CN113046561A - Grading extraction device and method for gold, silver and palladium precious metals in waste circuit boards - Google Patents

Abstract

The invention discloses a gold, silver and palladium precious metal grading extraction device and an extraction method in a waste circuit board, wherein the gold, silver and palladium precious metal grading extraction device in the waste circuit board can more fully stir and improve the purity during extraction by controlling the lifting of a stirring rod, and the gold, silver and palladium precious metal grading extraction method in the waste circuit board extracts gold: adding dibutylcarbinol into the leachate for reaction, extracting gold ions, separating residual liquid after completion, washing for 2 times by using 5% dilute hydrochloric acid, back-extracting by using oxalic acid 40g/L, reducing the gold ions into gold simple substances, heating and reducing, and leaching by using thiocyanate, so that during the leaching step, the toxicity is reduced, the safety is higher, the reaction time is short, the efficiency is higher, gold is extracted by using dibutylcarbinol in the extraction step, the back extraction is convenient, the reaction is easy, and the raw materials can be recycled.

Description

Grading extraction device and method for gold, silver and palladium precious metals in waste circuit boards

Technical Field

The invention relates to a precious metal extraction method, in particular to a device and a method for extracting gold, silver and palladium precious metals from waste circuit boards in a grading manner.

Background

The waste circuit board contains a plurality of harmful substances and a large amount of valuable substances. The waste circuit board usually contains 30% of plastic, 30% of inert oxide and 40% of metal (by weight), wherein the content of base metal (copper, lead, zinc and the like) accounts for about 30%, and the content of precious metal (gold, silver, platinum, palladium and the like) accounts for about 0.3% -0.4%. Therefore, the recovery of metals, especially noble metals, is a main driving force for recycling waste circuit boards. If not recovered, the metals in the waste circuit boards may cause soil and groundwater pollution. Therefore, the metal in the waste circuit board should be recovered from the viewpoint of environmental protection and resource utilization.

Because the concentration of noble metal is extremely low and the method is not suitable for electrolysis, the leaching and extraction mode is usually adopted for extraction, the traditional leaching method adopts cyanide for leaching, but the cyanide has the defect of high toxicity, and the cyanide leaching needs dozens of hours, so that the method is not safe enough and has extremely low efficiency.

In the traditional extraction method, methyl isobutyl ketone is used as an extracting agent, the selectivity is the best of all extracting agents, gold can be completely extracted under low acidity, but the back extraction after the gold extraction of the methyl isobutyl ketone is difficult, and the reduction back extraction and the distillation are needed to regenerate the gold. Because methyl isobutyl ketone has low flash point (16 ℃) and is inflammable, the solubility in water phase is high (2%), the application of the methyl isobutyl ketone in industrial production is greatly influenced, and other extracting agents have higher requirements on the pH value and have poor effect.

And current extraction device is when the extraction, and the height of puddler is fixed, and the scope that leads to the stirring is fixed, and some places stir and can not reach, cause the stirring not enough even, influence the purity of extraction.

Disclosure of Invention

The invention aims to provide a device and a method for extracting noble metals such as gold, silver and palladium from waste circuit boards in a grading manner, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a gold silver palladium noble metal hierarchical extraction element in old and useless circuit board, includes base 1, rotatory section of thick bamboo 6 and puddler 7, the last fixed surface of base 1 is connected with extraction box 2, the inside of extraction box 2 is equipped with division board 3 and extraction box 2's top surface fixedly connected with reciprocating motor 4, the lateral wall fixedly connected with of extraction box 2 gives vent to anger part 5, reciprocating motor 4's output and the inner wall joint of 6 fixed connection of a rotatory section of thick bamboo and puddler 7 and rotatory section of thick bamboo 6, puddler 7 and the interior roof of a rotatory section of thick bamboo 6 are through 8 fixed connection of first elastic component, the inside of extraction box 2 is equipped with air pressure device and the intercommunication of a rotatory section of thick bamboo 6, the outer wall fixedly connected with action wheel 9 of a rotatory section of thick bamboo 6, air pressure device is equipped with switching device and is.

As a further scheme of the invention: the lateral wall of a rotating cylinder 6 is provided with a limiting sliding groove, the top end of the stirring rod 7 is fixedly connected with a sliding block, the sliding block is clamped with the limiting sliding groove, and the first elastic piece 8 is fixedly connected with the sliding block.

As a still further scheme of the invention: the air pressure device comprises a fan 18 and an air outlet pipe 19, the fan 18 is fixedly connected with the extraction box 2, the air outlet of the fan 18 is communicated with the air outlet pipe 19, a switch device is arranged inside the air outlet pipe 19, and one end, far away from the fan 18, of the air outlet pipe 19 is communicated with the rotary cylinder 6 through a hose 20.

As a still further scheme of the invention: switching device includes lifter plate 15, deep bead 16, second from driving wheel 13 and cam 14, lifter plate 15 and play tuber pipe 19 pass through the upper surface fixed connection of second elastic component 17 fixed connection and deep bead 16 and lifter plate 15, deep bead 16 run through out tuber pipe 19 and with the inner wall joint of play tuber pipe 19, be located the solid fixed ring 11 of the last fixed surface of division board 3 on upper strata, the second cup joints mutually with cam 14 through connecting rod fixed connection and this connecting rod and the inner wall of solid fixed ring 11 from driving wheel 13, cam 14 and lifter plate 15's lower surface overlap joint, the second meshes with action wheel 9 from driving wheel 13.

As a still further scheme of the invention: the fixed ring 11 is provided with two sides which are respectively positioned on the rotary drum 6, a fan 12 and a first driven wheel 10 are arranged in the extraction box 2, and the fan 12 and the first driven wheel 10 are fixedly connected through a connecting rod and are meshed with the driving wheel 9 from the first driven wheel 10.

The method for extracting the gold, silver and palladium noble metals from the waste circuit board in a grading manner comprises the following steps:

s1: putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching by using 0.3mol/L thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to be 1-2, and reacting at normal temperature for 2-3 h;

s2: gold extraction: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing the gold simple substances;

s4: and (3) extracting palladium: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water;

s5: extracting silver: reducing by using reduced iron powder to obtain pure silver;

s6: and refining the prepared noble metal, and recycling the regenerated liquid after acid balance.

As a still further scheme of the invention: the thiocyanate is one or more of calcium thiocyanate, sodium thiocyanate, ammonium thiocyanate and potassium thiocyanate.

Compared with the prior art, the invention has the beneficial effects that:

this gold silver palladium noble metal hierarchical extraction element in old and useless circuit board, lift through the control puddler, make the stirring more abundant, purity when improving the extraction, this gold silver palladium noble metal hierarchical extraction method in old and useless circuit board leaches through using thiocyanate, when making the step of leaching, the toxicity reduces, and is safer, and reaction time is short, and efficiency is higher, use dibutylbarbinol extraction gold in the extraction step, the reextraction of being convenient for, easy reaction makes the raw materials can cyclic utilization.

Drawings

Fig. 1 is a schematic structural diagram of a gold, silver and palladium precious metal grading extraction device in a waste circuit board.

Fig. 2 is a schematic diagram of a gold, silver and palladium precious metal grading extraction device in a waste circuit board when a stirring rod descends.

Fig. 3 is an enlarged schematic view of a.

Fig. 4 is a process flow chart of a gold-silver-palladium precious metal grading extraction method in a waste circuit board.

In the figure: 1. a base; 2. an extraction box; 3. a partition plate; 4. a reciprocating motor; 5. an air outlet member; 6. a rotary drum; 7. a stirring rod; 8. a first elastic member; 9. a driving wheel; 10. a first driven wheel; 11. a fixing ring; 12. a fan; 13. a second driven wheel; 14. a cam; 15. a lifting plate; 16. a wind deflector; 17. a second elastic member; 18. a fan; 19. an air outlet pipe; 20. a hose.

Detailed Description

The technical solution of the present invention will be described in further detail with reference to specific embodiments.

Referring to fig. 1-3, a device for extracting precious metals of gold, silver and palladium from waste circuit boards by classification comprises a base 1, a rotary cylinder 6 and a stirring rod 7, the upper surface of the base 1 is fixedly connected with an extraction box 2, a partition plate 3 is arranged in the extraction box 2, the top surface of the extraction box 2 is fixedly connected with a reciprocating motor 4, the side wall of the extraction box 2 is fixedly connected with an air outlet part 5, the output end of the reciprocating motor 4 is fixedly connected with the rotary cylinder 6, the stirring rod 7 is clamped with the inner wall of the rotary cylinder 6, the stirring rod 7 is fixedly connected with the inner top wall of the rotary cylinder 6 through a first elastic piece 8, an air pressure device is arranged inside the extraction box 2 and is communicated with the rotary cylinder 6, the outer wall of the rotary drum 6 is fixedly connected with a driving wheel 9, and the air pressure device is provided with a switch device which is in transmission connection with the driving wheel 9.

In order to make puddler 7 can be along with rotatory in a rotatory, also can go up and down, in this embodiment, spacing spout has been seted up to the lateral wall of a rotatory section of thick bamboo 6, the top fixedly connected with slider of puddler 7 and this slider and spacing spout joint, first elastic component 8 and this slider fixed connection, this kind of joint belongs to common prior art, does not have to describe repeatedly.

Further, the air pressure device includes a fan 18 and an air outlet pipe 19, the fan 18 is fixedly connected with the extraction box 2, the air outlet of the fan 18 is communicated with the air outlet pipe 19, a switch device is arranged inside the air outlet pipe 19, and one end of the air outlet pipe 19, which is far away from the fan 18, is communicated with the rotary cylinder 6 through a hose 20.

Further, switching device includes that lifter plate 15, deep bead 16, second follow driving wheel 13 and cam 14, lifter plate 15 and play tuber pipe 19 pass through the upper surface fixed connection of second elastic component 17 fixed connection and deep bead 16 and lifter plate 15, deep bead 16 run through out tuber pipe 19 and with the inner wall joint of play tuber pipe 19, be located the solid fixed ring 11 of the last fixed surface of division board 3 on upper strata, the second cup joints with solid fixed ring 11's inner wall through connecting rod fixed connection and this connecting rod from driving wheel 13 and cam 14 mutually, cam 14 and lifter plate 15's lower surface overlap joint, the second meshes with action wheel 9 from driving wheel 13.

Further, fixed ring 11 is equipped with two and is located the both sides of a rotary drum 6 respectively, be equipped with fan 12 and the first driven wheel 10 in the extraction box 2, fan 12 and the first driven wheel 10 pass through connecting rod fixed connection and the first driven wheel 10 meshes with action wheel 9 mutually from.

The working principle of the invention is as follows: when reciprocating motor 4 drives rotatory section of thick bamboo 6 and rotates, rotatory section of thick bamboo 6 can drive puddler 7 and rotate, in the time of rotatory section of thick bamboo 6 pivoted, can drive cam 14 rotatory through action wheel 9, when cam 14's convex part rotated the top, can promote lifter plate 15 and rise, thereby release deep bead 16, deep bead 16 lives the wind shield that the fan 18 blew off, do not have atmospheric pressure in the rotatory section of thick bamboo 6, puddler 7 can be risen by the resilience force pulling of first elastic component 8, when cam 14's convex part rotated the below, deep bead 16 descends, fan 18 blows out, make the interior atmospheric pressure that produces of rotatory section of thick bamboo 6, push down puddler 7, thereby realize the lift of puddler 7, action wheel 9 also can drive fan 12 and rotate, accelerate the speed of gaseous ejection of compact.

The device is used for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading way, and the extracting method is compared with the traditional extracting method and recorded as follows:

example 1

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching with 0.3mol/L calcium thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to 1-2, and reacting at normal temperature for 2-3 h; then, gold was extracted: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

Example 2

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching with 0.3mol/L sodium thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to 1-2, and reacting at normal temperature for 2-3 h; then, gold was extracted: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

Example 3

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: 0.3mol/L ammonium thiocyanate and 15g/L manganese dioxide are used for leaching, sulfuric acid is added to adjust the pH value, the pH value is controlled to be 1-2, and the reaction is carried out for 2-3h at normal temperature; then, gold was extracted: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

Example 4

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching by using 0.3mol/L potassium thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to be 1-2, and reacting at normal temperature for 2-3 h; then, gold was extracted: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

Comparative example 1

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching by using 0.4mol/L potassium thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to be 1-2, and reacting at normal temperature for 2-3 h; then, gold was extracted: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

Comparative example 2

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching with 0.2mol/L potassium thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to 1-2, and reacting at normal temperature for 2-3 h; then, gold was extracted: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

Comparative example 3

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching by using 0.3mol/L potassium thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to be 1-2, and reacting at normal temperature for 2-3 h; then, gold was extracted: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into a gold simple substance, and heating and reducing; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

Comparative example 4

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching by using 0.3mol/L potassium thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to be 1-2, and reacting at normal temperature for 2-3 h; then, gold was extracted: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, and performing back extraction by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

Comparative example 1

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching with 0.3mol/L potassium cyanide and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to 1-2, and reacting at normal temperature for 2-3 h; then, gold was extracted: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

Comparative example 2

The method for extracting the gold, silver and palladium noble metals in the waste circuit board in a grading manner comprises the following steps: firstly, putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching by using 0.3mol/L potassium thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to be 1-2, and reacting at normal temperature for 2-3 h; then, gold was extracted: adding methyl isobutyl ketone into the leachate, reacting to extract gold ions, separating the residual liquid after the reaction is finished, washing the residual liquid for 2 times by using 5% dilute hydrochloric acid, performing back extraction by using 40g/L oxalic acid to reduce the gold ions into a gold simple substance, and heating and reducing the gold simple substance; next, palladium extraction: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water; next, silver is extracted: reducing by using reduced iron powder to obtain pure silver; and finally, refining the prepared precious metal, and recycling the regenerated liquid after acid balance.

While the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.

Claims (7)

1. A gold, silver and palladium precious metal grading extraction device in a waste circuit board, which comprises a base 1, a rotary cylinder 6 and a stirring rod 7, the upper surface of the base 1 is fixedly connected with an extraction box 2, a partition plate 3 is arranged in the extraction box 2, the top surface of the extraction box 2 is fixedly connected with a reciprocating motor 4, the side wall of the extraction box 2 is fixedly connected with an air outlet part 5, it is characterized in that the output end of the reciprocating motor 4 is fixedly connected with the rotary cylinder 6, the stirring rod 7 is clamped with the inner wall of the rotary cylinder 6, the stirring rod 7 is fixedly connected with the inner top wall of the rotary cylinder 6 through a first elastic piece 8, an air pressure device is arranged inside the extraction box 2 and is communicated with the rotary cylinder 6, the outer wall of the rotary drum 6 is fixedly connected with a driving wheel 9, and the air pressure device is provided with a switch device which is in transmission connection with the driving wheel 9.

2. The device for extracting noble metals such as gold, silver and palladium from waste circuit boards according to claim 1, wherein a limiting sliding groove is formed in a side wall of the rotating cylinder 6, a sliding block is fixedly connected to a top end of the stirring rod 7 and is clamped with the limiting sliding groove, and the first elastic member 8 is fixedly connected with the sliding block.

3. The device for extracting noble metals such as gold, silver and palladium in waste circuit boards according to claim 2, wherein the air pressure device comprises a fan 18 and an air outlet pipe 19, the fan 18 is fixedly connected with the extraction box 2, an air outlet of the fan 18 is communicated with the air outlet pipe 19, a switch device is arranged inside the air outlet pipe 19, and one end of the air outlet pipe 19, which is far away from the fan 18, is communicated with the rotary drum 6 through a hose 20.

4. The device for extracting noble metals, silver, palladium and gold from waste circuit boards according to claim 3, wherein the switch device comprises a lifting plate 15, a wind shield 16, a second driven wheel 13 and a cam 14, the lifting plate 15 and the wind outlet pipe 19 are fixedly connected through a second elastic member 17, the wind shield 16 is fixedly connected with the upper surface of the lifting plate 15, the wind shield 16 penetrates through the wind outlet pipe 19 and is clamped with the inner wall of the wind outlet pipe 19, a fixing ring 11 is fixedly connected with the upper surface of the upper layer of the partition plate 3, the second driven wheel 13 and the cam 14 are fixedly connected through a connecting rod, the connecting rod is sleeved with the inner wall of the fixing ring 11, the cam 14 is overlapped with the lower surface of the lifting plate 15, and the second driven wheel 13 is engaged with the driving wheel 9.

5. The device for extracting noble metals, such as gold, silver, palladium and precious metals, from waste circuit boards according to claim 4 is characterized in that two fixing rings 11 are provided and located on two sides of the rotary drum 6, a fan 12 and a first driven wheel 10 are provided in the extraction box 2, the fan 12 and the first driven wheel 10 are fixedly connected through a connecting rod, and the first driven wheel 10 is engaged with the driving wheel 9.

6. The classified extraction method for extracting the noble metals such as silver, palladium and gold from the waste circuit boards by using the extraction device of claim 1 is characterized by comprising the following steps:

s1: putting a precious metal material containing gold, silver and palladium into a reaction vat, and carrying out dissolution leaching: leaching by using 0.3mol/L thiocyanate and 15g/L manganese dioxide, adding sulfuric acid to adjust the pH value to be 1-2, and reacting at normal temperature for 2-3 h;

s2: gold extraction: adding dibutylcarbinol into the leaching solution, reacting to extract gold ions, separating residual liquid after completion, washing for 2 times by using 5% diluted hydrochloric acid, carrying out back extraction by using 40g/L oxalic acid to reduce the gold ions into gold simple substances, and heating and reducing the gold simple substances;

s4: and (3) extracting palladium: adding di-n-octyl thioether into the leachate, reacting, separating residual liquid after the reaction is finished, washing for 2 times by using 5% dilute hydrochloric acid, and back-extracting by using 3mol/L ammonia water;

s5: extracting silver: reducing by using reduced iron powder to obtain pure silver;

s6: and refining the prepared noble metal, and recycling the regenerated liquid after acid balance.

7. The method for extracting noble metals such as gold, silver and palladium from waste circuit boards according to claim 6, wherein the thiocyanate is one or more of calcium thiocyanate, sodium thiocyanate, ammonium thiocyanate and potassium thiocyanate.

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