KR20130024485A - Magnesium alloy using rare earth magnet scraps and manufacturing method of the same - Google Patents

Abstract

PURPOSE: An magnesium alloy using rare earth magnet scraps and a manufacturing method thereof are provided to share substances between different industries through an open type circulation technology, thereby improving the efficiency of recycling rare earth resources. CONSTITUTION: An magnesium alloy using rare earth magnet scraps comprises; a step for inserting the rare earth magnet scraps into molten magnesium; a step for dissolving the rare earth magnet scraps in the molten magnesium; a step for liquid-permeating the molten magnesium inside the rare earth magnet scraps; and a step for dispersing rare earth elements included in the rare earth magnet scraps to the molten magnesium. [Reference numerals] (AA) Diffusion direction of Nd; (BB) Penetrating direction of liquid magnesium; (CC) Rare earth scraps; (DD) Nd-exhausted Fe-B composition; (EE) Nd diffusion in solid scraps; (FF) Nd oxide; (GG) Nd diffusion through liquid; (HH) Mg melt

Description

Magnesium alloy using rare earth magnet scraps and manufacturing method of the same

The present invention relates to a magnesium alloy using a rare earth magnet scrap, and more particularly to a magnesium alloy containing a rare earth element by selectively dissolving the rare earth element contained in the rare earth magnet scrap using a molten magnesium. The present invention relates to a magnesium alloy using rare earth magnet scrap and a method of manufacturing the same.

Rare earth refers to elements such as lanthanum, cerium, and dysprosium, and is a kind of rare mineral. Such rare earths are known to be ubiquitous in a few regions, such as China, the United States, and the Commonwealth of Independent States. In addition, China has greatly increased its market share through the expansion of rare earth supply through the active intervention of the country since the mid-80s, and recently shows signs of resource weaponization by restricting the production and supply of rare earth resources. An emergency situation is in place to secure the rare earth, an essential element of electronic products.

As mentioned above, rare earths frequently mentioned in international disputes are neodymium (Nd) and dysprocium (Dy), which are rare earth elements for rare earth magnets that are essential for hard disk drivers, wind power generation, hybrid cars, and the defense industry. . The world is paying attention to the fact that as the world is rapidly transforming into a climate change paradigm, it is becoming a challenge for the stable growth of new growth businesses with green growth.

However, since neodymium and disprocium have abundant reserves of natural resources in addition to supply and demand stability, natural resources should be separated from other countries in terms of international and intergenerational equity of global resources. There is a need for new approaches that can be left to the potential needs of generations. Such alternatives may include reducing technologies or replacing them with more abundant resources, and on the other hand, the development of a circulating technology in which resources mined by human beings are continuously circulated without consumption. In the case of the circulation technology, it is highly evaluated that the environment and energy efficiency can be improved to minimize the environmental pollution during the productization process or the disposal of the used product, and to obtain a substance compared to natural resources.

The rare earth-containing scrap generated during the production process is partially reused, but the rare earth magnet circulation industry is in the introductory stage in that the circulation for most rare earth elements is not yet activated. Techniques for circulating rare earth elements using such rare earth magnet scraps have been introduced as follows.

Zaktnik [ref. 1: M. Zaktnik, I. R. Harris, A.J. Williams, Multiple recycling of NdFeB-type sintered magnets, Journal of alloys and compounds, Vol. 469, pp314-321] is a technique to circulate the rare earth magnet used in the VCM for HDD and applied the HD method (hydrogen decrepitation). However, we found a problem that the magnetic properties are deteriorated due to chemical composition change, phase change, etc. in the repetitive cycle, and suggested a method of adding Nd-hydrides to the cycle. Experimentally proved that the addition of Nd-hydride is a method of suppressing the deterioration of magnetic properties in repetitive cycles by maintaining the Nd-rich phase fraction in subsequent processes by supplementing the Nd loss generated in the cycle.

On the other hand, when circulating the Nd-based rare earth magnet, carbon or oxygen is a harmful impurity element that lowers the magnetic properties through the formation of reactants with the alloying elements. Saguchi et al. Proposed a circulation path that utilizes Nd-based rare earth magnet scrap as a raw material for remelting and presented a process technology to remove carbon and oxygen. That is, the process of removing carbon in the form of iron oxide or rare earth element oxide after reducing carbon with carbon by oxidative reaction in the scrap first, and then adding it as raw material of dissolution casting. Developed the technology.

Despite these efforts, however, due to problems such as deterioration of quality due to changes in chemical composition and coexistence in circulation cycles, and high cost and low efficiency, it is still commercially available among technologies for circulating resources using rare earth magnet scrap. This is not being developed.

The present invention has been made to solve the above-mentioned conventional problems, magnesium alloy containing rare earth elements by extracting rare earth elements from the rare earth magnet scrap without changes in chemical composition and compatibility by using magnesium molten metal and its The purpose is to provide a manufacturing method.

In addition, the present invention has another object to increase the efficiency of the rare earth resource recycling to share materials between different industries through the open circulation technology.

Method for producing a magnesium alloy using a rare earth magnet scrap according to the present invention for solving the above object is to charge a rare earth magnet scrap containing at least one rare earth element of neodymium and disprocium in magnesium molten metal step; Dissolving the rare earth magnet scrap in the molten magnesium; Liquid-penetrating the magnesium molten metal into the rare earth magnet scrap; Due to the liquid phase penetration of the molten magnesium, new solid / liquid interface is continuously formed inside the rare earth magnet scrap, and the rare earth elements contained in the rare earth magnet scrap are diffused into the magnesium molten metal.

In addition, the method for producing a magnesium alloy using the rare earth magnet scrap according to the present invention further includes a step of pretreating the rare earth magnet scrap before charging in the molten magnesium, the pretreatment step of the rare earth magnet scrap, demagnetizing rare earth magnet scrap Pyroprocessing; Washing the organics of the rare earth scrap; Hydro embrittlement the rare earth scrap; Dry crushing the rare earth magnet scrap to prepare a powder form; characterized in that comprises a.

Here, the dry crushing process, it is preferable to proceed in the order of jaw crushing, hammer miliing, jet milling.

In addition, the pretreatment process of the rare earth magnet scrap, more preferably comprises a step of dehydrogenating the rare earth magnet scrap of the powder form.

In addition, the pretreatment process of the rare earth magnet scrap, before demagnetizing the rare earth magnet scrap, further comprising the step of performing a reduction treatment to separate the oxide when the oxide is contained in the rare earth magnet scrap; desirable.

And in the process of charging the rare earth magnet scrap in the molten magnesium, it is characterized in that the loading ratio of the rare earth magnet scrap to adjust to have a composition below the equilibrium liquid line of Nd-Mg according to the temperature of the magnesium molten.

In addition, in the process of charging the rare earth magnet scrap in the molten magnesium, it may be configured to adjust the loading ratio of the rare earth magnet scrap to have a composition 5 mol.% Lower than the liquidus composition of Nd according to the temperature of the magnesium molten metal.

The process temperature for dissolving the rare earth magnet scrap in the molten magnesium is preferably in the range of 600 ° C to 1,000 ° C, and may be in the range of 700 ° C to 900 ° C.

In addition, the process temperature (T) for dissolving the rare earth magnet scrap in the molten magnesium may be set in the following range.

T1 + 25 ℃ ≤ T ≤ 1,000 ℃

(The T1 is the liquidus temperature determined according to the mole fraction of Nd when converted to 100 moles of Mg-Nd)

In addition, in the process of dissolving the rare earth magnet scrap in the molten magnesium, it is characterized in that the magnesium molten metal is stirred using any one method of mechanical stirring, physical stirring using a gas, stirring using an electromagnetic field.

Here, the rare earth magnet scrap is characterized in that it comprises a scrap generated in the magnet manufacturing process, or a sludge-type scrap generated in the magnet processing process.

And magnesium alloy using the rare earth magnet scrap according to the present invention, the step of dissolving rare earth magnet scrap containing at least one rare earth element of neodymium and disprocium in magnesium molten metal; Liquid-penetrating the magnesium molten metal into the rare earth magnet scrap; Due to the liquid permeation of the molten magnesium, new solid / liquid interface is continuously formed in the rare earth magnet scrap, and the rare earth elements contained in the rare earth magnet scrap are diffused into the magnesium molten metal. And rare earth elements dissolved in the rare earth magnet scrap.

In the magnesium alloy, when the mole fraction of magnesium and rare earth elements is calculated as 100%, the mole fraction of rare earth elements is preferably in the range of 10 mol.% To 80 mol.%.

According to the magnesium alloy using the rare earth magnet scrap according to the present invention having the configuration as described above and a method for producing the same, rare earth elements by extracting the rare earth element from the rare earth magnet scrap without changes in chemical composition and compatibility, using magnesium molten metal It is possible to produce a magnesium alloy containing.

In addition, according to the present invention, by separating the pure rare earth element through the vaporization of the magnesium alloy containing the rare earth element, it is possible to increase the resource recycling efficiency of the rare earth element.

1 is an explanatory diagram showing a pretreatment process of a rare earth magnet scrap according to the present invention.
2 is an equilibrium diagram of Mg-Nd.
Figure 3 is a schematic diagram showing a selective dissolution reaction process of rare earth magnet scrap using magnesium molten metal.
Figure 4 is a photograph showing the microstructure changes when the rare earth magnet scrap containing neodymium dissolved in the molten magnesium.
5 is a photograph showing the effect of reaction time on the selective melting of neodymium in rare earth magnet scrap using magnesium molten metal.
Figure 6 is a graph showing an experimental example for the extraction efficiency of neodymium according to the loading ratio of rare earth magnet scrap.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the magnesium alloy using a rare earth magnet scrap and a method for manufacturing the same.

The present invention relates to a method for producing a magnesium alloy to which rare earth elements contained in rare earth magnet scraps are added, using rare earth magnet scraps containing molten earth elements and molten magnesium.

Here, the rare earth element is a word referring to rare elements such as lanthanum, cerium, dysprosium, and the like. In particular, the rare earth element used in the present invention is a hard disk driver, wind power generation, hybrid vehicle, defense industry. The present invention relates to neodymium (Nd) and disprocium (Dy), which are rare earth elements essential for rare earth magnets.

In addition, the rare earth magnet scrap used in the present invention includes all of the soft scrap generated in the magnet manufacturing process, sludge-type scrap generated in the magnet processing process, and the magnet (hard scrap) contained in the product after use, neo It contains rare earth elements of eitherdium or disprosium.

The method of manufacturing a magnesium alloy using such rare earth magnet scrap proceeds to the following process.

Pretreatment process

First, the rare earth magnet scrap containing the rare earth element of neodymium or dysprosium is subjected to a pretreatment process.

1 shows a pretreatment process of a rare earth magnet scrap according to the present invention.

Referring to FIG. 1, the pretreatment process of the rare earth magnet scrap according to the present invention includes demagnetization, wet cleaning, hydrogen embrittlement, dry crushing, and dehydrogenation for the rare earth magnet scrap. Include.

Here, the demagnetization process is a process for removing the magnetism of the rare earth magnet scrap, the wet washing process is a process for removing the organic material of the rare earth magnet scrap. For example, the organic matter contained in the rare earth magnet scrap may be removed by ultrasonic cleaning. As described above, after the demagnetization and wet washing process of the rare earth magnet scrap, the hydrogen embrittlement process gives brittleness to the rare earth magnet scrap, thereby increasing resolution and inhibiting oxidation in the grinding process.

In the dry crushing process, the rare earth magnet scrap is produced in powder form. The dry crushing process is performed from coarse to fine grinding, and is used for jaw crushing, hammer miliing, and jet milling. It is preferable that crushing proceeds in order. For example, in the jaw crushing process, the scrap is crushed to a size of 10 mm, and in the hammer milling process, the scrap is crushed to a size of 1 mm, and finally, in the jet milling process, the powder is made of several tens of micrometers in size.

Thereafter, the formed powder is subjected to dehydrogenation through a reduced pressure heating process.

On the other hand, when the rare earth magnet scrap powder is oxidized in an arbitrary environment, Nd ₂ O ₃ oxide is generated inside the powder, and since the oxide is very stable, the neodymium element contained in the scrap when dissolving the rare earth magnet scrap powder in the molten magnesium The elution reaction of can be delayed.

Therefore, the pretreatment process of the rare earth magnet scrap according to the present invention preferably further includes a process for suppressing oxide generation in addition to a powder forming process for refining particles. That is, before the demagnetization of the rare earth magnet scrap, if the rare earth magnet scrap contains an oxide, a reduction process for separating the oxide is performed.

Charging  fair

Through the pretreatment process as described above, the rare earth magnet scrap, which has been subjected to micronization and oxidation suppression treatment, is charged with magnesium molten metal. As such, in the process of charging the rare earth magnet scrap into the molten magnesium, it is preferable to adjust the loading ratio of the rare earth magnet scrap to have a composition below the equilibrium liquid line of Nd-Mg according to the temperature of the magnesium molten metal. If the rare earth magnet scrap is charged into the molten magnesium so as to have a composition above the equilibrium liquid line of Nd-Mg, the rare earth element extraction efficiency is lowered while the amount of rare earth elements not dissolved in the molten magnesium increases.

More preferably, in the process of charging the rare earth magnet scrap in the molten magnesium, it is preferable to adjust the loading ratio of the rare earth magnet scrap to have a composition 5 mol.% Lower than the liquidus composition of neodium according to the temperature of the magnesium molten metal. Do. Since the concentration of neodymium contained in the magnesium liquid in the rare earth magnet scrap is higher than that of the equilibrium magnesium liquid, the rare earth is charged by charging at a composition about 5 mol.% Lower than that of the liquidus neodium at each process temperature. The extraction efficiency of the element can be improved.

Melting process

When the rare earth magnet scrap subjected to the pretreatment process as described above is charged to the magnesium molten metal, the charged rare earth magnet scrap is subjected to a process of dissolving in the magnesium molten metal.

2 shows an equilibrium diagram of Mg-Nd, and FIG. 3 shows a selective dissolution reaction of rare earth magnet scrap using magnesium molten metal, and FIG. 4 shows a rare earth magnet scrap containing neodymium dissolved in magnesium molten metal. The microstructural change in the case is shown. 5 shows the effect of reaction time on the selective melting of neodymium in rare earth magnet scrap using magnesium molten metal, and FIG. 6 shows an experimental example of extraction efficiency of neodymium according to the loading ratio of rare earth magnet scrap. have.

The present invention is a process technology based on the fact that rare earth elements such as neodymium and disprosium contained in rare earth magnet scraps are selectively dissolved in the liquid phase of the active metal, and the active metals that can be used in the present invention include magnesium and lead. Etc. are possible. However, it is preferable to use magnesium as the active metal in terms of materials, processes, and environments.

That is, by selectively dissolving the rare earth magnet scrap containing neodymium or dysprosium in the molten magnesium, it is possible to produce a magnesium alloy containing a rare earth element. Here, instead of general magnesium, eco magnesium (Eco-Mg) may be used as a material of the molten metal. When the rare earth magnet scrap is selectively dissolved in magnesium or eco magnesium molten metal, magnesium misch metal containing rare earth elements and an iron-boron compound as a residue are formed.

On the other hand, the process temperature for dissolving the rare earth magnet scrap in the molten magnesium is preferably in the range of 600 ℃ to 1,000 ℃. If the rare earth magnet scrap is not dissolved below 600 ° C, magnesium may be vaporized at a process temperature exceeding 1,000 ° C.

In addition, the process temperature for dissolving the rare earth magnet scrap in the molten magnesium is more preferably made in the range of 700 ℃ to 900 ℃ in consideration of the reaction rate of the selective dissolution reaction and the stability of the magnesium molten metal. The higher the melt temperature, the more actively the selective dissolution reaction develops, and therefore it is preferable to set the lower limit of the process temperature to 700 ° C or higher. Moreover, since the vaporization temperature of magnesium is about 1,090 degreeC, it is preferable to set the upper limit of a process temperature to 900 degrees C or less from a melt stability viewpoint.

In addition, as shown in Figure 2, the process temperature (T) for dissolving the rare earth magnet scrap in the molten magnesium is more preferably set as shown in the following formula.

T1 + 25 ℃ ≤ T ≤ 1,000 ℃

Here, T1 represents the temperature of the liquidus line determined according to the mole fraction of neodymium (Nd) when the molar fraction of Mg-Nd is 100.

When the loading ratio of rare earth magnet scrap and magnesium is determined, the liquid magnesium containing rare earth element is stable under chemical composition conditions in which rare earth elements (neodymium and disprosium) contained in the rare earth magnet are completely dissolved in magnesium. It is important to keep it. Therefore, the process temperature (T) proposed in the present invention is a minimum temperature of at least 25 degrees higher than the temperature (T1) of the liquidus line determined according to the mole fraction of Nd when converting the mole fraction of Mg-Nd into 100. It is preferable.

In addition, the upper limit temperature of the process technology for selectively dissolving rare earth magnet scrap using magnesium needs to consider the molten metal stability and vaporization temperature of magnesium. Although the vaporization temperature of magnesium is 1,090 ° C under equilibrium conditions, it is preferable to limit the process temperature to 1,000 ° C or less in terms of stability of the process, and more preferably to control the temperature to 900 ° C or less.

In addition, in consideration of the vapor pressure of magnesium in addition to the temperature, the inside of the process is preferably configured to pressurize using a protective gas or an inert gas.

When the rare earth magnet scrap is dissolved in the molten magnesium under the above process conditions, selective dissolution of the rare earth element by liquid magnesium occurs as follows.

Referring to FIG. 3, the molten magnesium is liquid-penetrated into the rare earth magnet scrap. As a result of the liquid permeation of the molten magnesium molten metal, a new solid / liquid interface is continuously formed inside the rare earth magnet scrap, and the rare earth elements contained in the rare earth magnet scrap diffuse into the magnesium molten metal, thereby causing selective dissolution of the rare earth elements. .

In the early rare earth magnet scrap and magnesium type, rare earth elements such as neodymium have a solubility in magnesium, but in the case of iron or boron, solubility with magnesium can be ignored. Therefore, in the macroscopic view, magnesium penetrates into the rare earth magnet, and rare earth elements such as neodium have a diffusion path that moves to the molten magnesium.

In the movement of magnesium, however, magnesium is not dissolved in the rare earth magnet and solid phase diffused, but mass transfer occurs through the liquid phase penetration through the grain boundary or interphase interface and defect structure of the rare earth magnet. Subsequently, new solid / liquid interfaces are formed. The internal penetration of the magnesium liquid has an effect of shortening the diffusion path of a long distance from the diffusion of the rare earth element to the initial solid / liquid interface of the rare earth magnet scrap and the magnesium liquid through the solid phase diffusion.

In addition, the rate of diffusion of rare earth elements through the liquid channel by the infiltrated magnesium is faster than that of solid phase diffusion through rare earth magnet scrap, so the overall reaction rate is also faster.

4 shows a process of selectively dissolving neodymium of rare earth magnet scrap in magnesium molten metal. Here, the charging ratio of the rare earth magnet scrap was adjusted so that the ratio of neodymium was 80 mol.% Based on Mg-Nd 100mol.%, And the process temperature was set up to 950 ° C or less, and the process time was also up to 10 hours or less. Set.

At this time, it can be seen that the selective dissolution reaction preferentially causes the liquid molten metal to penetrate into the rare earth magnet, and the solid phase diffusion of neodium into the new solid-liquid interface generated by the inner molten magnesium.

Meanwhile, in order to increase the overall reaction rate, it is required to secure a pretreatment technology capable of increasing the penetration rate of the magnesium liquid phase or reducing the penetration distance. For this purpose, the main pretreatment technique is to increase the defects through forced fracture and to reduce the penetration path through particle refinement.

In addition, in the process of dissolving the rare earth magnet scrap in the molten magnesium, it is preferable to stir the molten magnesium to effectively control the concentration gradient of the interface layer of the solid-liquid reaction interface. As the stirring method of the molten magnesium, mechanical stirring, physical stirring using a gas, stirring using an electromagnetic field are possible, and among them, it is preferable to use stirring using an electromagnetic field in consideration of the stability of the magnesium molten metal.

The magnesium alloy formed through this selective dissolution process can be manufactured in the form of a master alloy containing various rare earth elements. In particular, when the mole fraction of magnesium and neodymium is calculated as 100%, the mole fraction of neodymium is 10 mol.%. It is desirable to form a magnesium alloy in the range of -80 mol.%. If the mole fraction of neodymium is less than 10 mol.%, The process efficiency for extracting rare earth elements is inefficient. If the mole fraction of neodymium exceeds 80 mol.%, Neodymium is not completely dissolved in magnesium and remains in the rare earth scrap. It is also more desirable to form up to 60 mol.% Of micrometals in terms of stability of the process.

On the other hand, if the neodymium contained in the rare earth magnet scrap is selectively dissolved in the molten magnesium, the dissolution efficiency of the neodium will vary depending on the reaction time.

Referring to FIG. 5, as a result of comparing the case of maintaining at 720 ° C. for 30 minutes and the case of maintaining for 120 minutes, it was found that a significant amount of neodium was present in the rare earth magnet scrap when the experiment was conducted for 30 minutes, but 120 minutes. In case of maintenance, most of the neodymium contained in rare earth magnet scrap was eluted into magnesium molten metal.

Therefore, there is a time for sufficient elution of neodymium according to the temperature, and in order to shorten the time, a method of increasing the temperature of the melt to increase the activity of the melt, a method of controlling the reaction rate through pretreatment, and a method of artificially flowing the melt It is possible.

6, when using the selective dissolution process using the molten magnesium according to the present invention, it can be confirmed that the extraction efficiency of the neodymium contained in the rare earth magnet scrap can be improved.

For the purpose of evaluating the selective dissolution according to the proportion of the amount of material of the initial charging material, the charging ratio was expanded to 0.2, 0.3 and 0.5, and the experiment was conducted under the conditions of a pressure of 50torr, a process temperature of 850 ° C, and a process time of 1 hour.

As a result, it can be confirmed by the process technology according to the present invention that the theoretical content when neodium is completely dissolved in the molten magnesium and the measured content of neodium in the melt-cast neodymium-containing magnesium ingot appear similar. Therefore, the neodymium contained in the rare earth magnet scrap can be effectively extracted through the selective dissolution process using the molten magnesium according to the present invention.

And Table 1 below describes the extraction behavior of neodymium according to the loading ratio.

Charge amount (g) result Mg scrap Nd in scrap Theoretical
Nd ratio Ingot
Mass (g) Nd in
ingot (%) Material efficiency
(%) Nd Elution
efficiency 207 50 16.7 7.7 153.5 11.5 68.6 99.9 200 80 26.7 11.8 141.1 16.8 62.2 100.7 200 200 66.8 25.0 143.8 38.8 53.9 107.8

The results in Table 1 were calculated under the following conditions.

The scrap consists of a ratio of Nd: Fe: B = 33.4: 64.7: 1.9 (wt.%), And the theoretical Nd ratio represents the ratio of Nd when Nd is completely dissolved in Mg under charging conditions. In addition, Nd in ingot represents the measured value of the Nd content contained in the melt-cast ingot by ICP-MS, and the material efficiency is (cast ingot mass) / (sum of target material in the charging condition [= Magnesium + neodymium]) x100. Nd elution efficiency represents the rate of migration from scrap to melt.

While the invention has been shown and described with respect to the specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Anyone with it will know easily.

Claims (14)

Charging a rare earth magnet scrap containing at least one of the rare earth elements of neodium and disprosium into the molten magnesium;
Dissolving the rare earth magnet scrap in the molten magnesium;
Liquid-penetrating the magnesium molten metal into the rare earth magnet scrap;
Due to the liquid phase penetration of the molten magnesium, new solid / liquid interfaces are continuously formed inside the rare earth magnet scrap, so that the rare earth elements contained in the rare earth magnet scrap diffuse into the magnesium molten metal;
Method of producing a magnesium alloy using a rare earth magnet scrap, characterized in that it comprises a. The method of claim 1,
Further comprising the step of pre-treating the rare earth magnet scrap prior to charging in the molten magnesium,
The pretreatment process of the rare earth magnet scrap,
Demagnetizing the rare earth magnet scrap;
Washing the organics of the rare earth scrap;
Hydro embrittlement the rare earth scrap;
Dry crushing the rare earth magnet scrap into powder form;
Method for producing a magnesium alloy using a rare earth magnet scrap, characterized in that comprising a. The method of claim 2,
The dry crushing process,
Method of producing a magnesium alloy using rare earth magnet scrap, characterized in that the progress in the order of jaw crushing (hammer miliing), jet milling (jet milling). According to claim 2, The rare earth magnet scrap pretreatment step,
Dehydrogenating the rare earth magnet scrap in powder form;
Method of producing a magnesium alloy using a rare earth magnet scrap characterized in that it further comprises. According to claim 2, The rare earth magnet scrap pretreatment step,
Before demagnetizing the rare earth magnet scrap, carrying out a reduction treatment to separate the oxide when the rare earth magnet scrap contains an oxide;
Method of producing a magnesium alloy using a rare earth magnet scrap characterized in that it further comprises. The method of claim 1,
In the process of charging the rare earth magnet scrap in the molten magnesium,
A method of producing a magnesium alloy using rare earth magnet scraps, characterized in that the loading ratio of rare earth magnet scraps is adjusted to have a composition below the equilibrium liquid line of Nd-Mg according to the temperature of the magnesium molten metal. The method of claim 1,
In the process of charging the rare earth magnet scrap in the molten magnesium,
A method of producing a magnesium alloy using rare earth magnet scraps, characterized in that the charge ratio of the rare earth magnet scraps is adjusted to have a composition of 5 mol.% Lower than the liquidus composition of Nd according to the temperature of the molten magnesium. The method of claim 1,
Process temperature for dissolving the rare earth magnet scrap in the molten magnesium, the manufacturing method of magnesium alloy using rare earth magnet scrap, characterized in that made in the range of 600 ℃ ~ 1,000 ℃. The method of claim 1,
Process temperature for dissolving the rare earth magnet scrap in the molten magnesium, the manufacturing method of magnesium alloy using rare earth magnet scrap, characterized in that made in the range of 700 ℃ ~ 900 ℃. The method of claim 1,
A process temperature (T) for dissolving the rare earth magnet scrap in the molten magnesium is set in the following range, the manufacturing method of magnesium alloy using rare earth magnet scrap.
T1 + 25 ℃ ≤ T ≤ 1,000 ℃
(The T1 is the liquidus temperature determined according to the mole fraction of Nd when converted to 100 moles of Mg-Nd) The method of claim 1,
In the process of dissolving the rare earth magnet scrap in the molten magnesium, the magnesium alloy using the rare earth magnet scrap characterized in that the magnesium molten metal is stirred by any one of mechanical stirring, physical stirring using a gas, stirring using an electromagnetic field Manufacturing method. The method of claim 1,
The rare earth magnet scrap is a method of producing a magnesium alloy using a rare earth magnet scrap, characterized in that it comprises a scrap generated in the magnet manufacturing process, or a sludge-type scrap generated in the magnet processing process. Dissolving a rare earth magnet scrap containing at least one of the rare earth elements of neodium and disprosium in a molten magnesium; Liquid-penetrating the magnesium molten metal into the rare earth magnet scrap; Due to the liquid permeation of the molten magnesium molten metal, while forming a new solid / liquid interface continuously in the rare earth magnet scrap, the rare earth element contained in the rare earth magnet scrap is diffused into the magnesium molten metal; ,
Magnesium alloy using a rare earth magnet scrap, characterized in that the rare earth element dissolved in the rare earth magnet scrap is contained. The method of claim 13,
When the mole fraction of magnesium and rare earth elements is calculated as 100%, the magnesium alloy using rare earth magnet scrap, characterized in that the mole fraction of rare earth elements is in the range of 10 mol.% To 80 mol.%.

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