1

[0064] Compared with Example 3, Comparative Example 1 does not contain coal gangue, and other steps and raw materials are the same as those of Example 3.

[0065] The aluminum silicate ceramic fiber wool obtained in Examples 1-5 and Comparative Example 1 is formed by needle punching, drying, shaping, cutting and curling. The specific operations are as follows:

[0066] The aluminum silicate ceramic fiber is thrown to the front section with the blowing wind, and is captured on the panel by the triangular cotton collecting system under the action of negative pressure wind to form a uniform primary cotton felt; the primary cotton felt enters the needling system through the conveyor, and is double-sided needling (frequency is 60 times / min), which increases the tension of the primary cotton felt, and is trimmed on both sides at the same time, and the scraps are crushed and recycled into the cotton collecting box for reuse; after the needling is completed, it is sent to the 34-meter drying system, which is composed of 16 groups of electric heating rods in the hot air zone, and is baked and shaped at a temperature of 500°C for 30 minutes; during the transportation process of the shaped fiber roll felt, the meter counting system automatically measures the length according to the set parameters, and outputs a signal after 3600mm, and the roll felt is cut by the gate knife to make a roll felt with a size range of 3600mm×610mm×50mm, thus obtaining aluminum silicate ceramic fiber cotton.

[0067] Performance Testing

[0068] The aluminum silicate ceramic fiber wool prepared in the above Examples 1-5 and Comparative Example 1 was tested for performance according to GB / T16400-2023 standard, and the results are shown in Table 1; the acid leaching toxicity was tested according to GB 5085.3-2007 standard, and the results are shown in Table 2; the chemical composition of the aluminum silicate ceramic fiber is shown in Table 3.

[0069] Table 1

[0070]

[0071]

[0072] Table 2

[0073]

[0074]

[0075] Table 3

[0076]

[0077] From the data in Table 1, it can be seen that the aluminum silicate ceramic fiber wool produced meets the GB / T16400-2023 standard, and the compressive strength can reach 87kPa. From the data in Table 2, it can be seen that the heavy metals are stably fixed in the aluminum silicate ceramic fiber, and the heavy metal acid leaching concentration is much lower than the GB 5085.3-2007 standard. From the data in Table 3, it can be seen that the calcium present in the raw material is volatilized into the flue gas after high-temperature melting treatment at 2100-2800℃, and the CaO content remaining in the fiber is as low as 0.47%, thereby forming aluminum silicate ceramic fiber with high silicon and aluminum content.

[0078] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0079] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A process for producing aluminum silicate ceramic fiber by recycling hazardous waste fly ash, characterized in that: The following steps are involved: A1. Obtain fly ash and additive raw materials, and formulate a melting compounding scheme according to the material components in the fly ash and additives; the additives are kaolin, slag, talc, coal gangue and dolomite; A2. Determine the process formula according to the melting compounding scheme, then desalt the fly ash and dry it; the process formula is: by weight, 25-50 parts of fly ash, 13-20 parts of kaolin, 8-15 parts of slag, 6-11 parts of talc, 20-35 parts of coal gangue and 1-6 parts of dolomite; A3. Use fully sealed conveying method to transport fly ash and additives to the weighing bin, input the process formula into the program, and the system uses PLC to control automatic metering, batching and unloading; A4. The fly ash and additives are uniformly fed into the kiln through the sealed ash unloading system discharge port, melted at a high temperature of 2100-2800℃ to form a magma body, and the flue gas is treated; A5. Conduct composition test on magma body and acid leaching toxicity test; A6. Spin the fibers to obtain aluminum silicate ceramic fibers.

2. The process for producing aluminum silicate ceramic fiber by recycling hazardous waste fly ash according to claim 1, characterized in that: The slag is blast furnace slag or garbage incineration slag.

3. The process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash according to claim 1 is characterized in that: In step A2, the process formula is: by weight, 25-40 parts of fly ash, 13-18 parts of kaolin, 10-15 parts of slag, 6-8 parts of talc, 25-35 parts of coal gangue and 1-4 parts of dolomite.

4. The process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash according to claim 1 is characterized in that: In the step A2, the desalination pretreatment is to wash the fly ash with water through a multi-stage countercurrent washing process.

5. The process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash according to claim 1 is characterized in that: In the step A6, during the spinning process, the rotation speed is 7000-10000 r / min.

6. The process for producing aluminum silicate ceramic fiber by resource utilization of hazardous waste fly ash according to claim 1 is characterized in that: In the step A6, during the spinning process, the rotation speed is 8000-10000 r / min.

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