KR102460424B1 - Apparatus of recovering valuable metal of spent automotive catalyst using microwave - Google Patents

Abstract

A device for recovering valuable metals for spent catalysts for automobiles using microwaves, which uses low energy, uniformly decomposes ions, and has a structure for efficiently recovering valuable metals. The device includes a heating furnace having an inclination angle (θ) inclined with respect to the ground and indirectly heated by a high-temperature combustion gas, a stirring screw installed inside the heating furnace, a roller for inducing a seesaw motion of the heating furnace, and a pair and a chamber for thermally decomposing the spent catalyst fine powder injected into the rail of the furnace by microwaves, the roller moves along the rail, and the pair of rails has a rail spacing (D).

Description

Apparatus of recovering valuable metal of spent automotive catalyst using microwave

The present invention relates to an apparatus for recovering valuable metals, and more particularly, to an apparatus for recovering valuable metals in the platinum group such as palladium (Pd), platinum (Pt), and rhodium (Rh) from a spent catalyst for automobiles using microwaves.

The spent catalyst for automobiles is composed of a carrier such as γ-alumina and cordierite in which a platinum group metal such as palladium (Pd), platinum (Pt), and rhodium (Rh) and a metal oxide such as cerium oxide are mixed. Platinum group metals are usually contained in about 1 to 2 g per vehicle, of which platinum is about 0.5 to 1 g. Various methods have been used to extract platinum group metals from spent automobile catalysts, but the wet method of directly leaching platinum group metals with an acid or alkali solution is limited due to concerns about environmental problems such as water pollution. Accordingly, many pyrometallurgical methods have been adopted, in which a waste automobile catalyst is melted together with a collecting agent in a high-temperature furnace to collect platinum group metals in small portions, and then refined by a wet separation process.

Korean Patent No. 10-0250062 proposes a method for extracting platinum group metals from spent automobile catalysts using an electric furnace. However, in a high-temperature heating furnace such as an electric furnace, the amount of energy input up to a high temperature is more than necessary. Accordingly, there is a demand for a method of generating heat at a high temperature by inputting a relatively low energy. In addition, it is preferable that the collected molluscs are uniformly decomposed so that they can be easily refined in a subsequent wet separation process. Furthermore, the conventional recovery apparatus is structurally not suitable for efficiently recovering valuable metals.

An object of the present invention is to provide an apparatus for recovering valuable metals of a spent catalyst for automobiles using microwaves, which uses low energy, uniformly decomposes ions, and has a structure for efficiently recovering valuable metals.

The apparatus for recovering valuable metals for spent catalysts for automobiles using microwaves of the present invention has an inclination angle (θ) with respect to the ground, and a heating furnace that is indirectly heated by a high-temperature combustion gas, and agitation installed inside the heating furnace It includes a screw, a roller and a pair of rails for inducing a seesaw motion of the heating furnace, and a chamber for thermally decomposing the spent catalyst fine powder injected into the heating furnace by microwaves. At this time, the roller moves along the rail, and the pair of rails have a rail spacing (D).

In the apparatus of the present invention, the combustion gas is introduced from the combustion furnace for burning the harmful gas generated in the heating furnace. The combustion furnace may include a heat storage furnace. The seesaw motion prevents the fine powder from being caught in the gap of the stirring screw. The inside of the heating furnace may include a rotating screw for rotating the harmful gas generated in the heating furnace. The magnetron generating the microwave may be cooled by a circulation pipe. The combustion gas exhausted from the heating may be cooled by the second heat exchanger.

In a preferred apparatus of the present invention, the fine powder of the spent catalyst may be ionized by an ionizing agent. When the stirring and thermal decomposition of the fine powder in the heating furnace are completed, the stirring screw is rotated in the reverse direction to recover the fine powder to the chamber and discharged to the outside through a discharge pipe.

According to the apparatus for recovering valuable metals of spent catalysts for automobiles using microwaves of the present invention, by using microwaves and applying an inclined heating furnace, low energy is used, ion decomposition is uniformly performed, and valuable metals are efficiently recovered has a structure that

1 is a schematic view for explaining a recovery device according to the present invention.
FIG. 2 is a schematic view for explaining the pyrolyzer of FIG. 1 .
FIG. 3 is a view of the microwave-related part of FIG. 2 as viewed from the rear.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described in detail below. The embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art. On the other hand, terms indicating positions such as upper, lower, front, etc. are only related to those shown in the drawings. In practice, the recovery device can be used in any optional orientation, and in actual use, the spatial orientation changes according to the orientation and rotation of the recovery device.

An embodiment of the present invention uses a microwave and applies a slanted heating furnace to use low energy, uniform ion decomposition, and recovery of valuable metals from a spent catalyst for automobiles having a structure that efficiently recovers valuable metals present the device. To this end, a recovery device to which a microwave is used and an inclined heating furnace is applied will be studied in detail, and a method for recovering valuable metals by the recovery device will be described in detail. In an embodiment of the present invention, platinum group metals such as palladium (Pd), platinum (Pt), and rhodium (Rh) are recovered from a spent catalyst for automobiles and smelted in a dry manner before entering a wet separation process.

1 is a schematic diagram for explaining a recovery apparatus 100 according to an embodiment of the present invention. However, the drawings are not expressed in a strict sense, and there may be components not shown in the drawings for convenience of description.

Referring to FIG. 1 , the recovery device 100 includes a sub-processing unit 10 , a combustion furnace 30 , and a pyrolyzer 40 . The sub-processing unit 10 includes a plurality of heat exchangers 11 , 12 , 13 , a dust collector 16 , a scrubber 18 , a water separator 20 , an adsorption unit 21 , and a discharge unit 22 . The heat exchangers 11 , 12 , 13 include a first heat exchanger 11 connected to the combustion furnace 30 , a second heat exchanger 12 connected to the pyrolyzer 40 , and first and second heat exchangers ( 11 and 12) and a third heat exchanger (13) connected thereto. The first heat exchanger 11 cools the high-temperature combustion gas generated in the combustion furnace 30 , and the second heat exchanger 12 cools the high-temperature combustion gas that has passed through the pyrolyzer 40 . After the combustion gas generated in the combustion furnace 30 is utilized in the pyrolyzer 40 , the exhausted combustion gas is cooled in the second heat exchanger 12 . That is, the heat of the combustion gas passing through the combustion furnace 30 is not wasted and is utilized as energy in the pyrolyzer 40 .

The first and second heat exchangers 11 and 12 receive cooling water from the water supply pump 14 , and the cooling water is circulated through the first and second heat exchangers 11 and 12 . The third heat exchanger 13 cools the cooling water whose temperature is increased in the first and second heat exchangers 11 and 12 , and the third heat exchanger 13 is preferably an air cooling type. In some cases, the cooling water supplied from the water supply pump 14 may be circulated in contact with the third heat exchanger 13 to cool the third heat exchanger 13 . The first to third heat exchangers 11 , 12 , and 13 may use any known method for heat exchange, and may be variously modified within the scope of the present invention.

The combustion gas cooled by the first and second heat exchangers 11 and 12 flows into the dust collector 16 through the damper 15 . The damper 15 controls the amount of combustion gas discharged from the first and second heat exchangers 11 and 12, respectively. The dust collector 16 collects and removes fine particles floating in the combustion gas. The combustion gas that has passed through the dust collector 16 is sucked into the suction fan 17 and fed into the scrubber 18 . The scrubber 18 collects fine particles floating in the combustion gas using a liquid, and the liquid is usually water. The scrubber 18 is replenished with water from the make-up water tank 19 , and the combustion gas passing through the scrubber 18 is introduced into the water separator 20 . The water separator 20 separates the water contained in the combustion gas and flows it to the make-up water tank 19 . The adsorption unit 21 uses an adsorbent to adsorb the fine particles of the combustion gas that has passed through the water separator 20 , and discharges the combustion gas to the exhaust unit 22 such as a chimney.

The dust collector 16 , the scrubber 18 , the water separator 20 and the adsorption unit 21 can all be applied in a known manner and structure, and the dust collector 16 , the scrubber 18 , the water separator 20 and the adsorption unit 21 . Some of the parts 21 may not be employed. At least one of the dust collector 16 , the scrubber 18 , the water separator 20 , and the adsorption unit 21 may be appropriately selected in consideration of the amount of combustion gas, the type of particulate, and the like. In some cases, one dust collector 16 , one scrubber 18 , one water separator 20 , and one adsorption unit 21 are exemplified, but some of them may be installed in plurality.

The combustion furnace 30 introduces noxious gas generated inside the pyrolyzer 40 and burns it with the flame of the burner 31 . Noxious gas caused by the pyrolyzer 40 contains a non-decomposable gas, and is decomposed into a combustion gas that can be easily treated by pyrolysis with the flame. In the burner 31 , thermal energy due to the flame is emitted into the combustion furnace 30 . The burner 31 may use a clean fuel such as propane gas as a heat source. An embodiment of the present invention burns harmful gases by heating to about 950° C. or higher. Optionally, the combustion furnace 30 may include a heat storage furnace 32 . The heat storage furnace 32 stores waste heat and preheats the wind blown into the combustion furnace 30, but is not necessarily limited thereto, but a honeycomb structure is preferable. The harmful gas is generated inside the pyrolyzer 40 , and is distinguished from the combustion gas generated in the combustion furnace 30 .

The pyrolyzer 40 pyrolyzes the spent catalyst in the form of fine powder by using microwaves together with the high-temperature combustion gas introduced from the combustion furnace 30 . The microwave implements high-temperature heating up to about 2,400° C. with low energy. The fine powder of the spent catalyst is ionized by microwaves, and an ionizing agent such as NaOH may be added for the ion decomposition, or the spent catalyst and the ionizing agent may be separately mixed from the outside. Since the recovery device 100 of the present invention utilizes the high-temperature combustion gas flowing in from the combustion furnace 30 and implements high-temperature heat with low energy of microwaves, it can decompose ions more uniformly and reliably with low energy. . The pyrolyzer 40 and the ion decomposition process will be described in detail later.

FIG. 2 is a schematic view for explaining the pyrolyzer 40 of FIG. 1 , and FIG. 3 is a view of the microwave-related part of FIG. 2 viewed from the rear. In this case, the recovery device 100 will be referred to in FIG. 1 .

2 and 3, the pyrolyzer 40 includes an indirect heating portion (A) and a microwave-related portion (B). The indirect heating part (A) includes a heating furnace 41 , a gas flow path 42 , an intake port 43 , an exhaust port 44 , a stirring screw 45 , a roller 46 , a rail 47 , and a case 48 . ), including a drive gear 49 and a gear shaft 50 . In some cases, the heating furnace 41 is an indirect heating method for indirectly heating the spent catalyst, and may include a rotating screw 51 for rotating harmful gas therein. The rotating screw 51 is fixed to the inner wall of the gas flow path 42 in the form of a belt, and rotates with the rotation of the heating furnace 14 .

The heating furnace 41 sucks the high-temperature combustion gas from the combustion furnace 30 through the intake port 43 , and flows out to the second heat exchanger 12 through the gas flow path 42 and the exhaust port 44 . . That is, the heating furnace 41 uses the heat of the combustion gas in the combustion furnace 30 , and the combustion gas does not penetrate into the heating furnace 41 .

The stirring screw 45 stirs the spent catalyst in the form of fine powder, and when it rotates forward, the spent catalyst is stirred, and when it rotates in reverse, the spent catalyst is discharged. At this time, the spent catalyst is in a state of being thermally decomposed by microwaves. The stirring screw 45 is rotated by the driving gear 49 and the gear shaft 50 , and the driving gear 49 and the gear shaft 50 induce forward and reverse rotation of the stirring screw 45 , and the gear Shaft 50 is fixed to case 48 . The heating furnace 41 performs a seesaw motion by a roller 46 and a rail 47 . The seesaw motion is made by the rollers 46 moving along the rails 47 arranged in parallel while maintaining a predetermined rail spacing D. The rail spacing (D) is sufficient as long as it causes the seesaw motion in accordance with the object of the present invention. At this time, the rail 47 is connected to the gear shaft 50 .

The rollers 46 are positioned at an angle to each other, and the heating furnace 41 causes a seesaw motion in which the heating furnace 41 rotates alternately in the vertical direction. The roller 46 has a weight enough to cause a seesaw motion. If the weight of the roller 46 is too small, the seesaw motion does not occur. By the seesaw motion, the heating furnace 41 rotates in the upper direction and rotates in the lower direction alternately. The seesaw motion prevents the fine powder from being caught in gaps such as the stirring screw 45 . For example, the fine powder caught in the gap when rotating in the upward direction comes out of the gap when rotating in the downward direction. If the stirring screw 45 continues to rotate in one direction without a seesaw motion, the fine powder caught in the gap is not easily removed.

The heating furnace 41 of the present invention has an inclination angle θ inclined with respect to the ground. That is, the heating furnace 41 performs a seesaw motion while having an inclination angle θ. The inclination angle (θ) is the movement direction of the fine powder is determined in advance to facilitate stirring and discharging. If the movement direction of the fine powder is not determined, for example, if it is not inclined, a part of the fine powder may move in a direction opposite to the movement direction induced by the stirring screw 45 . If a part of the fine powder moves in the opposite direction, stirring or discharging is not performed properly.

The microwave-related part (B) provides microwaves and thermally decomposes the spent catalyst fine powder injected by the microwaves. The microwave-related part B includes a connection part 60 , an input hopper 61 , a chamber 62 , a waveguide 64 , a waveguide 65 , a plurality of magnetrons 66 and an exhaust pipe 67 . The spent catalyst fine powder is put into the input hopper 61 located at the upper part of the chamber 62 , is pyrolyzed by microwaves in the chamber 62 , and is transferred to the stirring screw 45 through the connection part 60 . When the stirring screw 45 is rotated forward, the thermally decomposed fine powder of the spent catalyst is stirred while thermal decomposition occurs again by the heating furnace 41 . When the stirring and thermal decomposition are completed, the stirring screw 45 is reversely rotated to recover the fine powder into the chamber 62 , and discharged to the outside through the discharge pipe 67 located at the lower part of the chamber 62 . The discharge pipe 67 includes a gate 68 and a gate driving motor 69 to open and close the discharge pipe 67 as necessary.

The plurality of magnetrons 66 are electrically connected to a power source 71 and are cooled by a circulation pipe 70 . Cooling water is circulated in the circulation pipe 70 to cool the magnetron 66 . Although not shown, the circulation pipe 70 may include elements for circulating cooling water and supplying power to the magnetron 66 . The magnetron 66 generates a microwave, and the waveguide 64 and the waveguide 65 transmit the microwave to the spent catalyst fine powder. The chamber 62 is provided with a transparent window 63, so that the state of the spent catalyst inside the chamber 62 can be checked.

In the manner in which the microwave is propagated, a frequency to be used is allocated according to the purpose. The frequency of microwave is 300 MHz to 3 GHz and the wavelength is 1 m to 10 cm. In particular, the frequencies used for industrial purposes are divided into four areas by area, and these are called ISM (Industrial, Scientific, Medical) frequency bands. The frequency used for heat generation is 2450ㅁ50MHz. When the spent catalyst fine powder is irradiated with microwaves, the electron bands repeat alignment and reverse alignment. The repetition generates a dipole moment or vibration in the molecule, and internal frictional heat is generated. By the internal frictional heat, the spent catalyst fine powder is thermally decomposed. Specifically, the microwave heats a carrier constituting the fine powder, such as alumina.

When the microwave is at a temperature of 900 to 950° C., the fine powder of the spent catalyst is ion decomposed by the microwave. If it is less than 900°C, the ion decomposition reaction may not sufficiently occur, and if it is greater than 950°C, it reacts with the carrier component of the spent catalyst (CaO, Al ₂ O ₃ , MgO, etc.), causing the quality to deteriorate. The ion decomposition is made by mixing with an ionizing agent such as NaOH, and specifically, it is a method of chemically bonding Na to the fine powder of the spent catalyst. When the microwave is irradiated, it generates heat by itself and decomposes into ions. In this case, the ionizing agent is preferably added in a weight ratio of about 1:100 with respect to the spent catalyst. Since the microwave generates heat by itself, ion decomposition is possible without continuous application of heat from the outside.

When the microwave is used, less energy is consumed by about 1/20 than that of the conventional method. Practically, about 1 kw of power is consumed to ionize 1 kg of spent catalyst with microwaves, but about 20 kw of power is consumed in the conventional method such as an electric furnace. In addition, if the microwave is used, ion decomposition is possible even at a low temperature, which is economical. That is, in the conventional method, ion decomposition does not occur at a temperature by the microwave of the present invention, for example, 900 to 950°C. Unlike the prior art, the present invention does not require a pressurization facility, so the structure is simple and the weight is light. In particular, since the present invention utilizes microwaves, the ion decomposition rate is approximately 10 times faster than that of the prior art.

As mentioned above, although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various modifications may be made by those skilled in the art within the scope of the technical spirit of the present invention. It is possible.

10; sub-processing unit
11, 12, 13; first to third heat exchangers
15; damper 16; Dust Collector
18; scrubber 20; water separator
21; adsorption unit 30; combustion furnace
31; burner 32; regenerative furnace
40; pyrolyzer 41; heating furnace
42; gas flow furnace 43; intake vent
44; vent 45; stirring screw
46; roller 47; rail
49; drive gear 50; gear shaft
51; rotating screw 60; connection
61; input hopper 62; chamber
64, 65; waveguide, waveguide
66; magnetron 67; discharge pipe
68; gate 69; gate drive motor
70; circulation pipe

Claims (9)

a heating furnace having an inclination angle (θ) inclined with respect to the ground and indirectly heated by a high-temperature combustion gas;
a stirring screw installed inside the heating furnace;
a roller and a pair of rails for inducing a seesaw motion of the heating furnace; and
and a chamber for thermally decomposing the spent catalyst fine powder input to the heating furnace by microwave;
The roller moves along the rail, and the pair of rails have a rail spacing (D),
The rollers are positioned at an angle to each other, and the heating furnace causes a seesaw motion in which the heating furnace rotates in the vertical direction alternately, and the seesaw motion prevents the fine powder from being caught in the gap of the stirring screw. A device for recovering valuable metals for spent catalysts. The apparatus of claim 1, wherein the combustion gas is introduced from a combustion furnace that burns harmful gas generated in the heating furnace. The apparatus of claim 1, wherein the combustion furnace includes a heat storage furnace. delete According to claim 1, wherein the inside of the heating furnace, the valuable metal recovery device for a spent catalyst for automobiles using microwaves, characterized in that it comprises a rotating screw for rotating the harmful gas generated in the heating furnace. According to claim 1, wherein the magnetron generating the microwave is characterized in that the cooling by a circulation pipe, a valuable metal recovery device for a spent catalyst for automobiles using microwaves. According to claim 1, wherein the combustion gas exhausted from the heating is cooled by a second heat exchanger, a valuable metal recovery device for a waste catalyst for automobiles using microwaves. The apparatus for recovering valuable metals of a spent catalyst for automobiles using microwaves according to claim 1, wherein the fine powder of the spent catalyst is ionically decomposed by an ionizing agent. According to claim 1, When the stirring and thermal decomposition of the fine powder in the heating furnace is completed, the stirring screw is rotated in the reverse direction to recover the fine powder to the chamber and discharged to the outside through a discharge pipe. A device for recovering valuable metals from spent catalysts for automobiles.

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