KR101183579B1 - High efficient neodymium leaching method using ultrasonic wave - Google Patents

Abstract

Disclosed is a high-efficiency neodymium leaching method using ultrasonic waves capable of selectively leaching neodymium, which is a target material, by applying ultrasonic waves while leaching a waste scrap powder obtained by crushing and grinding NbFeB-based permanent magnets into a sulfuric acid solution.
High efficiency neodymium leaching method using ultrasonic waves according to an embodiment of the present invention comprises the steps of (a) crushing and grinding the waste permanent magnet to obtain waste scrap powder; (b) roasting the waste scrap powder thus obtained; And (c) leaching reaction of neodymium, which is a target material, by applying ultrasonic waves while the waste oxide powder and the leaching solution treated with oxidizing oxide are added to a leaching tank.

Description

High efficiency neodymium leaching method using ultrasonic wave {HIGH EFFICIENT NEODYMIUM LEACHING METHOD USING ULTRASONIC WAVE}

The present invention relates to a neodymium leaching method, and more particularly, by subjecting waste scrap powder obtained by crushing and grinding NdFeB-based permanent magnet to leaching reaction with sulfuric acid solution and applying high-density ultrasonic wave, the target material neodymium (Nd) It relates to a high-efficiency neodymium leaching method using ultrasonic waves that can be selectively leached.

NdFeB-based permanent magnets are widely used in parts requiring high magnetic magnets such as cranking motors, computers, audio-visual components, magnetic separators, aerospace systems, and other equipment. .

The demand for NdFeB permanent magnets has soared, and the average annual growth rate of the global NdFeB permanent magnets market has been dominating the permanent magnets market for 30 ~ 70% depending on the type of magnet. Therefore, the generation of waste scrap is expected to increase rapidly due to the increased demand for NdFeB-based permanent magnets.

Generally, about 20-30% of neodymium (Nd) is contained in waste scrap powder obtained by crushing and crushing NdFeB-based permanent magnets, and recovering Nd from these NdFeB-based permanent magnets is the three major raw materials of Nd metal. It is one of the sources.

Therefore, in recent years, researches are being actively conducted to recycle waste permanent magnets that are used and discarded. In general, an acid leaching method is used to separate and recover neodymium from waste scrap powder. If the waste scrap powder is leached without oxidizing oxide, neodymium can be efficiently extracted at low sulfuric acid concentration. Since the leaching rate is also relatively high, there is a problem that the subsequent separation process becomes complicated.

Therefore, it is urgent to study ways to selectively improve the leaching rate of neodymium while lowering the leaching rate of iron.

Related prior arts are Korean Patent Registration No. 10-1047838 (2011.07.08 publication), which discloses a method for recovering residual actinium elements in a molten chloride salt, and leaches neodymium from NdFeB-based permanent magnets. There is no disclosure of the technology.

An object of the present invention is to provide a high-efficiency neodymium leaching method using ultrasonic waves to reduce the Fe leaching rate and selectively improve the Nd leaching rate by applying ultrasonic wave while leaching the waste oxide powder treated with roasted oxide to sulfuric acid solution will be.

Another object of the present invention is a high-efficiency neodymium leaching method using ultrasonic waves that can leach neodymium stably without destroying waste scrap powder by irradiating waste oxide powder treated with roasted oxide to sulfuric acid solution by indirect application of ultrasonic waves. To provide.

High efficiency neodymium leaching method using ultrasonic waves according to an embodiment of the present invention for achieving the above object comprises the steps of (a) crushing and grinding the waste permanent magnet to obtain waste scrap powder; (b) roasting the waste scrap powder thus obtained; And (c) leaching reaction of neodymium, which is a target material, by applying ultrasonic waves while the waste oxide powder and the leaching solution treated with oxidizing oxide are added to a leaching tank.

High efficiency neodymium leaching method using ultrasonic waves according to another embodiment of the present invention for achieving the above another object is to obtain a waste scrap powder by crushing and grinding the NdFeB waste permanent magnet; (b) roasting the obtained NdFeB waste scrap powder at 500˜900 ° C .; And (c) injecting waste oxide powder and leaching solution subjected to the oxidation treatment into a leaching tank located in an outer tank, and applying ultrasonic waves to leach and react neodymium as a target material. The ultrasonic application may be indirectly applied to the leaching tank in a state where an ultrasonic tip is loaded into the outer tank.

In the high-efficiency neodymium leaching method using ultrasonic waves according to the present invention, by directly irradiating ultrasonic waves while leaching the waste oxide powder treated with oxidized oxide to sulfuric acid solution, Fe leaching rate can be reduced and Nd leaching rate can be selectively increased. have.

In addition, the high-efficiency neodymium leaching method using ultrasonic waves according to the present invention by irradiating ultrasonic waste by indirect application while leaching the waste oxide powder treated with oxidized sulfuric acid solution, while reducing the leaching rate of Fe, it is stable without contamination of the waste scrap powder This has the effect of increasing the leaching rate of Nd.

1 is a process flowchart showing a high efficiency neodymium leaching method using ultrasonic waves according to an embodiment of the present invention.
Figure 2 is a photograph showing the waste scrap powder obtained by crushing and grinding the NdFeB waste permanent magnet.
FIG. 3 is a process schematic diagram illustrating the process of roasting oxide of FIG. 1.
4 is a view for explaining the leaching reaction process of FIG.
5 is a view for explaining a leaching reaction process according to another embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a high efficiency neodymium leaching method using ultrasonic waves according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a process flowchart showing a high efficiency neodymium leaching method using ultrasonic waves according to an embodiment of the present invention.

Referring to FIG. 1, the high efficiency neodymium leaching method using ultrasonic waves according to an embodiment of the present invention includes a waste scrap powder obtaining step (S110), a roasting oxide treatment step (S120), and a leaching reaction step (S130).

Waste scrap powder obtained

In the waste scrap powder obtaining step (S110), the waste permanent magnet is crushed and pulverized to obtain waste scrap powder.

At this time, the waste scrap powder can be obtained by crushing and crushing the waste permanent magnets generated during dismantling of used household appliances, automobiles, etc., specifically, may be obtained from NdFeB permanent magnets.

On the other hand, Figure 2 is a photograph showing the waste scrap powder obtained by crushing and grinding the NdFeB waste permanent magnet.

Referring to Figure 2, NdFeB waste permanent magnet is made of NdFeB waste scrap powder having an average particle size of 100 ~ 350 mesh (mesh) by the crushing and grinding process. In this case, when the average particle size of the NdFeB waste scrap powder exceeds 100 mesh, the leaching efficiency decreases because the particle size is too large, on the contrary, when the average particle size of the NdFeB waste scrap powder is less than 350 mesh, excessive grinding cost occurs. In addition, during leaching, the viscosity of the leaching slurry may increase rapidly, which may cause a problem of lowering the leaching efficiency.

Oxidation treatment

On the other hand, Figure 3 is a process schematic diagram showing the roasting process of FIG.

1 and 3, in the roasting oxide treatment step (S120), the waste scrap powder obtained by the waste scrap powder obtaining step (S110) is subjected to roasting treatment in an oxygen atmosphere of 500˜900 ° C. FIG.

In the oxidation oxidation treatment step (S120), when the heat treatment temperature is less than 500 ° C., there is a fear that a sufficient oxidation reaction does not occur. On the contrary, when the heat treatment temperature exceeds 900 ° C, it is not economical because the effect against the increase in cost is insignificant. At this time, the roasting oxide treatment time can be appropriately adjusted according to the amount of waste scrap powder added, but is not particularly limited, it is preferably carried out for a sufficient time for the oxidation reaction to occur.

The reason for carrying out such roasting treatment is that, when the leaching reaction with the leaching solution described later in the state of NdFeB waste scrap powder, the leaching does not proceed easily, so that the leaching rate is rapidly lowered. Therefore, the NdFeB waste scrap powder is preferably subjected to a process of oxidizing by oxidizing and roasting in an oxygen atmosphere in which oxygen gas is blown into a furnace maintained at a high temperature of 500 to 900 ° C.

In this step, when the NdFeB waste scrap powder is subjected to roasting treatment, the Nd contained in the waste scrap powder And Fe may be oxidized in the form of the following formulas (1), (2) and (3).

Formula (1): 2Nd + 3 / 2O ₂ → Nd ₂ O ₃

Formula (2): 2Fe + 3 / 2O ₂ → Fe ₂ O ₃

Formula (3): Nd + Fe + 3 / 2O ₂ → NdFeO ₃

Leaching reaction

On the other hand, Figure 4 is a view for explaining the leaching reaction process of FIG.

Referring to FIGS. 1 and 4, in the leaching reaction step (S130), while leaching the waste scrap powder and the leaching solution, which are subjected to oxidation treatment, are leached by applying ultrasonic waves.

At this time, the leaching tank 200 into which the waste scrap powder and the leaching solution are added is preferably stirred at a speed of 200 to 1000 rpm using the stirrer 220. If the stirring speed is less than 200 rpm, the waste scrap powder may not be uniformly mixed with the leaching solution. On the contrary, when the stirring speed exceeds 1000 rpm, there is a concern that the manufacturing cost may be increased without any further effect.

On the other hand, the leaching reaction is preferably carried out for 10 to 180 minutes at 40 ~ 90 ℃. If the leaching reaction temperature is less than 40 ℃ there is a problem that the leaching reaction does not occur well because the temperature is too low. On the contrary, when the leaching reaction temperature exceeds 90 ° C., the leaching reaction effect is insignificant compared to the temperature raising effect and thus is not economical.

In addition, when the leaching reaction time is less than 10 minutes, there is a fear that a smooth leaching reaction may not be performed because the leaching reaction time is insignificant. On the contrary, when the leaching reaction time exceeds 180 minutes, the synergistic effect compared to the leaching reaction time is insignificant and therefore it is not economical.

At this time, the leaching solution is preferably used a sulfuric acid solution of 0.1 ~ 3M. When the concentration of sulfuric acid solution is less than 0.1M, there is a problem that the waste scrap powder is difficult to dissolve in sulfuric acid solution. On the contrary, when the concentration of the sulfuric acid solution is more than 3M, the leaching synergistic effect compared to the input of the high concentration of sulfuric acid solution is insignificant, which is not economical and may cause environmental pollution.

In addition, in this step, it is preferable that the waste scrap powder and the sulfuric acid solution are mixed in a weight ratio of 1: 1 to 1: 100. When the weight ratio of the waste scrap powder and the sulfuric acid solution is less than 1: 1, the amount of the waste scrap powder added to the weight of the sulfuric acid solution is excessively added, so that the viscosity increases and the leaching efficiency is lowered. When the weight ratio exceeds 1: 100, the amount of sulfuric acid solution used increases, which may make it difficult to secure economic feasibility.

On the other hand, in this step, it is preferable that the ultrasonic wave is directly applied to the ultrasonic tip 240 by charging the ultrasonic tip 240 in the leaching tank 200. Ultrasonic application is preferably performed at a frequency of 15-30KHz and an output power condition of 3-10W. When the ultrasonic wave is applied, if the frequency is less than 15KHz or the output voltage is less than 3W, the cavitation effect due to the application of the ultrasonic wave may be insignificant and the leaching reaction may not be performed smoothly. On the contrary, when the frequency of the ultrasonic waves is 30 KHz or more, or the output voltage exceeds 10 W, the waste scrap powder may be destroyed due to excessive ultrasonic application.

As such, after applying ultrasonic waves to the waste scrap powder and the leaching solution filled in the leaching tank 200, when a predetermined time passes, the bubble collapse (temporarily bubble collapse) is localized at a temperature of 5000K and about 1000bar. Pressure and heating / cooling ratios of 10 ¹⁰ K / s have extreme conditions.

This sudden pressure change causes a collision between the waste scrap powder and the leaching solution. At this time, the destruction of the waste scrap powder, which is a solid particle, and an increase in the activation area occur, and as a result, the mass transfer speed in the liquid phase is increased to improve the leaching efficiency.

That is, during the leaching reaction step (S130), if the ultrasonic wave is continuously applied, the leaching speed is increased due to the mixing effect and the effective collision frequency increase by cavitation, thereby maximizing the selective leaching effect of neodymium. There is an advantage that the leaching reaction time can be shortened. In this leaching reaction step (S130), it is preferable to charge the ultrasonic tip 240 into the leaching tank 200 to directly irradiate the ultrasonic wave, in this case, the strength of the ultrasonic wave applied to the waste scrap powder and the leaching solution has a strong advantage This has the advantage of maximizing the ultrasonic effect.

On the other hand, as in the present invention, when the ultrasonic wave is applied during the leaching reaction, the Fe leaching rate is reduced, which is Fe ³⁺ ion reacts with the OH radical during the application of ultrasonic ferric oxide (Fe ₂ O ₃ ) or Precipitation reaction occurs to produce trivalent ferric hydroxide {FeOOH or Fe (OH) ₃ }, which eventually serves to reduce the Fe leaching rate by reducing the number of Fe ³⁺ ions.

At this time, Nd ³⁺ is a precipitation reaction to take place at a higher pH than the Fe ³⁺ Fe ^3+, so the first is selectively precipitated, the leaching rate is reduced, so may be made selective leaching of the Nd ³⁺ ions.

In the neodymium leaching method using ultrasonic waves according to an embodiment of the present invention described above, by applying ultrasonic waves while leaching the waste oxide powder treated with oxidized oxide in a sulfuric acid solution of 0.1 to 0.3M, Fe leaching rate is reduced and Nd leaching rate is reduced. Has the effect of selectively improving.

On the other hand, high efficiency neodymium leaching method using ultrasonic waves according to another embodiment of the present invention may be substantially the same as one embodiment. However, the high-efficiency neodymium leaching method using ultrasonic waves according to another embodiment of the present invention has a difference in performing ultrasonic waves in an indirect application method in the leaching reaction step. To explain.

5 is a view for explaining a leaching reaction process according to another embodiment of the present invention.

Referring to FIG. 5, the high efficiency neodymium leaching method using ultrasonic waves according to another embodiment of the present invention is characterized in that the ultrasonic irradiation is performed by an indirect application method during the leaching reaction step.

That is, in the case of the neodymium leaching method using ultrasonic waves according to another embodiment of the present invention, in the leaching reaction step, the leaching reaction by applying ultrasonic waves while putting the roasted oxidized scrap powder and leaching solution into the leaching tank located in the outer tank, Let's do it.

In this case, the ultrasonic application may be performed by indirectly applying the ultrasonic tip to the leaching tank while the ultrasonic tip is charged in the outer tank. As described above, when the ultrasonic wave is applied by the indirect application method, the leaching rate of neodymium is slightly lower than that of the direct application method, but the ultrasonic wave is not directly applied to the waste scrap powder and the leaching solution. There is an advantage that can prevent the contamination of the leaching solution by.

Example

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

1. Leaching Reaction Experiment

Example 1

NdFeB waste permanent magnet having the composition shown in Table 1 was pulverized to 200 mesh to obtain waste scrap powder, and then 100 g of the obtained waste scrap powder was charged into a furnace and subjected to roasting treatment for 2 hours while raising the temperature to 700 ° C. . Thereafter, 10 g of the waste oxide powder treated with roasted oxide was added to 200 ml of a 1.5 M sulfuric acid solution, and then a leaching reaction was performed by applying high-density ultrasonic waves at a frequency of 20 KHz and an output power of 8 W while stirring at 600 rpm. In this case, the ultrasonic application was performed by charging the ultrasonic tip into the leaching tank to directly apply the ultrasonic wave. The leaching reaction was carried out at 50 ° C. for 120 minutes, and samples were taken every 30 minutes, filtered, and analyzed by ICP to measure leaching rates.

Examples 2 to 4

A leaching reaction was carried out in the same manner as in Example 1, except that 2.0, 2.5, and 3.0 M sulfuric acid solutions were used instead of 1.5 M sulfuric acid solutions.

Example 5

At the time of ultrasonic application, the leaching reaction was carried out in the same manner as in Example 1 except that the ultrasonic tip was loaded in the outer tank, and indirectly applied to the leaching tank.

Examples 6-8

A leaching reaction was carried out in the same manner as in Example 5, except that 2.0, 2.5, and 3.0 M sulfuric acid solutions were used instead of 1.5 M sulfuric acid solutions.

Comparative Example 1

NdFeB waste permanent magnet having the composition shown in Table 1 was pulverized to 200 mesh to obtain waste scrap powder, and then 100 g of the obtained waste scrap powder was charged into a furnace and subjected to roasting treatment for 2 hours while raising the temperature to 700 ° C. . Thereafter, 10 g of the waste oxide powder subjected to roasting treatment was added to 200 ml of a 1.5 M sulfuric acid solution, followed by stirring at 600 rpm, and a leaching reaction was performed. At this time, ultrasonic waves were not applied, and the leaching reaction was performed at 50 ° C. for 120 minutes, and samples were collected and filtered every 30 minutes, and analyzed by ICP to measure leaching rates.

Comparative Examples 2 to 4

A leaching reaction was performed in the same manner as in Comparative Example 1 except that 2.0, 2.5, and 3.0 M sulfuric acid solutions were used instead of 1.5 M sulfuric acid solutions, respectively.

2. Component Analysis

Table 1 shows the chemical composition of the waste scrap powder sample. At this time, the sample was used J NdFeB-based permanent magnet waste scrap powder, was analyzed using ICP (Jobin-Yvon Model JY-38 Plus).

[Table 1]

Referring to Table 1, it was confirmed that the waste scrap powder sample was composed of 73.39 wt% Fe, 25.48 wt% Nd and about 0.86 wt% B.

3. Leach rate measurement

Table 2 shows the leaching rate when the leaching reaction was performed by the method according to Examples 1 to 8 and Comparative Examples 1 to 4.

[Table 2]

Referring to Table 2, it can be seen that in the case of Comparative Examples 1 to 4, the Fe leaching rate is relatively high compared to the Nd leaching rate compared to Examples 1 to 8.

In this case, it can be seen that Examples 1 to 4 to which ultrasonic waves are applied by the direct application method are higher in Nd leaching rate and Fe to Fe is lower than that of Examples 5 to 8 where ultrasonic waves are applied by indirect application method.

In particular, in the case of Examples 1 to 4 to which ultrasonic waves were applied by the direct application method during the leaching reaction, it can be seen that the leaching rate of Fe has the lowest value while the leaching rate of niodymium is the highest.

Based on the above experimental results, it was confirmed that when NdFeB waste scrap powder was leached into a sulfuric acid solution, ultrasonic waves were applied, the Nd leaching rate increased and the Fe leaching rate decreased.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. These changes and modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.

S110: waste scrap powder obtaining step
S120: roasting oxide treatment step
S130: leaching reaction step
200, 300: leaching tank 310: outer tank
220, 340: agitator 240, 340: ultrasonic tip

Claims (11)

(a) crushing and grinding the waste permanent magnet to obtain waste scrap powder;
(b) roasting the waste scrap powder thus obtained; And
and (c) leaching reaction of neodymium, which is a target material, by applying ultrasonic waves while the waste oxide powder and the leaching solution treated with oxidizing oxide are added to a leaching tank.
In the step (c), the leaching solution uses a sulfuric acid solution of 0.1 ~ 3M, the waste scrap powder and sulfuric acid solution is mixed in a weight ratio of 1: 1 to 1: 100, the leaching reaction is 40 ~ 90 ℃ 10 to 180 minutes in the neodymium leaching method, characterized in that the iron (Fe) leaching rate is reduced and the neodymium (Nd) leaching rate is selectively increased.
The method of claim 1,
The waste permanent magnet
Neodymium leaching method characterized in that the NdFeB permanent magnet.
The method of claim 1,
In the step (b)
The roasting oxide treatment
Neodymium leaching method carried out in an oxygen atmosphere of 500 ~ 900 ℃.
delete delete delete The method of claim 1,
In the step (c)
The ultrasonic application is a neodymium leaching method characterized in that the ultrasonic tip is directly applied by charging the ultrasonic tip into the leaching tank.
The method of claim 1,
In the step (c)
The neodymium leaching method characterized in that the roasted waste oxide powder and the leaching solution is stirred at a rate of 200 ~ 1000rpm.
The method of claim 1,
In the step (c),
The ultrasonic application is
Neodymium leaching method characterized in that performed at a frequency of 15 ~ 30KHz and an output power condition of 3 ~ 10W.
(a) crushing and grinding the NdFeB waste permanent magnet to obtain waste scrap powder;
(b) roasting the obtained NdFeB waste scrap powder at 500˜900 ° C .; And
(c) injecting waste oxide powder and leaching solution subjected to the oxidation treatment into a leaching tank positioned in an outer tank, and applying ultrasonic waves to leach and react neodymium as a target material.
In the step (c), the ultrasonic application is indirectly applied to the leaching tank in a state in which an ultrasonic tip is loaded into the outer tank, and the leaching solution uses 0.1-3 M sulfuric acid solution, and the waste scrap powder and sulfuric acid The solution is mixed at a weight ratio of 1: 1 to 1: 100, and the leaching reaction is carried out at 40 to 90 ° C. for 10 to 180 minutes, so that the iron (Fe) leaching rate is reduced and the neodymium (Nd) leaching rate is selectively Neodymium leaching method characterized by increasing.
The method of claim 10,
After step (b),
The NdFeB waste scrap powder is oxidized reaction in the form of the following formula (1), formula (2) and formula (3).

Formula (1): 2Nd + 3 / 2O ₂ → Nd ₂ O ₃
Formula (2): 2Fe + 3 / 2O ₂ → Fe ₂ O ₃
Formula (3): Nd + Fe + 3 / 2O ₂ → NdFeO ₃

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