Method for separating rubber abrasive dust and superfine talcum powder on surface of rubber abrasive dust

Abstract

The invention discloses a method for separating rubber abrasive dust and superfine talcum powder on the surface of the rubber abrasive dust. The method mainly aims at the rubber abrasive dust generated in a Lanbern abrasion test. The method comprises the following steps: firstly collecting abrasive dust, then preparing an aqueous solution containing a surfactant, and reducing the adhesive force between the abrasive dust and talcum powder by using the surfactant. The method comprises the following steps: adding rubber abrasive dust into a solution, introducing gas at a specific flow rate, and then filtering, cleaning and drying the abrasive dust. Through comparison and verification of a plurality of embodiments, compared with a traditional screening method, the method can effectively reduce the residual amount of talcum powder on the surface of the rubber abrasive dust, the residual amount is controlled to be about 1.0%-1.5%, and the residual amount is as high as 25.6% through the traditional screening method. The talcum powder on the surface of the rubber abrasive dust separated by the method is in a small-amount dispersed or extremely-small-amount dispersed state, the requirements of deep research on the microstructure, chemical components and the like of the rubber abrasive dust can be met, the problem that the talcum powder and the rubber abrasive dust are difficult to effectively separate by a traditional separation method is solved, and a reliable sample treatment means is provided for research on rubber wear particles.

Description

Technical Field

[0001] The invention relates to the field of spraying technology, in particular to a method for separating rubber wear debris and ultrafine talc powder on its surface. Background Art

[0002] As society develops, countries are increasingly prioritizing environmental protection. During use, tires generate large amounts of rubber debris due to continuous friction with the road. This debris not only pollutes the air as dust, but certain components in it can also harm soil and water environments, impacting ecological balance and human health. The Euro 7 standard, for the first time, includes particulate matter generated by tire wear, known as rubber debris, in its emissions standards, placing strict limits on the amount of dust and debris generated by vehicle tires.

[0003] The Lamborn abrasion test is currently a key method for testing the wear properties of rubber. This method is authoritative and widely recognized in the international rubber industry. To simulate the conditions of actual use, such as exposure to dust and other external substances, talcum powder is often added during the test. This, on the one hand, can adjust the coefficient of friction between the rubber and the friction surface to a certain extent, making the test conditions more similar to actual working conditions. On the other hand, it also helps prevent excessive adhesion of rubber debris to the surface of the experimental equipment during the test, ensuring a relatively stable and continuous test.

[0004] However, when further in-depth research is required on rubber scraps, such as analyzing the surface microstructure, chemical composition, particle size distribution and other characteristics of the scraps, the talc powder attached to the surface of the scraps will become an interference factor. Since rubber scraps and talc powder have certain similarities and correlations in physical and chemical composition, the separation of the two is extremely challenging. At present, traditional separation methods and some conventional physical separation methods, such as simple screening and sedimentation, cannot effectively distinguish between rubber scraps and talc powder particles with similar particle sizes that may adsorb each other. Chemical separation methods such as organic reagents may destroy or change the properties of the rubber scraps themselves, causing swelling or size shrinkage, thereby affecting the research and judgment of the true characteristics of the rubber scraps. Therefore, it is urgent to develop a method specifically for separating rubber scraps and talc powder on their surface generated by laboratory Lamborn abrasion experiments to meet the needs of in-depth research on rubber wear particles.

[0005] Based on this, a method for separating rubber grinding debris and ultrafine talc powder on its surface is now provided, which can eliminate the disadvantages of the existing device. Summary of the Invention

[0006] The object of the present invention is to provide a method for separating rubber grinding debris and ultrafine talc powder on its surface, which solves the problem of inconvenience in use in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for separating rubber scraps and ultrafine talc powder on their surface, characterized by comprising the following steps:

[0009] Step 1: Sample preparation: Collect the wear debris generated during the Lamborn abrasion test. Typically, the collected wear debris consists primarily of the wear debris itself and ultrafine talc powder, and no additional processing is required.

[0010] Step 2: Solution preparation: Accurately weigh an appropriate amount of surfactant, add it to the water solvent, and stir thoroughly to ensure that the surfactant is completely dissolved to form a uniform solution;

[0011] Step 3: Impurity separation: Accurately weigh 0.05-1.00g of rubber grinding sample and carefully add it to a clean beaker;

[0012] Slowly add 200-1000 mL of the pre-prepared solution into the beaker, ensuring that the wear debris sample is completely immersed in the solution;

[0013] Insert a suitable glass tube into the beaker, generally with a diameter of 4-8 mm. Introduce gas through the tube, controlling the airflow rate within 1 L / min and the ventilation time between 10-30 minutes. During the ventilation process, pay close attention to the airflow rate to prevent liquid or foam splashing due to excessive airflow, which may affect the operation and results.

[0014] Step 4: Filter:

[0015] Slowly pour the liquid in the beaker after the impurity separation operation into a stainless steel mesh of appropriate mesh size for filtration. Rinse the beaker with pure water to ensure that all the grinding debris particles enter the stainless steel mesh. During the filtration process, ensure that the filtrate passes through the filter evenly. The filtrate contains talcum powder. If necessary, it can be collected and tested, and the grinding debris left on the filter is retained.

[0016] Step 5: Cleaning:

[0017] Take an appropriate amount of pure water and slowly pour it into the stainless steel mesh containing the grinding chips to rinse the grinding chips; repeat the rinsing operation to ensure that the residual solution and impurities on the surface of the grinding chips are thoroughly cleaned;

[0018] Step 6: Drying:

[0019] The cleaned wear debris samples were placed in an oven for drying until the wear debris was completely dry.

[0020] On the basis of the above technical solutions, the present invention also provides the following optional technical solutions:

[0021] In an optional solution: in step 1, during the collection of wear chips, the representativeness of the wear chips should be ensured to avoid deviation of the wear chip sample due to improper collection method, which will affect the subsequent evaluation of the separation effect.

[0022] In an optional scheme: in step 2: the addition of surfactant should be appropriate, and the stirring process after addition should not produce overflowing foam, and the grinding chips can be well dispersed in the water solvent; the addition of surfactant is to reduce the surface energy of the grinding chips, reduce the contact angle between water molecules and grinding chips and talcum powder, and increase the wettability of water to both, thereby reducing the adhesion between the grinding chips and talcum powder; the amount of surfactant should be guaranteed during preparation to ensure the stability of the solution performance; common surfactants can play this role.

[0023] In one alternative, in step 4, when selecting a glass tube, ensure that its inner diameter and length are suitable for the current experimental setup, generate stable air bubbles in the solution, and evenly emerge from the gas device.

[0024] During ventilation, a gas flow meter can be used to precisely control the airflow rate and improve the repeatability of the experiment.

[0025] The gas can be compressed air or nitrogen, and the initial pressure can be set between 0.1-0.3 MPa.

[0026] In one optional solution: In step 4: the selection of the screen is based on the aperture size that can effectively intercept the abrasive particles and only pass the talcum powder particles. Before filtering, the filter should be checked to see if it is intact to avoid filtration failure due to filter damage; when pouring the liquid, it should be slow and even to avoid the liquid flow rate being too fast, which may cause the filter to overflow and the abrasive particles to be lost.

[0027] In an optional solution: In step five: Use pure water for cleaning to avoid introducing new impurities. During the rinsing process, gently shake the stainless steel mesh so that the grinding chips can fully contact the water to improve the cleaning effect. After each rinse, carefully observe or use concentrated filtrate to observe whether there is white powder at the bottom. If there is, increase the number of rinses appropriately.

[0028] In one optional solution: In step 6: Before placing the grinding chips into the oven, ensure that the oven has reached the preheating temperature and that the oven is clean and free of debris to avoid secondary contamination of the grinding chips; during the drying process, the degree of drying of the grinding chips can be regularly checked by quality testing to avoid changes in the properties of the grinding chips due to excessive drying time.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] This proposal uses water as the separation medium and the reagents used are low-priced, which reflects good economic efficiency and meets environmental protection requirements.

[0031] Avoiding secondary damage to grinding chips: This solution eliminates the need for vibrating screens or agitators to separate grinding chips. The vibrations generated by traditional vibrating screens and agitators can exert external forces on the grinding chips, causing damage and affecting their appearance and size.

[0032] Separation Advantages: Liquid is used to disperse wear debris particles, and surfactants are used to reduce the surface energy of the wear debris. This allows water molecules to reduce the electrostatic and van der Waals forces between the wear debris and talc, effectively reducing the adhesion between the wear debris and talc. At the same time, air bubble flotation replaces mechanical stirring and vibration, significantly reducing the adverse effects of extrusion and vibration on the wear debris.

[0033] Widely applicable: This method utilizes a liquid medium containing a surfactant to separate through bubble floating, without the need for equipment such as a vibrating screen. The method is easy to master, easy to use, and easy to promote. DETAILED DESCRIPTION

[0034] 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 embodiments described 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.

[0035] This proposal proposes an innovative separation technology for grinding dust and the ultrafine talc powder on its surface. This technology mainly uses water as the separation medium and relies on bubble flotation to achieve effective separation of grinding dust and ultrafine talc powder. Finally, pure grinding dust particles are obtained through a stainless steel sieve.

[0036] principle

[0037] Interfacial effects of water:

[0038] Grinding dust and talc typically have different surface properties. Talc is hydrophobic, while grinding dust may be hydrophilic or have varying degrees of hydrophobicity, resulting in different surface energies for grinding dust and talc. When an appropriate amount of surfactant is added to water, the surfactant molecules adsorb on the surfaces of grinding dust and talc particles. The surfactant has both hydrophilic and hydrophobic groups. The hydrophobic groups interact with the grinding dust and talc, while the hydrophilic groups extend into the water, allowing the grinding dust and talc mixture to be better dispersed in the water. The presence of water changes the interface between the two substances, forming a new interface on the surfaces of the two substances. The interfacial tension of water interacts with the adhesion between the two substances, reducing the original adhesion between the two substances.

[0039] Surface charge and electrostatic repulsion:

[0040] When grinding chips and talcum powder come into contact with water, their surfaces may adsorb ions in the water, thereby carrying a certain charge. If the grinding chips and talcum powder carry the same charge, according to Coulomb's law, the electrostatic repulsion generated can cause the two substances to separate.

[0041] Fluid dynamics effect:

[0042] When water wets two substances, if there is an external fluid dynamic effect, such as stirring, vibration, etc., the shear force of the water flow will act on the two substances to overcome the remaining adhesion force, thereby separating the two substances.

[0043] Steps

[0044] Sample preparation: Collect the wear debris generated during the Lamborn abrasion test. Typically, the collected wear debris consists primarily of the wear debris itself and ultrafine talc powder, and no additional processing is required.

[0045] Supplementary note: During the collection of wear chips, the representativeness of the wear chips should be ensured to avoid deviation of the wear chip samples due to improper collection methods, which will affect the subsequent evaluation of the separation effect.

[0046] Solution preparation: Accurately weigh an appropriate amount of surfactant, add it to the water solvent, and stir thoroughly to ensure that the surfactant is completely dissolved to form a uniform solution.

[0047] Supplemental Note: The surfactant should be added in an appropriate amount. After addition, stirring should not produce excessive foam and ensure that the grinding debris is well dispersed in the aqueous solvent. The surfactant is added to reduce the surface energy of the grinding debris, lowering the contact angle between water molecules and the grinding debris and talc, and increasing the wettability of both, thereby reducing the adhesion between the grinding debris and talc. The surfactant dosage should be carefully controlled during formulation to ensure stable solution properties. Common surfactants can serve this purpose.

[0048] Impurity separation:

[0049] 1 Accurately weigh 0.05-1.00g of rubber grinding sample and carefully add it to a clean beaker.

[0050] 2. Slowly add 200-1000 mL of the pre-prepared solution into the beaker, ensuring that the wear chip sample is completely immersed in the solution.

[0051] 3. Insert a suitable glass tube (typically 4-8 mm in diameter) into the beaker. Introduce gas through the tube, controlling the airflow rate to less than 1 L / min and maintaining the aeration time between 10 and 30 minutes. During the aeration process, pay close attention to the airflow rate to prevent excessive airflow from splashing liquid or foam, which could affect the operation and results.

[0052] Additional notes:

[0053] When selecting a glass tube, ensure that its inner diameter and length are suitable for the current experimental device, generate stable airflow bubbles in the solution, and the airflow bubbles should emerge evenly from the gas device.

[0054] During ventilation, a gas flow meter can be used to precisely control the airflow rate and improve the repeatability of the experiment.

[0055] The gas can be compressed air or nitrogen, and the initial pressure can be set between 0.1-0.3 MPa.

[0056] filter:

[0057] After the impurity separation operation, slowly pour the liquid in the beaker into a stainless steel mesh of appropriate mesh size for filtration. Rinse the beaker with pure water to ensure that all grinding debris particles enter the stainless steel mesh. During the filtration process, ensure that the filtrate passes through the filter evenly. The filtrate contains talc powder. If necessary, collect and test it, and retain the grinding debris remaining on the filter.

[0058] Additional notes:

[0059] The selection of the screen is based on the pore size that can effectively intercept the wear particles and only pass the talcum powder particles. Before filtering, the filter should be checked to see if it is intact to avoid filtration failure due to filter damage.

[0060] When pouring the liquid, it should be done slowly and evenly to avoid the liquid flowing too fast, which may cause the filter to overflow and the grinding chips to be lost.

[0061] Cleaning:

[0062] Take an appropriate amount of pure water and slowly pour it into the stainless steel mesh containing the grinding chips to rinse the grinding chips. Repeat the rinsing operation to ensure that the residual solution and impurities on the surface of the grinding chips are thoroughly cleaned.

[0063] Additional notes:

[0064] Use pure water to rinse to avoid introducing new impurities. Gently shake the stainless steel mesh during the rinse process to allow the grinding chips to fully contact the water and improve the cleaning effect. After each rinse, carefully observe or use concentrated filtrate to observe whether there is white powder at the bottom. If there is, increase the number of rinses appropriately.

[0065] dry:

[0066] The cleaned wear debris samples were placed in an oven for drying until the wear debris was completely dry.

[0067] Supplementary Note: Before placing the grinding chips in the oven, ensure that the oven has reached the preheating temperature and that the oven is clean and free of debris to avoid secondary contamination of the grinding chips. During the drying process, the degree of drying of the grinding chips can be regularly checked by quality testing to avoid changes in the properties of the grinding chips due to excessive drying time.

[0068]

[0069]

[0070] Comparative Example (Traditional Screening Method)

[0071] 0.5 g of rubber grinding debris was directly sieved using a common sieve with a pore size of 10 μm without any other operations such as solution treatment;

[0072] The residual talc on the surface of rubber scraps was observed by scanning electron microscopy, and the relative content of residual talc (in mass percentage) was determined by energy dispersive spectroscopy (EDS). The data are as follows:

[0073]

[0074]

[0075] The data clearly demonstrates that the separation method of this application, under different surfactants and operating parameters, can effectively reduce the amount of talc remaining on the surface of rubber scraps, resulting in a small or extremely small dispersion of talc on the surface of the rubber scraps, meeting the requirements of subsequent research on the microstructure of the rubber scraps. Traditional screening methods, on the other hand, produce extremely poor separation results, leaving large amounts of talc on the surface of the rubber scraps, making them unsuitable for in-depth research. This fully demonstrates the advantages of this extraction method.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for separating rubber scraps and ultrafine talc powder on their surface, characterized in that: The following steps are involved: Step 1: Sample preparation: Collect the wear debris generated during the Lamborn abrasion test. Typically, the collected wear debris mainly contains the wear debris itself and ultrafine talc powder. Step 2: Solution preparation: Accurately weigh an appropriate amount of surfactant, add it to the water solvent, and stir thoroughly to ensure that the surfactant is completely dissolved to form a uniform solution; Step 3: Impurity separation: Accurately weigh 0.05-1.00g of rubber grinding sample and carefully add it to a clean beaker; Slowly add 200-1000 mL of the pre-prepared solution into the beaker, ensuring that the wear debris sample is completely immersed in the solution; Insert a suitable glass tube into the beaker, usually with a diameter of 4-8 mm, and introduce gas through the tube, controlling the airflow rate within 1 L / min and the ventilation time between 10-30 minutes; Step 4: Filter: Slowly pour the liquid in the beaker after the impurity separation operation into a stainless steel mesh of appropriate mesh size for filtration. Rinse the beaker with pure water to ensure that all the grinding debris particles enter the stainless steel mesh. During the filtration process, ensure that the filtrate passes through the filter evenly. The filtrate contains talcum powder. Step 5: Cleaning: Take an appropriate amount of pure water and slowly pour it into the stainless steel mesh containing the grinding chips to rinse the grinding chips; repeat the rinsing operation to ensure that the residual solution and impurities on the surface of the grinding chips are thoroughly cleaned; Step 6: Drying: The cleaned wear debris samples were placed in an oven for drying until the wear debris was completely dry.

2. The method for separating rubber scraps and ultrafine talc powder on their surface according to claim 1, characterized in that: In the process of collecting wear chips in step 1, the representativeness of the wear chips should be ensured to avoid the deviation of the wear chip sample due to improper collection method, which will affect the evaluation of the subsequent separation effect.

3. The method for separating rubber scraps and ultrafine talc powder on their surface according to claim 1, characterized in that: In step 2: the surfactant should be added in an appropriate amount, and the stirring process after addition should not produce excessive foam, and the grinding chips should be well dispersed in the water solvent.

4. The method for separating rubber scraps and ultrafine talc powder on their surface according to claim 1, characterized in that: When selecting the glass tube in step 4, ensure that its inner diameter and length are suitable for the current experimental setup, generate stable air bubbles in the solution, and the air bubbles should emerge evenly from the gas device; The gas is compressed air or nitrogen, and the initial pressure can be set between 0.1-0.3MPa.

5. The method for separating rubber scraps and ultrafine talc powder on their surface according to claim 1, characterized in that: In step 4: the aperture size of the screen is matched with the intercepted wear debris particles.

6. The method for separating rubber scraps and ultrafine talc powder on their surface according to claim 1, characterized in that: In step five: Use pure water for cleaning to avoid introducing new impurities. During the rinsing process, gently shake the stainless steel mesh so that the grinding chips can fully contact the water to improve the cleaning effect. After each rinse, carefully observe or use concentrated filtrate to observe whether there is white powder at the bottom. If there is, increase the number of rinses appropriately.

7. The method for separating rubber scraps and ultrafine talc powder on their surface according to claim 1, characterized in that: In step 6: Before placing the grinding chips into the oven, ensure that the oven has reached the preheating temperature and that the oven is clean and free of debris to avoid secondary contamination of the grinding chips.

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