Rare earth neodymium-based oil sludge waste treatment method and rare earth neodymium-based magnetic powder

Abstract

The invention provides a rare earth neodymium-based oil sludge waste treatment method and rare earth neodymium-based magnetic powder. The invention relates to a rare earth neodymium-based oil sludge waste treatment method, which comprises: (1) mixing rare earth neodymium-based oil sludge and 50-150 ml of a composite cleaning agent 10 g, and carrying out ultrasonic stirring, negative pressure suction filtration and alcohol washing to obtain a primary purified rare earth neodymium-based powder material; (2) treating the primarily purified rare earth neodymium-based powder in inert gas at 600-900 DEG C for 30-60 minutes to obtain secondarily purified rare earth neodymium-based powder; (3) removing impurities from the secondarily purified rare earth neodymium-based powder to obtain rare earth neodymium-based powder; (4) mixing the rare earth neodymium-based powder with 10 g of calcium hydride according to a ratio of 5.5-7.5 g, and tabletting; and adding the rare earth neodymium-based magnetic powder into an inert gas, preserving heat at 950-1050 DEG C for 3-5 hours, cooling the inert gas to 30 + / -5 DEG C after the heat preservation is finished, so as to obtain a regenerated rare earth neodymium-based magnetic powder pressing sheet, and grinding, crushing, centrifuging, separating, drying and sieving under the protection of the inert gas, so as to obtain the regenerated rare earth neodymium-based magnetic powder. According to the method, the regeneration efficiency is greatly improved, and a feasible technology is provided for secondary resource recycling development of the rare earth neodymium-based waste.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling rare earth material renewable resources, and in particular to a rare earth neodymium-based oil sludge waste treatment method and a rare earth neodymium-based magnetic powder. Background Art

[0002] Sintered rare earth neodymium-based permanent magnet materials are widely used in computers, new energy vehicles, household appliances, health care, aerospace and other fields because of their excellent magnetic properties. Rare earth neodymium and other materials, as the main raw materials for the production of rare earth neodymium-based magnets, are non-renewable resources, and are consumed annually at a rate of nearly 100,000 tons. In addition, sintered rare earth neodymium-based permanent magnet materials will be accompanied by waste materials accounting for about 40% of the total weight of raw materials during the production and processing process, of which oil sludge waste accounts for 25-30%. The waste contains about 30wt% of rare earth elements, 70% of Fe, and valuable trace elements such as Co, Cu, Al, and Ga, resulting in serious waste of resources and environmental pollution. Therefore, the recycling of secondary resources of sintered rare earth neodymium-based waste is particularly important for saving resources, reducing industrial waste, and promoting the continuous high-quality development of the rare earth industry.

[0003] Rare earth neodymium-based oil sludge waste is the most oxidized waste with the most complex impurity components such as engine oil and coolant. In response to national strategic resource protection, rational utilization, energy conservation and emission reduction and other resource and environmental issues, my country's rare earth neodymium-based waste recycling has rapidly changed from traditional wet and pyrotechnic processes (strong acid, strong alkali, high temperature) to secondary resource recycling technologies with less pollution and shorter processes. At present, the rare earth neodymium-based oil sludge waste is treated by adding calcium and its compounds for reduction and diffusion, and the technology of preparing permanent magnet alloy powder and permanent magnet has attracted more and more attention from scientific researchers. It should be pointed out that in traditional processes or reduction and diffusion technologies, rare earth neodymium-based oil sludge waste must be deoiled, impurity-removed and purified before valuable rare earth elements can be extracted and alloy magnetic powder can be regenerated. The Chinese patent application (ZL201410369437.2) cleans the oil sludge waste by adding more than 8 organic solvents, but does not give clear results on the effect of oil sludge cleaning and the influence of rare earth and valuable elements in the waste. The Chinese patent application (ZL201510101336.1) uses distillation, which does not remove impurities thoroughly and has low efficiency. The Chinese patent application (ZL201710762926.8) and the Chinese patent application (ZL201910563061.1) improve the deoiling effect of oily sludge waste by adding dilute nitric acid and hydrochloric acid, but both cause losses to rare earth and valuable elements in the waste to varying degrees, thereby affecting the subsequent recovery and regeneration efficiency. Summary of the invention

[0004] The present disclosure provides a rare earth neodymium-based oil sludge waste treatment method and rare earth neodymium-based magnetic powder to at least solve one of the technical problems existing in the prior art.

[0005] According to a first aspect of the present disclosure, a method for treating rare earth neodymium-based oil sludge waste is provided, comprising the following steps:

[0006] The steps include:

[0007] (1) Mixing rare earth neodymium-based oil sludge and a composite cleaning agent at a mass volume ratio of 10 g:50-150 ml, and then ultrasonically stirring, negative pressure filtering, and alcohol washing to obtain a primary purified rare earth neodymium-based powder;

[0008] (2) treating the primary purified rare earth neodymium-based powder under inert gas protection at a temperature of 600 to 900° C. for 30 to 60 minutes to obtain a secondary purified rare earth neodymium-based powder;

[0009] (3) Screening the secondary purified rare earth neodymium-based powder to remove impurities and obtain rare earth neodymium-based powder.

[0010] (4) The rare earth neodymium-based powder obtained in step (3) is mixed with calcium hydride in a mass ratio of 10 g:5.5-7.5 g, and tabletted to obtain tablets; the tablets are then kept warm at a temperature of 950-1050° C. for 3-5 hours under the protection of inert gas, and after the insulation is completed, the inert gas is continuously introduced for cooling until the temperature drops to 30±5° C. to obtain regenerated rare earth neodymium-based magnetic powder tablets; the regenerated rare earth neodymium-based magnetic powder tablets are placed under the protection of inert gas, ground, crushed, centrifuged, separated, dried, and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0011] In one embodiment, the mass volume ratio of the rare earth neodymium-based sludge to the composite cleaning agent is 10 g:100 ml;

[0012] The composite cleaning agent includes the following raw materials in weight percentage: 5-10wt% surfactant, 0.1-1wt% alkaline salt, and the balance is ethanol or water. OH- in the alkaline solution can also undergo saponification reaction with fatty acids in machining oil and wire cutting coolant to generate soap salts, and the hydrophobic segment of the soap salts can adsorb oil stains, thereby stripping the oil stains from rare earth neodymium-based waste. Surfactants have both hydrophilic and lipophilic properties, and can form a dense adsorption layer at the interface of ethanol and grease, thereby reducing surface tension and making it easier to strip grease; surfactants can also change the interaction between greases, making it easier for grease to disperse in the cleaning agent and improving the efficiency of oil removal.

[0013] In one embodiment, the surfactant is one of a nonionic surfactant and an anionic surfactant, or a mixture of the two.

[0014] In one embodiment, the nonionic surfactant is a mixture of any one or more of Trition-X-100, fatty alcohol polyoxyethylene ether (AEO-9) and octylphenol (OP-10);

[0015] The anionic surfactant is a mixture of any one or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate and sodium secondary alkyl sulfonate;

[0016] Wherein, when the surfactant is a mixture of a nonionic surfactant and an anionic surfactant, the mass ratio of the nonionic surfactant to the anionic surfactant is 10:1 to 4:1;

[0017] The alkaline salt is a mixture of one or more of sodium hydroxide, sodium carbonate and sodium silicate.

[0018] In one embodiment, the nonionic surfactant is octylphenol (OP-10); the anionic surfactant is sodium dodecylbenzene sulfonate; and the alkaline salt is sodium hydroxide.

[0019] In one embodiment, in step (1), the ultrasonic stirring time is 20 to 60 minutes;

[0020] In the step (1), the pressure required for the negative pressure filtration is 10 -2 MPa;

[0021] In the step (1), ethanol is used for the alcohol washing, and the mass volume ratio of the rare earth neodymium-based sludge to ethanol is 10g:50-150ml.

[0022] In one embodiment, the inert gas in step (2) and step (4) is argon;

[0023] In the step (3), the sieving and impurity removal is to sifte the solid impurities in the secondary purified rare earth neodymium-based powder, and the mesh number of the sieve is 40 meshes.

[0024] In one embodiment, in step (4), the mass ratio of rare earth neodymium-based powder to calcium hydride is 10g:6.5g.

[0025] According to a second aspect of the present disclosure, a rare earth neodymium-based powder is provided, which is prepared by any one of the methods described above.

[0026] Compared with the prior art, the advantages of the method of the present application are: (1) The composite cleaning agent in the method of the present application is composed of an ethanol solution or an aqueous solution by adding a trace amount of alkali and a small amount of surfactant, does not produce strong corrosion products such as acidity, and is environmentally friendly. (2) In the method of the present application, the carbon, hydrogen and oxygen contents of the rare earth neodymium-based powder obtained after secondary purification treatment are reduced by about 99%, 98% and 60%, respectively, and the oil removal effect is significant. (3) During the purification process, the three-component composite cleaning agent provided in the method of the present application has no adverse effects such as corrosion on the rare earth elements and iron elements in the rare earth neodymium-based oil sludge waste, and there is almost no loss; in addition, in the method of the present application, the rare earth neodymium-based powder obtained through the purification process is crucial for the later preparation of regenerated high-performance rare earth neodymium-based magnetic powder. (4) After the powder material has been purified by the present application, it is further regenerated, and the coercivity of the obtained magnetic powder is increased from 310.05Oe to 6929.8Oe. The regeneration efficiency is greatly improved, which provides another feasible technology for the secondary resource recycling development of rare earth neodymium-based waste.

[0027] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, in which:

[0029] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0030] Figure 1 The TG-DSC spectra of the rare earth neodymium-based oil sludge waste before and after the secondary purification treatment of Example 1 of the present disclosure are shown;

[0031] Figure 2 The magnetic properties test results of the rare earth neodymium-based oil sludge waste before and after the secondary purification treatment of Example 1 of the present disclosure are shown;

[0032] Figure 3 The figure shows the magnetic property test results of the rare earth neodymium-based magnetic powder obtained through the regeneration treatment in Example 1 of the present disclosure. DETAILED DESCRIPTION

[0033] In order to make the purpose, features, and advantages of the present disclosure more obvious and easy to understand, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0034] In view of the shortcomings of the prior art, the present application adopts a three-component composite cleaning agent + high-temperature baking secondary treatment process to purify rare earth neodymium-based oil sludge waste. After treatment, the oxygen content, hydrogen content and carbon content of the powder are reduced by about 60%, 98% and 99% respectively, and the oil removal effect is significant. The purified powder is further regenerated to obtain a magnetic powder with a coercive force (Hcj) that is 6619.75Oe higher than that of the regenerated crude oil sludge waste, and the secondary resource recycling efficiency of rare earth neodymium-based waste is improved.

[0035] The present invention provides a method for treating rare earth neodymium-based oil sludge waste, which has the following main advantages: (1) In the method of the present invention, the composite cleaning agent used for purification treatment is composed of an ethanol solution or an aqueous solution by adding a trace amount of alkali and a small amount of surfactant, which does not produce strong corrosion products such as acidity and is environmentally friendly; (2) The carbon, hydrogen and oxygen contents of the rare earth neodymium-based powder after secondary purification treatment are reduced by about 99%, 98% and 60%, respectively, and the oil removal effect is significant; (3) The three-component composite cleaning agent provided by the present invention can remove rare earth elements and iron elements in the rare earth neodymium-based oil sludge waste during the purification process. There is no adverse effect such as corrosion, almost no loss, and compared with the current existing treatment process of purifying rare earth neodymium-based oil sludge in an acidic environment, which will cause loss of rare earth and iron elements, the secondary purification process in the method of the present application is crucial for the subsequent preparation of regenerated high-performance rare earth neodymium-based magnetic powder; (4) The powder after purification treatment of the present invention is further regenerated, and the coercive force of the obtained magnetic powder is increased from 310.05Oe to 6929.8Oe, and the regeneration efficiency is greatly improved, which provides another feasible technology for the secondary resource recycling development of rare earth neodymium-based oil sludge waste.

[0036] Specifically, the present application provides a method for treating rare earth neodymium-based oil sludge waste, comprising the following steps:

[0037] (1) Primary purification of rare earth neodymium-based oil sludge waste: rare earth neodymium-based oil sludge and composite cleaning agent are mixed at a mass volume ratio of 10g:50-150ml, and then ultrasonically stirred, negative pressure filtered, and washed with alcohol to obtain a primary purified rare earth neodymium-based powder;

[0038] (2) Secondary purification of rare earth neodymium-based oil sludge waste: treating the primary purified rare earth neodymium-based powder under inert gas protection at a temperature of 600 to 900° C. for 30 to 60 minutes to obtain a secondary purified rare earth neodymium-based powder;

[0039] (3) Removal of solid impurities: sieving the secondary purified rare earth neodymium-based powder to remove impurities, thereby obtaining a rare earth neodymium-based powder.

[0040] Step (4): powder regeneration treatment: the rare earth neodymium-based powder obtained in step (3) is mixed with calcium hydride in a mass ratio of 10g:5.5-7.5g, and tabletted to obtain tablets; the tablets are then kept warm at a temperature of 950-1050°C for 3-5h under the protection of inert gas, and after the end of the heat preservation, the inert gas is continuously introduced for cooling until the temperature drops to 30±5°C to obtain regenerated rare earth neodymium-based magnetic powder tablets; the regenerated rare earth neodymium-based magnetic powder tablets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugation, the upper impurity solution is poured out, and a high-purity rare earth neodymium-based magnetic powder is obtained. The rare earth neodymium-based magnetic powder is then placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0041] In the method of the present application, after secondary purification and impurity removal treatment, a rare earth neodymium-based powder with significant oil removal effect can be obtained; and by performing ICP testing on the rare earth neodymium-based powder after secondary purification, it is found that the rare earth elements and iron elements in the rare earth neodymium-based powder are almost not lost compared with before the purification treatment.

[0042] The rare earth neodymium-based powder after secondary purification was further regenerated, and it was found that the magnetic properties of the regenerated rare earth neodymium-based magnetic powder were significantly improved compared with the magnetic properties of the initial oil sludge regenerated magnetic powder, and the regeneration efficiency was greatly improved. This also proves that the purification treatment technology in this case can not only effectively remove oil from rare earth neodymium-based oil sludge waste, but also significantly improve the regeneration efficiency of rare earth neodymium-based powder. This technology provides another feasible solution for the secondary resource recycling development of rare earth neodymium-based oil sludge waste.

[0043] For example, in step (1), the rare earth neodymium-based oil sludge waste is purified once: rare earth neodymium-based oil sludge is added with a three-component composite cleaning agent (referred to as "composite cleaning agent"), the mass volume ratio of oil sludge: composite cleaning agent is 10g:50-150ml, and mechanically stirred in an ultrasonic cleaning machine for 20-60min, and then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 - 2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was repeatedly washed with ethanol solution for 1-3 times to obtain a purified rare earth neodymium-based powder.

[0044] Preferably, the mass volume ratio of the sludge to the composite cleaning agent is 10g:100ml, 10g:50ml, 10g:150ml.

[0045] Preferably, the composite cleaning agent comprises the following raw materials in weight percentage: 5wt% to 10wt% of surfactant, 0.1wt% to 1wt% of alkaline salt, and the balance is ethanol or water; for example, the weight percentage of the surfactant is 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%. The weight percentage of the alkaline salt is 0.1wt%, 0.2wt%, 0.4wt%, 0.5wt%, 1wt%.

[0046] Preferably, the weight percentage of the alkaline salt is 0.1wt% to 1wt%; the alkaline salt includes a mixture of one or more of sodium hydroxide, sodium carbonate and sodium silicate.

[0047] The surfactant is one of a nonionic surfactant and an anionic surfactant or a mixture of the two, and the weight percentage is 5wt% to 10wt%; the mass ratio of the nonionic surfactant to the anionic surfactant is 10:1 to 4:1. For example, the mass ratio of the nonionic surfactant to the anionic surfactant can be 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1.

[0048] The nonionic surfactant includes any one or more of Triton X-100, fatty alcohol polyoxyethylene ether (AEO-9) and octylphenol (OP-10). The anionic surfactant includes any one or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate and sodium secondary alkyl sulfonate.

[0049] More preferably, the alkaline salt is sodium hydroxide. The nonionic surfactant is octylphenol (OP-10). The anionic surfactant is sodium dodecylbenzene sulfonate.

[0050] Preferably, ethanol is used for alcohol washing. When ethanol is used to wash the powder after negative pressure filtration, the amount of ethanol can be configured according to the mass volume ratio of rare earth neodymium-based sludge to ethanol of 10g:50-150ml, and washing is performed 1-3 times.

[0051] For example, specifically, in step (2), the rare earth neodymium-based oil sludge waste is subjected to secondary purification treatment: the rare earth neodymium-based powder after the primary purification is loaded into a tubular furnace, the temperature is set at 600-900°C, the treatment time is 30-60 minutes, and argon gas is passed through the entire process for protection to obtain a secondary purified rare earth neodymium-based powder.

[0052] Preferably, for example, the set temperature may be 600°C, 700°C, 800°C, or 900°C.

[0053] For example, specifically, in step (3), solid impurities are removed by sieving the rare earth neodymium-based powder after secondary purification to further remove solid impurities, and the mesh size of the sieve is 40 meshes.

[0054] For example, in step (4), the purified powder is regenerated by stirring and mixing the sieved rare earth neodymium-based powder and calcium hydride in a glove box for 30 minutes; wherein the mass ratio of rare earth neodymium-based powder to calcium hydride is 10 g:5.5-7.5 g, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10 MPa, the tableted powder block (i.e., tablet material, the same below) is put into a quartz crucible, and the tablets are loaded into a tubular furnace with an argon atmosphere, the heating rate is set to 10°C / min, and when the temperature reaches 950-1050°C, the temperature is continuously kept for 3-5 hours to regenerate the rare earth neodymium-based powder; after the regeneration treatment is completed, argon is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, a regenerated rare earth neodymium-based magnetic powder tablet is obtained. The regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, and the crushed mixed powder is placed in an anhydrous ethanol solution. The rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugation, and the upper impurity solution is poured out to obtain high-purity rare earth neodymium-based magnetic powder. Thereafter, the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0055] Preferably, the mass ratio of rare earth neodymium-based powder to calcium hydride is 10:6.5g, 10g:5.5g, 10g:7.5g.

[0056] On the other hand, the present application also provides a rare earth neodymium-based magnetic powder, which is prepared by the above method.

[0057] The present application is further described in detail below with reference to specific embodiments:

[0058] Example 1

[0059] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0060] Step (1): 50 g of rare earth neodymium-based oil sludge is added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 20 minutes to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.2 wt% sodium hydroxide, 10 wt% surfactant, and the remainder of water, wherein the surfactant is a mixture of octylphenol (OP-10) and sodium dodecyl sulfate in a mass ratio of 4:1; and then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 -2MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed with 750 ml of ethanol solution, and washed once to obtain a purified rare earth neodymium-based powder;

[0061] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 800° C., processing time to 30 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0062] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0063] Step (4): stirring and mixing the impurity-removed secondary purified rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) and calcium hydride in a glove box at a mass ratio of 10 g:6.5 g for 30 min, loading the uniformly mixed powder into a tableting mold, manually adjusting the pressure to 10 MPa, placing the tableted powder block (i.e., tableting material, the same below) into a quartz crucible, and loading them together into an argon atmosphere tube furnace, setting the heating rate to 10°C / min, and when the temperature reaches 950°C, continuously keeping the temperature for 3 hours to regenerate the rare earth neodymium-based powder; regeneration After the treatment is completed, argon gas is continuously introduced for rapid cooling. When the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0064] In this Example 1, the oxygen, carbon and hydrogen content and ICP (atomic emission spectrometry) of the rare earth neodymium-based powder obtained after secondary purification and impurity removal of the rare earth neodymium-based oil sludge waste (i.e., the rare earth neodymium-based powder obtained in step 3) were tested, and the results are listed in Tables 1 and 2, respectively.

[0065] In this embodiment 1, the rare earth neodymium-based oil sludge waste is subjected to secondary purification and impurity removal to obtain a rare earth neodymium-based powder ( Figure 1-2 “Purified sludge” in the above) and initial rare earth neodymium-based sludge waste ( Figure 1-2 The TG-DSC (thermal analysis) and magnetic properties of the oil were tested, and the results are as follows: Figure 1 and Figure 2 In addition, the magnetic properties of the regenerated rare earth neodymium-based magnetic powder obtained by further regeneration of the rare earth neodymium-based powder after orientation and solidification were tested. The results are shown in Figure 3 shown.

[0066] in, Figure 1 The TG-DSC spectra of rare earth neodymium-based oil sludge waste before and after secondary treatment are shown. Figure 1 It can be seen that the quality of the rare earth neodymium-based sludge (i.e., initial sludge) before purification treatment decreases significantly with increasing temperature, indicating that a large amount of volatile impurities such as oil and dirt in the rare earth neodymium-based sludge are discharged during the process; the quality of the rare earth neodymium-based powder after secondary purification treatment does not change significantly with increasing temperature, which indicates that the rare earth neodymium-based powder after purification treatment has fewer impurities such as oil and dirt, and the purification effect is good.

[0067] Figure 2 The magnetic properties test diagram of rare earth neodymium-based powder and initial sludge after secondary purification is shown. Figure 2 It can be seen that the coercivity H of the initial sludge cj The H content of the powder after secondary purification is 58.77Oe. cj The coercivity before and after purification is 29.61Oe. cj The change is small, and the initial saturation magnetization intensity M of the sludge s The M of the powder after secondary purification is 50.96emu / g. s 75.29emu / g, M s An increase of 47.74%.

[0068] Figure 3 The commercially available recycled rare earth neodymium-based magnetic powder ( Figure 3 The regeneration step of the purified sludge is referred to as "purified sludge regeneration" in the above description), and the magnetic powder obtained by directly regenerating the initial rare earth neodymium-based sludge ( Figure 3 The magnetic property test results after orientation solidification (represented by "initial sludge regeneration" in the figure). The magnetic powder obtained by directly regenerating the so-called initial rare earth neodymium-based sludge is specifically that the rare earth neodymium-based sludge and calcium hydride are stirred and mixed in a glove box at a mass ratio of 10g:6.5g for 30 minutes, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10Mpa, the powder block after tableting (i.e., tableting material, the same below) is put into a quartz crucible, and they are loaded into a tubular furnace with an argon atmosphere, the heating rate is set to 10℃ / min, and when the temperature reaches 950℃, it is kept warm for 3 hours to regenerate the rare earth neodymium-based powder; After the regeneration treatment is completed, argon gas is continuously introduced for rapid cooling. When the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0069] from Figure 3 It can be seen that the saturation magnetization intensity M of the magnetic powder obtained by direct regeneration of the initial sludge is s 42.63emu / g, coercivity H cj The saturation magnetization intensity M of the final product obtained by the process of steps 1-4 in this application is s is 47.41emu / g, and the saturation magnetization intensity M s Compared with the former, the coercivity H is slightly improved. cj 6929.8Oe, coercivity H cj It increased by 6619.75Oe, which shows that the regeneration effect was significantly improved after purification treatment.

[0070] Example 2

[0071] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0072] Step (1): 50 g of rare earth neodymium-based oil sludge is added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 60 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.2 wt % of sodium hydroxide, 10 wt % of a surfactant, and the remainder of ethanol, wherein the surfactant is a mixture of octylphenol (OP-10) and sodium dodecylbenzene sulfonate in a mass ratio of 4:1; and then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed twice with ethanol solution, adding 500 ml of ethanol solution each time, to obtain a purified rare earth neodymium-based powder;

[0073] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 800° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0074] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0075] Step (4): the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) and calcium hydride are stirred and mixed in a glove box at a mass ratio of 10 g:6.5 g for 30 min, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10 MPa, the tableted powder block is put into a quartz crucible, and the powder is loaded into an argon atmosphere tube furnace, the heating rate is set to 10 ° C / min, and when the temperature reaches 950 ° C, it is continuously kept warm for 3 hours to regenerate the rare earth neodymium-based powder; the regeneration treatment is completed Then, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0076] In this Example 2, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0077] Example 3

[0078] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0079] Step (1): 50 g of rare earth neodymium-based sludge was added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 40 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 1 wt% sodium hydroxide, 10 wt% surfactant, and the remainder of water, wherein the surfactant is a mixture of fatty alcohol polyoxyethylene ether (AEO-9) and sodium dodecylbenzene sulfonate in a mass ratio of 4:1; and then the mixed solution was loaded into a Büchner sand core funnel, and the pump pressure was set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed with ethanol solution for 3 times, adding 250 ml of ethanol solution each time, to obtain a purified rare earth neodymium-based powder;

[0080] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 600° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0081] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0082] Step (4): regenerating the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) after impurity removal, specifically comprising: stirring and mixing the purified secondary rare earth neodymium-based powder and calcium hydride in a glove box at a mass ratio of 10 g:5.5 g for 30 min, loading the uniformly mixed powder into a tableting mold, manually adjusting the pressure to 10 MPa, placing the tableted powder block into a quartz crucible, and loading them into an argon atmosphere tube furnace, setting the heating rate to 10°C / min, and when the temperature reaches 1050°C, continuously keeping the temperature for 3 h, and regenerating the rare earth neodymium-based powder. The method comprises the following steps: performing a regeneration treatment; after the regeneration treatment is completed, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, a regenerated rare earth neodymium-based magnetic powder pressed sheet is obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheet is placed in an inert gas glove box, ground and crushed with a corundum mortar, and the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain a rare earth neodymium-based magnetic powder with a higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again, and sieved to obtain a commercially available regenerated rare earth neodymium-based magnetic powder.

[0083] In this Example 3, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0084] Example 4

[0085] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0086] Step (1): 50 g of rare earth neodymium-based sludge was added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 60 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.2 wt % of sodium hydroxide, 10 wt % of a surfactant, and the remainder of ethanol, wherein the surfactant is a mixture of fatty alcohol polyoxyethylene ether (AEO-9) and sodium dodecyl sulfate in a mass ratio of 4:1; and then the mixed solution was loaded into a Büchner sand core funnel, and the pump pressure was set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed twice with ethanol solution, adding 500 ml of ethanol solution each time, to obtain a purified rare earth neodymium-based powder;

[0087] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 800° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0088] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0089] Step (4): the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) after impurity removal is stirred and mixed with calcium hydride in a glove box at a mass ratio of 10g:6.5g for 30 minutes, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10Mpa, the tableted powder block is put into a quartz crucible, and the powder is loaded into an argon atmosphere tube furnace, the heating rate is set to 10°C / min, and when the temperature reaches 950°C, it is continuously kept warm for 5 hours to regenerate the rare earth neodymium-based powder; the regeneration treatment is completed Then, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0090] In Example 4, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0091] Example 5

[0092] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0093] Step (1): 50 g of rare earth neodymium-based sludge was added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 40 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 1 wt% sodium hydroxide, 10 wt% surfactant, and the remainder of water; the surfactant is a mixture of Triton X-100 (Trition-X-100) and sodium dodecyl sulfate in a mass ratio of 4:1; and then the mixed solution was loaded into a Büchner sand core funnel, and the pump pressure was set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed with ethanol solution for 3 times, adding 250 ml of ethanol solution each time, to obtain a purified rare earth neodymium-based powder;

[0094] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 900° C., processing time to 30 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0095] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0096] Step (4): the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) and calcium hydride are stirred and mixed in a glove box at a mass ratio of 10g:7.5g for 30 minutes, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10Mpa, the tableted powder block is placed in a quartz crucible, and the tablets are loaded into a tubular furnace with an argon atmosphere, the heating rate is set to 10°C / min, and when the temperature reaches 1050°C, the temperature is continuously kept for 5 hours to regenerate the rare earth neodymium-based powder; the regeneration process is completed Then, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0097] In this Example 5, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0098] Example 6

[0099] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0100] Step (1): 50 g of rare earth neodymium-based sludge was added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 60 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.2 wt % sodium hydroxide, 10 wt % surfactant, and the remainder ethanol; the surfactant is a mixture of Triton X-100 (Trition-X-100) and sodium dodecylbenzene sulfonate in a mass ratio of 4:1; and then the mixed solution was loaded into a Büchner sand core funnel, and the pump pressure was set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed twice with ethanol solution, adding 750 ml of ethanol solution each time to obtain a purified rare earth neodymium-based powder;

[0101] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 800° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0102] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0103] Step (4): the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) and calcium hydride are stirred and mixed in a glove box at a mass ratio of 10 g:6.5 g for 30 min, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10 MPa, the tableted powder block is put into a quartz crucible, and the powder is loaded into an argon atmosphere tube furnace, the heating rate is set to 10 ° C / min, and when the temperature reaches 950 ° C, it is continuously kept warm for 3 hours to regenerate the rare earth neodymium-based powder; the regeneration treatment is completed Then, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0104] In Example 6, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0105] Example 7

[0106] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0107] Step (1): 50 g of rare earth neodymium-based oil sludge was added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 20 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 1 wt% sodium carbonate, 10 wt% surfactant, and the remainder ethanol; the surfactant is a mixture of Triton X-100 (Trition-X-100) and sodium dodecyl sulfate in a mass ratio of 8:1; and then the mixed solution was loaded into a Büchner sand core funnel, and the pump pressure was set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was repeatedly washed with 500 ml of ethanol solution, and washed once to obtain a purified rare earth neodymium-based powder;

[0108] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 600° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0109] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0110] Step (4): regenerating the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) after impurity removal, specifically comprising: stirring and mixing the purified secondary rare earth neodymium-based powder after impurity removal and calcium hydride in a glove box at a mass ratio of 10 g:6.5 g for 30 min, loading the uniformly mixed powder into a tableting mold, manually adjusting the pressure to 10 MPa, placing the tableted powder block into a quartz crucible, and loading them into a tubular furnace with an argon atmosphere, setting the heating rate to 10°C / min, and when the temperature reaches 950°C, continuously keeping the temperature for 5 h, and regenerating the rare earth neodymium-based powder. The method comprises the following steps: performing a regeneration treatment; after the regeneration treatment is completed, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, a regenerated rare earth neodymium-based magnetic powder pressed sheet is obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheet is placed in an inert gas glove box, ground and crushed with a corundum mortar, and the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain a rare earth neodymium-based magnetic powder with a higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again, and sieved to obtain a commercially available regenerated rare earth neodymium-based magnetic powder.

[0111] In Example 7, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0112] Example 8

[0113] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0114] Step (1): 50 g of rare earth neodymium-based oil sludge is added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 60 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.5 wt % sodium carbonate, 5 wt % surfactant, and the remainder water; the surfactant is a mixture of Triton X-100 (Trition-X-100) and sodium dodecylbenzene sulfonate in a mass ratio of 4:1; and then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was repeatedly washed by adding 750 ml of ethanol solution in turn, and washed twice to obtain a purified rare earth neodymium-based powder;

[0115] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 800° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0116] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0117] Step (4): regenerating the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) after impurity removal, specifically comprising: stirring and mixing the purified secondary rare earth neodymium-based powder and calcium hydride in a glove box at a mass ratio of 10 g:5.5 g for 30 min, loading the uniformly mixed powder into a tableting mold, manually adjusting the pressure to 10 MPa, placing the tableted powder block into a quartz crucible, and loading them into an argon atmosphere tube furnace, setting the heating rate to 10°C / min, and when the temperature reaches 1050°C, continuously keeping the temperature for 3 h, and regenerating the rare earth neodymium-based powder. The method comprises the following steps: performing a regeneration treatment; after the regeneration treatment is completed, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, a regenerated rare earth neodymium-based magnetic powder pressed sheet is obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheet is placed in an inert gas glove box, ground and crushed with a corundum mortar, and the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain a rare earth neodymium-based magnetic powder with a higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again, and sieved to obtain a commercially available regenerated rare earth neodymium-based magnetic powder.

[0118] In Example 8, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0119] Example 9

[0120] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0121] Step (1): 50 g of rare earth neodymium-based sludge is added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 40 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 1 wt% sodium carbonate, 10 wt% surfactant and the remainder ethanol; the surfactant is a mixture of fatty alcohol polyoxyethylene ether (AEO-9) and sodium dodecylbenzene sulfonate in a mass ratio of 10:1; and then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed with ethanol solution for 3 times, adding 500 ml of ethanol solution each time, to obtain a purified rare earth neodymium-based powder;

[0122] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 600° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0123] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0124] Step (4): the purified secondary rare earth neodymium-based powder after impurity removal and calcium hydride (i.e., the rare earth neodymium-based powder obtained in step 3) are stirred and mixed in a glove box at a mass ratio of 10g:5.5g for 30 minutes, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10Mpa, the tableted powder block is placed in a quartz crucible, and the tablets are loaded into a tubular furnace with an argon atmosphere, the heating rate is set to 10°C / min, and when the temperature reaches 1050°C, the temperature is continuously kept for 3 hours to regenerate the rare earth neodymium-based powder; the regeneration treatment is completed Then, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0125] In this Example 9, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0126] Example 10

[0127] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0128] Step (1): 50 g of rare earth neodymium-based oil sludge is added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 60 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.4 wt % of sodium carbonate, 10 wt % of a surfactant, and the remainder of water; the surfactant is a mixture of fatty alcohol polyoxyethylene ether (AEO-9) and sodium dodecyl sulfate in a mass ratio of 8:1; and then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed with ethanol solution for 3 times, adding 500 ml of ethanol solution each time, to obtain a purified rare earth neodymium-based powder;

[0129] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 800° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0130] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0131] Step (4): the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) and calcium hydride are stirred and mixed in a glove box at a mass ratio of 10g:6.5g for 30 minutes, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10Mpa, the tableted powder block is placed in a quartz crucible, and the tablets are loaded into a tubular furnace with an argon atmosphere, the heating rate is set to 10°C / min, and when the temperature reaches 1050°C, the temperature is continuously kept for 5 hours to regenerate the rare earth neodymium-based powder; the regeneration process is completed Then, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0132] In this Example 10, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0133] Embodiment 11

[0134] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0135] Step (1): 50 g of rare earth neodymium-based oil sludge is added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 60 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.1 wt % sodium hydroxide, 5 wt % surfactant, and the remainder of water, wherein the surfactant is a mixture of octylphenol (OP-10) and sodium dodecylbenzene sulfonate in a mass ratio of 4:1; and then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed twice with ethanol solution, adding 500 ml of ethanol solution each time, to obtain a purified rare earth neodymium-based powder;

[0136] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 800° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0137] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0138] Step (4): the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) and calcium hydride are stirred and mixed in a glove box at a mass ratio of 10 g:5.5 g for 30 min, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10 MPa, the tableted powder block is placed in a quartz crucible, and the powder is loaded into an argon atmosphere tube furnace, the heating rate is set to 10 ° C / min, and when the temperature reaches 950 ° C, it is continuously kept warm for 3 hours to regenerate the rare earth neodymium-based powder; the regeneration process is completed Then, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0139] In this Example 11, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0140] Example 12

[0141] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0142] Step (1): 50 g of rare earth neodymium-based sludge is added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 40 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.5 wt % of sodium hydroxide, 8 wt % of a surfactant, and the remainder of water, wherein the surfactant is a mixture of fatty alcohol polyoxyethylene ether (AEO-9) and sodium dodecyl sulfate in a mass ratio of 10:1; and then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed with ethanol solution for 3 times, adding 250 ml of ethanol solution each time, to obtain a purified rare earth neodymium-based powder;

[0143] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 900° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0144] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0145] Step (4): the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) and calcium hydride are stirred and mixed in a glove box at a mass ratio of 10 g:7.5 g for 30 min, the uniformly mixed powder is loaded into a tableting mold, the pressure is manually adjusted to 10 MPa, the tableted powder block is put into a quartz crucible, and the powder is loaded into an argon atmosphere tube furnace, the heating rate is set to 10°C / min, and when the temperature reaches 950°C, the temperature is continuously kept for 5 hours to regenerate the rare earth neodymium-based powder; the regeneration process is completed Then, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, regenerated rare earth neodymium-based magnetic powder pressed sheets are obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheets are placed in an inert gas glove box, ground and crushed with a corundum mortar, the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain rare earth neodymium-based magnetic powder with higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again and sieved to obtain commercially available regenerated rare earth neodymium-based magnetic powder.

[0146] In Example 12, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0147] Embodiment 13

[0148] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0149] Step (1): 50 g of rare earth neodymium-based oil sludge is added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 60 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.5 wt% sodium carbonate, 10 wt% surfactant, and the remainder ethanol, and the surfactant is a mixture of octylphenol (OP-10) and sodium dodecylbenzene sulfonate in a mass ratio of 4:1; then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was repeatedly washed with 750 ml of ethanol solution, and washed once to obtain a purified rare earth neodymium-based powder;

[0150] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 800° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0151] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0152] Step (4): regenerating the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) after impurity removal, specifically comprising: stirring and mixing the purified secondary rare earth neodymium-based powder after impurity removal and calcium hydride in a glove box at a mass ratio of 10 g:6.5 g for 30 min, loading the uniformly mixed powder into a tableting mold, manually adjusting the pressure to 10 MPa, placing the tableted powder block into a quartz crucible, and loading them into an argon atmosphere tube furnace, setting the heating rate to 10°C / min, and when the temperature reaches 1050°C, continuously keeping the temperature for 3 h, and regenerating the rare earth neodymium-based powder. The method comprises the following steps: performing a regeneration treatment; after the regeneration treatment is completed, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, a regenerated rare earth neodymium-based magnetic powder pressed sheet is obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheet is placed in an inert gas glove box, ground and crushed with a corundum mortar, and the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain a rare earth neodymium-based magnetic powder with a higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again, and sieved to obtain a commercially available regenerated rare earth neodymium-based magnetic powder.

[0153] In Example 13, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0154] Embodiment 14

[0155] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0156] Step (1): 50 g of rare earth neodymium-based oil sludge was added to 500 ml of a three-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 60 min to obtain a mixed solution; wherein the three-component composite cleaning agent comprises 0.5 wt % of sodium carbonate, 8 wt % of a surfactant, and the remainder of water, wherein the surfactant is a mixture of octylphenol (OP-10) and sodium dodecyl sulfate in a mass ratio of 8:1; and then the mixed solution was loaded into a Büchner sand core funnel, and the pump pressure was set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was washed with ethanol solution for 3 times, adding 750 ml of ethanol solution each time, to obtain a purified rare earth neodymium-based powder;

[0157] Step (2): loading the primary purified rare earth neodymium-based powder into a tube furnace, setting the temperature to 800° C., processing time to 60 min, and introducing argon gas protection throughout the entire process to obtain a secondary purified rare earth neodymium-based powder;

[0158] Step (3): sieving the secondary purified rare earth neodymium-based powder through a 40-mesh sieve to further remove solid impurities to obtain a rare earth neodymium-based powder;

[0159] Step (4): regenerating the purified secondary rare earth neodymium-based powder (i.e., the rare earth neodymium-based powder obtained in step 3) after impurity removal, specifically comprising: stirring and mixing the purified secondary rare earth neodymium-based powder and calcium hydride in a glove box at a mass ratio of 10 g:5.5 g for 30 min, loading the uniformly mixed powder into a tableting mold, manually adjusting the pressure to 10 MPa, placing the tableted powder block into a quartz crucible, and loading them into an argon atmosphere tube furnace, setting the heating rate to 10°C / min, and when the temperature reaches 1050°C, continuously keeping the temperature for 3 h, and regenerating the rare earth neodymium-based powder. The method comprises the following steps: performing a regeneration treatment; after the regeneration treatment is completed, argon gas is continuously introduced for rapid cooling, and when the furnace temperature drops to 30±5°C, a regenerated rare earth neodymium-based magnetic powder pressed sheet is obtained; the regenerated rare earth neodymium-based magnetic powder pressed sheet is placed in an inert gas glove box, ground and crushed with a corundum mortar, and the crushed mixed powder is placed in an anhydrous ethanol solution, and the rare earth neodymium-based magnetic powder and impurity compounds are separated by centrifugal action, and the upper impurity solution is poured out to obtain a rare earth neodymium-based magnetic powder with a higher purity, and then the rare earth neodymium-based magnetic powder is placed in a drying dish to dry, ground again, and sieved to obtain a commercially available regenerated rare earth neodymium-based magnetic powder.

[0160] In Example 14, the oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder prepared in steps 1-3 are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0161] Comparative Example 1

[0162] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0163] Take 50g of rare earth neodymium-based oil sludge and add 500ml of a two-component composite cleaning agent, and mechanically stir in an ultrasonic cleaning machine for 60min to obtain a mixed solution; the two-component composite cleaning agent includes 1wt% hydrochloric acid and the remainder of ethanol; then load the mixed solution into a Büchner sand core funnel, set the pump pressure to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was added with 500 ml of ethanol solution for repeated washing, and washed twice. After washing, the rare earth neodymium-based powder was loaded into a tubular furnace, the temperature was set to 800°C, the processing time was 60 min, and argon gas was passed through the whole process for protection to obtain the rare earth neodymium-based powder after degreasing.

[0164] The oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder after deoiling of the rare earth neodymium-based oil sludge waste are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0165] Comparative Example 2

[0166] A method for treating rare earth neodymium-based oil sludge waste comprises the following steps:

[0167] Take 50g of rare earth neodymium-based oil sludge and add 500ml of a two-component composite cleaning agent, and mechanically stir in an ultrasonic cleaning machine for 60min to obtain a mixed solution; the two-component composite cleaning agent includes 1wt% nitric acid and the remainder ethanol; then fill the mixed solution into a Büchner sand core funnel, set the pump pressure to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was added with 500 ml of ethanol solution for repeated washing, and washed twice. After washing, the rare earth neodymium-based powder was loaded into a tubular furnace, the temperature was set to 800°C, the processing time was 60 min, and argon gas was passed through the whole process for protection to obtain the rare earth neodymium-based powder after degreasing.

[0168] The oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder after deoiling of the rare earth neodymium-based oil sludge waste are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0169] Comparative Example 3

[0170] 50g of rare earth neodymium-based oil sludge was added to 500ml of a two-component composite cleaning agent, and mechanically stirred in an ultrasonic cleaning machine for 60min to obtain a mixed solution; the two-component composite cleaning agent included 10wt% of a surfactant (the surfactant was octylphenol (OP-10)) and the remainder of ethanol; the mixed solution was then loaded into a Büchner sand core funnel, and the pump pressure was set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was added with 500 ml of ethanol solution for repeated washing, and washed twice. After washing, the rare earth neodymium-based powder was loaded into a tubular furnace, the temperature was set to 800°C, the processing time was 60 min, and argon gas was passed through the whole process for protection to obtain the rare earth neodymium-based powder after degreasing.

[0171] The oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder after deoiling of the rare earth neodymium-based oil sludge waste are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0172] Comparative Example 4

[0173] Take 50g of rare earth neodymium-based oil sludge and add 500ml of a two-component composite cleaning agent, and mechanically stir in an ultrasonic cleaning machine for 60min to obtain a mixed solution; wherein the two-component composite cleaning agent includes 0.2wt% sodium hydroxide and the remainder of water; then the mixed solution is loaded into a Büchner sand core funnel, and the pump pressure is set to 10 -2 MPa, negative pressure accelerated filtration was performed, and the powder obtained after filtration was added with 500 ml of ethanol solution for repeated washing, and washed twice. After washing, the rare earth neodymium-based powder was loaded into a tubular furnace, the temperature was set to 800°C, the processing time was 60 min, and argon gas was passed through the whole process for protection to obtain the rare earth neodymium-based powder after degreasing.

[0174] The oxygen, carbon and hydrogen contents of the rare earth neodymium-based powder after deoiling of the rare earth neodymium-based oil sludge waste are shown in Table 1, and the ICP test results of the rare earth neodymium-based powder are shown in Table 2.

[0175] The oxygen, carbon and hydrogen contents of the rare earth neodymium based powder are shown in Table 1, and the ICP test results of the rare earth neodymium based powder are shown in Table 2.

[0176] Table 1 Carbon, hydrogen and oxygen content of rare earth neodymium-based powder

[0177]

[0178]

[0179] Table 2 ICP test results of rare earth neodymium based powder

[0180] Group Nd% Pr％ Dy% Gd% B％ Ce% Al％ Cu% Co% Fe% Before pretreatment 17.05 4.78 0.98 0.93 0.82 1.99 0.40 0.12 0.64 72.29 Example 1 16.94 4.65 0.95 0.90 0.73 1.88 0.39 0.11 0.61 72.84 Example 2 17.06 4.85 1.01 0.96 0.79 1.95 0.36 0.11 0.60 72.31 Example 3 16.98 4.68 0.96 0.91 0.74 1.91 0.37 0.10 0.61 72.74 Example 4 17.01 4.81 0.97 0.92 0.79 1.93 0.39 0.11 0.62 72.45 Example 5 16.88 4.66 0.94 0.90 0.76 1.87 0.35 0.10 0.58 72.96 Example 6 16.94 4.67 0.97 0.92 0.78 1.87 0.35 0.11 0.59 72.8 Example 7 17.07 4.84 0.96 0.93 0.80 1.98 0.38 0.11 0.63 72.3 Example 8 17.09 4.77 0.98 0.91 0.75 1.93 0.41 0.12 0.61 72.43 Example 9 17.05 4.89 1.00 0.91 0.78 1.95 0.39 0.12 0.62 72.29 Example 10 16.91 4.71 0.92 0.89 0.73 1.89 0.36 0.10 0.60 72.89 Embodiment 11 16.88 4.68 0.93 0.90 0.75 1.86 0.36 0.11 0.61 72.92 Example 12 16.91 4.75 0.94 0.89 0.74 1.92 0.35 0.10 0.62 72.78 Embodiment 13 17.01 4.89 1.00 0.94 0.80 1.98 0.41 0.11 0.65 72.21 Embodiment 14 16.91 4.69 0.90 0.88 0.75 1.89 0.36 0.10 0.61 72.91 Comparative Example 1 10.51 2.01 0.55 0.76 0.61 1.23 0.29 0.05 0.49 83.5 Comparative Example 2 10.33 1.87 0.49 0.71 0.55 1.17 0.25 0.05 0.44 84.14 Comparative Example 3 16.96 4.77 0.95 0.89 0.73 1.94 0.38 0.12 0.60 72.60 Comparative Example 4 16.92 4.81 0.93 0.91 0.75 1.88 0.39 0.11 0.61 72.69

[0181] It can be seen from Tables 1 and 2 above that in the method of the present application, the carbon, hydrogen and oxygen contents of the rare earth neodymium-based powder after the secondary purification treatment are greatly reduced compared with the carbon, hydrogen and oxygen contents of the rare earth neodymium-based sludge before the purification treatment; and the contents of rare earth elements, iron elements and the like in the rare earth neodymium-based powder after the secondary purification treatment are not much different from those in the rare earth neodymium-based sludge before the treatment. It can be seen that there is almost no loss of rare earth elements and the like in the rare earth neodymium-based powder obtained by the secondary purification treatment in the method of the present application.

[0182] In addition, it can be seen from the above Tables 1-2 that the carbon, hydrogen and oxygen content of the rare earth neodymium-based powder prepared in the embodiment of the present application, especially the carbon content, is much lower than the carbon content of the powder obtained by purification treatment with hydrochloric acid and nitric acid in Comparative Example 1-2, and the loss of rare earth elements, iron elements, etc. after purification in Comparative Example 1-2 is large. Comparative Example 3 does not add alkaline salts, and the loss of rare earth elements is relatively small, but the carbon content is much higher than the purified powder after degreasing with the ternary composite cleaning agent in this embodiment with the addition of sodium hydroxide, and the degreasing effect is poor. Comparative Example 4 does not add surfactants, and the carbon content will be higher than the purified powder after degreasing with the ternary composite cleaning agent in this embodiment with the addition of surfactants, and the degreasing effect will also be relatively poor. This also shows that alkaline salts and surfactants play a synergistic role in the preparation of ternary composite cleaning agents, and the combination of the two can increase the degreasing effect.

[0183] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0184] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0185] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for treating rare earth neodymium-based oil sludge waste, characterized in that: The steps include: (1) Mixing rare earth neodymium-based oil sludge and a composite cleaning agent at a mass volume ratio of 10 g:50-150 ml, and then ultrasonically stirring, negative pressure filtering, and alcohol washing to obtain a primary purified rare earth neodymium-based powder; (2) treating the primary purified rare earth neodymium-based powder under inert gas protection at a temperature of 600 to 900° C. for 30 to 60 minutes to obtain a secondary purified rare earth neodymium-based powder; (3) sieving the secondary purified rare earth neodymium-based powder to remove impurities to obtain a rare earth neodymium-based powder; (4) The rare earth neodymium-based powder obtained in step (3) is mixed with calcium hydride in a mass ratio of 10 g:5.5-7.5 g, and tabletted to obtain tablets; the tablets are then kept warm at a temperature of 950-1050° C. for 3-5 hours under the protection of inert gas, and after the insulation is completed, the inert gas is continuously introduced for cooling until the temperature drops to 30±5° C. to obtain regenerated rare earth neodymium-based magnetic powder tablets; the regenerated rare earth neodymium-based magnetic powder tablets are placed under the protection of inert gas, ground, crushed, centrifuged, separated, dried, and sieved to obtain regenerated rare earth neodymium-based magnetic powder.

2. The method according to claim 1, characterized in that: The mass volume ratio of the rare earth neodymium-based sludge to the composite cleaning agent is 10g:100ml; The composite cleaning agent comprises the following raw materials in weight percentage: 5-10wt% of surfactant, 0.1-1wt% of alkaline salt, and the balance is ethanol or water.

3. The method according to claim 2, characterized in that: The surfactant is one of a nonionic surfactant and an anionic surfactant or a mixture of the two.

4. The method according to claim 3, characterized in that: The nonionic surfactant is a mixture of any one or more of Triton X-100, fatty alcohol polyoxyethylene ether and octyl phenol; The anionic surfactant is a mixture of any one or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate and sodium secondary alkyl sulfonate; Wherein, when the surfactant is a mixture of a nonionic surfactant and an anionic surfactant, the mass ratio of the nonionic surfactant to the anionic surfactant is 10:1 to 4:1; The alkaline salt is a mixture of one or more of sodium hydroxide, sodium carbonate and sodium silicate.

5. The method according to claim 4, characterized in that: The nonionic surfactant is octylphenol; the anionic surfactant is sodium dodecylbenzene sulfonate; and the alkaline salt is sodium hydroxide.

6. The method according to claim 1, characterized in that: In the step (1), the ultrasonic stirring time is 20 to 60 minutes; In the step (1), the pressure required for the negative pressure filtration is 10 -2 MPa; In the step (1), ethanol is used for the alcohol washing, and the mass volume ratio of the rare earth neodymium-based sludge to ethanol is 10g:50-150ml.

7. The method according to claim 1, characterized in that: The inert gas in step (2) and step (4) is argon; In the step (3), the sieving and impurity removal is to sifte the solid impurities in the secondary purified rare earth neodymium-based powder, and the mesh number of the sieve is 40 meshes.

8. The method according to claim 1, characterized in that: In the step (4), the mass ratio of the rare earth neodymium-based powder to calcium hydride is 10g:6.5g.

9. A rare earth neodymium-based magnetic powder, characterized in that: The invention is prepared by the method described in any one of claims 1 to 8.

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