Hollow fibers in incinerated ash and their manufacturing method

Abstract

This invention provides hollow fibers in incinerated ash and a method for producing the same. [Solution] The present invention provides a method for producing hollow fibers from incinerated ash, comprising: selecting incinerated ash in which the content of calcium element is greater than the content of silicon element in the elemental composition; mixing the selected incinerated ash with an organic solvent and a polymer to form a spinning solution; spinning the spinning solution using a wet-dry spinning method in a spinning apparatus to form a hollow fiber precursor; and sintering the hollow fiber precursor at a sintering temperature of 1100°C to 1200°C to form hollow fibers made of incinerated ash. Here, the specific surface area S of the hollow fibers from incinerated ash. BET is 0.1m 2 / g~0.5m 2 / g is the average pore size D of the micropores. p The range is 450nm to 850nm.

Description

[Technical Field]

[0001] The present invention relates to hollow fibers, and more particularly to hollow fibers from incinerated bottom ash and a method for producing the same. [Background technology]

[0002] Human life generates a large amount of waste every day, and statistics show that Taiwan needs to process several thousand tons of waste daily. Incineration of this waste produces a large amount of incinerated ash. Traditionally, this ash has been used primarily as a building material, such as by mixing it with cement or tiles to make sidewalks. However, due to regional constraints (such as areas designated for soil and water quality conservation), the reuse of this incinerated ash is limited, and some of it must be disposed of through landfill or other means, increasing the environmental burden.

[0003] Furthermore, the composition of incinerated ash is complex, containing various metallic and non-metallic elements such as silicon, aluminum, calcium, iron, and magnesium. In the past, techniques have been used to extract valuable metals such as aluminum and silicon from incinerated ash, but these methods usually only recover a portion of the metal, leaving a large amount of waste after extraction, and thus failing to completely solve the problem of incinerated ash treatment. [Overview of the project] [Problems that the invention aims to solve]

[0004] This invention primarily aims to improve upon the problems present in existing technologies, explore novel recycling methods and application methods for incinerator ash, and provide hollow fibers for incinerator ash and a method for manufacturing the same. [Means for solving the problem]

[0005] One aspect of the present invention provides a method for producing hollow fibers from incinerated ash. The method for producing hollow fibers from incinerated ash includes: a selection process, which includes selecting incinerated ash in which the content of calcium element is greater than the content of silicon element in its elemental composition; a spinning solution production process, which includes mixing the selected incinerated ash with an organic solvent and a polymer to form a spinning solution; and a hollow fiber production process, which includes spinning the spinning solution in a spinning apparatus using a wet-dry spinning method to form a hollow fiber precursor, and sintering the hollow fiber precursor at a sintering temperature of 1100°C to 1200°C to form hollow fibers made of incinerated ash.

[0006] Another aspect of the present invention provides incinerator ash hollow fibers manufactured by the method according to the above aspect. The calcium content in the elemental composition of the incinerator ash hollow fibers is greater than the silicon content, and the specific surface area S of the incinerator ash hollow fibers is BET is 0.1m 2 / g~0.5m 2 / g is the average pore size D of the micropores. p The range is 450nm to 850nm. [Effects of the Invention]

[0007] As described above, the hollow fibers of incinerated ash and the method for producing the same according to the present invention have the following technical features: "selecting incinerated ash in which the content of calcium element in the elemental composition is greater than the content of silicon element," "mixing the selected incinerated ash with an organic solvent and a polymer to form a spinning solution," and "spinning the spinning solution using a wet-dry spinning method in a spinning apparatus to form a hollow fiber precursor, and sintering the hollow fiber precursor at a sintering temperature of 1100°C to 1200°C to form hollow fibers made of the incinerated ash." Through these technical features, incinerated ash can be produced as hollow fibers with relatively high economic value.

[0008] Furthermore, this invention allows for the formation of hollow fibers at a lower sintering temperature without the need for additional flux by selecting incinerated bottom ash with a high calcium content and imparting flux properties, thereby reducing energy consumption and costs. Compared to conventional technologies that require advanced silicon raw material purification and the addition of multiple auxiliary agents, this invention directly uses bottom ash with a specific composition, shortening the process and improving feasibility. A spinning solution is prepared by uniformly dispersing the bottom ash powder in an organic solvent and a high-molecular-weight polymer, forming a hollow fiber precursor by wet-dry spinning, and stably solidifying the fibers at a relatively low sintering temperature, achieving a uniform pore distribution and appropriate pore size. The final product maintains good structure and mechanical strength even under low-temperature sintering conditions, has the ability to adsorb impurities, is beneficial for water treatment and wastewater purification applications, and facilitates separation of the aqueous phase, significantly improving economic benefits and practical value. [Brief explanation of the drawing]

[0009] [Figure 1] This is a flowchart of a method for manufacturing hollow fibers according to an embodiment of the present invention. [Figure 2] This is a spectral diagram obtained by analyzing the incinerated bottom ash selected according to an embodiment of the present invention using scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS). [Figure 3] This is a schematic diagram of a spinning apparatus according to an embodiment of the present invention. [Figure 4] This is a schematic diagram of a hollow fiber incinerator ash according to an embodiment of the present invention. [Figure 5A] This is a scanning electron microscope (SEM) image (magnification 50x) of a cross-section of a hollow fiber produced from the spinning solution of Example 1 of the present invention without ball milling. [Figure 5B] This is a scanning electron microscope (SEM) image (magnification 200x) of a cross-section of a hollow fiber produced from the spinning solution of Example 1 of the present invention without ball milling. [Figure 6A] This is a scanning electron microscope (SEM) image (magnification 50x) of a cross-section of a hollow fiber produced under the conditions of ball milling from the spinning solution of Example 2 of the present invention. [Figure 6B]This is a scanning electron microscope (SEM) image (magnification 200x) of a cross-section of a hollow fiber produced under the conditions of ball milling from the spinning solution of Example 2 of the present invention. [Figure 7] This is a scanning electron microscope (SEM) image (magnification 10,000x) of a hollow fiber manufactured under the conditions of a sintering temperature of 1200°C according to Example 2 of the present invention. [Figure 8] This is a scanning electron microscope (SEM) image (magnification 10,000x) of a hollow fiber manufactured under the conditions of a sintering temperature of 1150°C according to Example 3 of the present invention. [Modes for carrying out the invention]

[0010] To better understand the features and technical content of the present invention, the following detailed description and drawings of the present invention will be referenced; however, the provided description and drawings are for reference and illustrative purposes only and do not limit the present invention.

[0011] In the following explanations, when there are phrases such as "consider specific drawings" or "as shown in specific drawings," these are merely to emphasize that the content of the subsequent explanations is generally described in those specific drawings, and other drawings may also be consulted.

[0012] It should be understood that while this specification may use terms such as “First,” “Second,” and “Third” to describe various materials or properties, these materials or properties are not limited by these terms. These terms are primarily used to distinguish one material from another, or one property from another. Furthermore, the term “or” as used herein may, depending on the context, include any one or more combinations of the items listed in relation to the subject.

[0013] It should be noted that in this specification, when the numerical range of a parameter is described as being between one numerical value and another numerical value, it should be understood that both end values are included in that numerical range. In other words, unless explicitly stated or a different meaning can be inferred from the context, the numerical range includes the stated value on one side and the stated value on the other side. This explanation aims to clarify the scope of the technology and avoid unnecessary restrictions due to different interpretations.

[0014] [Method for manufacturing hollow fibers with incineration main ash] As shown in FIG. 1, in an embodiment of the present invention, a manufacturing method for manufacturing hollow fibers with incineration main ash is provided, which includes step S110, step S120, step S130, and step S140. It should be noted that the order and actual operation method of each step in this embodiment can be adjusted as needed and are not limited to those described in the embodiment.

[0015] Step S110 is a sorting operation that includes finding the source of incineration main ash and sorting out incineration main ash in which the content of calcium element in the elemental composition is greater than the content of silicon element. Here, the incineration main ash is generated after burning garbage.

[0016] In a certain embodiment of the present invention, the elemental composition of the selected incineration main ash must satisfy the following conditions after analysis by scanning electron microscope energy dispersive X-ray spectroscopy (SEM-EDS). (1) The weight percentage concentration of calcium element is 15 wt% or more, preferably 20 wt% or more, particularly preferably 25 wt% or more, and (2) the weight ratio of the weight percentage concentration of calcium element to the weight percentage concentration of silicon element (calcium (Ca) / silicon (Si)) is 2 or more, preferably 4 or more, particularly preferably 8 or more. The analysis parameters of the scanning electron microscope are as follows: a scanning electron microscope (SEM: Hitachi S-3400N) is used, the electron gun is a tungsten filament, and the acceleration voltage is 15.0 kV. The SEM-EDS analysis method may be based on, for example, ASTM E1508-12a, but is not limited thereto.

[0017] In addition, the elemental composition of the incineration main ash also contains other trace metal elements such as aluminum element, sodium element, magnesium element, molybdenum element, or iron element. The weight percentage concentration of the calcium element is higher than the weight percentage concentration of any trace metal element, but the present invention is not limited thereto.

[0018] In a certain embodiment of the present invention, the weight percentage concentration of calcium element in the selected incineration main ash is 25 wt% to 40 wt% (for example, 30 to 33 wt%), the weight percentage concentration of silicon element is 1 wt% to 10 wt% (for example, 2 to 3 wt%), and the weight ratio of calcium (Ca) to silicon (Si) (calcium (Ca) / silicon (Si)) is 10 to 15, but the present invention is not limited thereto.

[0019] Figure 2 is a spectrum diagram obtained by analyzing the selected incineration main ash in an embodiment of the present invention by scanning electron microscope energy dispersive X-ray spectroscopy (SEM-EDS), showing characteristic energy peaks of the elements contained in the incineration main ash.

[0020] Here, the Ca (calcium) peak is prominent, with a significant Ca energy peak at the high energy end (approximately 3.69 keV), indicating a high calcium content in the incineration ash. Calcium is one of the most characteristic and abundant elements in this ash. Regarding the Si (silicon) peak, an energy peak for Si is observed at approximately 1.74 keV, indicating that the ash contains silicate compounds, but in a lower proportion than calcium. Elements such as Al (aluminum), Na (sodium), Mg (magnesium), and Mo (molybdenum) have relatively small peak values, indicating that their content is relatively low compared to calcium and silicon. The spectrum shows an O (oxygen) peak, which indicates that at least some of the metallic elements exist in oxide form. In the elemental composition of the incineration ash, the weight percentage concentration of calcium is 31.69 wt%, the weight percentage concentration of silicon is 2.57 wt%, and the weight percentage concentration of aluminum is 1.1 wt%.

[0021] Furthermore, the calcium element in the incinerated bottom ash originates from calcium compounds such as calcium oxide (CaO) and calcium hydroxide (Ca(OH)2), the silicon element originates from silicon compounds such as silicon dioxide (SiO2), and the aluminum element originates from aluminum compounds such as aluminum oxide (Al2O3).

[0022] In another embodiment of the present invention, the composition of the selected incinerated bottom ash must satisfy the following conditions as a result of analysis by inductively coupled plasma emission spectrometry (ICP-OES): (1) The weight percentage concentration of calcium compounds (e.g., the total weight percentage concentration of calcium oxide and calcium hydroxide) is 30 wt% or more, preferably 40 wt% or more, and particularly preferably 50 wt% to 75 wt%; and (2) The weight percentage concentration of calcium compounds is 1.2 times or more, preferably 1.5 times or more, and particularly preferably 1.8 times or more, than the weight percentage concentration of silicon compounds (e.g., silicon dioxide). An example of an analytical method for an embodiment of the present invention is as follows: The properties of the incinerated bottom ash used are measured by microwave decomposition to determine the metal ion concentration, and the weight of the metal ions is determined by multiplying this by the volume and converting it. The microwave decomposition measurement method is as follows. 1. Place 0.1g of the sample (in this case, incinerated bottom ash) in a 100°C oven and dry for 2 hours. 2. Place 0.1 g of the dried sample into a decomposition bottle, add 9 mL of 70% nitric acid, 3 mL of hydrofluoric acid, and 3 mL of 37% hydrochloric acid, and pre-decompose for 30 minutes. 3. Heat at 180°C for 25 minutes, then keep warm for 10 minutes. 4. After cooling, add 15 mL of boric acid and pre-decompose for 30 minutes. 5. Repeat step 3. 6. The water sample after microwave decomposition is quantified, and the metal ion concentration is analyzed by ICP-OES. 7. ICP-OES model: Inductively coupled plasma-optical emission spectrometry (ICP-OES, Avio 200, PerkinElmer). However, the present invention is not limited thereto.

[0023] Step S120 is a pretreatment operation of incinerated bottom ash, which includes sequentially performing drying (S121), crushing (S122), sieving (S123), and calcination (S124) on the selected incinerated bottom ash. This removes most of the residual moisture and organic matter from the incinerated bottom ash, and yields incinerated bottom ash powder with an average particle size of 60 μm or less, preferably 55 μm or less, and particularly preferably 50 μm or less.

[0024] More specifically, the drying process (S121) includes placing the incinerated ash in a drying apparatus (e.g., an oven) and drying it at a drying temperature of 50°C to 200°C, preferably 130°C to 170°C, to remove most of the moisture remaining in the incinerated ash (for example, reducing the moisture content to 1 wt%, preferably 0.5 wt% or less). The drying time is, for example, 0.5 hours to 36 hours (e.g., 24 hours) and can be adjusted according to the actual operating requirements.

[0025] The crushing process (S122) involves crushing the dried incinerated bottom ash with a crushing device (such as a crusher) or crushing means (such as a hammer crusher) to crush relatively large particles or lumps in the incinerated bottom ash into relatively small particles or powder.

[0026] The sieving process (S123) includes sieving the crushed incinerated bottom ash with a particle size sorter (for example, with a mesh size of 200 mesh to 1000 mesh) to obtain incinerated bottom ash with an average particle diameter D50 of 60 μm or less, preferably 55 μm or less, and particularly preferably 50 μm or less.

[0027] The calcination process (S124) involves placing the sieved incineration bottom ash into a high-temperature device (e.g., a high-temperature furnace) and calcining it at a calcination temperature of 300°C to 800°C, preferably 500°C to 800°C (e.g., 750°C) to remove most of the organic matter remaining in the incineration bottom ash (for example, reducing the organic matter content to 1 wt% or less, preferably 0.5 wt% or less). Here, the calcination time is, for example, 0.5 hours to 12 hours (e.g., 3 hours) and can be adjusted according to the actual operating requirements.

[0028] It is worth noting that, through the above-mentioned pretreatment process for incinerated bottom ash, residual moisture and organic matter can be removed, resulting in finer and more uniform particle size, which facilitates subsequent spinning and hollow fiber manufacturing.

[0029] However, the present invention is not limited to the above embodiments, and in another embodiment of the present invention, the incinerated bottom ash may be used directly in the subsequent production of the spinning solution and hollow fibers without performing any pretreatment work on the incinerated bottom ash.

[0030] Step S130 is a spinning solution manufacturing operation, which includes further mixing the sorted and processed incinerated bottom ash with an organic solvent and a high-molecular-weight polymer to form a spinning solution.

[0031] Here, the organic solvent may be at least one selected from the group consisting of, for example, N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), and dimethyl sulfoxide (DMSO). In one embodiment of the present invention, N-methylpyrrolidone (NMP) is selected as the organic solvent.

[0032] Here, the polymer may be at least one selected from the group consisting of, for example, polyvinylpyrrolidone (PVP), polyethersulfone (PESf), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polyetherimide (PEI), polyetheretherketone (PEEK), polyvinyl alcohol (PVA), and polyethylene glycol (PEG).

[0033] In the composition of the spinning solution, the content of incinerated bottom ash is 35 to 65 wt%, preferably 40 to 60 wt%, and particularly preferably 45 to 55 wt%, based on 100 wt% of the total weight of the spinning solution. The content of organic solvent is 25 to 60 wt%, preferably 30 to 55 wt%, and particularly preferably 40 to 50 wt%. The content of high molecular weight polymer is 0.1 to 15 wt%, preferably 0.5 to 10 wt%, and particularly preferably 1 to 8 wt%.

[0034] In one embodiment of the present invention, the polymer comprises both polyvinylpyrrolidone (PVP) and polyethersulfone (PESf), with a polyvinylpyrrolidone (PVP) content of 0.5 wt% to 2 wt% and a polyethersulfone (PESf) content of 4 wt% to 6 wt%, but the present invention is not limited thereto.

[0035] Here, polyvinylpyrrolidone (PVP) is hydrophilic and helps to form a pore structure on the hollow fibers, while polyethersulfone (PESf) can be used as an adhesive and helps to adhere the incinerator ash when the hollow fibers are spun into yarn.

[0036] According to the above configuration, a hollow fiber spinning solution with appropriate viscosity and uniformly dispersed incinerated bottom ash is obtained, which is advantageous for subsequent spinning and hollow fiber production.

[0037] In one embodiment of the present invention, the spinning solution manufacturing process may selectively include grinding the spinning solution with a grinding device to uniformly mix all components in the spinning solution (including incinerated bottom ash, organic solvent, and high-molecular-weight polymer) and further reducing the particle size of the incinerated bottom ash particles.

[0038] Examples of grinding devices include ball mills, grinding machines, and bead mills. Preferably, a planetary ball mill is used as the grinding device, the orbital speed of the ball mill is, for example, 120 rpm to 240 rpm, preferably 160 rpm to 200 rpm, and the ball mill grinding time is, for example, 3 hours or more, preferably 12 hours or more, but the present invention is not limited thereto.

[0039] More specifically, the spinning solution manufacturing process can be carried out, for example, by mixing incinerated bottom ash, an organic solvent (such as NMP), and polyvinylpyrrolidone (PVP), and then ball-milling the mixture in a planetary ball mill at an orbital speed of 160 rpm to 200 rpm for 12 to 48 hours to form the mixture. Next, polyethersulfone (PESf) is added to the mixture, and the mixture is continuously ball-milled in a planetary ball mill at an orbital speed of 160 rpm to 200 rpm for 12 to 48 hours to form the spinning solution.

[0040] Therefore, all components in the spinning solution can be mixed more uniformly, achieving the goal of homogenization.

[0041] Referring to Figures 3 and 4, step S140 is a hollow fiber manufacturing operation, which involves spinning the spinning solution L1 in a spinning apparatus 100 (such as a spinning machine) using a dry-wet spinning method to form a hollow fiber precursor P' having a hollow structure, and then sintering the hollow fiber precursor P' at a sintering temperature of 1100°C to 1200°C to remove organic solvents and high-molecular-weight polymers, thereby forming a hollow fiber P mainly composed of incinerated bottom ash.

[0042] Specifically, the spinning nozzle 1 of the spinning apparatus 100 has a coaxial double-tube structure consisting of an outer tube 11 and an inner tube 12. Here, the spinning solution L1 is supplied to the outer tube 11, and the mesoporous solution L2 (for example, deionized water) is supplied to the inner tube 12. After the spinning solution L1 is discharged from the outer tube 11 of the spinning nozzle 1, it undergoes phase separation and solidification in the coagulation bath T to form the outer wall of the hollow fiber precursor P'. After the mesoporous solution L2 is discharged from the inner tube 12 of the spinning nozzle 1, the spinning solution L1 leaves a hollow internal cavity when solidified, and the solidified fiber has a hollow structure. Here, the coagulation bath T may be a liquid with the same composition as the mesoporous solution, such as deionized water, and the temperature may be room temperature, and the spinning solution L1 undergoes phase separation and solidifies in the coagulation bath T.

[0043] In one embodiment of the present invention, the diameter of the outer tube 11 of the spinning nozzle 1 is 1.5 mm to 4 mm, preferably 2 mm to 3 mm. The diameter of the inner tube 12 of the spinning nozzle 1 is 0.8 mm to 1.35 mm, preferably 0.9 mm to 1.3 mm. The difference between the diameter of the outer tube 11 and the diameter of the inner tube 12 is 0.5 mm to 2.5 mm, preferably 0.7 mm to 2.1 mm.

[0044] The flow rate of the liquid in the pore of the spinning nozzle 1 is 5 mL / min to 12 mL / min, preferably 7 mL / min to 10 mL / min. Here, the flow rate of the liquid in the pore refers to the respective flow rates of the spinning solution L1 and the mesoporous solution L2 (for example, the flow rate of the spinning solution L1 in the outer tube 11 is 5 mL / min to 12 mL / min, and the flow rate of the mesoporous solution L2 in the inner tube 12 is 5 mL / min to 12 mL / min).

[0045] In one embodiment of the present invention, after the formation of the hollow fiber precursor P', the hollow fiber manufacturing process further includes removing the hollow fiber precursor P' from the coagulation bath T, performing a washing and drying treatment, and finally performing a heat treatment to form hollow fibers P made of incinerated bottom ash.

[0046] Examples of drying methods include, for instance, air-drying the moist hollow fiber precursor at room temperature, or drying it in a drying apparatus (such as an oven) at a temperature of 50°C to 200°C until the moisture and organic solvent in the fiber are completely evaporated.

[0047] The heat treatment may, for example, involve placing a dried hollow fiber precursor in a high-temperature furnace and performing the heat treatment according to the following heat treatment process: The calcination stage involves raising the temperature to 300°C to 800°C at a rate of 1°C / min to 5°C / min and maintaining it for 0.5 to 12 hours (e.g., 1 hour) to remove high-molecular-weight polymers (e.g., PVP and PESf). In the sintering stage, the temperature is continuously raised to a sintering temperature of 1100°C to 1200°C and maintained for 0.5 to 12 hours (e.g., 3 hours) to sinter the inorganic metal components in the incineration ash and form a stable hollow fiber structure (diameter shrinkage rate after sintering is approximately 5% to 30%). Finally, the fiber temperature is lowered to room temperature by natural cooling to complete the production of hollow fibers.

[0048] It is worth noting that the incinerated bottom ash sorted in the above sorting process contains a specific proportion of calcium compounds (calcium oxide, calcium hydroxide, etc.) and a calcium / silicon weight ratio. This helps to lower the sintering temperature in the subsequent hollow fiber processing of the incinerated bottom ash, eliminating the need to add catalysts (such as AlF3) or metal flux separately.

[0049] If the incineration bottom ash is not sorted and does not have the specific composition ratio described above, it may be unfavorable for the production of hollow fibers (for example, the required sintering temperature may be too high, or hollow fibers may not be able to be formed).

[0050] Figures 5A and 5 are scanning electron microscope (SEM) images of cross-sections of hollow fibers produced from the spinning solution of Example 1 of the present invention without ball milling.

[0051] In Example 1, incinerator ash with the composition shown in Figure 2 was selected as the incinerator ash, and pretreatment was performed on the incinerator ash. The pretreatment involved removing moisture from the incinerator ash by placing it in an oven at 150°C, then pulverizing it, sieving the pulverized incinerator ash through a 45 μm sieve, and then placing the sieved incinerator ash in a high-temperature furnace at 750°C and holding it for 3 hours to remove organic matter, thereby obtaining incinerator ash powder. Next, 50 parts by weight of the incinerator ash powder, 44 parts by weight of N-methylpyrrolidone (NMP), 1 part by weight of polyvinylpyrrolidone (PVP), and 5 parts by weight of polyethersulfone (PESf) were mixed to form a spinning solution (without ball milling). Next, hollow fibers were spun by wet-dry spinning with a liquid flow rate of 7 mL / min for the spinning solution in the outer tube of the spinning nozzle and a liquid flow rate of 7 mL / min for the mesoporous solution (deionized water) in the inner tube. The sintering temperature of the hollow fibers was 1,200°C.

[0052] As can be seen from Figures 5A and 5B, the hollow fibers of Example 1 are generally formed in appearance, but have relatively large pores, a relatively loose structure, and are prone to being relatively brittle, although they are still within the scope of application.

[0053] Figures 6A and 6B are scanning electron microscope (SEM) images of cross-sections of hollow fibers produced under conditions in which the spinning solution of Example 2 of the present invention was subjected to ball milling.

[0054] The manufacturing conditions for the hollow fibers in Example 2 are almost the same as those in Example 1, but the main difference is that in Example 2, the spinning solution is further subjected to ball milling in a planetary ball mill at a rotational speed of 180 rpm for 48 hours during manufacturing, so that the incinerated bottom ash is uniformly dispersed and homogenized.

[0055] As can be seen from Figures 6A and 6B, the hollow fiber of Example 2 has smooth inner and outer walls, and finger-like pore structures exist at least at a certain thickness in the inner wall, which is advantageous for supporting the shape of the hollow fiber and makes it less prone to brittleness. The central part of the cross-section of the hollow fiber of Example 2 is dense and spongy (see Figure 7). Compared with Example 1 above, the hollow fiber of Example 2 has more stable performance and reliability.

[0056] Figure 8 is a scanning electron microscope (SEM) photograph of the hollow fiber of Example 3 of the present invention. The manufacturing method of the hollow fiber of Example 3 is substantially the same as that of Example 2, but the main difference is that the sintering temperature of the hollow fiber of Example 3 is lowered to 1150°C. As can be seen from the SEM photograph, even at a lower sintering temperature, hollow fibers are still formed, and the micropores increase, which is advantageous for the adsorption of impurities.

[0057] Regarding the size, the length of the incineration main ash hollow fiber of the embodiment of the present invention may be 3 cm to 15 cm, the outer diameter may be 1.0 mm to 2.5 mm, the inner diameter may be 0.6 mm to 1.8 mm, and the wall thickness may be 0.1 mm to 0.4 mm, but the present invention is not limited thereto.

[0058] In addition, the specific surface area S of the hollow fiber BET is 0.1 m 2 / g to 0.5 m 2 / g, preferably 0.25 m 2 / g to 0.45 m 2 / g, and the average pore diameter D of the micropores of the hollow fiber p is 450 nm to 850 nm, preferably 550 nm to 750 nm. It should be noted that micropores with an average pore diameter exceeding 50 nm belong to macroporous materials with larger pores. By having larger pores, they are suitable for adsorbing larger molecules and colloidal substances, and the fluid can pass through more easily.

[0059] Here, the specific surface area S of the hollow fiber BET and the average pore diameter D p can be analyzed using a gas adsorption analyzer (for example, the N2 adsorption / desorption method), but the present invention is not limited thereto.

[0060] Furthermore, the incineration main ash hollow fiber of the embodiment of the present invention is suitable for wastewater treatment, for example, the adsorption of dyes in wastewater.

[0061] In one embodiment, the adsorption of dyes in wastewater by the hollow fibers of Example 3 was tested. Below, the test method and results of the adsorption experiment of a methyl blue (MyB) dye solution using incineration bottom ash hollow fibers (BAHF) as an adsorbent in this application are described.

[0062] The experimental procedure involved using a 50 mL methyl blue dye solution and 2 g of incinerator ash hollow fiber (BAHF) as an adsorbent. The solution was stirred in a reciprocating shaking bath at a rotation speed of 100 rpm. Adsorption kinetics were observed in the experiment at different contact times (10, 30, 60, 120, 180 minutes, etc.). The effect of an initial methyl blue concentration of 200 mg / L on the adsorption capacity was evaluated. The temperature condition was 25°C. After the adsorption experiment was completed, the solution was filtered through 0.22 μm filter paper, and the residual dye was measured using a spectrophotometer.

[0063] Regarding the dye adsorption effect, hollow fiber incinerator ash (BAHF) can significantly remove the blue color of MyB dye within approximately 10 minutes, causing the solution to fade. This indicates that BAHF exhibits a rapid initial adsorption reaction to MyB dye. Experimental results showed that the adsorption capacity (qe) of BAHF for MyB was approximately 1 mg / g to 3 mg / g (e.g., 2 mg / g).

[0064] Generally, when the initial methyl blue concentration is 200 mg / L and the solution temperature is 25°C, adding 2 g of hollow fiber to 50 mL of methyl blue solution and stirring at 100 rpm can reduce the methyl blue concentration in the solution by at least 90% within 10 minutes, and the adsorption capacity is 1 mg / g to 3 mg / g.

[0065] [Advantageous effects of the embodiment] As described above, the hollow fibers of incinerated ash and the method for producing the same according to the present invention have the following technical features: "selecting incinerated ash in which the content of calcium element in the elemental composition is greater than the content of silicon element," "mixing the selected incinerated ash with an organic solvent and a polymer to form a spinning solution," and "spinning the spinning solution using a wet-dry spinning method in a spinning apparatus to form a hollow fiber precursor, and sintering the hollow fiber precursor at a sintering temperature of 1100°C to 1200°C to form hollow fibers made of the incinerated ash." Through these technical features, incinerated ash can be produced as hollow fibers with relatively high economic value.

[0066] Furthermore, this invention allows for the formation of hollow fibers at a lower sintering temperature without the need to separately add flux, by selecting incinerated bottom ash with a high calcium content and imparting flux properties, thereby reducing energy consumption and costs. Compared to conventional technologies that require advanced silicon raw material purification and the addition of multiple auxiliary agents, this invention directly uses bottom ash with a specific composition, shortening the process and improving feasibility. A spinning solution is prepared by uniformly dispersing the bottom ash powder in an organic solvent and a high-molecular-weight polymer, forming a hollow fiber precursor by wet-dry spinning, and stably solidifying the fibers at a relatively low sintering temperature, achieving a uniform pore distribution and appropriate pore size. The final product maintains good structure and mechanical strength even under low-temperature sintering conditions, has the ability to adsorb impurities, is advantageous for water treatment and wastewater purification applications, and facilitates separation of the aqueous phase, resulting in significantly improved economic benefits and practical value.

[0067] The information disclosed herein represents only preferred and feasible embodiments of the present invention, and the claims of the present invention are not limited thereto. Therefore, all equivalent technical modifications made using the description and drawings of the present invention are included within the scope of the claims of the present invention. [Explanation of Symbols]

[0068] S110 Process S110 S120 Process S120 S130 Process S130 S140 Process S140 100 Spinning machine 1. Spinning nozzle 11 Outer tube 12 Inner tube L1 Spinning Solution L2 Mesoporous Solution T Coagulation bath P' Hollow fiber precursor P Hollow Fiber

Claims

1. A sorting process including the selection of incineration bottom ash in which the calcium content is greater than the silicon content in its elemental composition, A spinning solution manufacturing operation, which includes mixing the selected incinerated bottom ash with an organic solvent and a high-molecular polymer to form a spinning solution, A method for producing hollow fibers from incinerated ash, comprising: spinning the aforementioned spinning solution in a spinning apparatus by a wet-dry spinning method to form a hollow fiber precursor; and sintering the hollow fiber precursor at a sintering temperature of 1100°C to 1200°C to form hollow fibers made of the aforementioned incinerated ash.

2. The method for producing hollow fibers from incinerated ash according to claim 1, wherein, in the sorting process, the elemental composition of the sorted incinerated ash satisfies the following conditions as a result of scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS) analysis. (1) The weight percentage concentration of calcium element is 15 wt% or more, and (2) The weight ratio of the weight percentage concentration of calcium element (calcium (Ca) / silicon (Si)) to the weight percentage concentration of silicon element is 2 or more.

3. The method for producing hollow fibers from incinerated bottom ash according to claim 1, wherein the calcium element in the incinerated bottom ash is derived from a calcium compound, the calcium compound includes calcium oxide and calcium hydroxide, the silicon element is derived from a silicon compound, the silicon compound includes silicon dioxide, and in the sorting process, the composition of the sorted incinerated bottom ash must satisfy the following conditions after analysis by inductively coupled plasma emission spectrometry (ICP-OES). (1) The weight percentage concentration of the calcium compound is 30 wt% or more, and (2) The weight percentage concentration of the calcium compound is 1.2 times or more the weight percentage concentration of the silicon compound.

4. A method for producing hollow fibers from incinerated bottom ash according to claim 1, further comprising, after the sorting work and before the spinning solution manufacturing work, a pretreatment work for incinerated bottom ash, wherein the pretreatment work for incinerated bottom ash includes sequentially performing drying, crushing, sieving, and calcination on the sorted incinerated bottom ash to remove residual moisture and organic matter from the incinerated bottom ash and to obtain incinerated bottom ash with an average particle size of 60 μm or less.

5. The drying process includes placing the selected incinerated bottom ash into a drying apparatus and drying it at a drying temperature of 50°C to 200°C in order to remove the residual moisture. The aforementioned crushing process includes crushing the dried incinerated bottom ash with a crushing device or crushing means, The sieving process includes obtaining incinerated bottom ash with an average particle size of 60 μm or less by sieving the crushed bottom ash with a particle size sorter, The method for producing hollow fibers from incinerated ash according to claim 4, wherein the aforementioned calcination treatment includes placing the sieved incinerated ash into a high-temperature apparatus and calcining it at a calcination temperature of 300°C to 800°C to remove the organic matter remaining in the incinerated ash.

6. The method for producing hollow fibers from incinerator ash according to claim 1, wherein the organic solvent is at least one selected from the group consisting of N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), and dimethyl sulfoxide (DMSO), and the polymer is at least one selected from the group consisting of polyvinylpyrrolidone (PVP), polyethersulfone (PESf), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polyetherimide (PEI), polyetheretherketone (PEEK), polyvinyl alcohol (PVA), and polyethylene glycol (PEG).

7. The method for producing hollow fibers from incinerated bottom ash according to claim 6, wherein, with the total weight of the spinning solution being 100 wt%, the content of the incinerated bottom ash is 35 wt% to 65 wt%, the content of the organic solvent is 25 wt% to 60 wt%, and the content of the high-molecular-weight polymer is 0.1 wt% to 15 wt%.

8. The method for producing hollow fibers from incinerator ash according to claim 7, wherein the organic solvent is selected as N-methylpyrrolidone (NMP), and the polymer comprises both polyvinylpyrrolidone (PVP) and polyethersulfone (PESf), with the polyvinylpyrrolidone (PVP) content being 0.5 wt% to 2 wt% and the polyethersulfone (PESf) content being 4 wt% to 6 wt%.

9. The method for producing hollow fibers from incinerated ash according to claim 1, wherein the spinning solution production operation includes grinding the spinning solution with a grinding device which is a planetary ball mill, the orbital speed of the planetary ball mill is 120 rpm to 240 rpm, and the ball mill grinding time is 3 hours or more.

10. Incineration ash hollow fibers manufactured by the method for manufacturing incineration ash hollow fibers described in any one of claims 1 to 9, The elemental composition of the hollow fibers in the incinerated ash contains more calcium than silicon, and the specific surface area S of the hollow fibers in the incinerated ash is greater. ＢＥＴ is 0.1m ２ / g to 0.5m ２ / g, and the average pore size D of the micropores. ｐ Hollow fibers from incinerated ash, characterized by having a wavelength of 450 nm to 850 nm.

11. The incinerated ash hollow fiber according to claim 10, wherein, under conditions where the initial methyl blue concentration of the incinerated ash hollow fiber is 200 mg / L and the solution temperature is 25°C, 2 g of the hollow fiber is added to 50 mL of methyl blue solution and stirred at 100 rpm, and the methyl blue concentration in the solution can be reduced by at least 90% within 10 minutes, and the adsorption capacity is 1 mg / g to 3 mg / g.

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