JP2012132051A - Method of recovering rare earth magnets and other metals - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of recovering rare earth magnets and other metals, capable of recovering the rare earth magnets and other metals, from which resin is removed, from a product in which the rare earth magnets, the metals other than the rare earth magnets, and the resin are contained and the rare earth magnets are integrated with the resin.SOLUTION: The method of recovering the rare earth magnets and other metals from the product, in which the rare earth magnets, the metals other than the rare earth magnets, and the resin are contained and the rare earth magnets are integrated with the resin, includes (a) a process for dismantling the product to separate a part A containing the rare earth magnets integrated with the resin from a part B containing the metals other than and the rare earth magnets, (b) a process for recovering the rare earth magnets by hydrothermally treating the separated part A to dismantle and peel off the resin, and (c) a process for recovering the metals from the separated part B.

Description

  The present invention relates to a method for recovering rare earth magnets and other metals.

  Rare metals (rare metals) and rare earths (rare earths) are widely used from general household electrical appliances to computer peripherals, electronic devices, automobiles, medical devices and the like. In particular, rare earth magnets such as rare earth magnet alloys containing rare earth such as Nd (neodymium) and Dy (dysprosium) have good magnetic performance, and are used in motors for generators, actuators for hard disks, motors and rotors in washing machines, etc. It is used.

  In order to use these rare substances, it is important to secure them in a stable manner, and demands for recycling are increasing due to social constraints due to the uneven distribution of resources and price increases due to increased demand. ing.

  On the other hand, the Home Appliance Recycling Law was enforced in April 2001, and it is obliged to recycle 4 items of home appliances such as air conditioners, TVs, refrigerators and washing machines. In the recycling process of these home appliances, metals such as iron, copper, and aluminum and resin waste such as plastic are separately collected. For example, as shown in FIG. 3, waste home appliances such as washing machines are pulverized as they are, and metal and resin waste are separated and collected by machine division using a sorting method using magnetic force, eddy current, specific gravity, and the like.

  Under such circumstances, recently, a compressor / rotor or motor / rotor including high-performance rare earth magnets has been used in washing machines and air conditioners. In particular, when rare earth magnets are used while being fixed to a resin or the like, the resin fixed to the rare earth magnets is removed by a conventional method such as manual disassembly or pulverization to remove the rare earth magnets. It is difficult to recover. In the case of manual work or mechanical dismantling, it is difficult to cleanly separate the resin for labor, and if it is pulverized, it is difficult to separate it from metal components such as iron.

  As a collection technique reported so far, there is a technique described in Patent Document 1. The technique described in Patent Document 1 is a technique for recovering rare earth elements from scrap or sludge generated in the magnet machining process of rare earth magnets.

JP 2002-60863 A

  However, this recovery technique is a rare earth element recovery technique for recovered rare earth magnet scrap and sludge. Since rare earth magnets contained in home appliances such as washing machines and air conditioners are only a few percent of the home appliances alone, in order to recover rare earth elements, first from the plastic or steel plate that is the housing of home appliances It is necessary to selectively collect rare earth magnets.

  In addition, when the rare earth magnets included in the household electrical appliance are integrated with the resin, such as being covered (sealed) with the resin or the resin being fixed, as described above. It is necessary to remove the resin from the rare earth magnets.

  The present invention has been made in view of the circumstances as described above, and has the following problems. Rare earth magnets, rare earth magnets that contain resin and other rare earth magnets, and rare earth magnets from which the rare earth magnets are integrated with resin, and other metals can be recovered It is an object to provide a method for collecting magnets and other metals.

  In order to solve the above problems, the method for recovering rare earth magnets and other metals according to the present invention includes rare earth magnets, metals and resins other than the rare earth magnets, and the rare earth magnets are combined with the resin. A method for recovering rare earth magnets and other metals from an integrated product, comprising: (a) disassembling the product to include a part A containing rare earth magnets integrated with a resin and the rare earth A step of separating the portion B containing a metal other than magnets, (b) a step of hydrothermally treating the separated portion A to decompose and peel off the resin and recover the rare earth magnets; And a step of recovering the metal from the separated part B.

  In the method for recovering rare earth magnets and other metals, the part B contains a resin, and in the step (c), the part B is pulverized to separate and recover the metal and the resin from the pulverized product. In the step (b), the resin recovered in the step (c) is preferably subjected to hot water treatment together with the part A.

  In the rare earth magnets and other metal recovery methods, it is preferable to cut and separate a part of the resin in the portion A.

  In the method for recovering rare earth magnets and other metals, in the step (c), the resin cut and separated from the part A is pulverized together with the part B, and the metal and the resin are separated from the pulverized product. In the step (b), the resin recovered in the step (c) is preferably subjected to hot water treatment together with the portion A.

  In the rare earth magnets and other metal recovery methods, it is preferable to separate and recover the resin from the pulverized material at the site B by sorting by specific gravity.

  In the rare earth magnets and other metal recovery methods, the metal in the part B contains a magnetic metal and a nonmagnetic metal, and the part B is pulverized in the step (c). It is preferable that the magnetic metal and the nonmagnetic metal are separated and recovered by magnetic force sorting.

  In the method for recovering rare earth magnets and other metals, the resin contains an inorganic substance, and after recovering the rare earth magnets from the hydrolyzed decomposition liquid in the step (b), the decomposition liquid is used. It is preferable to recover the liquid component containing the decomposition product of the resin by solid-liquid separation.

  In the method for recovering the rare earth magnets and the other metals, it is preferable to solid-liquid separate the decomposition solution to recover the solid content containing the inorganic substance, and dry and pulverize it to recover it as an inorganic filler.

  In the method for recovering rare earth magnets and other metals, the hot water treatment is preferably performed by adding 100 to 500 parts by mass of water to 100 parts by mass of the resin.

  In the rare earth magnets and other metal recovery methods, the hydrothermal treatment water preferably contains an alkali metal salt.

  According to the present invention, a rare earth magnet and a metal other than the rare earth magnet are removed from a product containing a rare earth magnet, a metal and a resin other than the rare earth magnet, and the rare earth magnet is integrated with the resin. It can be recovered.

It is the flowchart which showed one Embodiment of the collection | recovery methods of the rare earth magnets and other metals of this invention. It is a schematic diagram of the process flow of a hot water treatment. It is a flowchart of the collection method of the conventional waste household appliance.

  As described above, the present invention recovers rare earth magnets and other metals from products containing rare earth magnets, metals and resins other than these rare earth magnets, and rare earth magnets integrated with the resin. Is the method.

  Examples of the products targeted by the present invention include home appliances such as washing machines and air conditioners, but include rare earth magnets, metals and resins other than these rare earth magnets, and rare earth magnets and resins. There is no particular limitation as long as they are integrated. For example, computer peripheral devices, electronic devices, communication devices, automobiles, medical devices, and the like may be used. Further, motors, actuators, and the like included in the above-described products can also be products targeted by the present invention. These products include waste products such as used products.

  In the present invention, rare earth magnets include various rare earth metals including rare earth magnets such as samarium cobalt magnets and neodymium magnets, alloys containing them, and rare metals.

  Examples of metals other than rare earth magnets include magnetic metals such as iron, cobalt, and nickel, and nonmagnetic metals such as copper, aluminum, stainless steel, and brass.

  Examples of the resin include thermosetting resins such as unsaturated polyester resins and epoxy resins, but are not limited thereto. The resin may contain an inorganic filler such as calcium carbonate or calcium hydroxide, an inorganic material such as glass fiber, and other components.

  Rare earth magnets are integrated with a resin when all or part of the rare earth magnets are covered or sealed with a cured resin, or the resin is cured with or without an adhesive. It means being fixed to an object. The rare earth magnets are integrated with the resin as a powder or a molded body. When rare earth magnets are integrated with a resin as a molded body, according to the present method, the rare earth magnets can be recovered as a molded body.

  The rare earth magnets integrated with such a resin can be regarded as a component member of a product or a component constituting the product. For example, when the product to be collected is a household electrical appliance such as a washing machine or an air conditioner, the rare earth magnets integrated with the resin can be used as a constituent member of the rotor of the motor constituting the household electrical appliance. When the product to be collected is a motor, it can be a constituent member of a rotor constituting the motor. The rotor is configured, for example, by molding a rare earth magnet compact and an iron frame with a thermosetting resin.

  The rare earth magnets integrated with the resin as a constituent member in this manner include members other than resins and rare earth magnets, for example, metal members such as iron and copper, inorganic members such as carbon fibers, and organic members. It may be.

  On the other hand, metals other than rare earth magnets can also be regarded as components of products and parts constituting them. For example, when the product to be collected is a household electrical appliance such as a washing machine or an air conditioner, the metal other than the rare earth magnets can be a constituent member of the stator of the motor constituting the household electrical appliance. When the product to be collected is a motor, it can be a constituent member of a stator that constitutes the motor. The stator is configured, for example, by providing a copper wire around a ring-shaped iron core and molding the periphery with a thermosetting resin.

  As described above, metals other than rare earth magnets as constituent members may include inorganic members such as resins and carbon fibers, organic members, and the like.

  The present invention includes (a) a part A containing a rare earth magnet integrated with a resin by disassembling the product (hereinafter also simply referred to as part A) and a part B containing a metal other than the rare earth magnet (hereinafter, And simply separating the portion B). Further, (b) a step of hydrothermally treating the separated part A to decompose and peel the resin and recovering the rare earth magnets, and (c) a step of recovering the metal from the separated part B are also provided.

  In the following, the rare earth magnets and other metals in FIG. 1 will be described with reference to the flowchart of recovery of the rare earth magnets and the schematic diagram of the hot water treatment process flow in FIG. The flow chart for collecting rare earth magnets and other metals shown in FIG. 1 shows an embodiment of the method for collecting rare earth magnets and other metals according to the present invention. This is an applied example.

  In this embodiment, first, the product itself such as a discarded home appliance is disassembled. For example, a part other than a rare earth magnet and a part A in which rare earth magnets integrated with a resin are disassembled by using machine tools, jigs, etc. It divides | segments into the site | part B with which the metal is made into the structural member.

  In FIG. 1, waste home appliances such as washing machines are dismantled and the waste motor is collected, and the waste motor is disassembled and divided into a rotor (part A) and a stator (part B). As described above, the rotor is configured by molding a rare earth magnet molded body and an iron frame with a thermosetting resin. The stator is configured by providing a copper wire around a ring-shaped iron core and molding the periphery with a thermosetting resin.

  Further, in this dismantling operation, a part that has been disassembled into parts can be separated into a part A and other parts by performing a cutting operation using a machine tool or a jig. it can. For example, for part A, a part of the resin can be separated from part A, for example, by cutting part of the resin. As will be described later, the separated resin is subjected to processing such as crushing and crushing together with the portion B, and is separated into a metal and a resin by mechanical separation. The separated resin is treated with hot water together with the part A. When hydrothermal treatment is performed on the portion A in which the resin is included in a lump, the lump resin has a poor decomposition efficiency, and thus it is necessary to make the reaction conditions for the hydrothermal treatment more stringent. By separating a part of the resin in the site A, the reaction conditions of the hydrothermal treatment can be made gentler and the resin can be easily removed from the rare earth magnets.

  Further, when the portion A contains a metal other than the rare earth magnets, it can be separated as the portion B by cutting all or part of the portion containing the metal other than the rare earth magnets.

  Even when the product is composed of one part, it can be separated into the part A and the part B by performing a similar operation such as cutting.

  The above dismantling work can also be performed manually. Where the part A and the part B are present in the product is known from the characteristics of the product, they can be selectively and easily collected. In the dismantling operation, processing such as crushing and crushing is not performed.

  After the dismantling operation, a demagnetizing step of demagnetizing the rare earth magnet included in the part A can be performed. For example, in the case of FIG. 1, this demagnetization step can be performed after removing the waste motor or after removing the rotor.

  Next, the separated part A is treated with hot water.

  In the hot water treatment, first, as shown in FIG. 2, the separated portion A <b> 20 is stored in the mesh-like storage body 10, and this mesh-like storage body 10 is put into the decomposition tank 1. Then, hot water treatment is performed. Although the part A20 can be directly put into the decomposition tank 1 for hot water treatment, it is easier to take out the members such as the rare earth magnets 30 remaining after the hot water treatment by using the mesh container 10 and the efficiency. Is preferable because it is good.

  The mesh-like storage body 10 only needs to have a mesh structure that allows water to enter the inside thereof and prevents members such as the rare earth magnets 30 remaining after the portion A20 from being subjected to the hot water treatment from falling outside. As the overall structure of the mesh-like storage body 10, for example, a bowl-shaped one with an open top can be adopted.

  The decomposition tank 1 is a pressure vessel having a lid portion 8 and is preferably provided with a quick lid opening / closing mechanism defined by JIS or the like in which the lid portion 8 operates to be freely opened and closed. The lid 8 can be opened and closed by a bolting method, but it is preferable to open and close the lid 8 by a quick lid opening / closing mechanism in view of workability in a large-scale industrial apparatus.

  The hot water treatment is performed according to the following flow. As shown in FIG. 2, water from the water storage tank 2 is pressurized by a pump 3, heated while exchanging heat with a heat medium in a heat exchanger 4, and pressurized hot water is supplied to the decomposition tank 1. . In the decomposition tank 1, the hot water treatment of the part A20 is performed with pressurized hot water. The hot water discharged from the decomposition tank 1 is cooled while exchanging heat with water supplied from the water storage tank 2 to the decomposition tank 1, and is cooled while exchanging heat with cold water in the heat exchanger 5. The pressure is reduced. Since the depressurized water may contain organic matter and inorganic matter, water treatment such as removal of organic matter and inorganic matter is performed in the water circulation drainage facility 7, and most of the water is supplied to the water tank 2 and circulated. Used, some drained. When the water in the water storage tank 2 is insufficient, water is appropriately replenished from the outside.

  The pressurized hot water supplied to the decomposition tank 1 is, for example, liquid water heated to about 180 ° C. to 350 ° C., and is in a subcritical state. The pressure is, for example, about 2 to 15 MPa.

  The hot water treatment may be performed by continuing to pass the pressurized hot water through the decomposition tank 1, but after passing for a certain period of time, the supply of the pressurized hot water is stopped and the pressurized hot water is supplied as it is. You may carry out by hold | maintaining in the decomposition tank 1. FIG. In this embodiment, since the heat source required for decomposition | disassembly of resin in site | part A20 is supplied from this pressurized hot water, it is desirable that the decomposition tank 1 is a heat insulation container.

  Water is supplied to the decomposition tank 1, a jacket or the like is provided around the decomposition tank 1, and a heat medium is circulated around the decomposition tank 1, so that the site A20 in a subcritical state at a reaction temperature of 180 ° C. to 350 ° C. Can also be heat-treated.

  The amount of water supplied to the decomposition tank 1 is preferably 100 to 500 parts by mass with respect to 100 parts by mass of the resin in the part A20, for example. If the amount of water supplied is in the above range, the resin can be efficiently decomposed.

  The hydrolysis reaction of the resin in the part A20 proceeds by the hot water treatment. As the hydrolysis reaction proceeds, the resin has a low molecular weight, and the resin is removed from the rare earth magnets by separating the resin from the rare earth magnets or partially dissolved in water, thereby separating the rare earth magnets. Even when the resin is fixed to the rare earth magnets via the adhesive, it is possible to remove the resin and the adhesive from the rare earth magnets by eliminating the function as the adhesive by this hot water treatment. When the part A20 includes a metal member such as iron or an inorganic member such as carbon fiber, these members are also separated from the resin. Moreover, the demagnetization of the rare earth magnet can be partially possible.

  Such hot water treatment is preferably performed with pressurized hot water containing an alkali metal salt such as sodium hydroxide or potassium hydroxide. By including the alkali metal salt, for example, the hydrolysis reaction of the resin can be effectively advanced at a temperature of 180 ° C. to 270 ° C. In addition, valuable materials can be recovered from the decomposition product of the resin.

  After the hot water treatment, the inside of the decomposition tank 1 is cooled to room temperature to about 80 ° C. by reducing the pressure and passing cold water. The decomposition tank 1 can also be naturally cooled.

  After decompression and cooling, the mesh container 10 is dispensed from the decomposition tank 1. The rare earth magnets 30 from which the resin has been removed can be recovered from the discharged mesh-like storage body 10. When the part A20 includes a metal member such as iron or an inorganic member such as carbon fiber, these members are obtained together with the rare earth magnets 30 with the resin removed. In the case of FIG. 1, the rotor structure is generally a structure in which a rare earth magnet is inserted into an electromagnetic steel plate (iron frame), and after the resin separation, the iron frame and the rare earth magnet are recovered in an integrated state.

  The rare earth magnet is mechanically extracted from the collected iron frame, and can be collected while maintaining the magnet shape. This extraction may be performed manually or a jig for extraction may be used. Moreover, you may isolate | separate by giving a mechanical vibration.

  In the decomposition tank 1 after dispensing the mesh-like storage body 10, components in the portion A20 other than those recovered from the mesh-like storage body 10, for example, a decomposition product of the resin, remain together with water as a decomposition solution. When the resin contains an inorganic filler such as calcium carbonate or calcium hydroxide or an inorganic substance such as glass fiber, these remain in the decomposition solution as a solid content. This solid content can be recovered as inorganic waste by solid-liquid separation of the decomposition solution by a method such as filtration. The recovered inorganic waste can be reused as an inorganic filler (regenerated inorganic filler) by drying and pulverizing.

  On the other hand, valuable materials can be recovered from the separated filtrate of the decomposition solution. For example, if the resin is an unsaturated polyester resin, a polybasic vinyl monomer copolymer such as styrene maleic acid copolymer (SFC) or a polyester-derived monomer such as polyhydric alcohol and polybasic acid can be obtained. it can.

  About the site | part B which disassembled and isolate | separated the product, processing, such as a grinding | pulverization or crushing, is performed with a grinder etc., for example, it can refine | miniaturize to the magnitude | size about a particle size of 10 mm-15 mm. When the resin is separated by cutting a part of the resin at the site A, the separated resin can be subjected to a treatment such as pulverization or crushing together with the site B. After processing such as pulverization or crushing, the metal and the resin can be separated and recovered by mechanical separation by a known sorting method using magnetic force, eddy current, specific gravity, or the like.

  Even when a plurality of types of metals are present together with the resin, the plurality of types of metals and resins can be separately collected by these sorting methods or by a combination of these sorting methods. For example, in the case of a metal containing a magnetic metal and a nonmagnetic metal, it can be divided into a magnetic metal, a nonmagnetic metal, and a resin by magnetic force sorting or eddy current sorting. After the metal and the resin are separated and collected by mechanical separation using a known sorting method, the collected metal can be divided into a magnetic metal and a non-magnetic metal by magnetic sorting or eddy current sorting.

  In FIG. 1, the stator is pulverized. Moreover, the resin lump part which cut | disconnected and isolate | separated some resin in a rotor before heat processing of a rotor is grind | pulverized with a stator. After the pulverization process, it is divided into metal and resin by mechanical separation. The mechanical separation can be performed by simple specific gravity, such as using wind power or settling in water, but is not limited to this as long as the metal and the resin can be collected separately. Separation and collection can also be performed by the above-described methods such as magnetic force and eddy current. In FIG. 1, the separated and collected metal is further divided into iron and copper by simple magnetic separation. Here, if magnetic metal and non-magnetic metal can be selected, it is not limited to magnetic selection, and for example, iron and copper can be separated by eddy current selection. Further, after the stator is pulverized, it can be divided into iron, copper and resin by magnetic sorting or eddy current sorting.

  The separately collected resin can be treated with hot water together with the part A. By treating the resin with hot water, valuable materials such as those described above can be collected, so that the reuse rate of the product dismantled product can be increased. Moreover, since the separately collected resin is refined by a process such as pulverization or crushing, the decomposition efficiency is good.

  Furthermore, the filling rate of a decomposition tank can be improved and a hot water process can be performed efficiently. That is, the part A is not subjected to processing such as pulverization or crushing, and is stored as a single component or a separated part thereof stacked in the decomposition tank, so that a large number of voids are generated in the decomposition tank. . The resin that is refined can be filled into the gap, and by filling the gap with the refined resin, the filling rate of the decomposition tank can be improved and the operating rate of the apparatus can be improved. .

  For example, when the part A is a rotor, the rotor has a double cylindrical shape having an annular portion (inner and outer) on the inner side and the outer side, and a gap is formed between the inner and outer sides. Filling this gap with a finely sized resin can improve the filling rate of the decomposition tank even when a plurality of rotors are stacked and stored in a mesh-like storage body and put into the decomposition tank. .

  As described above, according to the method of the present invention, a rare earth magnet obtained by removing a resin from a product containing a rare earth magnet, a metal and a resin other than the rare earth magnet, and the rare earth magnet integrated with the resin. And other metals can be recovered. Since the rare earth magnets integrated with the resin are collected by a simple dismantling operation, there is little economic burden and the cost of collecting the rare earth magnets can be reduced. It is also possible to recover the rare earth magnets as a molded body.

20 Part A containing rare earth magnets integrated with resin
30 Rare earth magnets

Claims (10)

Rare earth magnets, a method of recovering rare earth magnets and other metals from products containing metals and resins other than these rare earth magnets, wherein the rare earth magnets are integrated with the resin,
(A) disassembling the product and separating a part A containing rare earth magnets integrated with a resin and a part B containing a metal other than the rare earth magnets;
(B) a step of hydrothermally treating the separated part A to decompose and peel off the resin and recover the rare earth magnets;
(C) recovering the metal from the separated site B;
A method for recovering rare earth magnets and other metals.   The part B contains a resin. In the step (c), the part B is pulverized and the metal and the resin are separated and recovered from the pulverized product. In the step (b), the part B is recovered in the step (c). The method for recovering rare earth magnets and other metals according to claim 1, wherein the resin is subjected to hot water treatment together with the part A.   3. The method for recovering rare earth magnets and other metals according to claim 1, wherein a part of the resin in the part A is cut and separated.   In the step (c), the resin cut and separated from the portion A is pulverized together with the portion B, and the metal and the resin are separated and recovered from the pulverized product. In the step (b), the resin is separated in the step (c). 4. The method for recovering rare earth magnets and other metals according to claim 3, wherein the recovered resin is subjected to hot water treatment together with the part A.   The method for recovering rare earth magnets and other metals according to any one of claims 2 to 4, wherein the resin is separated and recovered from the pulverized material at the site B by sorting by specific gravity.   The metal in the part B contains a magnetic metal and a nonmagnetic metal. In the step (c), the part B is pulverized and the magnetic metal and the nonmagnetic metal are separated from the pulverized product by magnetic separation. The method for recovering rare earth magnets and other metals according to any one of claims 1 to 5, wherein the recovery is performed.   The resin contains an inorganic substance, and after the rare earth magnets are recovered from the decomposition solution after the hydrothermal treatment in the step (b), the decomposition solution is subjected to solid-liquid separation to obtain a liquid component containing the decomposition product of the resin. The method for recovering rare earth magnets and other metals according to any one of claims 1 to 6, wherein the recovery is performed.   8. The rare earth magnet and the other metal according to claim 7, wherein the decomposition liquid is separated into solid and liquid to recover a solid content containing the inorganic substance, which is dried, pulverized, and recovered as an inorganic filler. Recovery method.   The rare earth magnet according to any one of claims 1 to 8, wherein the hot water treatment is performed by adding 100 to 500 parts by mass of water with respect to 100 parts by mass of the resin. Metal recovery method.   The method for recovering rare earth magnets and other metals according to any one of claims 1 to 9, wherein the water for the hot water treatment contains an alkali metal salt.

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