JP2000271507A - Method and apparatus for recovering useful metal from electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently recover useful metals from electronic parts by a simple and easy method hardly causing problems of energy wasting or environmental pollution by suspending powder formed by crushing electronic parts containing useful metals in a fluid and causing the fluid to pass through a magnetic-field- applied zone to recover powder attracted magnetically. SOLUTION: Powder obtained by crushing electronic parts containing useful metals is suspended in a fluid e.g. by using a supply vessel 2 equipped with an agitator 1. The fluid containing the powder suspended is circulated e.g. with a pump means 7 and solenoid valves 3, 4. A magnetic field is applied to the fluid containing the powder suspended therein e.g. with the coils 8, 9, 10 of electromagnets. The fluid is introduced into the magnetic-field-applied zone with a tank 12 and a pump 11 to be cleaned. The magnetized powder in the magnetic-field-applied zone is recovered with a recovery vessel 13, a pump 11 for introducing the fluid thereinto, and solenoid valves 5, 6. Thus, useful metals contained in electronic parts are efficiently recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for recovering useful metals from electronic components. In particular, the present invention relates to a method for easily and efficiently recovering nickel from a ceramic capacitor.

[0002]

2. Description of the Related Art Electronic components such as capacitors, transistors, resistors, and transformers generally include metal materials such as nickel, copper, and aluminum used for electrodes and lead wires, ceramic materials used for dielectrics, and epoxy materials. Resin, polyolefin resin, polyester resin,
Polymer materials such as fluororesins are used. In recent years, with the production and consumption of electronic devices and the like equipped with such electronic components in large quantities, the number of electronic components that have been rejected in the production process and the number of unnecessary electronic devices have increased, While the problem of waste disposal arises, there is a need for recovering and reusing useful metals from such waste from the viewpoint of recycling useful resources. Among these useful metals, nickel is particularly useful in dental materials and the like, but is widely used in the electronic and electrical industries, and in particular, in recent years, due to the growing demand for ceramic capacitors, a large amount of nickel has been used in this field. Used in

Heretofore, in recovering metal materials and the like from electronic parts, attempts have been made to separate the metal materials from other materials by mechanical means such as chemical treatment, heating, compression and impact. For example, Japanese Patent Application Laid-Open No. Hei 10-29622
No. 5 discloses that a printed circuit board to be processed is heated to remove electronic components, the printed circuit board and other electronic components are each crushed into small pieces, and a compressive impact force is applied to the small pieces to crush them.
Separating into a resin material crushed by a crushing action and a flatly crushed metal material, and separating the resin material and the metal material into a metal material which is made into a material by screening in a sieve screening step, A method for collecting printed circuit boards is disclosed.

However, in recent years, electronic components have been further miniaturized. For example, a multilayer ceramic chip capacitor has a size of about several millimeters square, and a metal material is converted from another material such as a resin material by mechanical means. Separation is extremely difficult. In addition, as the number of steps required for collecting the metal material increases, the energy consumption increases and the efficiency decreases. In particular, when various types of metals such as nickel and copper are used in electronic components, not only separates metal materials from other materials such as resin materials, but also separates and collects metal materials for each type. There is a need to. Above all, when the use ratio of such a plurality of metal materials in an electronic component is close to each other, each metal material is converted to a metal unless the mixture of the plurality of metal materials is separated so that each metal material becomes rich. It cannot be reused through a refining process or the like depending on the material. On the other hand, in the case of chemical treatment using a large amount of a solvent or the like, new problems such as operational safety and treatment of waste liquid occur, which is not desirable. Therefore, at present, a method for easily and efficiently recovering useful metals from electronic components that have been miniaturized has not been obtained.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention is useful for electronic components with high efficiency and high yield by employing a simple process that consumes less energy and does not easily cause environmental pollution problems. An object is to provide a method capable of recovering a metal.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that when recovering a metal material from an electronic component containing a useful metal, the electronic component is crushed. The inventors have found that it is possible to easily and efficiently recover a useful metal by selectively recovering a powder containing a large amount of a useful metal from the obtained powder, and have completed the present invention. That is, the present invention provides (1) a step of suspending a powder obtained by crushing an electronic component containing a useful metal in a fluid, and (2) a step of suspending the fluid in which the powder is suspended in at least a magnetic field application region. Provided is a method for recovering a useful metal from an electronic component, the method including a step of circulating so as to pass three times, and a step of (3) a step of recovering a powder magnetized in a magnetic field application region. The present invention also provides (A) means for suspending a powder obtained by crushing an electronic component containing a useful metal in a fluid, (B) a flow path and a pump for circulating the fluid in which the powder is suspended. Means, (C) means for applying a magnetic field to the fluid in which the powder is suspended, (D) means for introducing and cleaning the fluid into the magnetic field application region, and (E) collecting the magnetically adhered powder in the magnetic field application region. An apparatus for recovering useful metals from electronic components, including means, is provided.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The useful metals to which the present invention is directed are metals which can be magnetized by applying a magnetic field, and which have ferromagnetism, for example, nickel, iron, cobalt, or any of these. Alloy. Of these,
Nickel is a useful metal suitable as an object of the present invention because it is useful in the field of electronic components and there is a demand for recovery. In the present invention, the “electronic component containing a useful metal” is not particularly limited as long as it is an electronic component using the above-described metal, and examples thereof include a capacitor, a diode, a transistor, a thyristor, a resistor, a coil, and a transformer. Can be mentioned. INDUSTRIAL APPLICABILITY The present invention can be effectively applied particularly to capacitors, especially ceramic capacitors whose size has been reduced from a conventional disk type to a chip type. As a ceramic chip capacitor, a ceramic dielectric layer having a thickness of several tens of microns and internal electrodes having a thickness of several microns are alternately stacked in layers, and the main component of the ceramic is barium titanate, and the internal electrodes are Some are made of nickel and the external electrodes are made of copper.

[0008] As a means for crushing an electronic component containing a useful metal as described above into powder, a dodge crusher, a cone crusher, a disk crusher, a rotary crusher, a ball mill, a tube mill, a rod mill, or the like may be used. it can. The particle size of the powder obtained by crushing is preferably adjusted by means such as sieving. In this case, it is preferable to use a powder having a particle size of 65 mesh or less. Further, by controlling the particle size distribution of the powder, the powder containing a large amount of useful metals may be selected in advance based on the average particle size. The powder obtained by the crushing preferably contains 2% by weight or more of useful metals, more preferably 7% by weight or more. The present invention can be applied to the case where the useful metal occupies a main proportion, for example, about 70% of the total metal material present in the pulverized electronic component. It is applicable even in the following cases.

In step (1) of the method according to the present invention, a powder obtained by crushing an electronic component containing a useful metal is suspended in a fluid. As the fluid used to suspend the powder, a fluid such as a gas or liquid inert to the useful metal to be recovered can be used.
The fluid is desirably a liquid from the viewpoint of improving the dispersion state of the powder, recovering the powder containing a large amount of useful metal more efficiently, and preventing the powder having a low content of useful metal from being entrapped. Examples of liquids that can be used in the method of the present invention include water, alcohols such as methanol or ethanol, organic solvents, and the like. Among them, it is preferable to use water from the viewpoint of safety of operation and waste liquid treatment. The liquid may contain a surfactant, an emulsifier, and the like, for the purpose of stably suspending the powder in the fluid and the like, as long as the effects of the present invention are not impaired.
Also, by taking into account the zeta potential of ceramic materials used in electronic components and the zeta potential of useful metals to be recovered, the charge state of powders containing a large amount of ceramic materials and powders containing many useful metals is considered. Is desirably controlled so that these powders are well dispersed without agglomeration in a liquid. This is done by using a pH adjuster such as caustic soda to adjust the pH of the liquid.
Can be adjusted. In this case, the pH of the liquid is desirably 7 to 10. As a means for suspending the powder in the fluid, any commonly used stirring means such as a propeller-type stirrer, a turbine-type stirrer, and a centrifugal pump can be adopted. When a liquid is used as the fluid and the powder is suspended in the liquid, the pulp concentration of the suspension is desirably 2% or more, preferably 5% to 15%. In this case, "pulp concentration" means the weight of the powder based on the weight of the liquid.

In the step (2) of the method according to the present invention, the fluid in which the powder obtained in the step (1) is suspended is subjected to a magnetic field application area at least three times, preferably 5 to 40 times, more preferably Circulate so that it passes 10 to 30 times.
The magnetic field application region can be formed by any means for generating a magnetic field, but it is preferable to use an electromagnet in that the magnitude of the generated magnetic field can be controlled at any time. The strength of the magnetic field generated by the magnetic field generating means is 50 G (Gauss) from the viewpoint of the efficiency and yield of recovering useful metals.
The above is desirable, and it is preferably within the range of 80G to 320G. As the magnetic field application region, it is sufficient that at least one magnetic field generating means is provided in the flow path of the fluid in which the powder is suspended. However, from the viewpoint of the efficiency of useful metal recovery, the magnetic field generating means is provided in the flow path. Are desirably provided at two or more locations, for example, three locations in series.
The size of each magnetic field generating means is 10 m along the flow path.
It is desirable to have a length of at least m. Further, it is desirable that the interval at which the magnetic field generating means is provided is 30 mm or more.

In the present invention, the fluid in which the powder is suspended is circulated so as to pass through the magnetic field application region at least three times. This means that if the fluid in which the powder is suspended passes through the magnetic field application region only once, the applied magnetic field needs to be extremely strong in order to obtain a sufficient yield. As a result, In addition to the problem of energy consumption and workability, the knowledge that the content of useful metals is not necessarily high will also be recovered, and the purity of useful metals in the entire recovered powder is considered to be reduced. It is based on

As the means for circulating the fluid in which the powder is suspended, any known means can be employed depending on the type of the fluid. For example, when the fluid is a gas, a ventilator, a blower Or a compressor can be used, and when the fluid is a liquid, a centrifugal pump such as a propeller pump, a reciprocating pump such as a piston pump,
A rotary pump such as a screw pump can be used. The flow path for circulating the fluid is not particularly limited as long as it is not affected by corrosion or the like by the fluid,
It can be formed of PVC pipe, acrylic pipe, silicon tube, glass pipe, steel pipe, cast iron pipe, copper pipe, aluminum pipe, lead pipe, concrete pipe, etc. Of these, PVC pipe, acrylic pipe, silicon tube, glass It is preferable to use a tube or the like. In particular, with respect to the flow path in the magnetic field application area, it is possible to observe how the powder is magnetized, and to effectively magnetize the powder containing the useful metal in the magnetic field application area and detach it during recovery. Therefore, it is preferable to use an acrylic tube. The inner diameter of the flow path is desirably 10 mm to 50 mm.
The wall thickness of the tube is desirably 1 mm to 5 mm. The circulation flow rate of the fluid is preferably 1 to 5 liters per minute. The time for circulating the fluid is preferably 2 minutes or more, and more preferably 5 minutes or more. In addition, the temperature of the fluid during circulation
It is desirable that the temperature is in the range of 30C to 30C.

In the step (3) of the method according to the present invention, the powder magnetized in the magnetic field application area is recovered. When collecting the magnetically attached powder in the magnetic field application region, first, supply of the fluid in which the powder is suspended to the magnetic field application region is stopped.
Next, if necessary, a fluid is introduced into the magnetic field application region for cleaning, and then the application of the magnetic field in the magnetic field application region is stopped. As the fluid used for washing, it is preferable to use the same fluid as that used for suspending the powder.
The flow rate of the cleaning fluid may be 1 liter to 5 liters per minute, but it should be the same or lower than the value adopted when circulating the fluid in which the powder is suspended. Is preferred. Further, the cleaning time is desirably 5 seconds or more. It is considered that a part of the powder magnetized in the magnetic field application region is naturally separated from the magnetic field application region by stopping the application of the magnetic field. It is desirable to carry out the recovery by introducing into As the fluid used in this case, it is preferable to use the same fluid as that used for suspending the powder.
The flow rate of the fluid for recovery is desirably 1 to 5 liters per minute. Also, the collection time is desirably 5 minutes or more. In addition, when the supply of the fluid in which the powder is suspended to the magnetic field application region is stopped or when the fluid is introduced into the magnetic field application region, switching can be performed using an electromagnetic valve or the like provided in the flow path. it can.

In the method of the present invention, a series of steps from step (1) to step (3) may be repeated twice or more, preferably at least three times.

Next, an apparatus for recovering useful metals from electronic components according to the present invention will be described. The configuration of the apparatus of the present invention can be, for example, as shown in FIG. The device according to the present invention has means (A) for suspending powder obtained by crushing electronic components containing useful metals in a fluid. The suspension means (A) can be constituted by, for example, a supply tank 2 provided with a stirrer 1. The supply tank 2 has an inlet for powder and fluid, and an outlet for fluid in which powder is suspended. Furthermore, supply tank 2
However, when a part of the flow path for circulating the fluid in which the powder is suspended is formed, the supply tank 2 has an inlet for the circulating fluid. The outlet of the fluid in which the powder is suspended in the supply tank 2 is connected to a flow path for circulating the fluid in which the powder is suspended. The flow path and the pump means (B) for circulating the fluid in which the powder is suspended in the apparatus of the present invention are a flow path and a pump means having an inlet for the fluid in which the powder is suspended from the means (A). 7 is provided. The means (B) may be provided with an outlet for the fluid circulating to the supply tank 2. The means (B) may include solenoid valves 3 and 4 for controlling the circulation of the fluid.

The device according to the invention comprises means (C) for applying a magnetic field to the fluid in which the powder is suspended. The magnetic field applying means (C) can be constituted by, for example, coils 8, 9 and 10 of electromagnets provided in a flow path of a fluid in which powder is suspended. The device according to the invention also comprises means (D) for cleaning by introducing a fluid into the magnetic field application area. Such a washing means comprises a tank 12 for supplying a fluid.
And a pump 11 for introducing a fluid from the tank to the magnetic field application region. The device according to the invention further comprises means (E) for recovering the powder magnetized in the magnetic field application region. The powder recovery means (D) includes a recovery tank 13, a tank 12 for supplying a fluid as needed, a pump 11 for introducing a fluid from the tank to the recovery tank 13 through a magnetic field application region, and a fluid. May be composed of solenoid valves 5 and 6 for controlling the circulation of air.

In FIG. 1, the solenoid valves 3 and 5 may be replaced by one three-way solenoid valve, and similarly, the solenoid valves 4 and 6 may be replaced by one three-way solenoid valve. In this case, a circuit as shown in FIG. 2 can be used as a circuit for controlling the opening and closing of each three-way solenoid valve. That is, in FIG. 2, the solenoid valve A is a three-way solenoid valve corresponding to the solenoid valves 3 and 5 in FIG. 1, but after circulating the fluid in which the powder is suspended for a set time, the timer 1 is switched. Is turned on, the electromagnetic valve A is switched, and at the same time, the pump 11 in FIG. 1 is turned on, and the fluid is introduced into the magnetic field application region, so that cleaning can be performed. Also,
In FIG. 2, a solenoid valve B is a three-way solenoid valve corresponding to the solenoid valves 4 and 6 in FIG. 1, but when a predetermined time elapses after the switch of the timer 1 is turned on, the switch of the one-shot timer 2 is switched. Is turned on, the switch of the timer 3 is turned on at the same time, the solenoid valve B is switched, the application of the magnetic field is stopped, the pump 11 in FIG. 1 is turned on, and the fluid is introduced into the magnetic field application area. The magnetized powder can be recovered.

[0018]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. Example 1 As a powder obtained by crushing an electronic component containing a useful metal, a powder obtained by crushing a waste ceramic chip capacitor was used. The components of this powder were subjected to quantitative analysis using an atomic absorption spectrophotometer (Japan Jarrell Ash AA-8200 type) in comparison with a standard sample of nickel and copper. .
It was 60% by weight. The remaining amount (88.54%) is barium titanate. This powder was sieved and used had a particle size of 65 mesh or less. Supply tank 2 with stirrer 1
Put 1 liter of water in
By charging 0 g, a suspension having a pulp concentration of 10% was obtained.
The pH of the suspension was adjusted to 8.5. Next, with the solenoid valves 3 and 4 opened and the solenoid valves 5 and 6 closed, the pump 7 is operated to set the circulation flow rate so as to pass through the coils 8, 9 and 10 of the electromagnet constituting the magnetic field application region. 2 liters per minute and suspension for 5 minutes (10 times)
Circulated. In this case, the coils 8, 9 and 1
For 0, those having a length of 30 mm along the flow path were used at intervals of 130 mm, and the strength of the magnetic field in each coil was 80 G. In addition, an acrylic tube having an inner diameter of 18 mm and a thickness of 2 mm was used as a flow path. The temperature of the suspension during circulation was about 15 ° C. Next, the electromagnetic valve 3 was closed, the electromagnetic valve 5 was opened, and water was introduced from the tank 12 into the magnetic field application region at a flow rate of 2 liters per minute using the pump 11, and washing was performed for 10 seconds. Next, the electromagnetic valve 4 is closed, the electromagnetic valve 6 is opened, and the application of the magnetic field by the coils 8, 9 and 10 is stopped. The powder that had been magnetized in the magnetic field application area was collected by the collection tank 13. After repeating the above steps three times, the recovered powder was analyzed using an atomic absorption spectrophotometer (JARL-AJ-8200).
Quantitative analysis of nickel was performed by comparison with a nickel standard sample, and the nickel content in the recovered powder was regarded as nickel quality (%). Furthermore, the actual nickel yield (%) was determined by the following equation. Nickel actual yield (%) = (C × c) × 100 / (F ×
f) (where C is the weight of the recovered powder, c is the nickel quality of the recovered powder determined by atomic absorption, F is the total amount of the powder used, and f is the nickel component of the powder used. The obtained nickel quality was 14.62 (%), and the actual nickel yield was 38.51 (%).

Examples 2 to 4 Except that the strength of the magnetic field was 190 G (Example 2), 300 G (Example 3), and 320 G (Example 4), the waste ceramic was used in the same manner as in Example 1. Nickel was recovered from the powder obtained by crushing the chip capacitor, and the nickel quality (%) and the actual nickel yield (%) were determined.
Table 1 shows the results.

[0020]

Table 1 Example 1 Nickel grade (%) Nickel actual yield (%) 2 15.74 40.50 3 18.30 68.14 4 15.66 66.45

Examples 5 to 8 Each suspension was treated for 2.5 minutes (5 times) (Example 5),
10 minutes (20 times) (Example 6), 15 minutes (30 times)
(Example 7) and recovery of nickel from powder obtained by crushing a waste ceramic chip capacitor in the same manner as in Example 2 except that circulation was performed for 20 minutes (40 times) (Example 8). Was performed to determine the nickel grade (%) and the actual nickel yield (%). Table 2 shows the results.

[0022]

Table 2 Example 2 Nickel grade (%) Nickel actual yield (%) 5 16.47 37.94 6 12.99 61.56 7 13.03 42.708 8 14.30 46.83

Examples 9-12 Nickel was recovered from the powder obtained by crushing the waste ceramic chip capacitor in the same manner as in Example 6, except that the strength of the magnetic field was 300 G. The quality (%) and the actual nickel yield (%) were determined (Example 9). Further, the pulp concentration was 5% (Example 10);
Nickel was recovered from the powder obtained by crushing the waste ceramic chip capacitor in the same manner as in Example 9 except that 5% (Example 11) and 15% (Example 12) were used. The nickel grade (%) and the actual nickel yield (%) were determined. Table 3 shows the results.

[0024]

TABLE 3 Example nickel grade (%) Nickel actual yield (%) 9 15.67 75.04 10 14.20 37.48 11 12.65 61.56 12 11.58 42.99

Examples 13 to 15 The cleaning time of the magnetic field application region with water was 5 seconds (Example 1).
3) Recovery of nickel from powder obtained by crushing a waste ceramic chip capacitor in the same manner as in Example 9 except that the time was 15 seconds (Example 14) and 20 seconds (Example 15). Was performed to determine the nickel grade (%) and the actual nickel yield (%). Table 4 shows the results.

[0026]

Table 4 Table 4 Example nickel grade (%) Nickel actual yield (%) 13 14.71 53.22 14 21.46 66.41 15 24.33 64.69

Examples 16 to 18 Before charging the powder, a ball mill was used for 30 minutes (Example 1).
6) Recovery of nickel from powder obtained by crushing waste ceramic chip capacitors as in Example 15, except that grinding was performed for 60 minutes (Example 17) and 90 minutes (Example 18). And nickel grade (%)
And the actual nickel yield (%) were determined. Table 5 shows the results.

[0028]

Table 5 Example 5 Nickel grade (%) Nickel actual yield (%) 16 33.32 63.42 17 33.28 63.80 18 33.30 63.70

[Brief description of the drawings]

FIG. 1 is a schematic view of one embodiment of the device of the present invention.

FIG. 2 is a circuit diagram for switching an electromagnetic valve that can be used in the device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stirrer 2 Supply tank 3, 4, 5, 6 Solenoid valve 7, 11 Pump 8, 9, 10 Coil 12 Tank 13 Recovery tank

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Eiichi Kuzuno, 1-1, Tegami Gakuen-cho, Akita City, Akita Prefecture Inside Akita University (72) Kunihiko Takahashi 3-5-2 Hashimotodai, Sagamihara City, Kanagawa Prefecture Yokohama Metal Co., Ltd.

Claims (2)

[Claims] (1) a step of suspending a powder obtained by crushing an electronic component containing a useful metal in a fluid, (2)
The fluid in which the powder is suspended should be
A method for recovering useful metals from electronic components, comprising a step of circulating the metal component so as to make a round passage, and a step of (3) recovering the magnetically adhered powder in the magnetic field application region. (A) means for suspending a powder obtained by crushing an electronic component containing a useful metal in a fluid, (B)
Flow path and pump means for circulating the fluid in which the powder is suspended, (C) means for applying a magnetic field to the fluid in which the powder is suspended, and (D) means for introducing and cleaning the fluid in the magnetic field application region And (E) an apparatus for recovering a useful metal from an electronic component, comprising: means for recovering magnetically adhered powder in a magnetic field application region.