CN115961138A - Regenerated magnetic powder, method for preparing regenerated magnetic powder by chlorination-reduction diffusion combined method and application thereof - Google Patents
Regenerated magnetic powder, method for preparing regenerated magnetic powder by chlorination-reduction diffusion combined method and application thereof Download PDFInfo
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Abstract
The invention provides a regenerated magnetic powder, a method for preparing the regenerated magnetic powder by using a chlorination-reduction diffusion combined method and application thereof, wherein the method comprises the following steps: (1) Mixing neodymium iron boron oil sludge and a solid chlorinating agent, and performing selective chlorination roasting to obtain a roasted product; (2) And mixing the roasted product with a reducing agent, and carrying out calcium reduction diffusion reaction to obtain the regenerated magnetic powder. According to the invention, the neodymium iron boron oil sludge is recovered by a chloride-calcium reduction-diffusion combined method, and the low-oxygen low-impurity-content regenerated magnetic powder which can be used for preparing a high-performance regenerated sintered magnet is obtained. In addition, the rare earth-rich alloy can be doped to prepare the regenerated magnet with excellent performance, and the problem of low performance of the regenerated magnet caused by high oxygen content of the regenerated magnetic powder is solved. The method can improve the calcium removal efficiency and the intrinsic magnetic property of the regenerated magnetic powder, reduce the temperature of the calcium reduction diffusion reaction, reduce the cost and realize the aims of short flow, low cost, green and high-efficiency recovery of the neodymium iron boron oil sludge.
Description
Technical Field
The invention belongs to the technical field of rare earth permanent magnet waste recycling, and particularly relates to regenerated magnetic powder, a method for preparing the regenerated magnetic powder by using a chlorination-reduction diffusion combined method and application of the regenerated magnetic powder.
Background
The sintered neodymium iron boron magnet is the most important rare earth permanent magnet material, and the market demand and the yield of the sintered neodymium iron boron in China are increased year by year along with the high-speed development of new energy automobiles, wind power energy conservation, electronic information and other industries in recent years. In 2020, the yield of the sintered neodymium iron boron magnet in China is about 18.55 ten thousand tons, and the oil sludge waste which accounts for about 20-30wt.% of the total yield is generated in the machining process of the magnet, which means that about 4-6 ten thousand tons of oil sludge waste is generated. The oil sludge waste material not only contains about 30wt.% of rare earth elements, but also contains valuable trace elements such as Co, cu, al, ga and the like, and has great recovery value. Therefore, in recent years, the recycling of the waste neodymium iron boron sludge has received more and more attention.
At present, the industrial recovery mode of the neodymium iron boron oil sludge waste is mainly to separate and extract rare earth elements in the waste through a traditional hydrometallurgy process, and mainly comprises the steps of oxidizing roasting, acid dissolution leaching, neutralization impurity removal, extraction separation, oxalic acid precipitation and the like. If the neodymium iron boron magnetic powder is prepared, a series of links such as fused salt electrolysis, rapid solidification smelting, hydrogen explosion, jet milling and the like are needed, the process is long, the energy consumption is high, and the problem of high pollution caused by the fused salt electrolysis process is difficult to avoid. In addition, as environmental regulations at home and abroad become stricter, the environmental cost for mining rare earth ores is increasingly raised; meanwhile, in order to keep the advantages of rare earth resources in China, improve social and economic benefits and sustainable development of the rare earth industry, researchers develop a new process and a new method for green and efficient recycling of neodymium iron boron oil sludge waste.
For example, CN103882234B discloses a method for preparing regenerated neodymium iron boron magnetic powder by recovering neodymium iron boron oil sludge waste materials by using coprecipitation and calcium reduction diffusion technologies, but the method has many flows and is complicated to operate, mixed oxides of rare earth and iron are obtained by using coprecipitation technologies, the amount of reducing agent metal calcium is increased, the cost is increased, the metal calcium reacts violently with the oxide of iron, splashing is easily generated, the control is not easy, and the increase of the amount of calcium causes difficulty in impurity removal and oxygen control in a washing process, resulting in higher O and Ca contents of the obtained regenerated magnetic powder and poorer magnetic performance.
CN104690277B discloses a method for preparing a regenerative sintered magnet by recovering neodymium iron boron oil sludge by using a reduction diffusion technology, the regeneration of the neodymium iron boron oil sludge is realized by the steps of pretreatment, acid dissolution, coprecipitation, roasting, calcium reduction diffusion, powder mixing, sintering and the like, but the neodymium iron boron phase in the oil sludge is damaged in the regeneration process, fe and Fe-B alloy are also needed to be added, the consumption of a reducing agent in the calcium reduction process is increased, the recovery cost is increased, the difficulty of calcium removal and oxygen control in the washing process is increased, the reduction temperature is very high and is above 1160 ℃, and the energy consumption is higher.
CN104690270B discloses a short-flow method for preparing a regenerated sintered magnet by recovering oil sludge waste materials by a reduction diffusion method, the method removes organic matters in the waste materials by distillation and ultrasonic cleaning without acid dissolution, and then directly obtains regenerated magnetic powder by the reduction diffusion method, but extra Nd is added in the reduction diffusion process 2 O 3 And Fe-B and other raw materials cause the increase of the consumption of the reducing agent, which is not beneficial to reducing the recovery cost. CN109338113B discloses a method for recovering neodymium iron boron trepanning oil sludge waste by Ca chloride reduction diffusion technology, which proposes to use KCl as a low melting point adjuvant to reduce reaction temperature and shorten reaction time, but it uses an air-blast drying oven to purify oil sludge, so that the oxygen content in the oil sludge is increased, the calcium required in calcium reduction is correspondingly increased, and it is not beneficial to reduce cost. Because the calcium particles are large, the calcium particles can not be fully mixed with the oil sludge in the diffusion processThe contact, therefore, the method has the phenomenon of uneven reaction, and the calcium reduction process needs to consume a far excessive amount of calcium, so the cost is high.
CN110157916B discloses a method for preparing high-performance anisotropic neodymium iron boron magnetic powder by utilizing neodymium iron boron oil-based slice oil sludge at low cost, and mentions that the reaction distance can be reduced by pressing reactants into a block before calcium reduction diffusion heating, so that the reaction sufficiency is increased to a certain extent, but the recovery processing amount is limited by static sintering of the block; in addition, the low-temperature washing and calcium removal of the regenerated magnetic powder by using an ice-water mixture reduces the oxygen content of the regenerated magnetic powder to a certain extent. However, in the method, the by-products after the calcium reduction diffusion are calcium oxide, and due to the characteristics of being insoluble in water and alcohol, the calcium oxide is mainly washed and removed by deionized water or ice deionized water, and because a large amount of heat is released in the reaction process of the calcium oxide and the water, calcium hydroxide insoluble in water is formed, and the solubility of oxygen in water is higher than that of organic solvents such as ethanol, the regenerated magnetic powder after the washing and calcium removal process has the problems of high O content (> 4000ppm, and the oxygen content of some regenerated magnetic powder even reaches more than 8000 ppm), incomplete removal of impurity Ca and the like, so that the intrinsic magnetic performance of the regenerated magnetic powder is low, and the application of the regenerated magnetic powder in the preparation of high-performance regenerated sintered neodymium iron boron magnets is limited.
In a word, although the recovery of the neodymium iron boron oil sludge waste material by the calcium reduction diffusion method has the great advantages of short process, high efficiency and environmental protection, the problems of large calcium usage amount, high reaction temperature, high O content in the regenerated neodymium iron boron magnetic powder, incomplete removal of impurity Ca and the like still exist.
Therefore, the development of a green and efficient method for preparing low-oxygen and low-impurity-content regenerated magnetic powder by recycling neodymium iron boron oil sludge waste is a technical problem to be solved urgently.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a regenerated magnetic powder, a method for preparing the regenerated magnetic powder by using a chlorination-reduction diffusion combined method and application thereof. The neodymium iron boron oil sludge is recovered by a chloride-calcium reduction diffusion combined method, and the low-oxygen low-impurity-content regenerated magnetic powder which can be used for preparing a high-performance regenerated sintered magnet is obtained. The method can improve the calcium removal efficiency and the intrinsic magnetic property of the regenerated rare earth permanent magnet material, simultaneously can reduce the temperature of calcium reduction diffusion reaction and the dosage of a reducing agent, reduces the cost, and also realizes the purposes of short flow, low cost, green and high-efficiency recovery of the neodymium iron boron oil sludge.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a method for preparing a regenerated magnetic powder by using a combined chlorination-reduction diffusion method, wherein the method comprises the following steps:
(1) Mixing neodymium iron boron oil sludge and a solid chlorinating agent, and performing selective chlorination roasting to obtain a roasted product;
(2) And mixing the roasted product with a reducing agent, and carrying out calcium reduction diffusion reaction to obtain the regenerated magnetic powder.
The invention recovers the neodymium iron boron oil sludge by a chloride-calcium reduction diffusion combined method, namely, rare earth elements in the oil sludge are selectively converted into rare earth chloride by selective chloridizing roasting, thereby converting calcium reduction diffusion byproducts into CaCl which is easily dissolved in water and alcohol from CaO which is difficult to dissolve in water and alcohol 2 And further the low-oxygen and low-impurity-content regenerated magnetic powder which can be used for preparing the high-performance regenerated sintered neodymium-iron-boron magnet is obtained. The method can improve the calcium removal efficiency and the intrinsic magnetic property of the regenerated magnetic powder, can reduce the temperature of the calcium reduction diffusion reaction, reduces the cost, and realizes the purposes of short flow, low cost, green and high-efficiency recovery of the neodymium iron boron oil sludge.
In the invention, the adopted solid chlorinating agent is a low-melting-point chlorinating agent, which can play a role of fluxing, reduce the temperature of the calcium reduction diffusion reaction and the dosage of metal calcium and reduce the production cost.
Preferably, the solid chlorinating agent of step (1) comprises NH 4 Cl、FeCl 2 、FeCl 3 、AlCl 3 、CoCl 2 、NiCl 2 NaClO or NaClO 3 Any one or a combination of at least two of them.
Preferably, the neodymium iron boron oil sludge and the solid chlorinating agent are mixed according to the mass of the rare earth chloride, wherein the mass ratio of the neodymium iron boron oil sludge to the solid chlorinating agent is 1-5 times of the stoichiometric ratio.
In the invention, if the use amount of the solid chlorinating agent is too small, the selective chlorination reaction is incomplete, and the rare earth component is not fully converted; if the dosage of the solid chlorinating agent is too large, components such as metal Fe and the like easily participate in chlorination reaction, so that the selectivity of the chlorination reaction on rare earth components is reduced.
Preferably, the selective chloridizing roasting of the step (1) is carried out in an inert atmosphere or a vacuum atmosphere, wherein the gas in the inert atmosphere comprises nitrogen and/or argon, and the vacuum degree in the vacuum atmosphere<1.0×10 -3 Pa, for example, may be 0.8X 10 -3 Pa、0.5×10 -3 Pa、0.3×10 -3 Pa、1×10 -4 Pa or 0.5X 10 -4 Pa, and the like.
Preferably, the temperature of the chlorination roasting in the step (1) is 250 to 850 ℃ for the selective chlorination roasting, and may be, for example, 250 ℃, 300 ℃, 350 ℃, 400 ℃, 450 ℃, 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃ or the like.
In the invention, if the temperature of the chlorination roasting is too low, the chlorination reaction is not sufficient; if the temperature of the chloridizing roasting is too high, the chlorinating agent is easily decomposed or volatilized.
Preferably, the time of the selective chlorination roasting in the step (1) is 1-4h, and can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h or 4h, etc.
Preferably, the neodymium iron boron oil sludge obtained in the step (1) is pretreated before being mixed with the solid chlorinating agent, and the specific steps are as follows:
and (3) cleaning and magnetically separating the oil sludge in sequence by using a cleaning solution, and drying to obtain the purified oil sludge.
Preferably, the cleaning liquid used in the cleaning process includes any one of or a combination of at least two of an ethanol solution, a 0.5g/L sodium hydroxide-5% OP emulsifier mixed aqueous solution, a 0.5g/L sodium hydroxide-5% OP emulsifier mixed ethanol solution, a 0.1mol/L hydrochloric acid-5% OP emulsifier mixed aqueous solution, or a 0.1mol/L hydrochloric acid-5% OP emulsifier mixed ethanol solution, wherein the 5% OP emulsifier is one type of emulsifier OP series (a condensate of alkylphenol and ethylene oxide).
Preferably, the reducing agent in step (2) comprises elemental calcium and/or calcium hydride.
Preferably, the mass fraction of the reducing agent in step (2) is 5-30%, for example, 5%, 10%, 15%, 20%, 25%, or 30% based on 100% of the mass of the neodymium iron boron oil sludge.
In the invention, if the mass fraction of the reducing agent is too small, the reaction is insufficient, and the morphology of the magnetic powder is poor; if the mass fraction of the reducing agent is too large, a large number of byproducts are produced, which is not beneficial to impurity removal.
Preferably, the calcium reduction diffusion reaction in the step (2) is performed in an inert atmosphere or a vacuum atmosphere, wherein the gas in the inert atmosphere comprises nitrogen and/or argon, and the vacuum degree in the vacuum atmosphere<1.0×10 -3 Pa, for example, may be 0.8X 10 -3 Pa、0.5×10 -3 Pa、0.3×10 -3 Pa、1×10 -4 Pa or 0.5X 10 -4 Pa, and the like.
Preferably, the temperature of the calcium reduction diffusion reaction in step (2) is 750-1050 ℃, for example, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃, 1000 ℃ or 1050 ℃ and the like.
Preferably, the time of the calcium reduction diffusion reaction in step (2) is 1-3h, such as 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, 2.2h, 2.4h, 2.6h, 2.8h or 3h.
Preferably, the method further comprises washing, magnetically separating and drying the reaction product after the calcium reduction diffusion reaction in the step (2) is finished.
Preferably, the detergent used for washing comprises any one of or a combination of at least two of absolute ethyl alcohol, ethylene glycol, n-propanol, n-butanol, n-pentanol, methanol-ammonium chloride solution, methanol-ammonium nitrate, methanol-ammonium acetate, deionized water, ice deionized water, propylene glycol or glycerol.
Preferably, the solid-liquid ratio of the reaction product to the detergent is 1g (10-100) mL, and may be, for example, 1g.
Preferably, the washing time is 10-180min, such as 10min, 30min, 50min, 70min, 90min, 120min, 150min or 180 min.
Preferably, the number of washing is 1 to 3, for example, 1, 2, 3, etc.
As a preferred technical solution, the method comprises the steps of:
sequentially cleaning and magnetically separating the neodymium iron boron oil sludge by using a cleaning solution, and drying to obtain purified neodymium iron boron oil sludge;
(II) mixing a solid chlorinating agent with the purified neodymium iron boron oil sludge, and selectively chlorinating and roasting for 1-4 hours at 250-850 ℃ in an inert atmosphere or a vacuum atmosphere to obtain a roasted product;
and mixing the neodymium iron boron oil sludge and the solid chlorinating agent according to the mass of the rare earth chloride by 1-5 times of the stoichiometric ratio.
(III) mixing the roasted product with a reducing agent, carrying out calcium reduction diffusion reaction for 1-3h in an inert atmosphere or vacuum atmosphere at the temperature of 750-1050 ℃, and after the reaction is finished, washing, carrying out magnetic separation and drying to obtain the regenerated magnetic powder;
wherein the mass fraction of the reducing agent is 5-30%.
In a second aspect, the present invention provides a regenerated magnetic powder, which is prepared by the preparation method of the first aspect;
preferably, the oxygen content of the regenerated magnetic powder is less than 1500ppm, and may be 1400rpm, 1300rpm, 1200rpm, 1100rpm, 1000rpm, or the like, for example.
In a third aspect, the invention provides a regenerated sintered neodymium-iron-boron magnet, which is obtained by mixing and sintering the regenerated magnetic powder and the rare earth-rich alloy in the second aspect.
Preferably, the rare earth-rich alloy is RE-M, wherein RE represents a rare earth element and M represents a metal alloy.
Preferably, the rare earth-rich alloy comprises RE-Cu、RE-Cu-Al、RE-Cu-Al-Ga、(RE) 4 Fe 14 B or RE 6 Fe 13 Any one or a combination of at least two of Ga.
Preferably, the mass fraction of the rare earth-rich alloy is 5-40% based on 100% of the mass of the regenerated sintered neodymium-iron-boron magnet, and may be, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or the like.
Preferably, the sintering temperature is 1020-1080 ℃, for example 1020 ℃, 1030 ℃, 1040 ℃, 1050 ℃, 1060 ℃, 1070 ℃ or 1080 ℃.
Preferably, the sintering time is 3-4h, for example, 3h, 3.1h, 3.2h, 3.3h, 3.4h, 3.5h, 3.6h, 3.7h, 3.8h, 3.9h or 4h, etc.
Preferably, the sintering is preceded by a dehydrogenation treatment.
Preferably, the sintering is followed by annealing, which includes primary annealing and secondary annealing.
Preferably, the temperature of the primary annealing is 850-900 ℃, such as 850 ℃, 860 ℃, 870 ℃, 880 ℃, 890 ℃ or 900 ℃ and the like.
Preferably, the time of the primary annealing is 1 to 3 hours, and can be 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3 hours, etc.
Preferably, the temperature of the secondary annealing is 450 to 500 ℃, such as 450 ℃, 460 ℃, 470 ℃, 480 ℃, 490 ℃, 500 ℃ and the like.
Preferably, the time of the secondary annealing is 1 to 3 hours, and may be 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, or the like.
The recitation of numerical ranges herein includes not only the above-recited values, but also any values between any of the above-recited numerical ranges not recited, and for brevity and clarity, is not intended to be exhaustive of the specific values encompassed within the range.
Compared with the prior art, the invention has the following beneficial effects:
(1) The neodymium iron boron oil sludge is recovered by a chloride-calcium reduction diffusion combined method, so that the low-oxygen low-impurity-content regenerated magnetic powder which can be used for preparing a high-performance regenerated sintered neodymium iron boron magnet is obtained;
(2) The method provided by the invention can improve the calcium removal efficiency and the intrinsic magnetic property of the regenerated magnetic powder, and simultaneously can reduce the temperature of the calcium reduction diffusion reaction and the dosage of the reducing agent, thereby being more beneficial to reducing the cost and obtaining the regenerated magnetic powder with lower oxygen content;
(3) The method provided by the invention can realize the purposes of short flow, low cost, green and high-efficiency recovery of the neodymium iron boron oil sludge.
Drawings
FIG. 1 shows Δ G of main elements in neodymium iron boron oil sludge subjected to chlorination reaction θ T -T diagram.
FIG. 2 is a diagram showing the Δ G of the calcium reduction diffusion reaction of the compound formed by the main elements in the NdFeB sludge provided by the invention θ T -T diagram.
Fig. 3 is an XRD spectrum of the purified neodymium iron boron oil sludge and the regenerated magnetic powder in example 1 of the present invention.
FIG. 4 shows Nd-doped articles of examples 1 and 2 of the present invention 4 Fe 14 B, preparing a demagnetization curve of the regenerative sintered neodymium iron boron magnet after the rare earth-rich alloy powder.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
The following examples all pretreat the neodymium iron boron oil sludge, and the specific steps include:
ultrasonically cleaning the neodymium iron boron oil sludge by using 0.5g/L sodium hydroxide-5% OP emulsifier mixed ethanol solution for 30min, cleaning for 3 times, cleaning for 2 times by using ethanol, and then carrying out magnetic separation and vacuum drying to obtain the purified neodymium iron boron oil sludge.
Example 1
The embodiment provides a method for preparing regenerated magnetic powder by using a chlorination-reduction diffusion combined method, which comprises the following steps:
(1) Uniformly mixing 100g of purified neodymium iron boron oil sludge and 35g of ammonium chloride, briquetting under the pressure of 30MPa, and then putting the mixture into a tube furnace, and preserving heat for 3 hours at 400 ℃ under the protection of argon atmosphere to perform selective chloridizing roasting to obtain a roasted product;
mixing the neodymium iron boron oil sludge and the solid chlorinating agent according to 2 times of the stoichiometric ratio by mass of rare earth chloride;
(2) Mixing the roasted product with 30g of metal calcium, briquetting the mixture under the pressure of 30MPa, carrying out heat preservation at 950 ℃ for 3 hours under the protection of argon gas for calcium reduction diffusion reaction, grinding the reduction diffusion powder to about 100 meshes after the reaction is finished, putting the powder into a beaker filled with absolute ethyl alcohol according to the solid-to-liquid ratio of 1.
The embodiment also provides a regenerative sintered neodymium-iron-boron magnet, which is prepared by the following steps:
mixing the above regenerated magnetic powder with 30wt.% Nd 4 Fe 14 Uniformly mixing the B rare earth-rich alloy powder, performing orientation compression under a 1.8T magnetic field and cold isostatic pressing under 225MPa, sintering at 1070 ℃ for 3h after dehydrogenation treatment, and performing primary annealing and secondary annealing at 900 ℃ and 500 ℃ respectively for 3h to finally obtain the B rare earth-rich alloy powder with the magnetic property of B r ＝12.44，H cj ＝18.28，(BH) max A regenerative sintered neodymium iron boron magnet of =37.38 MGOe.
Fig. 3 shows XRD patterns of the purified neodymium iron boron sludge and the regenerated magnetic powder in this example.
Example 2
The embodiment provides a method for preparing regenerated magnetic powder by using a chlorination-reduction diffusion combined method, which comprises the following steps:
(1) Uniformly mixing 100g of purified oil sludge and 35g of ammonium chloride, briquetting under the pressure of 30MPa, and then placing into a tubular furnace, and preserving heat at 400 ℃ for 3 hours under the protection of nitrogen atmosphere for selective chloridizing roasting to obtain a roasted product;
mixing the neodymium iron boron oil sludge and the solid chlorinating agent according to 2 times of the stoichiometric ratio by mass of rare earth chloride;
(2) Mixing the roasted product with 20g of metal calcium, briquetting the mixture under the pressure of 30MPa, carrying out heat preservation at 950 ℃ for 3 hours under the nitrogen protective atmosphere to carry out calcium reduction diffusion reaction, grinding reduction diffusion powder to about 100 meshes after the reaction is finished, putting the powder into a beaker filled with absolute ethyl alcohol according to the solid-to-liquid ratio of 1.
The embodiment also provides a regenerative sintered neodymium-iron-boron magnet, which is prepared by the following steps:
mixing the above regenerated magnetic powder with 20wt.% of Nd 4 Fe 14 Uniformly mixing the B rare earth-rich alloy powder, performing orientation compression under a 1.8T magnetic field and cold isostatic pressing under 225MPa, sintering at 1050 ℃ for 3.5h after dehydrogenation treatment, and performing primary annealing and secondary annealing at 850 ℃ and 450 ℃ respectively, wherein the annealing time is 3h, and finally obtaining the alloy powder with the magnetic property of Br =12.50, hcj =17.79, (BH) max A regenerative sintered neodymium iron boron magnet of =37.95 MGOe.
FIG. 4 shows Nd doping of examples 1 and 2 4 Fe 14 B, preparing a demagnetization curve of the regenerative sintered neodymium iron boron magnet after the rare earth-rich alloy powder.
Example 3
The embodiment provides a method for preparing regenerated magnetic powder by using a chlorination-reduction diffusion combined method, which comprises the following steps:
(1) Mixing 100g of neodymium iron boron purified oil sludge and 35g of ammonium chloride uniformly, briquetting under the pressure of 30MPa, and then putting into a tube furnace to ensure that the vacuum degree is 0.5 multiplied by 10 -3 Keeping the temperature of 300 ℃ for 4 hours in a vacuum atmosphere of Pa to perform selective chloridizing roasting to obtain a roasted product;
mixing the neodymium iron boron oil sludge and the solid chlorinating agent according to 2 times of the stoichiometric ratio by mass of rare earth chloride;
(2) Will calcine to produceMixing the above materials with 20g of calcium metal, briquetting under 30MPa, and vacuum-pumping under 0.5 × 10 -3 And (2) keeping the temperature of 750 ℃ for 3 hours in a Pa vacuum atmosphere to carry out calcium reduction diffusion reaction, grinding reduction diffusion powder to about 100 meshes after the reaction is finished, putting the reduction diffusion powder into a beaker filled with ice deionized water according to the solid-to-liquid ratio of 1.
The embodiment also provides a regenerative sintered neodymium-iron-boron magnet, which is prepared by the following steps:
mixing the above regenerated magnetic powder with 5wt.% of Nd 4 Fe 14 Uniformly mixing the B rare earth-rich alloy powder, performing orientation compression under a 1.8T magnetic field and cold isostatic pressing under 225MPa, sintering at 1020 ℃ for 4h after dehydrogenation treatment, and performing primary annealing and secondary annealing at 870 ℃ and 470 ℃ respectively for 2h to finally obtain the alloy powder with the magnetic property of B r ＝11.66，H cj ＝16.49，(BH) max A regenerative sintered neodymium iron boron magnet of =31.78 MGOe.
Example 4
The embodiment provides a method for preparing regenerated magnetic powder by using a chlorination-reduction diffusion combined method, which comprises the following steps:
(1) Uniformly mixing 100g of neodymium iron boron purified oil sludge and 35g of ammonium chloride, briquetting under the pressure of 30MPa, and then placing into a tube furnace, and preserving heat at 800 ℃ for 1h under the protection of argon atmosphere for selective chloridizing roasting to obtain a roasted product;
the neodymium iron boron oil sludge and the solid chlorinating agent are mixed according to the mass of the rare earth chloride, wherein the mass of the neodymium iron boron oil sludge is 2 times of the stoichiometric ratio of the solid chlorinating agent;
(2) Mixing the roasted product with 10g of calcium hydride, briquetting the mixture under the pressure of 30MPa, then preserving the heat at 1050 ℃ for 1h under the argon protective atmosphere to carry out calcium reduction diffusion reaction, grinding the reduction diffusion powder to about 100 meshes after the reaction is finished, putting the powder into a beaker filled with absolute ethyl alcohol according to the solid-to-liquid ratio of 1.
The embodiment also provides a regenerative sintered neodymium-iron-boron magnet, which is prepared by adopting the following steps:
mixing the above regenerated magnetic powder with 10 wt% (Nd-Dy) 70 Cu 30 Uniformly mixing rare earth-rich alloy powder, then carrying out orientation compression under a 1.8T magnetic field and cold isostatic pressing under 225MPa, sintering at 1080 ℃ for 3h after dehydrogenation treatment, then respectively carrying out primary annealing and secondary annealing at 880 ℃ and 480 ℃, wherein the annealing time is 3h, and finally obtaining the alloy powder with the magnetic property of Br =12.25, hcj =23.71, (BH) max A regenerative sintered neodymium iron boron magnet of =36.68 MGOe.
FIG. 1 shows the Δ G of main elements in NdFeB sludge chlorinated by examples 1-4 θ T -T-plot.
FIG. 2 shows the Δ G of the calcium reduction diffusion reaction of the compounds formed by the main elements of the NdFeB sludge provided in examples 1-4 θ T -T diagram.
The applicant states that the present invention is illustrated by the above examples of the process of the present invention, but the present invention is not limited to the above process steps, i.e. it is not meant that the present invention must rely on the above process steps to be carried out. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.
Claims (10)
1. A method for preparing regenerated magnetic powder by using a chlorination-reduction diffusion combined method, which is characterized by comprising the following steps:
(1) Mixing neodymium iron boron oil sludge and a solid chlorinating agent, and performing selective chlorination roasting to obtain a roasted product;
(2) And mixing the roasted product with a reducing agent, and carrying out calcium reduction diffusion reaction to obtain the regenerated magnetic powder.
2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,characterized in that the solid chlorinating agent in the step (1) comprises NH 4 Cl、FeCl 2 、FeCl 3 、AlCl 3 、CoCl 2 、NiCl 2 NaClO or NaClO 3 Any one or a combination of at least two of;
preferably, the neodymium iron boron oil sludge and the solid chlorinating agent are mixed according to the mass of the rare earth chloride, wherein the mass ratio of the neodymium iron boron oil sludge to the solid chlorinating agent is 1-5 times of the stoichiometric ratio.
3. The process according to claim 1 or 2, characterized in that the selective chloriding roasting of step (1) is carried out in an inert atmosphere or in a vacuum atmosphere, the gases of which comprise nitrogen and/or argon, the vacuum degree of which is such that<1.0×10 -3 Pa；
Preferably, the temperature of the selective chlorination roasting in the step (1) is 250-850 ℃;
preferably, the time of the selective chlorination roasting in the step (1) is 1-4h.
4. The method according to any one of claims 1 to 3, wherein the neodymium iron boron oil sludge of step (1) is pretreated before being mixed with the solid chlorinating agent, and the specific steps are as follows:
sequentially cleaning and magnetically separating the neodymium iron boron oil sludge by using a cleaning solution, and drying to obtain purified neodymium iron boron oil sludge;
preferably, the cleaning solution used in the cleaning process includes any one of an ethanol solution, a 0.5g/L sodium hydroxide-5% op emulsifier mixed aqueous solution, a 0.5g/L sodium hydroxide-5% op emulsifier mixed ethanol solution, a 0.1mol/L hydrochloric acid-5% op emulsifier mixed aqueous solution, or a 0.1mol/L hydrochloric acid-5% op emulsifier mixed ethanol solution, or a combination of at least two thereof.
5. The method according to any one of claims 1 to 4, wherein the reducing agent of step (2) comprises elemental calcium and/or calcium hydride;
preferably, the mass fraction of the reducing agent in the step (2) is 5-30% based on 100% of the mass of the neodymium iron boron oil sludge;
preferably, the calcium reduction diffusion reaction in the step (2) is performed in an inert atmosphere or a vacuum atmosphere, wherein the gas in the inert atmosphere comprises nitrogen and/or argon, and the vacuum degree in the vacuum atmosphere<1.0×10 -3 Pa；
Preferably, the temperature of the calcium reduction diffusion reaction in the step (2) is 750-1050 ℃;
preferably, the time of the calcium reduction diffusion reaction in the step (2) is 1-3h.
6. The method according to any one of claims 1 to 5, further comprising washing, magnetically separating and drying the reaction product after the calcium reduction-diffusion reaction of step (2) is completed;
preferably, the detergent used for washing comprises any one or a combination of at least two of absolute ethyl alcohol, ethylene glycol, n-propanol, n-butanol, n-pentanol, methanol-ammonium chloride solution, methanol-ammonium nitrate solution, methanol-ammonium acetate solution, deionized water, ice deionized water, propylene glycol or glycerol;
preferably, the solid-to-liquid ratio of the reaction product to the detergent is 1g (10-100) mL;
preferably, the washing time is 10-180min;
preferably, the number of washing is 1 to 3.
7. Method according to any of claims 1-6, characterized in that the method comprises the steps of:
sequentially cleaning and magnetically separating the neodymium iron boron oil sludge by using a cleaning solution, and drying to obtain purified neodymium iron boron oil sludge;
(II) mixing a solid chlorinating agent with the purified neodymium iron boron oil sludge, and selectively chloridizing and roasting for 1-4h at 250-850 ℃ in an inert atmosphere or a vacuum atmosphere to obtain a roasted product;
the neodymium iron boron oil sludge and the solid chlorinating agent are mixed according to the mass of the rare earth chloride, wherein the mass ratio of the neodymium iron boron oil sludge to the solid chlorinating agent is 1-5 times of the stoichiometric ratio;
(III) mixing the roasted product with a reducing agent, carrying out calcium reduction diffusion reaction for 1-3h in an inert atmosphere or vacuum atmosphere at the temperature of 750-1050 ℃, and after the reaction is finished, washing, carrying out magnetic separation and drying to obtain the regenerated magnetic powder;
wherein the mass fraction of the reducing agent is 5-30%.
8. A regenerated magnetic powder, characterized in that it is prepared by the method according to any one of claims 1-7;
preferably, the oxygen content of the regenerated magnetic powder is less than 1500ppm.
9. A regenerative sintered NdFeB magnet, which is characterized in that the regenerative sintered NdFeB magnet is obtained by mixing and sintering the regenerative magnetic powder and the rare earth-rich alloy powder according to claim 9.
10. The regenerative sintered neodymium-iron-boron magnet according to claim 9, wherein the rare earth-rich alloy is RE-M, wherein RE represents a rare earth element and M represents a metal alloy;
preferably, the rare earth-rich alloy comprises RE-Cu, RE-Cu-Al-Ga, (RE) 4 Fe 14 B or RE 6 Fe 13 Any one or a combination of at least two of Ga;
preferably, the mass fraction of the rare earth-rich alloy is 5-40% based on 100% of the mass of the regenerative sintered neodymium-iron-boron magnet;
preferably, the sintering temperature is 1020-1080 ℃;
preferably, the sintering time is 3-4h;
preferably, the sintering is preceded by a dehydrogenation treatment;
preferably, annealing is carried out after sintering, and the annealing comprises primary annealing and secondary annealing;
preferably, the temperature of the primary annealing is 850-900 ℃;
preferably, the time of the primary annealing is 1-3h;
preferably, the temperature of the secondary annealing is 450-500 ℃;
preferably, the time of the secondary annealing is 1-3h.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6051047A (en) * | 1997-05-22 | 2000-04-18 | Nankai University | Co-precipitation-reduction-diffusion process for the preparation of neodymium-iron-boron permanent magnetic alloys |
| CN109338113A (en) * | 2018-11-28 | 2019-02-15 | 北京工业大学 | A kind of method of Ca- chloride vat blue RS technology recycling neodymium iron boron sets of holes greasy filth waste material |
| CN109852809A (en) * | 2019-04-10 | 2019-06-07 | 江苏集萃安泰创明先进能源材料研究院有限公司 | A kind of short route recycles the method for neodymium iron boron alloy powder and the preparation method of recycled sinter magnet from neodymium iron boron greasy filth waste material |
| CN110157916A (en) * | 2019-06-26 | 2019-08-23 | 北京工业大学 | A kind of method using neodymium iron boron oil base slice greasy filth preparation high-performance anisotropy NdFeB magnetic powder of low cost |
| CN110317945A (en) * | 2019-07-02 | 2019-10-11 | 中南大学 | A kind of method of ferric manganese ore chlorination reduction roasting production manganese carbonate and iron powder |
| CN112877541A (en) * | 2021-01-11 | 2021-06-01 | 中国科学院过程工程研究所 | Recycled alloy prepared based on neodymium iron boron oil sludge and preparation method thereof |
| CN114864260A (en) * | 2022-04-20 | 2022-08-05 | 北京工业大学 | Method for realizing batch regeneration of neodymium iron boron oil sludge waste by using rotary diffusion technology |
-
2022
- 2022-12-30 CN CN202211739157.7A patent/CN115961138B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6051047A (en) * | 1997-05-22 | 2000-04-18 | Nankai University | Co-precipitation-reduction-diffusion process for the preparation of neodymium-iron-boron permanent magnetic alloys |
| CN109338113A (en) * | 2018-11-28 | 2019-02-15 | 北京工业大学 | A kind of method of Ca- chloride vat blue RS technology recycling neodymium iron boron sets of holes greasy filth waste material |
| CN109852809A (en) * | 2019-04-10 | 2019-06-07 | 江苏集萃安泰创明先进能源材料研究院有限公司 | A kind of short route recycles the method for neodymium iron boron alloy powder and the preparation method of recycled sinter magnet from neodymium iron boron greasy filth waste material |
| CN110157916A (en) * | 2019-06-26 | 2019-08-23 | 北京工业大学 | A kind of method using neodymium iron boron oil base slice greasy filth preparation high-performance anisotropy NdFeB magnetic powder of low cost |
| CN110317945A (en) * | 2019-07-02 | 2019-10-11 | 中南大学 | A kind of method of ferric manganese ore chlorination reduction roasting production manganese carbonate and iron powder |
| CN112877541A (en) * | 2021-01-11 | 2021-06-01 | 中国科学院过程工程研究所 | Recycled alloy prepared based on neodymium iron boron oil sludge and preparation method thereof |
| CN114864260A (en) * | 2022-04-20 | 2022-08-05 | 北京工业大学 | Method for realizing batch regeneration of neodymium iron boron oil sludge waste by using rotary diffusion technology |
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