High-pressure-resistant tailing pipe fitting material and preparation method thereof

Abstract

The invention relates to a high-pressure-resistant tailing pipe fitting material and a preparation method thereof, and belongs to the technical field of tailing material processing. The high-pressure-resistant tailing material is prepared by the following preparation method: A, providing a tailing pipe fitting obtained by extrusion molding of ultra-high molecular weight polyethylene; b, laser scanning is adopted in at least part of the area of the inner wall face of the tailing pipe fitting to form a micro-texture with pits; and C, the surfaces of the microtextures are coated with elastomer coating liquid, and the pits are at least filled with the elastomer coating liquid. The ultra-high molecular weight polyethylene is adopted as a base material, and the inner wall micro-texture laser treatment and elastomer coating technology is combined, so that dispersion and absorption of impact stress are achieved, the inner wall of the pipe fitting has good wear resistance, and finally the comprehensive performance of the tailing pipe fitting material is improved; the tailing pipe fitting material is better suitable for high-pressure slurry conveying scenes in the fields of mines, metallurgy, electric power, chemical engineering and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material processing, and particularly relates to a high-pressure resistant tailings pipe material and a preparation method thereof. Background Art

[0002] Tailings conveying pipelines are wear-resistant and corrosion-resistant pipes specifically designed for conveying mine tailings slurry. They are widely used in industries such as coal, electricity, chemicals, and mining. During tailings conveying, traditional tailings pipe fittings (such as ordinary polyethylene and steel pipes) must withstand high pressure and the impact of the slurry. These materials are prone to deformation and rupture under high-pressure environments, and suffer from insufficient pressure resistance and poor wear resistance, resulting in a short service life for the fittings. Frequent pipe replacement not only increases costs and maintenance workload, but also affects production efficiency.

[0003] To address these issues, existing tailings conveying pipes mostly use ultra-high molecular weight polyethylene (UHMWPE) or ceramic composite pipes. While UHMWPE pipes possess a certain degree of high-pressure resistance and wear resistance, they are susceptible to structural fatigue due to deformation of the inner layer under high-pressure environments. Furthermore, their smooth inner wall surface can easily lead to accelerated wear due to localized stress concentration when impacted by high-velocity, high-particle-concentration slurry particles. Furthermore, their poor melt fluidity makes them difficult to form using conventional extrusion processes. While ceramic composite pipes possess high hardness and wear resistance, they suffer from issues such as brittleness, poor impact resistance, and complex manufacturing processes, and are unable to meet the demands of high-pressure conveying.

[0004] Existing technologies improve pressure resistance by increasing wall thickness or using composite metal layers, but this sacrifices lightweighting and cost-effectiveness. Surface treatment often relies on chemical coatings, which offer limited improvement in wear resistance and are prone to flaking. Therefore, there is an urgent need to develop a tailings pipe material that combines high-pressure and wear resistance. Summary of the Invention

[0005] The present invention aims to provide a high-pressure tailings pipe material and a preparation method thereof, which has good wear resistance.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing a high-pressure resistant tailings pipe material comprises the following steps:

[0008] A. Provide tailings pipe fittings made from ultra-high molecular weight polyethylene extrusion molding;

[0009] B. forming a micro texture with pits on at least a portion of the inner wall of the tailings pipe by laser scanning;

[0010] C. Coating an elastomer coating liquid on the micro-textured surface, and allowing the elastomer coating liquid to at least fill the recesses.

[0011] In this technical solution, the tailings conveying pipeline is continuously extruded using ultra-high molecular weight polyethylene. The molecular weight of ultra-high molecular weight polyethylene is usually 200-600w, which is much higher than that of ordinary high-density polyethylene (HDPE, molecular weight 30-50w). In addition, the molecular chain of ultra-high molecular weight polyethylene is long and tightly wound, forming a highly crystalline structural area, which gives the material excellent high pressure resistance, shear resistance and impact resistance.

[0012] On the one hand, setting up a micro-texture with pits can increase the micro-roughness of the inner wall. When the tailings particles collide with the pipe wall, these pits can disperse the impact force and distribute the impact force over a larger surface area, thereby reducing local stress concentration, reducing the local wear rate, and reducing the wear and damage risk of the pipe wall.

[0013] On the other hand, the formation of micro-texture also provides more attachment points for the elastomer coating, thereby improving the bonding strength between the elastomer coating and the pipe wall. The elastic coating formed after the elastomer coating is cured has good elasticity and toughness, and can undergo elastic deformation when the tailings particles hit the pipe wall, thereby buffering or absorbing part of the impact energy, reducing the direct wear of hard particles on the ultra-high molecular weight polyethylene substrate, and reducing the impact force on the pipe wall. At the same time, filling the micro-texture pits further enhances the wear resistance of the inner wall, thereby effectively improving the overall wear resistance of the tailings pipe fittings.

[0014] Specifically, the specific preparation process of step A is: ultra-high molecular weight polyethylene particles and various additives are mixed evenly in a certain proportion to ensure that the components are fully dispersed; then, the mixed material is added to an extruder, the material is plasticized and extruded through the screw of the extruder, and the tailings pipe fittings are obtained after cooling and shaping.

[0015] Preferably, the additives used to prepare the tailings pipes include at least one of an antioxidant, a light stabilizer, a cross-linking agent, a filler, a lubricant, and an anti-ultraviolet agent.

[0016] As a preferred technical solution of the present invention, in step B, before laser scanning the inner wall surface of the micro-texture, the inner wall surface of the tailings pipe is first cleaned with anhydrous ethanol or ultrasonically cleaned with deionized water to remove oil stains and impurities on the inner wall surface of the tailings pipe to ensure uniform energy absorption during laser processing.

[0017] As a preferred technical solution of the present invention, in step B, the laser type used for laser scanning is at least one of a fiber laser marker, a CO2 laser, a fiber laser, a YAG laser, a femtosecond laser, and a nanosecond laser.

[0018] As a preferred technical solution of the present invention, in step B, the laser scanning is performed with a laser power of 10-30 W, a scanning speed of 500-2000 mm / s, and a pulse frequency of 20-50 kHz.

[0019] As a preferred technical solution of the present invention, the micro texture is hexagonal.

[0020] Specifically, the hexagon can be a bionic pitcher plant structure or a honeycomb structure.

[0021] Further preferably, the pits have a diameter of 50-200 μm, a depth of 30-100 μm, and a spacing of 100-300 μm; wherein, if the spacing between the pits is too small, the texture will merge, while if it is too large, the hydrophobicity will be reduced.

[0022] Preferably, the area of ​​the pits accounts for 15-22% of the total area of ​​the inner wall of the pipe. If the pit area ratio is too low, the contact surface of the elastomer coating will be reduced, while if it is too high, the hydrophobicity will be reduced.

[0023] As a preferred technical solution of the present invention, after step B, the inner wall of the pipe is ultrasonically cleaned with deionized water or purged with nitrogen to remove residues on the inner wall of the pipe and enhance the adhesion of the elastomer.

[0024] As a preferred technical solution of the present invention, the elastomer coating liquid includes at least one of a polyurethane dispersion and a silicone rubber dispersion.

[0025] Preferably, the polyurethane dispersion comprises 40-60 wt% of polyester diol, 15-35 wt% of isocyanate, 10-20 wt% of acetone and NMP complex, and 4-8 wt% of hydrophilic chain extender.

[0026] Preferably, the hydrophilic chain extender is a DMPA chain extender or a sulfonic acid chain extender.

[0027] Furthermore, the silicone rubber dispersion includes 30-50wt% of polydimethylsiloxane emulsion or hydrogenated nitrile rubber, 10-20wt% of reinforcing filler, 1-3wt% of crosslinking agent, 2-5wt% of emulsifier, 2-4wt% of vulcanizing agent, 1-2wt% of structure control agent, 1-5wt% of acetone, and the balance is deionized water.

[0028] Preferably, the reinforcing filler is fumed silica with a particle size of 10-40 nm; the crosslinking agent is vinyltrimethoxysilane or silane coupling agent KH-550, and the structure control agent is hexamethyldisilazane; the emulsifier is non-ionic polyether modified silicone oil or polyoxyethylene ether emulsifier; and the vulcanizing agent is DBPH and TAIC crosslinking aid.

[0029] As a preferred technical solution of the present invention, the elastomer coating liquid includes the following components and parts by weight: 60-70 parts of polyurethane dispersion, 10-20 parts of silicone rubber dispersion, 5-8 parts of nano-silicon dioxide, 10-15 parts of epoxy resin and 3-5 parts of curing agent.

[0030] As a preferred technical solution of the present invention, in step C, the coating process of the elastomer coating liquid on the micro-textured surface is at least one of spraying, brushing or dipping.

[0031] Preferably, in step C, the thickness of the coating of the elastomer coating liquid applied on the micro-textured surface is 50-100 μm.

[0032] Preferably, after step C, the micro-textured surface is subjected to thermal curing or UV curing treatment, with the thermal curing condition being 80-100° C. / 1-2 h; and the UV curing condition being a wavelength of 365 nm and an irradiation time of 1-3 min.

[0033] The present invention coats an elastomer coating liquid on the inner wall of the pipe, causing the elastomer coating liquid to undergo a cross-linking reaction on the inner wall of the pipe to form a coating with elasticity and toughness, which is tightly bonded to the inner wall of the pipe and enhances the inner wall's ability to buffer and withstand impact forces.

[0034] Beneficial effects of the present invention:

[0035] (1) The present invention adopts ultra-high molecular weight polyethylene as the base material, combines the inner wall micro-texture laser processing and elastomer coating technology, realizes the dispersed absorption of impact stress, makes the inner wall of the pipe have good wear resistance, and ultimately improves the comprehensive performance of the tailings pipe material, making the tailings pipe material better suitable for high-pressure slurry transportation scenarios in the fields of mining, metallurgy, electric power, chemical industry, etc.

[0036] (2) The high-pressure tailings pipe fitting material produced by the present invention has significant advantages in high-pressure resistance and wear resistance compared with existing tailings pipe fitting materials. It can effectively meet the stringent requirements in the tailings transportation process, extend the service life of the pipe fittings, reduce production costs, and has broad application prospects. DETAILED DESCRIPTION

[0037] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0038] Example 1

[0039] A high-pressure tailings pipe material is prepared by the following preparation method:

[0040] A. Provide tailings pipe fittings made from ultra-high molecular weight polyethylene extrusion.

[0041] B. The inner surface of the tailings pipe was cleaned with anhydrous ethanol. A fiber laser marking machine was then used to scan the inner surface of the pipe to create a microtexture with pits. The laser scanning power was 20W, the scanning speed was 1200mm / s, and the frequency was 30kHz. The resulting microtexture was a hexagonal pitcher plant-like structure. The pits had a diameter of 80±5μm, a depth of 70±5μm, and a spacing of 200μm.

[0042] C. Coating an elastomer coating liquid on the micro-textured surface, and allowing the elastomer coating liquid to at least fill the recesses.

[0043] The elastomer coating liquid includes the following components in parts by weight: 65 parts of polyurethane dispersion, 13 parts of silicone rubber dispersion, 6 parts of nano-silicon dioxide, 12 parts of epoxy resin and 4 parts of curing agent.

[0044] The polyurethane dispersion comprises 50 wt% of polyester diol, 28 wt% of isocyanate, 15 wt% of acetone and NMP complex, and 7 wt% of DMPA chain extender.

[0045] The silicone rubber dispersion includes 40 wt% of polydimethylsiloxane emulsion, 15 wt% of fumed silica, 2 wt% of vinyltrimethoxysilane crosslinker, 4 wt% of nonionic polyether modified silicone oil, 1.5 wt% of hexamethyldisilazane, 3 wt% of acetone, and the balance is deionized water.

[0046] The coating thickness of the elastomer coating liquid is 80±5 μm.

[0047] Example 2

[0048] A high-pressure tailings pipe material is prepared by the following preparation method:

[0049] A. Provide tailings pipe fittings made from ultra-high molecular weight polyethylene extrusion.

[0050] B. The inner surface of the tailings pipe was ultrasonically cleaned with deionized water. Subsequently, a fiber laser marking machine was used to create a microtexture with pits on the inner surface of the pipe. The laser scanning power was 30W, the scanning speed was 1500mm / s, and the frequency was 40kHz. The resulting microtexture had a honeycomb structure with pits measuring 80±5μm in diameter and 70±5μm in depth, with a spacing of 100μm.

[0051] C. Coating an elastomer coating liquid on the micro-textured surface, and allowing the elastomer coating liquid to at least fill the recesses.

[0052] The elastomer coating liquid includes the following components in parts by weight: 60 parts of polyurethane dispersion, 20 parts of hydrogenated nitrile rubber dispersion, 5 parts of nano-silicon dioxide, 10 parts of epoxy resin and 5 parts of curing agent.

[0053] The polyurethane dispersion comprises 50 wt% of polyester diol, 28 wt% of isocyanate, 15 wt% of acetone and NMP complex, and 7 wt% of DMPA chain extender.

[0054] The silicone rubber dispersion comprises 45 wt% of hydrogenated nitrile rubber, 20 wt% of fumed silica, 3.5 wt% of bis-2,5 peroxide curing agent and TAIC crosslinking aid, 2 wt% of polyoxyethylene ether emulsifier, 1.5 wt% of silane coupling agent KH-550, 3 wt% of acetone, and the balance is deionized water.

[0055] The coating thickness of the polyurethane dispersion elastomer coating liquid is 80±5 μm.

[0056] Example 3

[0057] The difference between this embodiment and embodiment 1 is that in step S3 of this embodiment, the elastomer coating liquid is only a polyurethane dispersion, and the remaining components, preparation steps and parameters are the same.

[0058] Example 4

[0059] The difference between this embodiment and embodiment 1 is that in step S3 of this embodiment, the elastomer coating liquid is only a silicone rubber dispersion, and the remaining components, preparation steps and parameters are the same.

[0060] Comparative Example 1

[0061] The difference between this comparative example and Example 1 is that the tailings pipe fittings in this comparative example do not undergo steps B and C.

[0062] Comparative Example 2

[0063] The difference between this comparative example and Example 1 is that the tailings pipe fittings in this comparative example do not undergo step C.

[0064] Comparative Example 3

[0065] The difference between this comparative example and Example 1 is that the tailings pipe fitting of this comparative example does not undergo step B; in step C, the elastomer coating liquid is directly sprayed onto the inner wall surface of the tailings pipe fitting.

[0066] The tailings pipe fittings of Examples 1-4 and Comparative Examples 1-3 were subjected to the following performance tests:

[0067] (1) Pressure resistance test

[0068] Referring to GB / T6111-2018 "Test method for internal pressure resistance of thermoplastic pipes for fluid transportation", seal both ends of the pipe, inject water, increase the pressure to 25MPa at a rate of 0.5MPa / s, maintain the pressure for 10 minutes, and observe whether the pipe is broken.

[0069] (2) Wear resistance test

[0070] According to ASTM G65 standard, gravel flow test was adopted, with 50N grinding wheel (SiO2 abrasive) loaded, and the mass loss (mg) of the pipe fitting was measured after 3 hours of testing at a flow rate of 200 rpm and a pressure of 2 MPa.

[0071] The test results are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] From the test results in Table 1, it can be seen that in the wear resistance test, the wear amount of the pipe fittings of Examples 1-4 is significantly lower than that of Comparative Examples 1-3, indicating that their wear resistance is better, which can effectively meet the stringent requirements in the tailings transportation process and extend the service life of the pipe fittings.

[0076] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a high-pressure resistant tailings pipe material, characterized in that: The method comprises the following preparation steps: A. Provide tailings pipe fittings made from ultra-high molecular weight polyethylene extrusion molding; B. forming a micro texture with pits on at least a portion of the inner wall of the tailings pipe by laser scanning; C. Coating an elastomer coating liquid on the micro-textured surface, and allowing the elastomer coating liquid to at least fill the recesses.

2. The method for preparing a high-pressure resistant tailings pipe material according to claim 1, characterized in that: In step B, the laser type used for laser scanning is at least one of a fiber laser marking machine, a CO2 laser, a fiber laser, a YAG laser, a femtosecond laser, and a nanosecond laser.

3. The method for preparing a high-pressure resistant tailings pipe material according to claim 1, characterized in that: In step B, the laser scanning is performed with a laser power of 10-30 W, a scanning speed of 500-2000 mm / s, and a pulse frequency of 20-50 kHz.

4. The method for preparing a high-pressure resistant tailings pipe material according to claim 1, characterized in that: The micro texture is hexagonal.

5. The method for preparing a high-pressure resistant tailings pipe material according to claim 1, characterized in that: The pits have a diameter of 50-200 μm, a depth of 30-100 μm, and a spacing of 100-300 μm.

6. The method for preparing a high-pressure resistant tailings pipe material according to claim 1, characterized in that: The area of ​​the pit accounts for 15-22% of the total area of ​​the inner wall of the pipe.

7. The method for preparing a high-pressure resistant tailings pipe material according to claim 1, characterized in that: The elastomer coating liquid includes at least one of a polyurethane dispersion and a silicone rubber dispersion.

8. The method for preparing a high-pressure resistant tailings pipe material according to claim 1 or 7, characterized in that: The elastomer coating liquid comprises the following components in parts by weight: 60-70 parts of polyurethane dispersion, 10-20 parts of silicone rubber dispersion, 5-8 parts of nano silicon dioxide, 10-15 parts of epoxy resin and 3-5 parts of curing agent.

9. The method for preparing a high-pressure resistant tailings pipe material according to claim 1, characterized in that: In step C, the thickness of the coating of the elastomer coating liquid applied on the micro-textured surface is 50-100 μm.

10. A high-pressure resistant tailings pipe material, characterized in that: The high-pressure tailings pipe fitting is prepared by the preparation method of the high-pressure tailings pipe fitting material according to any one of claims 1 to 9.

Images