Manufacturing method of mining high-temperature-resistant enameled wire and product thereof

Abstract

The invention discloses a manufacturing method of a mining high-temperature-resistant enameled wire and a product thereof. The manufacturing method comprises the following steps: carrying out gradient annealing treatment on a metal conductor; under the protection of inert gas, dipping the metal conductor in the insulating paint; coating the insulating paint on the surface of the metal conductor through a multi-time coating and baking process; continuously coating a protective layer on the surface of the metal conductor; and continuously carrying out pulse electromagnetic field treatment to finally obtain the required mining high-temperature-resistant enameled wire. Through synergistic interaction of polyimide, the nano boron nitride-aluminum oxide composite filler, the phosphorus-containing flame retardant and the hexagonal boron nitride sheet layer, the high temperature resistance, the heat resistance, the insulativity and the mechanical strength of the enameled wire are remarkably improved, the protective layer is designed outside the insulating layer, the corrosion resistance, the explosion-proof performance and the mechanical performance of the enameled wire are remarkably improved, and the service life of the enameled wire is prolonged. And the device is suitable for high-corrosion, high-humidity and explosive environments of mines, and meets the reliable operation requirements of mine motors under extreme working conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of enameled wires, and in particular relates to a method for manufacturing a high-temperature resistant enameled wire for mining and a product thereof. Background Art

[0002] Enameled wire, a primary type of winding wire, consists of a conductor and an insulation layer. Because enameled wire used in mine motors is constantly exposed to multiple extreme operating conditions, including high temperatures (>200°C), high humidity (RH ≥95%), hydrogen sulfide corrosion (H2S concentration >100ppm), and mechanical vibration, traditional enameled wire is unable to meet these requirements. Therefore, there is an urgent need to develop a new type of high-temperature-resistant enameled wire for mining applications.

[0003] Based on this, the present invention discloses a method for manufacturing a high-temperature resistant enameled wire for mining and a product thereof, which integrates high-temperature resistance, insulation, explosion-proofness and corrosion resistance. Summary of the Invention

[0004] In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide a method for manufacturing a high-temperature resistant enameled wire for mining and a product thereof.

[0005] In order to achieve the above-mentioned purpose and the above-mentioned technical effect, the technical solution adopted by the present invention is:

[0006] A method for manufacturing a high-temperature resistant enameled wire for mining, comprising the following steps:

[0007] Step 1: performing gradient annealing treatment on the metal conductor;

[0008] Step 2: Prepare insulating varnish, and immerse the metal conductor obtained in step 1 in the insulating varnish under the protection of inert gas;

[0009] Step 3: Applying insulating paint to the surface of the metal conductor through multiple coating and baking processes;

[0010] Step 4: Continue coating the surface of the metal conductor obtained in step 3 with a protective layer;

[0011] Step 5: Continue pulse electromagnetic field treatment to finally obtain the required high-temperature resistant enameled wire for mining.

[0012] Furthermore, in step 1, the step of performing gradient annealing on the metal conductor includes:

[0013] The metal conductor is first electrochemically polished to a surface roughness of ≤0.7 μm, and then subjected to a gradient annealing treatment, with the annealing temperature sequentially being 280° C.-300° C. / 10 min→430° C.-450° C. / 8 min→580° C.-600° C. / 5 min.

[0014] Furthermore, in step 2, the insulating varnish includes the following components in parts by weight:

[0015] 40-60 parts of polyimide resin

[0016] 15-25 parts of composite filler

[0017] 10-15 parts of phosphorus-containing flame retardant

[0018] 5-8 layers of hexagonal boron nitride.

[0019] Furthermore, the particle size of the composite filler is 60-120 nm, and the composite filler is a nano boron nitride-aluminum oxide composite filler.

[0020] Furthermore, the nano boron nitride-aluminum oxide composite filler is prepared by the following steps:

[0021] Boron nitride nanosheets and gamma-alumina are ball-milled and mixed evenly in a mass ratio of 1:2-4, and then plasma activated at 800-1000°C, and then surface-grafted with a silane coupling agent.

[0022] Furthermore, in step 3, the insulating varnish is coated on the surface of the metal conductor using a three-coating and three-baking process. The drying temperature after the first coating is 250-280°C, the drying temperature after the second coating is 300-330°C, and the drying temperature after the third coating is 350-380°C.

[0023] Furthermore, the coating thickness of each time is controlled within 5-15 μm, and the total coating thickness of the insulating varnish is controlled within 30-40 μm.

[0024] Furthermore, in step 4, the thickness of the protective layer is 5-10 μm.

[0025] Furthermore, in step 4, a protective layer is coated on the surface of the metal conductor obtained in step 3 by an electrostatic spraying process, with a spraying voltage of 30-60 kV and a temperature of 70-110°C.

[0026] Furthermore, in step five, the magnetic field strength is 0.5-1.5 T, the frequency is 50-100 Hz, and the processing time is 30-70 s.

[0027] The present invention also discloses a method for manufacturing a high-temperature resistant enameled wire for mining, wherein the high-temperature resistant enameled wire for mining comprises a metal conductor, an insulating layer and a protective layer arranged in sequence from the inside to the outside, and the insulating layer is made of insulating varnish.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention discloses a method for manufacturing a high-temperature resistant enameled wire for use in mines and the product thereof. By synergistically enhancing the performance of polyimide, nano-boron nitride-alumina composite filler, phosphorus-containing flame retardant, and hexagonal boron nitride flakes, the high-temperature resistance, heat resistance, insulation, and mechanical strength of the enameled wire are significantly improved. A protective layer is designed outside the insulating layer, which significantly improves the corrosion resistance, explosion resistance, and mechanical properties of the enameled wire. The wire is adapted to the highly corrosive, high-humidity, and explosive environment of mines and meets the requirements for reliable operation of mine motors under extreme working conditions. DETAILED DESCRIPTION

[0030] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0031] The following is a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that will be provided later.

[0032] The present invention discloses a method for manufacturing a high-temperature resistant enameled wire for mining, comprising the following steps:

[0033] Step 1: performing gradient annealing treatment on the metal conductor;

[0034] Step 2: Prepare insulating varnish, and immerse the metal conductor obtained in step 1 in the insulating varnish under the protection of inert gas;

[0035] Step 3: Applying insulating paint to the surface of the metal conductor through multiple coating and baking processes;

[0036] Step 4: Apply a protective layer to the surface of the metal conductor obtained in step 3 by electrostatic spraying, with a spraying voltage of 30-60 kV, a temperature of 70-110° C., and a thickness of the protective layer of 5-10 μm;

[0037] Step 5: Continue pulsed electromagnetic field treatment with a magnetic field strength of 0.5-1.5T, a frequency of 50-100Hz, and a treatment time of 30-70s to obtain the desired high-temperature resistant enameled wire for mining. This step helps to improve crystallinity and tensile strength.

[0038] In step 1 of the present invention, the metal conductor is a copper-silver alloy conductor with a layered twisted structure of 19 strands, each 0.25 mm in diameter. The inner layer comprises 7 strands twisted clockwise, and the outer layer comprises 12 strands twisted counterclockwise, with a twist pitch ratio of 8-10:1. The present invention utilizes a layered, reverse-twisted conductor design that balances flexibility and tensile strength.

[0039] In the present invention, the step of performing gradient annealing on the metal conductor includes:

[0040] The metal conductor is first electrochemically polished to a surface roughness of ≤0.7μm, followed by a gradient annealing process at temperatures ranging from 280°C to 300°C for 10 minutes, then from 430°C to 450°C for 8 minutes, and finally from 580°C to 600°C for 5 minutes. This step helps eliminate internal stress and improve ductility.

[0041] In step 2, the insulating varnish includes the following components in parts by weight:

[0042] 40-60 parts of polyimide resin

[0043] 15-25 parts of composite filler

[0044] 10-15 parts of phosphorus-containing flame retardant

[0045] 5-8 layers of hexagonal boron nitride.

[0046] Among them, polyimide resin is the matrix material, which has good heat resistance, mechanical strength, dielectric properties and film-forming properties. The imide ring in its molecular chain can form hydrogen bonds / van der Waals forces with the active surface of the composite filler to enhance the interfacial bonding strength.

[0047] The particle size of the composite filler is 60-120 nm. The composite filler is a nano boron nitride-aluminum oxide composite filler and is prepared by the following steps:

[0048] Boron nitride nanosheets and gamma-alumina are ball-milled and mixed evenly in a mass ratio of 1:2-4, and then plasma activated at 800-1000°C, and then surface-grafted with a silane coupling agent.

[0049] Boron nitride (BN) has high thermal conductivity, with a thermal conductivity coefficient of ≥30W / m·K. Alumina (Al2O3) has high hardness and arc resistance. Boron nitride and alumina are compounded and treated with plasma activation to generate a large number of active hydroxyl groups on the filler surface, which can provide more reaction sites for the subsequent surface grafting of silane coupling agents, thereby achieving covalent (such as Si-O-Si) grafting. After the composite filler is grafted with the silane coupling agent, it can be chemically bonded (such as Si-OC) with the polyimide resin, thereby reducing interface defects, improving the interface compatibility between the filler and the resin, and the overall performance of the insulating paint.

[0050] The introduction of phosphorus-containing flame retardants is beneficial to improving the flame retardancy of the enameled wire. The gas-phase free radical capture effect of the phosphorus-containing flame retardant itself and the thermal insulation barrier effect of the composite filler work synergistically to increase the limiting oxygen index to ≥38%.

[0051] Hexagonal boron nitride has a lamellar structure and high insulation properties. Its synergistic effect with composite fillers helps to improve the heat dissipation capacity of enameled wire.

[0052] The synergistic effect between the raw materials used in the preparation of insulating varnish can significantly improve the high temperature resistance, heat resistance, insulation, flame retardancy and explosion resistance, corona resistance and mechanical strength of the formed insulating layer.

[0053] In step three, the insulating varnish is coated on the surface of the metal conductor using a three-coating and three-baking process. The thickness of each coating is controlled at 5-15 μm, and the total coating thickness of the insulating varnish is controlled at 30-40 μm. The drying temperature after the first coating is 250-280°C, the drying temperature after the second coating is 300-330°C, and the drying temperature after the third coating is 350-380°C.

[0054] Through the design, the insulating paint is first impregnated to achieve the initial bonding with the metal conductor, and then three coatings and three bakings are carried out to achieve performance optimization, improve the adhesion of the insulating paint, the interlayer bonding strength and the density, and at the same time help to release internal stress, reduce defects, avoid cracking and falling off, etc., and improve the overall performance of the insulation layer.

[0055] In step four, the protective layer is made of a compound of fluororubber and graphene. Fluororubber has high corrosion resistance, high temperature resistance and elasticity. The bonding force between fluororubber and polyimide resin is good, which is convenient for improving the interface bonding force. The introduction of graphene can improve the mechanical properties of the protective layer and extend the service life of the protective layer. The sheet structure of graphene forms a dense barrier to prevent the penetration of gases such as hydrogen sulfide. At the same time, graphene has high thermal conductivity and electrical conductivity, which is beneficial to improve the heat dissipation capacity of the enameled wire, avoid local temperature rise, avoid charge accumulation causing sparks, and improve explosion resistance.

[0056] The present invention also discloses a method for manufacturing a high-temperature resistant enameled wire for mining, which is prepared by the method. The high-temperature resistant enameled wire for mining comprises a metal conductor, an insulating layer and a protective layer arranged in sequence from the inside to the outside, and the insulating layer is made of the above-mentioned insulating paint.

[0057] The high-temperature resistant enameled wire for mining disclosed in the present invention meets the following requirements:

[0058] Temperature resistance ≥ 240°C, IEC 60317-13 standard;

[0059] Breakdown voltage ≥12kV / mm, GB / T 4074.5 test;

[0060] Hydrogen sulfide corrosion resistance: After 1000 hours in an environment with a H2S concentration of 200ppm, the insulation resistance decrease rate is less than 5%;

[0061] Mechanical bending resistance: no cracks after DIN 46453 standard bending test;

[0062] Explosion-proof: Limiting oxygen index LOI ≥ 38%, passed IEC 60079-0 explosive environment test.

[0063] Example 1

[0064] A method for manufacturing a high-temperature resistant enameled wire for mining, comprising the following steps:

[0065] Step 1: performing gradient annealing treatment on the metal conductor;

[0066] Step 2: Prepare insulating varnish, and immerse the metal conductor obtained in step 1 in the insulating varnish under the protection of inert gas;

[0067] Step 3: Applying insulating paint to the surface of the metal conductor through multiple coating and baking processes;

[0068] Step 4: Apply a protective layer on the surface of the metal conductor obtained in step 3 by electrostatic spraying, with a spraying voltage of 50 kV and a temperature of 90° C. The thickness of the protective layer is 10 μm;

[0069] Step 5: Continue pulse electromagnetic field treatment with a magnetic field intensity of 1.0 T, a frequency of 100 Hz, and a treatment time of 30 s, and finally obtain the required high-temperature resistant enameled wire for mining.

[0070] In step 1, the metal conductor is a copper-silver alloy conductor with a layered twisted structure of 19 strands of 0.25 mm diameter, with 7 inner strands twisted clockwise and 12 outer strands twisted counterclockwise, with a twist pitch ratio of 8:1.

[0071] The steps of performing gradient annealing on the metal conductor include:

[0072] The metal conductor is first electrochemically polished to a surface roughness of 0.7 μm, and then subjected to a gradient annealing treatment, with the annealing temperature being 290° C. / 10 min→440° C. / 8 min→590° C. / 5 min.

[0073] In step 2, the insulating varnish includes the following components in parts by weight:

[0074] 55 parts of polyimide resin

[0075] 18 parts of composite filler

[0076] 15 parts of phosphorus-containing flame retardant

[0077] 7 parts of hexagonal boron nitride sheets.

[0078] Among them, polyimide resin is the matrix material, which has good high heat resistance, high mechanical strength, dielectric properties and film-forming properties. The imide ring in its molecular chain can form hydrogen bonds / van der Waals forces with the active surface of the composite filler to enhance the interfacial bonding strength.

[0079] The particle size of the composite filler is 70 nm. The composite filler is a nano boron nitride-aluminum oxide composite filler and is prepared by the following steps:

[0080] Boron nitride nanosheets and gamma-alumina are ball-milled and mixed evenly in a mass ratio of 1:4, and then plasma activated at 800-1000° C., and then a silane coupling agent is grafted onto the surface.

[0081] Hexagonal boron nitride has a lamellar structure and high insulation properties. Its synergistic effect with composite fillers helps to improve the heat dissipation capacity of enameled wire.

[0082] The synergistic effect between the raw materials used in the preparation of insulating varnish can significantly improve the high temperature resistance, heat resistance, insulation, flame retardancy and explosion resistance, corona resistance and mechanical strength of the formed insulating layer.

[0083] In step three, the insulating varnish is coated on the surface of the metal conductor using a three-coating and three-baking process. The thickness of each coating is controlled at 5-15 μm, and the total coating thickness of the insulating varnish is controlled at 30 μm. The drying temperature after the first coating is 270°C, the drying temperature after the second coating is 320°C, and the drying temperature after the third coating is 360°C.

[0084] This embodiment also discloses a high-temperature resistant enameled wire for mining, which is prepared using the above-mentioned method for preparing the high-temperature resistant enameled wire for mining.

[0085] Example 2

[0086] A method for manufacturing a high-temperature resistant enameled wire for mining, comprising the following steps:

[0087] Step 1: performing gradient annealing treatment on the metal conductor;

[0088] Step 2: Prepare insulating varnish, and immerse the metal conductor obtained in step 1 in the insulating varnish under the protection of inert gas;

[0089] Step 3: Applying insulating paint to the surface of the metal conductor through multiple coating and baking processes;

[0090] Step 4: applying a protective layer on the surface of the metal conductor obtained in step 3 by electrostatic spraying, with a spraying voltage of 60 kV and a temperature of 110° C., and a thickness of the protective layer of 10 μm;

[0091] Step 5: Continue pulse electromagnetic field treatment with a magnetic field intensity of 1.5 T, a frequency of 50 Hz, and a treatment time of 70 s, and finally obtain the required high-temperature resistant enameled wire for mining.

[0092] In step 1, the metal conductor is a copper-silver alloy conductor with a layered twisted structure of 19 strands of 0.25 mm diameter, with 7 inner strands twisted clockwise and 12 outer strands twisted counterclockwise, with a twist pitch ratio of 10:1.

[0093] The steps of performing gradient annealing on the metal conductor include:

[0094] The metal conductor is first electrochemically polished to a surface roughness of 0.6 μm, and then subjected to a gradient annealing treatment, with the annealing temperature being 300° C. / 10 min→450° C. / 8 min→600° C. / 5 min.

[0095] In step 2, the insulating varnish includes the following components in parts by weight:

[0096] 50 parts of polyimide resin

[0097] 22 parts of composite filler

[0098] 15 parts of phosphorus-containing flame retardant

[0099] 8 parts of hexagonal boron nitride sheets.

[0100] Among them, polyimide resin is the matrix material, which has good high heat resistance, high mechanical strength, dielectric properties and film-forming properties. The imide ring in its molecular chain can form hydrogen bonds / van der Waals forces with the active surface of the composite filler to enhance the interfacial bonding strength.

[0101] The particle size of the composite filler is 100 nm. The composite filler is a nano boron nitride-aluminum oxide composite filler and is prepared by the following steps:

[0102] Boron nitride nanosheets and γ-alumina are ball-milled and mixed uniformly in a mass ratio of 1:3, and then plasma activated at 1000°C, and then surface-grafted with a silane coupling agent.

[0103] Hexagonal boron nitride has a lamellar structure and high insulation properties. Its synergistic effect with composite fillers helps to improve the heat dissipation capacity of enameled wire.

[0104] The synergistic effect between the raw materials used in the preparation of insulating varnish can significantly improve the high temperature resistance, heat resistance, insulation, flame retardancy and explosion resistance, corona resistance and mechanical strength of the formed insulating layer.

[0105] In step three, the insulating varnish is coated on the surface of the metal conductor using a three-coating and three-baking process. The thickness of each coating is controlled at 5-15 μm, and the total coating thickness of the insulating varnish is controlled at 40 μm. The drying temperature after the first coating is 280°C, the drying temperature after the second coating is 330°C, and the drying temperature after the third coating is 380°C.

[0106] The rest is the same as in Example 1.

[0107] This embodiment also discloses a high-temperature resistant enameled wire for mining, which is prepared using the above-mentioned method for preparing the high-temperature resistant enameled wire for mining.

[0108] Example 3

[0109] A method for manufacturing a high-temperature resistant enameled wire for mining, comprising the following steps:

[0110] Step 1: performing gradient annealing treatment on the metal conductor;

[0111] Step 2: Prepare insulating varnish, and immerse the metal conductor obtained in step 1 in the insulating varnish under the protection of inert gas;

[0112] Step 3: Applying insulating paint to the surface of the metal conductor through multiple coating and baking processes;

[0113] Step 4: Apply a protective layer to the surface of the metal conductor obtained in step 3 by electrostatic spraying, with a spraying voltage of 30 kV and a temperature of 70° C. The thickness of the protective layer is 5 μm;

[0114] Step 5: Continue pulse electromagnetic field treatment with a magnetic field intensity of 0.5 T, a frequency of 50 Hz, and a treatment time of 30 s, and finally obtain the required high-temperature resistant enameled wire for mining.

[0115] In step 1, the metal conductor is a copper-silver alloy conductor with a layered twisted structure of 19 strands of 0.25 mm diameter, with 7 inner strands twisted clockwise and 12 outer strands twisted counterclockwise, with a twist pitch ratio of 8:1.

[0116] The steps of performing gradient annealing on the metal conductor include:

[0117] The metal conductor is first electrochemically polished to a surface roughness of 0.7 μm, and then subjected to a gradient annealing treatment, with the annealing temperature being 280° C. / 10 min→430° C. / 8 min→580° C. / 5 min.

[0118] In step 2, the insulating varnish includes the following components in parts by weight:

[0119] 40 parts of polyimide resin

[0120] 25 parts of composite filler

[0121] 15 parts of phosphorus-containing flame retardant

[0122] 8 parts of hexagonal boron nitride sheets.

[0123] The particle size of the composite filler is 60 nm. The composite filler is a nano boron nitride-aluminum oxide composite filler and is prepared by the following steps:

[0124] Boron nitride nanosheets and γ-alumina were ball-milled and mixed uniformly in a mass ratio of 1:2, and then plasma activated at 800°C, and then surface-grafted with a silane coupling agent.

[0125] Hexagonal boron nitride has a lamellar structure and high insulation properties. Its synergistic effect with composite fillers helps to improve the heat dissipation capacity of enameled wire.

[0126] The synergistic effect between the raw materials used in the preparation of insulating varnish can significantly improve the high temperature resistance, heat resistance, insulation, flame retardancy and explosion resistance, corona resistance and mechanical strength of the formed insulating layer.

[0127] In step three, the insulating varnish is coated on the surface of the metal conductor using a three-coating and three-baking process. The thickness of each coating is controlled at 5-15 μm, and the total coating thickness of the insulating varnish is controlled at 30 μm. The drying temperature after the first coating is 250°C, the drying temperature after the second coating is 300°C, and the drying temperature after the third coating is 350°C.

[0128] The rest is the same as Example 1.

[0129] This embodiment also discloses a high-temperature resistant enameled wire for mining, which is prepared using the above-mentioned method for preparing the high-temperature resistant enameled wire for mining.

[0130] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.

[0131] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for producing a high-temperature resistant enameled wire for mining, characterized in that: The following steps are involved: Step 1: performing gradient annealing treatment on the metal conductor; Step 2: Prepare insulating varnish, and immerse the metal conductor obtained in step 1 in the insulating varnish under the protection of inert gas; Step 3: Applying insulating paint to the surface of the metal conductor through multiple coating and baking processes; Step 4: Continue coating the surface of the metal conductor obtained in step 3 with a protective layer; Step 5: Continue pulse electromagnetic field treatment to finally obtain the required high-temperature resistant enameled wire for mining.

2. The method for manufacturing a high-temperature resistant enameled wire for mining according to claim 1, characterized in that: In step 1, the step of performing gradient annealing on the metal conductor includes: The metal conductor is first electrochemically polished to a surface roughness of ≤0.7 μm, and then subjected to a gradient annealing treatment, with the annealing temperature sequentially being 280° C.-300° C. / 10 min→430° C.-450° C. / 8 min→580° C.-600° C. / 5 min.

3. The method for manufacturing a high-temperature resistant enameled wire for mining according to claim 1, characterized in that: In step 2, the insulating varnish includes the following components in parts by weight: 40-60 parts of polyimide resin 15-25 parts of composite filler 10-15 parts of phosphorus-containing flame retardant 5-8 layers of hexagonal boron nitride.

4. The method for manufacturing a high-temperature resistant enameled wire for mining according to claim 3, characterized in that: The particle size of the composite filler is 60-120 nm. The composite filler is a nano boron nitride-aluminum oxide composite filler and is prepared by the following steps: Boron nitride nanosheets and gamma-alumina are ball-milled and mixed evenly in a mass ratio of 1:2-4, and then plasma activated at 800-1000°C, and then surface-grafted with a silane coupling agent.

5. The method for manufacturing a high-temperature resistant enameled wire for mining according to claim 1, characterized in that: In step three, the insulating varnish is coated on the surface of the metal conductor using a three-coat and three-bake process. The drying temperature after the first coating is 250-280°C, the drying temperature after the second coating is 300-330°C, and the drying temperature after the third coating is 350-380°C.

6. The method for manufacturing a high-temperature resistant enameled wire for mining according to claim 5, characterized in that: The coating thickness of each time is controlled at 5-15 μm, and the total coating thickness of the insulating varnish is controlled at 30-40 μm.

7. The method for manufacturing a high-temperature resistant enameled wire for mining according to claim 1, characterized in that: In step 4, the thickness of the protective layer is 5-10 μm.

8. The method for manufacturing a high-temperature resistant enameled wire for mining according to claim 1, characterized in that: In step 4, a protective layer is coated on the surface of the metal conductor obtained in step 3 by an electrostatic spraying process, with a spraying voltage of 30-60 kV and a temperature of 70-110°C.

9. The method for manufacturing a high-temperature resistant enameled wire for mining according to claim 1, characterized in that: In step five, the magnetic field strength is 0.5-1.5 T, the frequency is 50-100 Hz, and the processing time is 30-70 s.

10. The high-temperature resistant enameled wire for mining prepared by the method for preparing the high-temperature resistant enameled wire for mining according to any one of claims 1 to 9, characterized in that: The high-temperature resistant enameled wire for mining comprises a metal conductor, an insulating layer and a protective layer which are arranged in sequence from the inside to the outside, and the insulating layer is made of insulating varnish.