A method for separating rod-like glass fibers from glass fiber powder

Abstract

The application discloses a method for separating rod-shaped glass fibers from glass fiber powder, and belongs to the technical field of rod-shaped glass fiber separation. The method is used for solving the technical problems of the existing glass fiber powder, such as the existence of ground and granular glass fiber powder with a very small aspect ratio or metal salt, and the complicated separation process, high cost and non-green environmental protection of the existing high-quality glass fiber powder. The method comprises the following steps: adding the glass fiber powder, purified water and decontamination additives into a flotation machine to perform preliminary flotation treatment. The method adds the decontamination additives in the preliminary flotation process of the glass fiber, and disperses the glass fiber by using sodium hexametaphosphate, so that the rod-shaped glass fiber with a very small aspect ratio and low metal salt content is prepared. Through optimization of the process and a settling cylinder, the separation and extraction process of the rod-shaped glass fiber is simplified, the use of acid and alkali is not involved in the whole separation process, and the method is green, environmental protection and non-pollution.

Description

Technical Field

[0001] This invention relates to the field of rod-shaped glass fiber separation technology, and specifically to a method for separating rod-shaped glass fibers from glass fiber powder. Background Technology

[0002] Glass fiber powder is an inorganic fiber powder obtained by chopping, grinding, and sieving glass fibers. It can be mixed with organic materials such as plastics, resins, and rubber to produce composite materials, making it an excellent matrix reinforcement material. Compared to glass fibers, glass fiber powder exhibits better flowability and dispersion uniformity in plastic, resin, and rubber matrices. It can fundamentally solve the "floating fiber" phenomenon often found in glass fiber reinforced composites, improving the aesthetics and performance of the products. Furthermore, although the length of glass fiber powder is much shorter than that of glass fibers, it has a larger specific surface area for the same mass, demonstrating significant application potential. Unlike common powdered fillers such as silica powder, glass powder, and wood flour, glass fiber powder appears macroscopically as a white powder, but microscopically, its length is variable, ranging from a few micrometers to several hundred micrometers, and it contains both long rod-shaped glass fibers and ground granular glass fibers. Glass fiber reinforced resin matrix composites possess irreplaceable advantages such as high specific strength and specific stiffness, good thermal stability, and strong designability, and have been widely used in various fields of national production, including aerospace, automobile manufacturing, medical equipment, chemical industry, and consumer goods. The main factors affecting the performance of glass fiber reinforced composites include fiber content, fiber length, and the compatibility of the fiber-resin matrix interface. Among them, the fiber length in glass fiber powder is uneven. Studies have found that as the aspect ratio of the reinforcing short fibers increases, the strength, toughness and stiffness of the composite material also increase (Influence of aspect ratio of reinforcing short fibers on the mechanical properties of composite materials, Zhang Yafang, Qi Lei, Zhang Chunmei, Journal of Guangzhou University, 7 (2008) 32-34). However, in glass fiber powder, in addition to rod-shaped glass fiber powder with a large aspect ratio, there are also ground granular glass fiber powder or metal salts with a very small aspect ratio. In their application, the reinforcing effect of glass fiber powder on plastics, resins, rubber and other materials will inevitably be weakened. Therefore, if the granular glass fiber powder present in the glass fiber powder can be reduced or even eliminated, and only rod-shaped glass fiber powder with a large aspect ratio is retained, the quality of glass fiber powder will be significantly improved.

[0003] Chinese patent (publication number CN114904889A) discloses a method for preparing high-quality glass fiber powder from recycled glass fiber materials. This method mainly involves pulverizing, dispersing and demagnetizing, cutting, cleaning, and treating with a processing agent in a glass fiber pulverizing, cutting, and cleaning equipment, followed by continuous processing, filtration, concentration, and drying. This avoids excessive dust generation during the transfer of glass fiber materials in each step, thus reducing losses and energy consumption, and improves the pulverizing efficiency and cleaning efficiency of the recycled glass fiber materials. However, the processing agent used in this method is sodium hydroxide solution, hydrochloric acid solution, or potassium permanganate aqueous solution, and the waste liquid after treatment still poses a significant environmental hazard. Furthermore, the process flow is relatively lengthy and complex, increasing processing costs.

[0004] Chinese patent (publication number CN113698636A) discloses a modification process for reinforcing filled ground glass fibers. The method first involves immersing the ground glass fibers in a hydrochloric acid solution, treating them at room temperature, and then washing and drying them for later use. Then, a modifier for the ground glass fibers is prepared using a sodium hydroxide-ethanol-water solution, a hydrochloric acid-water solution, an organosilicon polymer, ethanol, butanol, an surfactant, and an interface agent. Finally, the ground glass fibers and the modifier are placed in a high-speed mixing ceramic jar and dried at 75-80℃ and 1000-1500 r / min to obtain the sample. This method uses ethanol and butanol as diluents, is non-toxic and harmless, simple to operate, and the obtained powder can better fill organic matrices. However, the process introduces acids and alkalis, the waste liquid is environmentally harmful, the process is complex, and the treatment cost is increased.

[0005] Currently, the demand for glass fiber in my country continues to grow, and improving the quality of glass fiber powder is conducive to promoting the healthy development of the entire glass fiber industry. Therefore, it is particularly important to develop a method for producing high-quality glass fiber powder that is green, harmless, has a simple and clear process, and is easy to operate.

[0006] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a method for separating rod-shaped glass fibers from glass fiber powder, which solves the problems in the prior art where glass fiber powder contains not only rod-shaped glass fiber powder with a large aspect ratio, but also ground granular glass fiber powder or metal salts with a very small aspect ratio. In their application, this will inevitably weaken the reinforcing effect of glass fiber powder on materials such as plastics, resins, and rubber. The existing process for separating high-quality glass fiber powder from glass fiber introduces acids and alkalis, resulting in environmentally harmful waste liquid. The process is complex, has high treatment costs, is not green and environmentally friendly, and the separation of settled glass fiber powder from the upper suspension is inconvenient.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] A method for separating rod-shaped glass fibers from glass fiber powder includes the following steps:

[0010] Step 1: Preliminary flotation

[0011] Glass fiber powder, purified water, and decontamination additives are added to a flotation machine for preliminary flotation treatment to eliminate oil stains, black spots, metal and other impurities in the glass fiber powder and to pre-disperse the glass fiber powder to obtain pretreated glass fiber powder.

[0012] Step 2: Slurry preparation and ultrasonic treatment

[0013] Pretreated glass fiber powder and purified water were added to a beaker to prepare a slurry. The prepared solution was then ultrasonically dispersed for 40-60 minutes to separate the agglomerated and adhered powder particles in the slurry, resulting in a glass fiber powder mixed solution.

[0014] Step 3: Disperse

[0015] Add a dispersion solution dropwise to the glass fiber powder mixture solution, stir at room temperature for 20-30 minutes to disperse the slurry and obtain a glass fiber powder dispersion.

[0016] Step 4: Settlement

[0017] The glass fiber powder dispersion was placed in a settling tube and allowed to settle naturally at room temperature for 5-10 minutes. The lower layer of settled solid was then separated and extracted to obtain the wet rod-shaped glass fiber.

[0018] Step 5: Washing and drying

[0019] The wet rod-shaped glass fiber was washed three times with anhydrous ethanol, then washed three times with purified water and dried under vacuum. The filter cake was transferred to a drying oven at 85-95℃ and dried under vacuum until constant weight to obtain rod-shaped glass fiber powder.

[0020] Furthermore, in step one, the ratio of glass fiber powder, purified water, and detergent additive is 10g:200g:6g. The detergent additive is composed of detergent adsorbent, polyethylene glycol 400, and sodium methyl sulfonate of fatty acids in a ratio of 4g:2g:1g. The stirring speed of the flotation machine is 1000-4000 r / min, and the aeration rate is 0.1-0.5 m³ / min. 3 / h.

[0021] Furthermore, the decontamination adsorbent is processed by the following steps:

[0022] A1. Add 2-chloroethylamine, ethanol, and sodium hydroxide to a three-necked flask and stir until the system is dissolved. Raise the temperature of the three-necked flask to 34-40°C and add carbon disulfide dropwise to the three-necked flask at room temperature. After the addition is complete, keep the reaction at the temperature for 20-22 hours and then process to obtain intermediate I.

[0023] The principle of the synthesis reaction of intermediate I is as follows:

[0024]

[0025] A2. Add intermediate I, notoginsenoside R1, composite catalyst and N,N-dimethylformamide into a three-necked flask and stir. Raise the temperature of the three-necked flask to 90-100℃ and keep it at that temperature for 6-8 hours. Then, after post-treatment, obtain the decontamination adsorbent.

[0026] The synthesis reaction principle of the stain-removing adsorbent is as follows:

[0027]

[0028]

[0029] Furthermore, in step A1, the ratio of 2-chloroethylamine to carbon disulfide is 1 mol: 1.01 mol, and the ratio of 2-chloroethylamine, ethanol, and sodium hydroxide is 1 g: 8 g: 0.5 g. The post-processing operation includes: after the reaction is complete, the temperature of the three-necked flask is lowered to 10-15°C, the mixture is filtered, the filter cake is washed three times with anhydrous ethanol and then dried under vacuum, the filter cake is transferred to a drying oven at 50-60°C and dried under vacuum to constant weight to obtain intermediate I.

[0030] Furthermore, in step A2, the ratio of intermediate I to notoginsenoside R1 is 1 mol: 1.02 mol, and the ratio of notoginsenoside R1, the composite catalyst, and N,N-dimethylformamide is 10 g: 0.3 g: 60 g. The composite catalyst is composed of palladium chloride and triphenylphosphine in a ratio of 1 g: 1.5 g. The post-treatment operation includes: after the reaction is complete, maintaining the temperature of the three-necked flask at 90-100°C, removing N,N-dimethylformamide under reduced pressure, and then lowering the temperature of the three-necked flask to room temperature. The crude decontamination adsorbent was obtained. The decontamination adsorbent and anhydrous ethanol were added to a three-necked flask at a ratio of 1g:3.5mL and stirred. The temperature of the three-necked flask was raised to reflux, and the mixture was kept at this temperature until the system was clear. The mixture was filtered while hot, and the filtrate was transferred to another three-necked flask and stirred. The temperature of the three-necked flask was lowered to 5-8℃, and the mixture was kept at this temperature for 30-50 minutes to allow crystals to precipitate. The mixture was then filtered, and the filter cake was washed with anhydrous ethanol at 5-8℃ and dried under vacuum. The filter cake was then transferred to a drying oven at 50-60℃ and dried under vacuum until constant weight was obtained to obtain the decontamination adsorbent.

[0031] Furthermore, in step two, the ratio of pretreated glass fiber powder to purified water is 1g:100mL. The ultrasonic method is as follows: the ultrasonic titanium probe is immersed about 2cm below the surface of the prepared solution, and the ultrasonic amplitude is set to 70%, the mode is "2s on 2s off", and the frequency is 20kHz.

[0032] Furthermore, in step three, the ratio of the glass fiber powder mixed solution to the dispersion solution is 30g:1g, and the dispersion solution is composed of sodium hexametaphosphate and purified water in a ratio of 1g:5g.

[0033] Furthermore, the settling pipe in step three includes a vertical cylinder. A horizontally mounted mounting plate is fixedly connected to the outside of one side of the vertical cylinder, and one end of the mounting plate extends to the inside of the vertical cylinder. A connecting plate is rotatably mounted on the mounting plate, and a driving assembly for driving the connecting plate to rotate is mounted on the mounting plate. A liquid guide pipe is fixedly connected to the outside of one side of the connecting plate. A float is mounted on the end of the liquid guide pipe away from the connecting plate, and the other end of the liquid guide pipe extends to the inside of the connecting plate. A drain pipe is sleeved on the outside of the mounting plate, and one end of the drain pipe extends to the inner center of the connecting plate and connects to the liquid guide pipe.

[0034] Furthermore, a connecting bend is rotatably installed at the end of the liquid guide tube away from the mounting plate, and a flexible rubber tube is sleeved on the top of the connecting bend. The float is made of low-density plastic, and the bottom of the float is fixedly connected to the top of the flexible rubber tube.

[0035] Furthermore, the drive assembly includes a worm gear rotatably mounted inside the mounting plate and coaxially arranged with the connecting plate, and a worm cooperating with the worm gear. The worm gear is fixedly connected to the connecting plate through a connecting shaft. One end of the worm extends to the outside of the mounting plate, and a handwheel is installed at the end of the worm located outside the mounting plate.

[0036] The present invention has the following beneficial effects:

[0037] 1. The method for separating rod-shaped glass fibers from glass fiber powder according to the present invention, compared with traditional methods, focuses on modifying the surface of glass fiber powder to improve its application in reinforced composite materials, thereby enabling the glass fiber powder to bond more tightly with the matrix and improving the stress transfer efficiency between the matrix and the fiber. The present invention proposes a novel approach to directly separate rod-shaped glass fiber powder from glass fiber powder, resulting in a tighter bond with the matrix and easier stress transfer between the matrix and the fiber. Furthermore, the method has a simple process flow, including only preliminary flotation, ultrasonic dispersion, sedimentation treatment, and drying and collection, making it easy to implement for industrial production. The entire process does not involve the use of acids or alkalis, making it green, environmentally friendly, and pollution-free.

[0038] 2. The method of separating rod-shaped glass fibers from glass fiber powder according to the present invention involves reacting 2-chloroethylamine with carbon disulfide in an ethanol / sodium hydroxide system. The amino group (NH2) in 2-chloroethylamine and the carbon-sulfur bond (C=S) in carbon disulfide undergo a nucleophilic addition reaction to obtain intermediate I. The NMR spectrometry data of intermediate I are: m / z: 176.9480 (100.0%), 178.9435 (32.0%), 178.9412 (99.0%). 0.0%), 177.9495 (3.2%), 180.9381 (2.9%), 177.9456 (1.6%), 179.9460 (1.0%); Intermediate I and notoginsenoside R1 undergo a substitution addition reaction under the catalysis of a composite catalyst, forming carbon disulfide on the notoginsenoside R1 molecule, thus preparing a decontamination adsorbent. The NMR detection data of the decontamination adsorbent m / z: 1031.4931 (100.0%), 1032.4964 (51.9%), 1033.4998 (13.2%), 1033.4869 (9.0%), 1034.4922 (4.7%), 1033.4955 (3.5%), 1034.5032 (2.2%), 1034.4987 (1.8%), 1032.4925 (1.6%), 1035.4956 (1.2%), Panax notoginseng saponin R1 itself has excellent The surfactant properties are enhanced by introducing carbon disulfide functional groups into Panax notoginseng saponins. The introduction of carbon disulfide functional groups can provide stronger lipophilicity, which helps to dissolve and remove grease and stains, and clean glass fibers. Furthermore, because the sulfur atom on the disulfide bond is a strong chelating ligand, it can donate a pair of electrons to form a coordinate bond with a metal, which can chelate with metal ions in glass fiber powder to form metal complexes and reduce the metal content in glass fiber powder.

[0039] 3. The method for separating rod-shaped glass fibers from glass fiber powder according to the present invention introduces carbon disulfide functional groups into the decontamination adsorbent. Sulfur has lipophilic properties in molecules, increasing the lipophilicity of the molecules. Sodium methyl ester sulfonate is an anionic surfactant, typically containing hydrophobic alkyl chains and hydrophilic sulfonic acid groups. Polyethylene glycol is a hydrophilic polymer. By compounding the decontamination adsorbent, polyethylene glycol 400, and sodium methyl ester sulfonate in a certain proportion, the effect of removing stains from the glass fiber surface is improved. At the same time, the decontamination additive can form in the flotation machine. Stable, fine foams are used to initially separate the finely ground glass fiber powder with a small aspect ratio from the glass fiber powder. After slurry preparation and ultrasonication, the agglomerated and adhered powder particles in the glass fiber powder are separated, and then dispersed using sodium hexametaphosphate solution. Sodium hexametaphosphate works in conjunction with the cleaning additives adhering to the glass fiber powder to further promote the separation of the finely ground glass fiber powder with a small aspect ratio from the rod-shaped glass fiber powder with a large aspect ratio, thus preparing rod-shaped glass fiber powder with a low content of finely ground glass fiber powder with a small aspect ratio.

[0040] 4. The method for separating rod-shaped glass fibers from glass fiber powder according to the present invention improves the structure of the settling tube. Through the cooperation of the vertical cylinder, connecting plate, liquid guide tube, flexible rubber tube, float, drain pipe and drive component, the position of the float can be adjusted according to the location of the interface boundary between the lower slurry layer and the upper suspension layer. The buoyancy of the float is fully utilized. Due to its structure, the upper opening of the float always remains horizontal, so that the floating top is consistent with the interface boundary between the lower slurry layer and the upper suspension layer, thereby facilitating the separation of the upper suspension and meeting the requirements for settling and separation of glass fiber powder dispersions with different glass fiber powder contents. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a flowchart of the method for separating rod-shaped glass fiber powder from glass fiber powder according to the present invention.

[0043] Figure 2 These are optical microscope images of glass fiber powder before and after sedimentation in Example 4 of the present invention;

[0044] Figure 3 This is a three-dimensional structural diagram of the settling pipe in this invention;

[0045] Figure 4 This is a schematic diagram of the cross-sectional structure of the settling pipe in this invention;

[0046] Figure 5 For the present invention Figure 3 Enlarged structural diagram at point A in the middle;

[0047] Figure 6 This is a schematic diagram of the cooperation structure between the connecting plate, the liquid guide pipe, the liquid drain pipe and the transmission assembly in this invention.

[0048] In the diagram: 100, vertical cylinder; 200, mounting plate; 201, connecting plate; 202, liquid guide pipe; 203, connecting bend pipe; 204, flexible rubber hose; 205, float; 207, drain pipe; 300, drive assembly; 301, connecting shaft; 302, worm gear; 303, worm; 304, handwheel. Detailed Implementation

[0049] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] Example 1

[0051] Please see Figure 2-5 This embodiment provides a settling tube for separating rod-shaped glass fibers from glass fiber powder, including a vertical cylinder 100. A horizontally arranged mounting plate 200 is fixed to the outside of one side of the vertical cylinder 100, and one end of the mounting plate 200 extends to the inside of the vertical cylinder 100. A vertically arranged mounting groove (not shown) is formed on the outer wall of the side of the mounting plate 200 located inside the vertical cylinder 100. A circular connecting plate 201 is rotatably installed inside the mounting groove, and a liquid guide pipe 202 is fixed to the outside of one side of the connecting plate 201. A connecting bend is rotatably installed at the end of the liquid guide pipe 202 away from the connecting plate 201. The top of the connecting bend 203 is fitted with a flexible rubber tube 204. A float 205 made of low-density plastic is fixed to the top of the flexible rubber tube 204. The other end of the liquid guide tube 202 extends to the inner side of the connecting plate 201. A drain pipe 207 is fitted to the outside of the mounting plate 200. One end of the drain pipe 207 extends to the inner center of the connecting plate 201 and is connected to the liquid guide tube 202. A valve (not shown) is installed at the end of the drain pipe 207 located outside the mounting plate 200. A drive assembly 300 for driving the connecting plate 201 to rotate is installed on the mounting plate 200.

[0052] The vertical cylinder 100 is made of transparent material. The drive assembly 300 drives the connecting plate 201 to rotate, causing the liquid guide tube 202 to rotate around the axis of the connecting plate 201. The height of the end of the liquid guide tube 202 away from the mounting plate 200 relative to the bottom of the vertical cylinder 100 is adjusted. Under the action of buoyancy, the float 205 maintains a horizontal upward trend. The height of the top surface of the float 205 is adjusted so that the top of the float 205 is just above the glass fiber powder dispersion during settling. The interface between the lower sediment layer and the upper suspension layer formed by sedimentation in the pipe is flush with the bottom of the drain pipe 207 located outside the vertical cylinder 100. When the interface between the lower sediment layer and the upper suspension layer is below the mounting plate 200, the upper suspension layer can be separated by the siphon principle. The funnel-shaped float 205 provides a large contact area with the interface layer while increasing its buoyancy.

[0053] The drive assembly 300 includes a worm gear 302 rotatably mounted inside the mounting plate 200 and coaxially arranged with the connecting plate 201, and a worm 303 cooperating with the worm gear 302. The worm gear 302 is fixedly connected to the connecting plate 201 through the connecting shaft 301. One end of the worm 303 extends to the outside of the mounting plate 200, and a handwheel 304 is installed at the end of the worm 303 located outside the mounting plate 200.

[0054] Rotating the handwheel 304 drives the worm gear 303 to rotate, which in turn drives the worm wheel 302 to rotate, thereby driving the connecting plate 201 to rotate. By utilizing the principle that the worm gear 303 drives the worm wheel 302 to rotate in one direction, the liquid guide tube 202 will not rotate when the handwheel 304 is not rotated, thus achieving an automatic positioning effect. This simplifies the design of the drive assembly and optimizes the means of adjusting and positioning the relative height of the float 205.

[0055] Example 2

[0056] Please see Figure 2-5 This embodiment provides a method for separating rod-shaped glass fibers from glass fiber powder, comprising the following steps:

[0057] S1. Preparation of detergency additives

[0058] Weigh out 15.0 g of 2-chloroethylamine, 120 g of ethanol, and 7.5 g of sodium hydroxide and add them to a three-necked flask. Stir until the system is dissolved. Raise the temperature of the three-necked flask to 34°C and add 14.5 g of carbon disulfide dropwise to the three-necked flask at room temperature. After the addition is complete, keep the reaction at this temperature for 20 h. Then lower the temperature of the three-necked flask to 10°C, filter the mixture, wash the filter cake three times with anhydrous ethanol, and dry it under vacuum. Transfer the filter cake to a drying oven at 50°C and dry it under vacuum to constant weight to obtain intermediate I.

[0059] Palladium chloride and triphenylphosphine were mixed evenly at a ratio of 1g:1.5g to obtain a composite catalyst.

[0060] Weigh out 20g of intermediate I, 107.2g of notoginsenoside R1, 3.22g of composite catalyst and 643.2g of N,N-dimethylformamide and add them to a three-necked flask and stir. Raise the temperature of the three-necked flask to 90℃ and keep it at that temperature for 6 hours. Keep the temperature of the three-necked flask at 90℃ and remove N,N-dimethylformamide by vacuum distillation. Lower the temperature of the three-necked flask to room temperature to obtain crude decontamination adsorbent.

[0061] Add the cleaning adsorbent and anhydrous ethanol at a ratio of 1g:3.5mL to a three-necked flask and stir. Raise the temperature of the three-necked flask to reflux the system and keep it warm until the system is clear. Filter while hot. Transfer the filtrate to another three-necked flask and stir. Lower the temperature of the three-necked flask to 5℃ and keep it warm for 30min to allow crystals to precipitate. Filter and wash the filter cake with anhydrous ethanol at 5℃ and dry it under vacuum. Transfer the filter cake to a drying oven at 50℃ and dry it under vacuum to constant weight to obtain the cleaning adsorbent.

[0062] The stain-removing adsorbent, polyethylene glycol 400, and sodium fatty acid methyl sulfonate were mixed evenly in a ratio of 4g:2g:1g to obtain a stain-removing additive.

[0063] S2, Preliminary Flotation

[0064] Weigh out 20g of glass fiber powder, 400g of purified water, and 12g of detergent additive, and add them to an XFD-Ⅲ type single-cell flotation machine. The stirring speed of the flotation machine is 1000r / min, and the aeration rate is 0.1m³. 3 After initial flotation treatment, the glass fiber powder is filtered, washed, and dried to obtain pretreated glass fiber powder.

[0065] S3, Slurry preparation, ultrasonic treatment

[0066] Pretreated glass fiber powder and purified water were added to a beaker at a ratio of 1g:100mL to prepare a slurry. An ultrasonic titanium probe was immersed about 2cm below the surface of the prepared solution. The ultrasonic amplitude was set to 70%, the mode was "2s on 2s off", and the frequency was 20kHz. The mixture was ultrasonically dispersed for 40 minutes to obtain a glass fiber powder mixed solution.

[0067] S4, Dispersion

[0068] Sodium hexametaphosphate and purified water were mixed evenly at a ratio of 1g:5g to obtain a dispersion solution;

[0069] A dispersion solution was added dropwise to the glass fiber powder mixture solution, and the mixture was stirred at room temperature for 20 minutes to obtain a glass fiber powder dispersion. The amount of dispersion solution used was 1 / 30 of the weight of the glass fiber powder mixture solution.

[0070] S5, Settlement

[0071] The glass fiber powder dispersion is placed into a settling tube and allowed to settle naturally for 5 minutes at room temperature. The height of the float 205 relative to the bottom inner wall of the settling tube is adjusted so that the top of the float 205 is flush with the interface between the lower slurry layer and the upper suspension layer formed by the glass fiber powder dispersion in the settling tube. The valve on the drain pipe 207 is opened to separate the upper suspension layer, resulting in wet rod-shaped glass fibers.

[0072] S6. Washing and drying

[0073] The wet rod-shaped glass fiber was washed three times with anhydrous ethanol, then washed three times with purified water, and then dried under vacuum. The filter cake was transferred to a drying oven at 85°C and vacuum dried to constant weight to obtain rod-shaped glass fiber powder.

[0074] Example 3

[0075] Please see Figure 2-5 This embodiment provides a method for separating rod-shaped glass fibers from glass fiber powder, comprising the following steps:

[0076] S1. Preparation of detergency additives

[0077] Weigh out 15.0 g of 2-chloroethylamine, 120 g of ethanol, and 7.5 g of sodium hydroxide and add them to a three-necked flask. Stir until the system is dissolved. Raise the temperature of the three-necked flask to 37°C and add 14.5 g of carbon disulfide dropwise to the three-necked flask at room temperature. After the addition is complete, keep the reaction at this temperature for 21 h. Then lower the temperature of the three-necked flask to 13°C and filter. Wash the filter cake three times with anhydrous ethanol and dry it under vacuum. Transfer the filter cake to a drying oven at 55°C and dry it under vacuum to constant weight to obtain intermediate I.

[0078] Palladium chloride and triphenylphosphine were mixed evenly at a ratio of 1g:1.5g to obtain a composite catalyst.

[0079] Weigh out 20g of intermediate I, 107.2g of notoginsenoside R1, 3.22g of composite catalyst and 643.2g of N,N-dimethylformamide and add them to a three-necked flask and stir. Raise the temperature of the three-necked flask to 95℃ and keep it at that temperature for 7h. Keep the temperature of the three-necked flask at 95℃ and remove N,N-dimethylformamide by vacuum distillation. Lower the temperature of the three-necked flask to room temperature to obtain crude decontamination adsorbent.

[0080] Add the cleaning adsorbent and anhydrous ethanol at a ratio of 1g:3.5mL to a three-necked flask and stir. Raise the temperature of the three-necked flask to reflux the system and keep it warm until the system is clear. Filter while hot. Transfer the filtrate to another three-necked flask and stir. Lower the temperature of the three-necked flask to 7℃ and keep it warm for 40min to allow crystals to precipitate. Filter and wash the filter cake with anhydrous ethanol at 7℃ and dry it under vacuum. Transfer the filter cake to a drying oven at 55℃ and vacuum dry it to constant weight to obtain the cleaning adsorbent.

[0081] The stain-removing adsorbent, polyethylene glycol 400, and sodium fatty acid methyl sulfonate were mixed evenly in a ratio of 4g:2g:1g to obtain a stain-removing additive.

[0082] S2, Preliminary Flotation

[0083] Weigh out 20g of glass fiber powder, 400g of purified water, and 12g of detergent additive, and add them to an XFD-Ⅲ type single-cell flotation machine. The stirring speed of the flotation machine is 2500r / min, and the aeration rate is 0.3m³. 3 After initial flotation treatment, the glass fiber powder is filtered, washed, and dried to obtain pretreated glass fiber powder.

[0084] S3, Slurry preparation, ultrasonic treatment

[0085] Pretreated glass fiber powder and purified water were added to a beaker at a ratio of 1g:100mL to prepare a slurry. An ultrasonic titanium probe was immersed about 2cm below the surface of the prepared solution. The ultrasonic amplitude was set to 70%, the mode was "2s on 2s off", and the frequency was 20kHz. The mixture was ultrasonically dispersed for 50 minutes to obtain a glass fiber powder mixed solution.

[0086] S4, Dispersion

[0087] Sodium hexametaphosphate and purified water were mixed evenly at a ratio of 1g:5g to obtain a dispersion solution;

[0088] A dispersion solution was added dropwise to the glass fiber powder mixture solution, and the mixture was stirred at room temperature for 25 minutes to obtain a glass fiber powder dispersion. The amount of dispersion solution used was 1 / 30 of the weight of the glass fiber powder mixture solution.

[0089] S5, Settlement

[0090] The glass fiber powder dispersion is placed into a settling tube and allowed to settle naturally for 8 minutes at room temperature. The height of the float 205 relative to the bottom inner wall of the settling tube is adjusted so that the top of the float 205 is flush with the interface between the lower slurry layer and the upper suspension layer formed by the glass fiber powder dispersion in the settling tube. The valve on the drain pipe 207 is opened to separate the upper suspension layer, thus obtaining the rod-shaped wet glass fiber product.

[0091] S6. Washing and drying

[0092] The wet rod-shaped glass fiber was washed three times with anhydrous ethanol, then washed three times with purified water, and then dried under vacuum. The filter cake was transferred to a drying oven at 90°C and dried under vacuum until constant weight to obtain rod-shaped glass fiber powder.

[0093] Example 4

[0094] Please see Figure 2-5 This embodiment provides a method for separating rod-shaped glass fibers from glass fiber powder, comprising the following steps:

[0095] S1. Preparation of detergency additives

[0096] Weigh out 15.0 g of 2-chloroethylamine, 120 g of ethanol, and 7.5 g of sodium hydroxide and add them to a three-necked flask. Stir until the system is dissolved. Raise the temperature of the three-necked flask to 40°C and add 14.5 g of carbon disulfide dropwise to the three-necked flask at room temperature. After the addition is complete, keep the reaction at this temperature for 22 h. Then lower the temperature of the three-necked flask to 15°C, filter the mixture, wash the filter cake three times with anhydrous ethanol, and dry it under vacuum. Transfer the filter cake to a drying oven at 60°C and dry it under vacuum to constant weight to obtain intermediate I.

[0097] Palladium chloride and triphenylphosphine were mixed evenly at a ratio of 1g:1.5g to obtain a composite catalyst.

[0098] Weigh out 20g of intermediate I, 107.2g of notoginsenoside R1, 3.22g of composite catalyst and 643.2g of N,N-dimethylformamide and add them to a three-necked flask and stir. Raise the temperature of the three-necked flask to 100℃ and keep it at that temperature for 8 hours. Keep the temperature of the three-necked flask at 100℃ and remove N,N-dimethylformamide by vacuum distillation. Lower the temperature of the three-necked flask to room temperature to obtain crude decontamination adsorbent.

[0099] Add the cleaning adsorbent and anhydrous ethanol at a ratio of 1g:3.5mL to a three-necked flask and stir. Raise the temperature of the three-necked flask to reflux the system and keep it warm until the system is clear. Filter while hot. Transfer the filtrate to another three-necked flask and stir. Lower the temperature of the three-necked flask to 8℃ and keep it warm for 50min to allow crystals to precipitate. Filter and wash the filter cake with anhydrous ethanol at 8℃ and dry it under vacuum. Transfer the filter cake to a drying oven at 60℃ and vacuum dry it to constant weight to obtain the cleaning adsorbent.

[0100] The stain-removing adsorbent, polyethylene glycol 400, and sodium fatty acid methyl sulfonate were mixed evenly in a ratio of 4g:2g:1g to obtain a stain-removing additive.

[0101] S2, Preliminary Flotation

[0102] Weigh out 20g of glass fiber powder, 400g of purified water, and 12g of detergent additive, and add them to an XFD-Ⅲ type single-cell flotation machine. The stirring speed of the flotation machine is 4000r / min, and the aeration rate is 0.5m³. 3 After initial flotation treatment, the glass fiber powder is filtered, washed, and dried to obtain pretreated glass fiber powder.

[0103] S3, Slurry preparation, ultrasonic treatment

[0104] Pretreated glass fiber powder and purified water were added to a beaker at a ratio of 1g:100mL to prepare a slurry. An ultrasonic titanium probe was immersed about 2cm below the surface of the prepared solution. The ultrasonic amplitude was set to 70%, the mode was "2s on 2s off", and the frequency was 20kHz. The mixture was ultrasonically dispersed for 60min to obtain a glass fiber powder mixed solution.

[0105] S4, Dispersion

[0106] Sodium hexametaphosphate and purified water were mixed evenly at a ratio of 1g:5g to obtain a dispersion solution;

[0107] A dispersion solution was added dropwise to the glass fiber powder mixture solution, and the mixture was stirred at room temperature for 30 minutes to obtain a glass fiber powder dispersion. The amount of dispersion solution used was 1 / 30 of the weight of the glass fiber powder mixture solution.

[0108] S5, Settlement

[0109] The glass fiber powder dispersion is placed into a settling tube and allowed to settle naturally for 10 minutes at room temperature. The height of the float 205 relative to the bottom inner wall of the settling tube is adjusted so that the top of the float 205 is flush with the interface between the lower slurry layer and the upper suspension layer formed by the glass fiber powder dispersion in the settling tube. The valve on the drain pipe 207 is opened to separate the upper suspension layer, thus obtaining the rod-shaped wet glass fiber product.

[0110] S6. Washing and drying

[0111] The wet rod-shaped glass fiber was washed three times with anhydrous ethanol, then washed three times with purified water and dried under vacuum. The filter cake was transferred to a drying oven at 95°C and dried under vacuum until constant weight to obtain rod-shaped glass fiber powder.

[0112] Comparative Example 1

[0113] The difference between this comparative example and Example 4 is that step S1 is omitted and no cleaning additive is added in step S2.

[0114] Comparative Example 2

[0115] The difference between this comparative example and Example 4 is that no dispersion solution was added in step S4.

[0116] Comparative Example 3

[0117] The difference between this comparative example and Example 4 is that no cleaning additive was added in step S2 and no dispersion solution was added in step S4.

[0118] Performance testing:

[0119] The rod-shaped glass fiber powder samples prepared in Examples 2-4 and Comparative Examples 1-3, as well as the glass fibers before sedimentation, were tested using a laser particle size analyzer. The metal content in the rod-shaped glass fiber powder samples prepared in Examples 2-4 and Comparative Examples 1-3 was detected using X-ray fluorescence spectroscopy. The specific test results are shown in the table below:

[0120]

[0121] Data Analysis:

[0122] By comparing and analyzing the data in the table above, the average particle size of the rod-shaped glass fiber powder prepared by this invention is 22.30 μm for D10, 59.83 μm for D10, and 202.37 μm for D10. No iron, chromium, or arsenic metals were detected in the sample. (This information is consistent with the appendix to the specification.) Figure 2 The optical microscope images of glass fiber powder before (1) and after (2) sedimentation in Example 4 clearly show that the content of ground granular glass fiber powder with a small aspect ratio decreases after processing by the method in Example 4, and rod-shaped glass fiber powder with a large aspect ratio is obtained. The detection data of the present invention are better than those of the comparative example, indicating that the present invention can separate granular glass fiber powder with a small aspect ratio from glass fiber powder and obtain rod-shaped glass fiber powder with a large aspect ratio and low metal content.

[0123] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

[0124] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0125] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for separating rod-shaped glass fibers from glass fiber powder, characterized in that, Includes the following steps: Step 1: Preliminary flotation Glass fiber powder, purified water, and decontamination additives are added to a flotation machine for preliminary flotation treatment to remove oil stains, black spots, and metals from the glass fiber powder and to pre-disperse the glass fiber powder to obtain pretreated glass fiber powder. Step 2: Slurry preparation and ultrasonic treatment Pretreated glass fiber powder and purified water were added to a beaker to prepare a slurry. The prepared solution was then ultrasonically dispersed for 40-60 minutes to separate the agglomerated and adhered powder particles in the slurry, resulting in a glass fiber powder mixed solution. Step 3: Disperse Add a dispersion solution dropwise to the glass fiber powder mixture solution, stir at room temperature for 20-30 minutes to disperse the slurry and obtain a glass fiber powder dispersion. Step 4: Settlement The glass fiber powder dispersion was placed in a settling tube and allowed to settle naturally at room temperature for 5-10 minutes. The lower layer of settled solid was then separated and extracted to obtain the wet rod-shaped glass fiber. Step 5: Washing and drying The wet rod-shaped glass fiber was washed three times with anhydrous ethanol, then washed three times with purified water and dried under vacuum. The filter cake was transferred to a drying oven at 85-95℃ and dried under vacuum until constant weight to obtain rod-shaped glass fiber powder.

2. The method for separating rod-shaped glass fibers from glass fiber powder according to claim 1, characterized in that, In step one, the ratio of glass fiber powder, purified water, and detergent additive is 10g:200g:6g. The detergent additive consists of a detergent adsorbent, polyethylene glycol 400, and sodium methyl sulfonate in a ratio of 4g:2g:1g. The stirring speed of the flotation machine is 1000-4000 r / min, and the aeration rate is 0.1-0.5 m³ / min. 3 / h.

3. The method for separating rod-shaped glass fibers from glass fiber powder according to claim 2, characterized in that, The decontamination adsorbent is produced by the following steps: A1. Add 2-chloroethylamine, ethanol, and sodium hydroxide to a three-necked flask and stir until the system is dissolved. Raise the temperature of the three-necked flask to 34-40°C and add carbon disulfide dropwise to the three-necked flask at room temperature. After the addition is complete, keep the reaction at the temperature for 20-22 hours and then process to obtain intermediate I. A2. Add intermediate I, notoginsenoside R1, composite catalyst and N,N-dimethylformamide into a three-necked flask and stir. Raise the temperature of the three-necked flask to 90-100℃ and keep it at that temperature for 6-8 hours. Then, after post-treatment, obtain the decontamination adsorbent.

4. The method for separating rod-shaped glass fibers from glass fiber powder according to claim 3, characterized in that, In step A1, the ratio of 2-chloroethylamine to carbon disulfide is 1 mol: 1.01 mol, wherein the ratio of 2-chloroethylamine, ethanol, and sodium hydroxide is 1 g: 8 g: 0.5 g, and the post-processing operation includes: after the reaction is complete, the temperature of the three-necked flask is reduced to 10-15°C, the mixture is filtered, the filter cake is washed three times with anhydrous ethanol and then dried under vacuum, the filter cake is transferred to a drying oven at 50-60°C and dried under vacuum to constant weight to obtain intermediate I.

5. The method for separating rod-shaped glass fibers from glass fiber powder according to claim 3, characterized in that, In step A2, the ratio of intermediate I to notoginsenoside R1 is 1 mol: 1.02 mol, wherein the ratio of the notoginsenoside R1, the composite catalyst, and N,N-dimethylformamide is 10 g:0.3 g:60 g, and the composite catalyst is composed of palladium chloride and triphenylphosphine in a ratio of 1 g:1.5 g. The post-treatment operation includes: after the reaction is complete, maintaining the temperature of the three-necked flask at 90-100°C, removing N,N-dimethylformamide by vacuum distillation, and then lowering the temperature of the three-necked flask to room temperature to obtain a crude decontamination adsorbent. Add the adjuvant and anhydrous ethanol at a ratio of 1g:3.5mL to a three-necked flask and stir. Raise the temperature of the three-necked flask to reflux the system and keep it warm until the system is clear. Filter while hot and transfer the filtrate to another three-necked flask and stir. Lower the temperature of the three-necked flask to 5-8℃ and keep it warm for 30-50 minutes to allow crystals to precipitate. Filter and wash the filter cake with anhydrous ethanol at 5-8℃ and then dry it under vacuum. Transfer the filter cake to a drying oven at 50-60℃ and vacuum dry it to constant weight to obtain the decontamination adsorbent.

6. The method for separating rod-shaped glass fibers from glass fiber powder according to claim 1, characterized in that, In step two, the ratio of pretreated glass fiber powder to purified water is 1g:100mL. The ultrasonic method is as follows: the ultrasonic titanium probe is immersed about 2cm below the surface of the prepared solution, and the ultrasonic amplitude is set to 70%, the mode is "2s on 2s off", and the frequency is 20kHz.

7. The method for separating rod-shaped glass fibers from glass fiber powder according to claim 1, characterized in that, In step three, the ratio of the glass fiber powder mixed solution to the dispersion solution is 30g:1g, and the dispersion solution is composed of sodium hexametaphosphate and purified water in a ratio of 1g:5g.

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