Device for extracting rare and precious metals from waste residues

Abstract

The invention relates to the technical field of alkaline residue treatment equipment, and particularly discloses a device for extracting rare and precious metals from waste residues, the device comprises a feeding mechanism, a converter and a vacuum furnace which are sequentially connected along production steps, a flue gas outlet of the converter is connected with a flue gas pipe, and a water cooling flue, a dust removal mechanism and a heat exchanger are sequentially arranged in the flue gas pipe; the tail end of the smoke pipe is connected with a desulfurizer; the lead slag of the converter is transferred to a side blowing reduction furnace of a slag refining procedure through a transfer trolley, a liquid inlet of the vacuum furnace is connected with a liquid outlet of the converter, the vacuum furnace comprises a primary vacuum furnace and a secondary vacuum furnace, and lead-tin alloy produced by the secondary vacuum furnace is returned to the primary vacuum furnace. The device aims at solving the problems that the purity of metallic tin prepared from the alkaline residues by an existing device is low, and the alkaline residues need to be pretreated before smelting.

Description

Technical Field

[0001] The invention relates to the technical field of alkali slag treatment equipment, and in particular to a device for extracting rare and precious metals from waste slag. Background Art

[0002] In the production and refining process of crude lead, alkali refining is used to remove impurity elements such as tin and antimony in the lead liquid, which will produce a large amount of alkali slag, also known as refined slag. Therefore, these alkali slags contain a certain amount of rare and precious metals such as tin. If the tin in the alkali slag can be extracted to produce metallic tin, the production and operation costs can be reduced and the economic benefits of the enterprise can be further improved. The traditional method is mainly to carry out reduction smelting through a reverberatory furnace. Under high temperature conditions (1100-1400℃), a reducing agent is added. During the smelting process, tin oxides and oxides of certain impurities (such as lead, antimony, arsenic, etc.) are reduced to crude tin under the action of the reducing agent; however, the use of this process has the problems of low tin reduction rate and difficulty in metal separation, resulting in low tin recovery rate.

[0003] In view of the above problems, the existing alkali slag extraction device has been improved, mainly by performing a wet neutralization and leaching process on the alkali slag to dissolve tin in the solution in the form of sodium stannate, and then forming a solid tin slag filter cake by filter pressing; increasing the tin content in the tin slag, and then adding auxiliary materials to mix and add it to the medium frequency furnace for heating and smelting, and after reaching the slag discharge conditions, the melt is placed in the slag bag, and after solidification and cooling, the upper scum is removed from the slag bag to obtain crude tin. However, although this method improves the recovery rate of tin, the purity of the obtained metallic tin is low, generally around 70%, contains more impurities, and the alkali slag needs to be pretreated before smelting. Summary of the invention

[0004] In view of the shortcomings of the prior art, the technical problem solved by the present invention is to provide a device for extracting rare and precious metals from waste slag, so as to solve the problem that the purity of metallic tin produced from alkaline slag by the existing device is low and the alkaline slag needs to be pretreated before smelting.

[0005] In order to solve the above problems, the technical solution adopted by the present invention is: a device for extracting rare and precious metals from waste slag, comprising a feeding mechanism, a converter, and a vacuum furnace connected in sequence along the production steps, the flue gas outlet of the converter is connected to a smoke pipe, and the smoke pipe is sequentially provided with a water-cooled flue, a dust removal mechanism, and a heat exchanger, and the end of the smoke pipe is connected to a desulfurization device; the lead slag outlet of the converter is transferred to the side-blowing reduction furnace of the refining slag process by a transfer trolley, the liquid inlet of the vacuum furnace is connected to the liquid outlet of the converter, the vacuum furnace comprises a primary vacuum furnace and a secondary vacuum furnace connected in sequence, the lead-containing crude tin produced by the primary vacuum furnace is fed into the secondary vacuum furnace, the secondary vacuum furnace produces refined tin and lead-tin alloy, and the produced lead-tin alloy is returned to the primary vacuum furnace.

[0006] The beneficial effects of this scheme are: the alkali slag is smelted in a converter to obtain a lead-tin alloy and lead slag, and the lead slag is returned to the side-blown reduction furnace in the lead refining process and used as a raw material for lead refining again, thereby improving the utilization rate of the raw materials and fully extracting the effective substances of the raw materials. The obtained lead-tin alloy is sent to a vacuum furnace for refining, and the two metals are evaporated and condensed separately under high temperature vacuum conditions by utilizing the different characteristics of tin and lead vapor pressures, thereby achieving separation; the purity of the obtained refined tin can reach 99.9%.

[0007] Furthermore, the secondary vacuum furnaces are provided with two, which are connected in sequence. The purity of the metallic tin is improved through multi-stage refining.

[0008] Furthermore, the feeding mechanism comprises a feeding conveyor belt and a preheating chamber. The preheating chamber is arranged above the feeding port of the converter. A preheating tube is wound around the side wall of the preheating chamber. The heat exchanger adopts a tubular heat exchanger. The water medium pipe of the heat exchanger is connected to the cooling water pipe of the water-cooled flue, and the cooling water pipe is connected to the preheating tube. A partition is arranged between the heat exchanger and the water-cooled flue. The partition is provided with a one-way valve that only allows flue gas to flow from the water-cooled flue to the heat exchanger. A slide plate parallel to the partition is arranged on the other side of the heat exchanger. The slide plate can slide back and forth along the length direction of the flue. The slide plate and the flue together form a first-level heat exchange chamber. The flue tubes on both sides of the sliding starting point of the slide plate are provided with a limiting mechanism, and the limiting mechanism releases the limit after the air pressure in the first-level heat exchange chamber reaches a set value. A push rod is arranged at the sliding end point of the slide plate, and the push rod can push the slide plate back to the starting point and be limited by the limiting mechanism again. The flue tube is provided with a smoke exhaust port near the sliding end point.

[0009] The dust removal mechanism is arranged in the first-level heat exchange chamber, and the dust removal mechanism includes a filter screen arranged parallel to the partition, and a dust removal brush moving up and down in the vertical direction. The dust removal brush is arranged in the horizontal direction and in contact with the heat exchange tube. A rotating rod and a guide rod are respectively provided at both ends of the dust removal brush. A volute spring is connected to the upper end of the rotating rod, and a thread is arranged on the rotating rod. The dust removal brush is threadedly connected to the rotating rod and is slidably connected to the guide rod. A pull rope is wrapped around the rotating rod, and one end of the pull rope is detachably fixed to the slide plate. The rotation direction of the rotating rod pulled by the pull rope is opposite to the rotation direction of the rotating rod driven by the volute spring.

[0010] By setting a heat exchanger, the incoming low-temperature water is heated up to medium-temperature water, and by relatively sealing the heat exchange chamber, the slide plate is released when the flue gas accumulates to a sufficient pressure in the heat exchange chamber, so that the flue gas can flow out from the exhaust port. Since the flue gas has an accumulation process in the heat exchange chamber, and the low-temperature water continuously flows into the heat exchanger, it can fully exchange heat with the low-temperature water in the heat exchange tube to reduce the flue gas temperature, which is convenient for subsequent entry into the desulfurization device for desulfurization treatment, and there is no need to set too many or too long heat exchangers to ensure that the flue gas and the heat exchanger are fully exchanged and cooled; secondly, the medium-temperature water after the first heating enters the cooling water pipe of the water-cooled flue again for a second heating to high-temperature water, and finally enters the preheating pipe to preheat the alkali slag raw material in the preheating chamber, thereby reducing the heat required for the converter to heat the alkali slag; and the medium-temperature water entering the water-cooled flue exchanges heat with the high-temperature flue gas just discharged from the converter, which plays a role in the initial cooling of the high-temperature flue gas.

[0011] The movement of the slide plate and the scroll spring drive the dust removal brush to move up and down, thereby removing the smoke and dust on the surface of the heat exchanger.

[0012] Furthermore, the filter is slidably connected to the smoke pipe and a compression spring is provided between the smoke pipe and the partition, a first wedge block is provided at the upper end of the filter, and a second wedge block matching the first wedge block is provided at the end of the dust removal brush close to the filter, and the first wedge block matching the second wedge block are both trapezoidal.

[0013] When the dust removal brush moves downward, the filter is squeezed toward the partition side through the inclined surface of the first wedge block and the second wedge block. After passing the second wedge block, the filter shakes back and forth under the elastic force of the compression spring, so that the smoke and dust attached to the filter can be shaken off into the dust box for collection.

[0014] Furthermore, the limiting mechanism is an arc-shaped convex strip, and a switch is provided in the smoke pipe at the end point of the sliding. The switch is electrically connected to the push rod. The slide plate slides to the end point of the sliding and presses the switch. After the switch is pressed, the push rod retracts once and pushes the slide plate back to its original position after a delay of 3-10S. When the air pressure in the heat exchange chamber is large enough, the slide bar is pushed over the limiting convex strip under the action of the air pressure. After passing over the convex strip, the slide plate is no longer limited and is quickly pushed to the end point of the sliding under the action of the air pressure, so that the smoke exhaust port is connected to the heat exchange chamber, so that the low-temperature smoke after heat exchange is quickly discharged from the smoke exhaust port to the desulfurization device, and the harmless smoke after desulfurization treatment by the desulfurization device is then discharged to the external environment. There is no need to set up too many control mechanisms, and the control structure is simple.

[0015] Furthermore, the limiting mechanism is an electromagnetic strip, iron sheets are installed on both sides of the slide, and an air pressure sensor and a controller are provided in the heat exchange chamber. The controller is electrically connected to the air pressure sensor and the electromagnetic strip respectively, and the controller is used to control the on and off of the electromagnetic strip according to the detection value of the air pressure sensor.

[0016] When the air pressure sensor detects that the temperature in the heat exchange chamber reaches the set upper limit, the controller controls the electromagnetic strip to cut off the power, so that the slide slides to the end of the slide under the action of air pressure, so that the smoke exhaust port is connected to the heat exchange chamber, and the smoke in the heat exchange chamber is quickly discharged from the smoke exhaust port, so that the air pressure in the heat exchange chamber is reduced. When the air pressure drops to the set lower limit, the controller controls the electromagnetic strip to energize, and controls the push rod to extend and retract once to push the slide back to its original position and be limited by the electromagnetic strip. The upper and lower limits of air pressure can be flexibly set by the controller, so as to realize flexible control of the smoke residence time, and the control is more precise. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the entire device of the present invention.

[0018] Figure 2 This is a schematic diagram of the interior of the smoke tube of Example 1.

[0019] Figure 3 This is a schematic diagram of the interior of the smoke tube of Example 2. DETAILED DESCRIPTION

[0020] The following is further described in detail through specific implementation methods:

[0021] The figure marks in the drawings of the specification include: feed conveyor belt 1, preheating chamber 11, preheating tube 12, converter 2, vacuum furnace 3, smoke pipe 4, water-cooled flue 41, heat exchanger 42, partition 43, one-way valve 431, filter 44, second wedge block 441, dust removal brush 45, rotating rod 451, guide rod 452, volute spring 453, pull rope 454, first wedge block 456, slide plate 46, limiting convex strip 461, push rod 47, switch 48, electromagnetic strip 49, sensor 491, cooling tower 5, desulfurization device 6, dust collecting box 7, chute 71.

[0022] Embodiment 1 is basically as attached Figure 1 , Attachment Figure 2 As shown: a device for extracting rare and precious metals from waste slag, comprising a feeding mechanism, a converter 2, and a vacuum furnace 3 connected in sequence along the production steps, the smoke outlet of the converter 2 is connected with a smoke pipe 4, and the smoke pipe 4 is sequentially provided with a water-cooled flue 41, a dust removal mechanism, and a heat exchanger 42, and the end of the smoke pipe 4 is connected with a desulfurization device 6; the lead slag outlet of the converter 2 is transported to the side-blowing reduction furnace of the refining slag process by a transfer trolley, the liquid inlet of the vacuum furnace 3 is connected to the liquid outlet of the converter 2, the vacuum furnace 3 comprises a primary vacuum furnace 3 and a secondary vacuum furnace 3, the lead-tin alloy produced by the secondary vacuum furnace 3 is returned to the primary vacuum furnace 3, and two secondary vacuum furnaces 3 are provided in this embodiment, and the two secondary vacuum furnaces 3 are sequentially connected.

[0023] The alkali slag is smelted by the converter 2 to obtain the lead-tin alloy and lead slag, and the lead slag is returned to the side-blown reduction furnace in the lead refining process and used as the raw material for lead refining again, thereby improving the utilization rate of the raw materials and fully extracting the effective substances of the raw materials. The obtained lead-tin alloy is sent to the vacuum furnace 3 for refining, and the two metals are evaporated and condensed respectively under high temperature vacuum conditions by utilizing the different characteristics of the vapor pressure of tin and lead, thereby achieving separation; by setting up a multi-stage vacuum furnace for multiple evaporation and condensation, the purity of refined tin is improved, and the purity of the obtained refined tin can reach 99.9%. The lead-tin alloy separated by the secondary vacuum furnace is returned to the primary vacuum furnace and continued to be used as the raw material for refined tin purification, thereby increasing the output of refined tin and reducing the waste of raw materials.

[0024] The feeding mechanism includes a feeding conveyor belt 1 and a preheating chamber 11. The preheating chamber 11 is arranged above the feeding port of the converter 2. A preheating pipe 12 is wound around the side wall of the preheating chamber 11. The heat exchanger 42 adopts a tubular heat exchanger 42. The water medium pipeline of the heat exchanger 42 is connected to the cooling water pipe of the water-cooled flue 41. The cooling water pipe is connected to the preheating pipe 12. The water outlet of the preheating pipe 12 is connected to the cooling tower 5, or connected to other heat-using units. When connected to the heat-using units, it can be used as production hot water or domestic hot water; a partition 43 is provided between the heat exchanger 42 and the water-cooled flue 41, and the partition 43 has only A one-way valve 431 is provided for flue gas to flow from the water-cooled flue 41 to the heat exchanger 42. A slide plate 46 parallel to the partition plate 43 is provided on the other side of the heat exchanger 42. The slide plate 46 can slide back and forth along the length direction of the smoke pipe 4. The slide plate 46 and the smoke pipe 4 together form a primary heat exchange chamber. The smoke pipe 4 on both sides of the sliding starting point of the slide plate 46 are provided with a limiting mechanism, which releases the limit after the air pressure in the primary heat exchange chamber reaches a set value. A push rod 47 is provided at the sliding end point of the slide plate 46, and the push rod 47 can push the slide plate 46 back to the starting point and be limited by the limiting mechanism again. A smoke exhaust port is provided near the sliding end point of the smoke pipe 4.

[0025] The heat exchanger 42 is provided to heat the incoming low-temperature water to medium-temperature water, and the heat exchange chamber is relatively sealed. When the flue gas accumulates to a sufficient pressure in the heat exchange chamber, the limit of the slide plate 46 is released, so that the flue gas can flow out from the exhaust port. Since the flue gas has an accumulation process in the heat exchange chamber, and the low-temperature water continuously flows into the heat exchanger 42, it can fully exchange heat with the low-temperature water in the heat exchange tube, thereby reducing the flue gas temperature, which is convenient for the subsequent entry into the desulfurization device 6 for desulfurization treatment, and there is no It is necessary to set up too many or too long heat exchangers 42 to ensure that the flue gas and the heat exchanger 42 are fully exchanged for heat and cooled; secondly, the medium-temperature water after the first heating enters the cooling water pipe of the water-cooled flue 41 again for a second heating to become high-temperature water, and finally enters the preheating pipe 12 to preheat the alkali slag raw material in the preheating chamber 11, thereby reducing the heat required for the converter 2 to heat the alkali slag; and the medium-temperature water entering the water-cooled flue 41 exchanges heat with the high-temperature flue gas just discharged from the converter 2, which plays a role in the initial cooling of the high-temperature flue gas.

[0026] The limiting mechanism is an arc-shaped convex strip. A switch 48 is provided in the smoke pipe 4 at the end of the slide. The switch 48 is electrically connected to the push rod 47. The slide plate 46 slides to the end of the slide and presses the switch 48. After the switch 48 is pressed, the push rod 47 retracts and contracts once to push the slide plate 46 back to its original position after a delay of 3-10S. When the air pressure in the heat exchange chamber is large enough, the slide bar is pushed over the limiting convex strip 461 under the action of the air pressure. After passing over the convex strip, the slide plate 46 is no longer limited and is quickly pushed to the end of the slide under the action of the air pressure, so that the smoke exhaust port is connected to the heat exchange chamber, so that the low-temperature flue gas after heat exchange is quickly discharged from the smoke exhaust port to the desulfurization device 6, and the harmless flue gas after desulfurization treatment by the desulfurization device 6 is then discharged to the external environment.

[0027] The dust removal mechanism is arranged in the primary heat exchange chamber. The dust removal mechanism includes a filter screen 44 arranged parallel to the partition 43, and a dust removal brush 45 moving up and down in the vertical direction. The dust removal brush 45 is arranged in the horizontal direction and in contact with the heat exchange tube. Two dust removal brushes 45 are symmetrically arranged along the length center axis of the heat exchanger 42; a rotating rod 451 and a guide rod 452 are respectively arranged at both ends of the dust removal brush 45, and the rotating rod 451 and the guide rod 452 are arranged in the vertical direction. A volute spring 453 is connected to the upper end of the rotating rod 451, and a thread is arranged on the rotating rod 451. The dust removal brush 45 is threadedly connected to the rotating rod 451 and is slidably connected to the guide rod 452; a pull rope 454 is wound around the rotating rod 451, and one end of the pull rope 454 is detachably fixed to the slide plate 46 by bolts; the rotation direction of the rotating rod 451 pulled by the pull rope 454 is opposite to the rotation direction of the rotating rod 451 driven by the volute spring 453. A dust collecting box 7 for collecting smoke is provided at the lower end of the filter 44; the heat exchange tube is fixed to the smoke pipe 4 by bolts, and the smoke pipe 4 at the lower end of the heat exchange tube is provided with an inclined groove 71, and the end of the inclined groove 71 is connected to the integrated box, so that the smoke falling from the heat exchange tube falls into the inclined groove 71, and after passing through the inclined groove 71, it enters the dust collecting box 7 and is collected.

[0028] When the slide plate 46 moves to the end of the slide, the pull rope 454 is pulled. Since the pull rope 454 is wound on the rotating rod 451, the rotating rod 451 is driven to rotate clockwise after the pull rope 454 is pulled. Since the dust removal brush 45 is threadedly connected to the rotating rod 451 and is limited by the guide rod 452, the dust removal brush 45 moves downward to brush away the smoke and dust on the surface of the heat exchanger 42. When the slide plate 46 moves to the end of the slide, the switch 48 is pressed. After a delay of 8S, the push rod 47 is extended and retracted once, and the slide plate 46 is pushed to cross the limit bar, and then the push rod 47 returns to its position. When the slide plate 46 returns to its position, since the pull rope 454 no longer limits the rotating rod 451, the rotating rod 451 is driven by the spiral spring 453 to rotate counterclockwise, and the pull rope 454 is retracted on the rotating rod 451 again; at the same time, the rotating rod 451 rotates to drive the dust removal brush 45 to move upward and return to its position.

[0029] Most of the smoke is filtered through the filter screen 44, and a small part of the small particles of smoke enter the heat exchange chamber. The dust attached to the surface of the heat exchange tube is brushed off by the dust removal brush 45 to ensure the heat exchange efficiency.

[0030] The filter 44 is slidably connected to the smoke pipe 4 and a compression spring is provided between the smoke pipe 4 and the partition 43. A first wedge block 456 is provided at the upper end of the filter 44, and a second wedge block 441 cooperating with the first wedge block 456 is provided at one end of the dust removal brush 45 close to the filter 44. The first wedge block 456 and the second wedge block 441 cooperating with each other are both trapezoidal.

[0031] When the dust removal brush 45 moves downward, the filter 44 is squeezed toward the partition 43 side through the inclined surface of the first wedge block 456 and the second wedge block 441. After passing over the second wedge block 441, the filter 44 shakes back and forth under the action of the elastic force of the compression spring, so that the smoke and dust attached to the filter 44 can be shaken off into the dust box 7 for collection.

[0032] Example 2 Figure 3 As shown, the same as Example 1 is not repeated here, and the difference is that the limiting mechanism is an electromagnetic strip 49, iron sheets are installed on both sides of the slide plate 46, and an air pressure sensor 491 and a controller are provided in the heat exchange chamber. The controller is electrically connected to the air pressure sensor 491, the electromagnetic strip 49, and the push rod 47 respectively, and the controller is used to control the on and off of the electromagnetic strip 49 according to the detection value of the air pressure sensor 491. When the air pressure sensor 491 detects that the temperature in the heat exchange chamber reaches the set upper limit value, the controller controls the electromagnetic strip 49 to cut off the power, so that the slide plate 46 slides to the sliding end under the action of air pressure, so that the smoke exhaust port is connected with the heat exchange chamber, and the smoke in the heat exchange chamber is quickly discharged from the smoke exhaust port, so that the air pressure in the heat exchange chamber is reduced. When the air pressure is reduced to the set lower limit value, the controller controls the electromagnetic strip 49 to be energized, and controls the push rod 47 to extend and retract once to push the slide plate 46 back to its original position and be limited by the electromagnetic strip 49.

[0033] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A device for extracting rare and precious metals from waste residues, characterized in that: It includes a feeding mechanism, a converter and a vacuum furnace which are connected in sequence along the production steps. The smoke outlet of the converter is connected with a smoke pipe, and the smoke pipe is sequentially provided with a water-cooled flue, a dust removal mechanism and a heat exchanger. The end of the smoke pipe is connected with a desulfurization device. The lead slag of the converter is transported to the side-blowing reduction furnace of the slag refining process by a transfer trolley. The liquid inlet of the vacuum furnace is connected with the liquid outlet of the converter. The vacuum furnace includes a primary vacuum furnace and a secondary vacuum furnace which are connected in sequence. The lead-containing crude tin produced by the primary vacuum furnace is fed into the secondary vacuum furnace. The secondary vacuum furnace produces refined tin and lead-tin alloy. The lead-tin alloy produced by the secondary vacuum furnace is returned to the primary vacuum furnace.

2. The device for extracting rare and precious metals from waste slag according to claim 1, characterized in that: The secondary vacuum furnaces are provided with two, and the two secondary vacuum furnaces are connected in sequence.

3. The device for extracting rare and precious metals from waste slag according to claim 1, characterized in that: The feeding mechanism comprises a feeding conveyor belt and a preheating chamber. The preheating chamber is arranged above the feeding port of the converter. A preheating tube is wound around the side wall of the preheating chamber. The heat exchanger adopts a tubular heat exchanger. The water medium pipe of the heat exchanger is connected to the cooling water pipe of the water-cooled flue, and the cooling water pipe is connected to the preheating tube. A partition is arranged between the heat exchanger and the water-cooled flue. The partition is provided with a one-way valve that only allows flue gas to flow from the water-cooled flue to the heat exchanger. A slide plate parallel to the partition is arranged on the other side of the heat exchanger. The slide plate can slide back and forth along the length direction of the flue pipe. The slide plate and the flue pipe together form a primary heat exchange chamber. The flue pipes on both sides of the sliding starting point of the slide plate are provided with limiting mechanisms. The limiting mechanisms release the limit after the air pressure in the primary heat exchange chamber reaches a set value. A push rod is arranged at the sliding end point of the slide plate. The push rod can push the slide plate back to the starting point and be limited by the limiting mechanism again. A smoke exhaust port is arranged near the sliding end point of the smoke pipe. The dust removal mechanism is arranged in the first-level heat exchange chamber, and the dust removal mechanism includes a filter screen arranged parallel to the partition, and a dust removal brush moving up and down in the vertical direction. The dust removal brush is arranged in the horizontal direction and in contact with the heat exchange tube. A rotating rod and a guide rod are respectively provided at both ends of the dust removal brush. A volute spring is connected to the upper end of the rotating rod, and a thread is arranged on the rotating rod. The dust removal brush is threadedly connected to the rotating rod and is slidably connected to the guide rod. A pull rope is wrapped around the rotating rod, and one end of the pull rope is detachably fixed to the slide plate. The rotation direction of the rotating rod pulled by the pull rope is opposite to the rotation direction of the rotating rod driven by the volute spring.

4. The device for extracting rare and precious metals from waste residue according to claim 3, characterized in that: The filter is slidably connected to the smoke pipe and a compression spring is provided between the smoke pipe and the partition. A first wedge block is provided at the upper end of the filter, and a second wedge block matching the first wedge block is provided at one end of the dust removal brush close to the filter. The first wedge block and the second wedge block matching are both trapezoidal.

5. The device for extracting rare and precious metals from waste residue according to claim 3, characterized in that: The limiting mechanism is an arc-shaped convex strip. A switch is arranged in the smoke tube at the end point of the sliding. The switch is electrically connected to the push rod. The slide plate slides to the end point of the sliding to press the switch. After a delay of 3-10S after the switch is pressed, the push rod retracts once to push the slide plate back to its position.

6. The device for extracting rare and precious metals from waste residue according to claim 3, characterized in that: The limiting mechanism is an electromagnetic strip, iron sheets are installed on both sides of the slide, and an air pressure sensor and a controller are arranged in the heat exchange chamber. The controller is electrically connected to the air pressure sensor and the electromagnetic strip respectively, and the controller is used to control the on and off of the electromagnetic strip according to the detection value of the air pressure sensor.

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