Method for pretreating and dephosphorizing waste wind power gear oil

Abstract

The invention relates to a method for pretreating and dephosphorizing waste wind power gear oil, which comprises the following steps of: thermally mixing the waste wind power gear oil and metal powder to ensure that phosphorus in the oil product reacts with metal to form a magnetic phosphide, and then separating the metal powder and the magnetic phosphide from lubricating oil through magnetic separation treatment, so that the dephosphorizing effect of the lubricating oil is improved. And the purpose of dephosphorization is achieved. Moreover, phosphorus is removed in a mode that excessive metal and phosphorus are subjected to chemical reaction, and compared with phosphorus removal in a physical adsorption mode in the prior art, the problem that the phosphorus removal effect is poor due to the fact that the adsorption capacity is reduced when an adsorbent is used for treating lubricating oil which is high in phosphorus content and weak in polarity of phosphorus-containing species is solved.

Description

Technical Field

[0001] The present disclosure relates to the field of waste lubricating oil regeneration, and in particular, to a method for pre-treating and dephosphorizing waste wind power gear oil. Background Art

[0002] As one of the main forms of renewable energy generation, wind power has seen its installed capacity continue to rise in recent years. As the core equipment of wind power generation, wind turbines are composed of rotor blades, shafts, gearboxes, generators and other components, and wind power lubricants, especially main gear oils, play a vital role in reducing friction of rotating parts and ensuring the normal operation of the unit.

[0003] The demand for wind turbine lubricants will continue to grow rapidly in the future. If they can be recycled, it will greatly reduce the hazardous waste emissions of wind power companies and save a lot of operation and maintenance investment. Compared with waste automotive oil, waste fan oil has a lower degree of deterioration, but it has high viscosity, heavy distillation range, degraded components and additives. Therefore, the regeneration process applicable to automotive waste oil is not applicable to waste fan oil.

[0004] Since the additives in wind power lubricating oil include phosphorus-containing additives, if the chemical method is used to regenerate the lubricating oil, a large amount of deposition will occur on the refined catalyst, resulting in an increase in the pressure difference of the catalyst bed and rapid deactivation. Therefore, it is necessary to remove the phosphorus species before regeneration. The existing pretreatment dephosphorization method mainly uses aluminum oxide and / or bleaching earth to adsorb the phosphorus species in the lubricating oil, and then removes the aluminum oxide and / or bleaching earth to achieve the purpose of dephosphorization. However, the existing pretreatment dephosphorization method has a poor dephosphorization effect when treating lubricating oils with high phosphorus content and weak polarity of phosphorus-containing species. Summary of the invention

[0005] The purpose of the present invention is to provide a method for pre-treatment and dephosphorization of waste wind power gear oil, so as to solve the problem of poor dephosphorization effect when treating lubricating oil with high phosphorus content and weak polarity of phosphorus-containing species in the prior art.

[0006] In order to achieve the above-mentioned purpose, the present disclosure provides a method for pretreatment and dephosphorization of waste wind power gear oil, the method comprising: subjecting the waste wind power gear oil to a heat mixing treatment with metal powder, and subjecting the obtained heat mixing product to a magnetic separation treatment to obtain a dephosphorized gear oil; the phosphorus content in the waste wind power gear oil is 200~500ppm; the metal powder comprises iron powder or iron-containing alloy powder.

[0007] Optionally, the particle size of the metal powder is less than 220 mesh.

[0008] Optionally, the particle size of the metal powder is 60-200 mesh.

[0009] Optionally, the content of iron powder in the iron-containing alloy powder is above 50 wt %.

[0010] Optionally, the weight ratio of the metal powder to the waste wind power gear oil is (0.05~0.3):1.

[0011] Optionally, the weight ratio of the metal powder to the waste wind power gear oil is (0.1~0.2):1.

[0012] Optionally, the conditions of the thermal mixing treatment include: a temperature of 150-320° C. and a time of 4 to 24 hours.

[0013] Optionally, the conditions of the thermal mixing treatment include: temperature of 200-300° C. and time of 8-16 h.

[0014] Optionally, the thermal mixing process is performed under an inert atmosphere.

[0015] Optionally, the iron-containing alloy powder further comprises nickel powder and / or cobalt powder in addition to iron powder.

[0016] Through the above technical solution, the present invention heat mixes the waste wind power gear oil with the metal powder so that the phosphorus in the oil reacts with the metal to form a magnetic phosphide, and then through magnetic separation treatment, the metal powder and the magnetic phosphide can be separated from the lubricating oil to achieve the purpose of dephosphorization. In addition, the present invention uses the method of chemical reaction between excess metal and phosphorus to remove phosphorus. Compared with the physical adsorption method used in the prior art to remove phosphorus, it avoids the problem of poor dephosphorization effect caused by the decrease in adsorption capacity of the adsorbent when treating lubricating oil with a high phosphorus content and weak polarity of phosphorus-containing species.

[0017] Other features and advantages of the present disclosure will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0018] The specific embodiments of the present disclosure are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.

[0019] The present invention provides a method for pre-treatment and dephosphorization of waste wind power gear oil, which comprises: subjecting the waste wind power gear oil to a heat mixing treatment with metal powder, and subjecting the obtained heat mixing product to a magnetic separation treatment to obtain a dephosphorized gear oil; the phosphorus content in the waste wind power gear oil is 200-500 ppm; and the metal powder comprises iron powder or iron-containing alloy powder.

[0020] Through the above technical solution, the present invention heat mixes the waste wind power gear oil with the metal powder so that the phosphorus in the oil reacts with the metal to form a magnetic phosphide, and then through magnetic separation treatment, the metal powder and the magnetic phosphide can be separated from the lubricating oil to achieve the purpose of dephosphorization. In addition, the present invention uses the method of chemical reaction between excess metal and phosphorus to remove phosphorus. Compared with the physical adsorption method used in the prior art to remove phosphorus, it avoids the problem of poor dephosphorization effect caused by the decrease in adsorption capacity of the adsorbent when treating lubricating oil with a high phosphorus content and weak polarity of phosphorus-containing species.

[0021] In a preferred embodiment, the waste wind power gear oil disclosed in the present invention is a conventional choice in the art, and the present invention does not make any special requirements. For example, the waste wind power gear oil disclosed in the present invention is a lubricating oil with a phosphorus content of 300-450 ppm.

[0022] In a further preferred embodiment, the phosphorus content of the waste wind power gear oil described in the present invention can be in the range of any one or any two of 300ppm, 310ppm, 320ppm, 330ppm, 340ppm, 350ppm, 360ppm, 370ppm, 380ppm, 390ppm, 400ppm, 410ppm, 420ppm, 430ppm, 440ppm and 450ppm.

[0023] In one embodiment, the phosphorus in the waste wind power gear oil generally exists in the form of phosphorus-containing compounds such as phosphate esters, amine phosphates, and alkyl metal sulfide salts. For example, the phosphorus-containing compounds include one or more of tricresyl phosphate, triphenyl phosphate, thiophosphate amine, and alkyl zinc sulfide phenol. In this embodiment, the phosphorus-containing compounds in the waste wind power gear oil have lower polarity than automotive lubricants and are not easily adsorbed using existing physical adsorption methods.

[0024] In this embodiment, alumina or bleaching earth is often used in the prior art to adsorb phosphorus-containing substances in waste wind power gear oil. Since alumina or bleaching earth contains pores that can accommodate phosphides, during the mixing process of alumina or bleaching earth and waste wind power gear oil, the phosphides enter the pores and form bonds with the pore walls to achieve the purpose of adsorbing phosphorus; however, on the one hand, the pore volume of the adsorbent is limited, and as the phosphides in the pores gradually increase, the adsorption capacity of the adsorbent decreases; on the other hand, the entry of phosphides into the pores of the adsorbent requires that the phosphide molecules directly collide into the pores during movement. When the phosphorus content in the lubricating oil reaches a low level, the probability of the above phenomenon occurring is extremely small. Therefore, dephosphorization by physical adsorption cannot fully remove the phosphides in the lubricating oil. In the present application, iron or an iron-containing alloy is used to chemically react with the phosphorus-containing substances in the waste wind power gear oil. When the iron content added is excessive, the chemical reaction will always occur until the phosphorus content is insufficient to support the above reaction. The method disclosed in the present invention is not only applicable to lubricating oils with lower phosphorus content, but also to lubricating oils with higher phosphorus content, especially when treating lubricating oils with higher phosphorus content, the effect is better.

[0025] In a preferred embodiment, the iron-containing alloy powder used in the present disclosure is an iron binary alloy powder or an iron ternary alloy powder.

[0026] In one embodiment, the iron-containing alloy powder used in the present disclosure includes nickel powder and / or cobalt powder in addition to iron powder.

[0027] In a preferred embodiment, the iron-containing alloy powder is an iron-nickel binary alloy powder, an iron-cobalt binary alloy powder or an iron-cobalt-nickel ternary alloy powder.

[0028] In one embodiment, the content of iron powder in the iron-containing alloy powder is greater than 50 weight %.

[0029] In a preferred embodiment, the content of iron powder in the ferroalloy powder can be flexibly adjusted according to the phosphorus content in the waste wind power gear oil and the addition amount of the ferroalloy powder. For example, the content of iron powder in the ferroalloy powder can be one of 50 weight%, 55 weight%, 60 weight%, 65 weight%, 70 weight%, 75 weight%, 80 weight%, 85 weight%, 90 weight%, 95 weight% and 99 weight% or a range formed by any two of them.

[0030] In the above embodiment, when the iron-containing alloy powder and the waste wind power gear oil are subjected to a hot mixing treatment, the nickel powder and / or cobalt powder reduce phosphorus to trivalent phosphorus, and the trivalent phosphorus and iron form iron phosphide, which is a gray-black or gray-brown solid substance that is magnetic and can be attracted by a magnet. When the iron powder in the iron-containing alloy powder is at an appropriate content, the synergistic effect between the various metals in the iron-containing alloy powder can be enhanced, further enhancing the reaction activity of the phosphating reduction method, and further enhancing the dephosphorization effect.

[0031] In one embodiment, the particle size of the metal powder is less than 220 mesh.

[0032] In a preferred embodiment, the particle size of the metal powder is 60-200 mesh.

[0033] In this embodiment, the particle size of the metal powder can be flexibly selected according to actual production needs. For example, the particle size of the metal powder can be 60 mesh, 70 mesh, 80 mesh, 90 mesh, 100 mesh, 110 mesh, 120 mesh, 130 mesh, 140 mesh, 150 mesh, 160 mesh, 170 mesh, 180 mesh, 190 mesh and 200 mesh, or any range between two of them. The use of metal powder with a suitable particle size can not only ensure that the metal powder is evenly dispersed in the waste wind power gear oil, but also increase the contact area between the metal powder and the waste wind power gear oil, so that the phosphide reacts fully, and further improves the reaction effect of the phosphating reduction reaction. In addition, the particle size of the metal powder should not be too fine. If the particle size is too fine, the material cost is high and the separation difficulty is increased.

[0034] In one embodiment, the weight ratio of the metal powder to the waste wind power gear oil is (0.05~0.3):1.

[0035] In a preferred embodiment, the weight ratio of the metal powder to the waste wind power gear oil is (0.1-0.2):1.

[0036] In this embodiment, the weight ratio of the metal powder to the waste wind power gear oil can be flexibly selected according to the phosphorus content in the waste wind power gear oil, as long as the iron content in the metal powder is excessive compared to the phosphorus in the waste wind power gear oil. For example, the molar ratio of iron in the metal powder to phosphorus in the waste wind power gear oil in the present application is 1 to 10. Preferably, the molar ratio of iron in the metal powder to phosphorus in the waste wind power gear oil can be in the range of one or any two of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. By using a suitable amount of metal powder to ensure that the iron content in the metal powder is excessive compared to the phosphorus in the waste wind power gear oil, during the hot mixing process, even when the phosphorus content is very low, it can still be ensured that the direction of the reaction is to form iron phosphide, thereby being able to fully remove the phosphorus in the waste wind power gear oil.

[0037] In one embodiment, the temperature of the thermal mixing treatment is 150-320°C.

[0038] In a preferred embodiment, the temperature of the thermal mixing treatment is 200-300°C.

[0039] In this embodiment, since the phosphating-reduction reaction of phosphorus and iron needs to be carried out at a certain temperature, the conversion of phosphorus into iron phosphide can be achieved by selecting a suitable reaction temperature. Further preferably, the temperature of the hot mixing treatment can be one of 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C and 300°C, or any two of them.

[0040] In one embodiment, the heat mixing treatment is performed for 4 to 24 hours.

[0041] In a preferred embodiment, the heat mixing treatment time is 8 to 16 hours.

[0042] In this embodiment, selecting a suitable reaction time can not only achieve sufficient conversion of phosphorus into iron phosphide, but also reduce the problem of energy waste. Further preferably, the time for the hot mixing treatment can be in the range of one or any two of 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h and 16h.

[0043] In one embodiment, the thermal mixing process described in the present disclosure is performed under an inert atmosphere or in a closed device.

[0044] In a preferred embodiment, the thermal mixing process described in the present disclosure is performed under an inert atmosphere.

[0045] In one embodiment, the inert atmosphere includes one or more of a nitrogen atmosphere, an argon atmosphere, and a neon atmosphere.

[0046] In this embodiment, during the phosphating-reduction reaction, if there is oxygen in the atmosphere, the metal and phosphorus will react with oxygen to form metal oxide and phosphorus oxide respectively. The metal oxide is not magnetic and cannot be removed by subsequent magnetic separation. Therefore, in order to improve the phosphorus removal rate, the phosphating-reduction reaction can be carried out in the absence of oxygen or with very little oxygen, preferably in the absence of oxygen.

[0047] In one embodiment, the reactor for the hot mixing treatment described in the present disclosure is a conventional choice in the art, and the present application does not make special requirements. For example, the phosphating reduction reaction is carried out in a stainless steel reactor. The phosphating reduction reaction can be mixed using a magnetic stirring device or a mechanical stirring device, preferably a mechanical stirring device.

[0048] In one embodiment, the magnetic separation treatment described in the present disclosure refers to a technique of subjecting a substance to a magnetic field treatment. The magnetic separation treatment described in the present disclosure is a conventional choice in the art, and this application does not make any special requirements. For example, the present disclosure uses a magnetic filtration device for magnetic separation treatment.

[0049] In a specific embodiment, the magnetic filtering device includes a ferromagnetic component, a magnetic isolation component, a cylindrical permanent magnet, a grid soft magnetic component and a handle component; wherein, there are two ferromagnetic components, each of which is provided with a semi-cylindrical groove that matches the curvature of the cylindrical permanent magnet, the two ferromagnetic components are pieced together to form a ferromagnetic shell, and the semi-cylindrical grooves of the two ferromagnetic components correspond to each other to form a mounting position for the cylindrical permanent magnet, the cylindrical permanent magnet is installed in the mounting position, the magnetic isolation component is arranged between the contact surfaces of the two ferromagnetic components and at one end of the cylindrical permanent magnet, for isolating the magnetic force of the cylindrical permanent magnet, the handle component is detachably connected to the other end of the cylindrical permanent magnet, for rotating the cylindrical permanent magnet, and the grid soft magnetic component is respectively installed at the top and bottom of the ferromagnetic shell.

[0050] In this embodiment, before use, the central cylindrical permanent magnet is rotated by a handle member to switch the magnetic field. At this time, the magnetic lines of force of the internal cylindrical permanent magnet will pass through the grid soft magnetic member, and the grid soft magnetic member will acquire magnetism. The device can be placed at the bottom of the oil tank of the wind turbine lubrication system to automatically absorb impurities in the lubricating oil. After the impurities are saturated with adsorbed impurities, the device only needs to be taken out of the oil tank, and the central cylindrical permanent magnet is rotated 90° in the opposite direction by the handle member, and the impurities on the device will automatically fall off. At this time, the magnetic lines of force of the cylindrical permanent magnet are bound in the ferromagnetic member, and the grid soft magnetic member loses its magnetic lines of force, and the external appearance is demagnetized. The adsorbed impurities will fall from the grid soft magnetic member because the grid soft magnetic member loses its magnetism, thereby achieving the purpose of facilitating the cleaning of impurities on the device.

[0051] In one embodiment, the method for pretreatment and dephosphorization of waste wind power gear oil comprises: The waste wind power gear oil with a phosphorus content of 200-500 ppm and metal powder with a particle size of less than 220 mesh are placed in a reactor for phosphating reduction reaction and subjected to heat mixing treatment under inert atmosphere; the metal powder comprises iron powder or iron-containing alloy powder with an iron powder content of more than 50 weight %; the weight ratio of the metal powder to the waste wind power gear oil is (0.05-0.3):1; the conditions of the heat mixing treatment include: a temperature of 150-320°C and a time of 4-24 hours; The hot mixed treatment product is subjected to magnetic separation treatment by a magnetic filtering device to obtain dephosphorized gear oil.

[0052] The present disclosure is further described below by way of examples, but the present disclosure is not limited thereby. The properties of the waste wind power gear oil used in the following examples and comparative examples are shown in Table 1.

[0053] Table 1 Properties of waste wind power gear oil

[0054] Example 1 The methods for pretreatment and dephosphorization of waste wind power gear oil include: 100g of waste wind power gear oil and 13g of iron powder with a particle size of 200 mesh are placed in a stainless steel synthesis kettle and subjected to a heat mixing treatment under closed conditions; the weight ratio of the iron powder to the waste wind power gear oil is 0.13:1; the conditions of the heat mixing treatment include: a temperature of 280°C and a time of 12h; The hot mixed treatment product is subjected to magnetic separation treatment by a magnetic filtering device to obtain dephosphorized gear oil.

[0055] The properties of the dephosphorized gear oil are shown in Table 2.

[0056] Example 2 The methods for pretreatment and dephosphorization of waste wind power gear oil include: 100 g of waste wind power gear oil and 15.2 g of iron-nickel alloy powder with a particle size of 120 mesh are placed in a stainless steel synthesis kettle and subjected to a heat mixing treatment under closed conditions; the iron powder content in the iron-nickel alloy powder is 70% by weight; the weight ratio of the iron-copper alloy powder to the waste wind power gear oil is 0.152:1; the conditions of the heat mixing treatment include: a temperature of 250° C. and a time of 8 hours; The hot mixed treatment product is subjected to magnetic separation treatment by a magnetic filtering device to obtain dephosphorized gear oil.

[0057] The properties of the dephosphorized gear oil are shown in Table 2.

[0058] Example 3 The methods for pretreatment and dephosphorization of waste wind power gear oil include: 100 g of waste wind power gear oil and 10.6 g of iron-cobalt-nickel alloy powder with a particle size of 100 mesh are placed in a stainless steel synthesis kettle and subjected to heat mixing treatment under nitrogen conditions; the content of iron powder in the iron-cobalt-nickel alloy powder is 55% by weight; the weight ratio of the iron-cobalt-nickel alloy powder to the waste wind power gear oil is 0.106:1; the conditions of the heat mixing treatment include: temperature of 300° C. and time of 18 hours; The hot mixed treatment product is subjected to magnetic separation treatment by a magnetic filtering device to obtain dephosphorized gear oil.

[0059] The properties of the dephosphorized gear oil are shown in Table 2.

[0060] Example 4 The method for pretreatment and dephosphorization of waste wind power gear oil is the same as that in Example 3, except that the particle size of the iron-cobalt-nickel alloy powder is 210 meshes. The properties of the dephosphorized gear oil are shown in Table 2.

[0061] Example 5 The method for pretreatment and dephosphorization of waste wind power gear oil is the same as that in Example 3, except that the content of iron powder in the iron-cobalt-nickel alloy powder is 45% by weight. The properties of the dephosphorized gear oil are shown in Table 2.

[0062] Example 6 The method for pretreatment and dephosphorization of waste wind power gear oil is the same as that in Example 3, except that the amount of iron-cobalt-nickel alloy powder added is 3 g; the weight ratio of the iron-cobalt-nickel alloy powder to the waste wind power gear oil is 0.03:1. The properties of the dephosphorized gear oil are shown in Table 2.

[0063] Example 7 The method for pretreatment and dephosphorization of waste wind power gear oil is the same as that in Example 3, except that the hot mixing treatment is carried out under closed conditions. The properties of the dephosphorized gear oil are shown in Table 2.

[0064] Example 8 The method for pretreatment and dephosphorization of waste wind power gear oil is the same as that in Example 3, except that the iron-cobalt-nickel alloy powder is replaced with an equal weight of iron powder. The properties of the dephosphorized gear oil are shown in Table 2.

[0065] Comparative Example 1 The method for pretreatment and dephosphorization of waste wind power gear oil is the same as that in Example 1, except that the iron powder is replaced with an equal weight of aluminum oxide powder. The properties of the dephosphorized gear oil are shown in Table 2.

[0066] Test Case The dephosphorized gear oils obtained in Examples 1 to 8 and Comparative Example 1 were respectively measured using the GB17476 method to obtain the phosphorus content of the dephosphorized gear oils; The dephosphorization rate of the method disclosed in the present invention is calculated using the following formula: Dephosphorization rate = (phosphorus content in waste wind power gear oil - phosphorus content in dephosphorized gear oil) / phosphorus content in waste wind power gear oil; The oil yield of the method disclosed herein is calculated using the following formula: Oil yield = weight of dephosphorized gear oil / weight of waste wind power gear oil.

[0067] Table 2 Properties of dephosphorized gear oils of Examples and Comparative Examples

[0068] As shown in Table 2, according to the comparison of the data in Examples 1 to 8 with Comparative Example 1, it can be seen that the method disclosed in the present invention can avoid the problem of poor dephosphorization effect caused by the decrease in adsorption capacity of the adsorbent when treating lubricating oils with high phosphorus content and weak polarity of phosphorus-containing species, and improve the effect of dephosphorization treatment. According to the comparison of the data in Examples 3 and 4, when the particle size of the metal powder is 60 to 200 mesh, the dephosphorization rate of the dephosphorization treatment can be improved. According to the comparison of the data in Examples 3 and 5, when the content of iron powder in the iron-containing alloy powder is above 50% by weight, the dephosphorization rate of the dephosphorization treatment can be improved. According to the comparison of the data in Examples 3 and 6, when the weight ratio of the metal powder to the waste wind power gear oil is (0.05 to 0.3): 1, the dephosphorization rate of the dephosphorization treatment can be improved. According to the comparison of the data in Examples 3 and 7, when the hot mixing treatment is carried out under an inert atmosphere, the dephosphorization rate of the dephosphorization treatment can be improved. According to the comparison of the data in Example 3 and Example 8, when the metal powder is iron-cobalt-nickel alloy powder, the dephosphorization rate of the dephosphorization treatment can be improved.

[0069] The preferred embodiments of the present disclosure are described in detail above; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0070] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0071] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for pretreatment and dephosphorization of waste wind power gear oil, characterized in that: The method includes: The waste wind power gear oil is subjected to a heat mixing treatment with metal powder, and the obtained heat mixing product is subjected to a magnetic separation treatment to obtain a dephosphorized gear oil; The phosphorus content in the waste wind power gear oil is 200-500 ppm; The metal powder includes iron powder or iron-containing alloy powder.

2. The method according to claim 1, characterized in that The particle size of the metal powder is less than 220 meshes.

3. The method according to claim 1, characterized in that The particle size of the metal powder is 60-200 meshes.

4. The method according to claim 1, characterized in that: The content of iron powder in the iron-containing alloy powder is above 50% by weight.

5. The method according to claim 1, characterized in that The weight ratio of the metal powder to the waste wind power gear oil is (0.05-0.3):

1.

6. The method according to claim 1, characterized in that The weight ratio of the metal powder to the waste wind power gear oil is (0.1~0.2):

1.

7. The method according to claim 1, characterized in that The conditions of the heat mixing treatment include: a temperature of 150-320° C. and a time of 4-24 hours.

8. The method according to claim 1, characterized in that: The conditions of the heat mixing treatment include: a temperature of 200-300° C. and a time of 8-16 hours.

9. The method according to claim 1, characterized in that: The thermal mixing process is performed under an inert atmosphere.

10. The method according to claim 1, characterized in that The iron-containing alloy powder includes nickel powder and / or cobalt powder in addition to iron powder.

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