Electronic waste efficient chlorination comprehensive recovery device and method

Abstract

The invention discloses an electronic waste efficient chlorination comprehensive recovery device and method, and relates to the technical field of chemical metallurgy, the electronic waste efficient chlorination comprehensive recovery device comprises a chlorination reaction cavity, a heating system, a vacuum system, an atmosphere control system and a condensation separation system; the heating system is used for controlling the temperature of the chlorination reaction cavity; the vacuum system is communicated with the heating system; the atmosphere control system comprises a chlorine gas source and a protective gas source; and the temperature of the condensation separation system is gradually reduced. Through the high-purity graphite heating assembly, the sealing structure and the atmosphere control system, the highest heating temperature is 1700 DEG C, the temperature limit of 1200 DEG C of a traditional quartz tube furnace can be broken through, the chlorine corrosion problem is solved, chlorine is not leaked, and the environment is not polluted. High-valued recovery of different metal resources can be achieved through low-temperature pyrolysis, high-temperature chlorination volatilization and three-stage condensation settling separation, and the method has the advantages of being low in energy consumption, high in recovery rate, environmentally friendly and the like and is suitable for industrial metal resource recovery.

Description

Technical Field

[0001] This invention relates to the field of chemical and metallurgical technology, and in particular to a highly efficient chlorination and comprehensive recycling device and method for electronic waste. Background Technology

[0002] With the rapid advancement of technology and the significant improvement in people's living standards, the use of electronic and electrical products has exploded, making electronic waste the fastest-growing type of hazardous solid waste globally. Electronic waste is like an "urban mine," rich in renewable metal resources such as gold, silver, and copper, with its precious metal content dozens or even hundreds of times higher than that of natural mineral deposits. However, it also harbors hidden dangers; many toxic and harmful components, if not recycled, will pose a significant threat to the Earth's ecological environment and human health. Therefore, how to achieve the clean, efficient, and safe separation and recycling of metal resources from electronic waste has become an urgent industry challenge. Data shows that one ton of ore can only yield a few grams to tens of grams of gold, while one ton of electronic waste can yield approximately 900 grams of gold, 1500-3000 grams of silver, 60 grams of palladium, 130 kilograms of copper, and some tin, nickel, and other metals. Its potential value and commercial opportunities are self-evident, and its recycling prospects are extremely broad.

[0003] Currently, the mainstream technological approach for treating electronic waste involves first using mechanical processing or anaerobic pyrolysis to physically separate metals from non-metals, obtaining copper-rich mixed metal powder. Then, hydrometallurgical, pyrometallurgical, or electrochemical methods are used to selectively extract the target metal elements. However, this system has significant drawbacks: because the mixed metal powder is highly complex, often containing more than ten metal elements, obtaining high-purity metal products requires extensive purification using various metallurgical and refining techniques. This not only lengthens the process and significantly increases maintenance costs but also imposes a heavy environmental burden. Especially given the increasingly stringent environmental standards, this process can lead to toxic substance leaks and the discharge of waste gas, wastewater, and solid waste, easily causing secondary air and soil pollution and seriously violating the principles of green development.

[0004] Faced with the bottlenecks of traditional processing technologies and the upgrading of environmental protection requirements, developing a more environmentally friendly and efficient electronic waste metal recycling device is not only the key to breaking through the industry's technical dilemma, but also an inevitable choice to promote the sustainable development of the circular economy. Summary of the Invention

[0005] To address the above technical problems, this invention provides a highly efficient chlorination-based comprehensive recycling device and method for electronic waste, thereby achieving efficient recycling of metal resources and reducing pollutant emissions.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a high-efficiency chlorination volatilization comprehensive recovery device for electronic waste, comprising:

[0008] Chlorination reaction chamber;

[0009] A heating system, comprising a heating chamber disposed within a reaction furnace, for controlling the temperature of the chlorination reaction chamber;

[0010] A vacuum system, which is connected to both the heating chamber and the chlorination reaction chamber;

[0011] An atmosphere control system includes a chlorine gas source and a protective gas source. The chlorine gas source is connected to the chlorination reaction chamber (8), and the protective gas source is connected to both the heating chamber and the chlorination reaction chamber.

[0012] A condensation separation system is provided, with one end connected to the chlorination reaction chamber and the other end connected to the tail gas treatment device. The temperature of the condensation separation system decreases gradually from one end to the other.

[0013] Optionally, the chlorination reaction chamber includes a tee, an outer sleeve, an inner sleeve, and a sleeve;

[0014] The first port of the tee is connected to the feeding structure, the second port of the tee is connected to one end of the outer sleeve, and the third port of the tee is connected to one end of the condensation separation system.

[0015] The inner sleeve is disposed inside the outer sleeve, and a screen plate is disposed on the inner sleeve, the screen plate being located in the middle of the outer sleeve;

[0016] The other end of the outer sleeve is connected to one end of the sleeve;

[0017] A preheating pipe is provided inside the sleeve, and a heat storage material is provided inside the sleeve outside the preheating pipe;

[0018] One end of the preheating pipe is connected to the chlorine gas source, and the other end is connected to the inner sleeve.

[0019] Optionally, the other end of the sleeve is connected to a lifting device, which controls the connection and disconnection of the outer sleeve and the tee by changing the height of the sleeve.

[0020] Optionally, the condensation separation system includes a segmented heating structure and a cooling structure arranged sequentially from the three-way outlet to the exhaust gas treatment device.

[0021] Optionally, the heating structure includes a porous condenser tube and a tubular resistance furnace. The porous condenser tube is disposed inside the quartz tube of the tubular resistance furnace. One end of the quartz tube is connected to the tee, and the other end is connected to the cooling structure.

[0022] Optionally, the cooling structure includes a cooling unit.

[0023] This invention also provides a method for the above-mentioned high-efficiency chlorination volatilization comprehensive recovery device for electronic waste, which mainly includes the following steps:

[0024] a. Place the pretreated waste circuit boards into the reactor;

[0025] b. Evacuate the heating chamber and chlorination reaction chamber in the heating system;

[0026] c. Introduce protective gas into the heating chamber and the chlorination reaction chamber;

[0027] d. Under a protective atmosphere, the chlorination reaction chamber is heated to the first temperature and held at that temperature to remove organic matter from the waste circuit boards;

[0028] e. Chlorine gas is introduced into the chlorination reaction chamber through a chlorine gas source, and the chlorination reaction chamber is heated to a second temperature to obtain metal chloride vapor;

[0029] f. Metal chloride vapor enters the condensation separation system for step-by-step cooling, and different metal chloride crystals are obtained at different temperature ranges in the condensation separation system.

[0030] Optionally, step d may also include the following steps:

[0031] d1. Under a protective atmosphere, the temperature in the chlorination reaction chamber is increased to the first temperature of 300-500℃ at a rate of 1-10℃ / min, and held for 20-60min to remove organic resin and low-boiling-point impurities.

[0032] Optionally, step e includes the following steps:

[0033] e1. The chlorine gas introduced is a mixed gas with a chlorine concentration of 10-30 vol%, and the flow rate is 10-20 L / min. The reaction temperature is raised to the second temperature of 1500℃ or above using a gradient heating program.

[0034] Optionally, in step e1,

[0035] The negative pressure inside the chlorination reaction chamber is dynamically controlled between -5kPa and -20kPa, and the chlorine flow rate is adjusted in real time by a chlorine content monitoring sensor to maintain a chlorine content of ≤50ppm.

[0036] The gradient temperature ramping program is as follows:

[0037] First stage: 600-800℃, heating rate 8℃ / min, chlorine concentration 25-30 vol%.

[0038] Second stage: 800-1250℃, heating rate 5℃ / min, chlorine concentration 20-25 vol%.

[0039] Third stage: 1250-1500℃, heating rate 3℃ / min, chlorine concentration 10-15 vol%.

[0040] The present invention achieves the following technical effects compared to the prior art:

[0041] When using the efficient chlorination comprehensive recycling device and method for electronic waste provided by this invention, electronic waste is placed in the chlorination reaction chamber. A vacuum system is used to evacuate the heating system and the chlorination reaction chamber, reducing the oxygen content within them. Then, a protective gas source is used to introduce protective gas into the heating system and the chlorination reaction chamber, further reducing the oxygen content and preventing oxidation of components within the reactor during heating. The heating system gradually increases the temperature within the chlorination reaction chamber. Chloride gas is introduced into the chlorination reaction chamber through a chlorine gas source. Utilizing the characteristic that the boiling point of metal chlorides is lower than that of metals, the metal reacts with the chlorine gas at high temperature to form corresponding metal chloride vapors, reducing the temperature required for metal recovery. The metal chloride vapors enter the condensation separation system. Due to the different melting points of different types of metal chlorides, as the temperature in the condensation system gradually decreases, the metal chloride vapors gradually cool at different locations within the condensation system to form metal chloride crystals. This facilitates subsequent purification of different types of metal chlorides, thereby reducing pollutant emissions during subsequent metal purification and achieving efficient, green recycling and high-value utilization of metal resources. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of the high-efficiency chlorination volatilization comprehensive recycling device for electronic waste of the present invention;

[0044] Figure 2 This is a cross-sectional structural schematic diagram of the high-efficiency chlorination volatilization comprehensive recovery device for electronic waste of the present invention;

[0045] Figure 3This is a cross-sectional schematic diagram of the chlorination reaction chamber in the high-efficiency chlorination and volatilization comprehensive recovery device for electronic waste of the present invention;

[0046] Figure 4 This is a schematic diagram of the graphite felt shielding layer and the high-purity graphite rod heating element in the high-efficiency chlorination and volatilization comprehensive recycling device for electronic waste of the present invention;

[0047] Figure 5 This is a schematic diagram of the rotary feeding structure in the high-efficiency chlorination and volatilization comprehensive recovery device for electronic waste of the present invention;

[0048] Figure 6 This is a schematic diagram of the rotary feeding structure for removing the flange cover plate in the high-efficiency chlorination volatilization comprehensive recycling device for electronic waste of the present invention;

[0049] Figure 7 This is a cross-sectional schematic diagram of the porous condenser tube in the heating structure of the high-efficiency chlorination and volatilization comprehensive recovery device for electronic waste of the present invention;

[0050] Figure 8 This is a schematic diagram of the porous condenser tube in the high-efficiency chlorination volatilization comprehensive recovery device for electronic waste of the present invention.

[0051] Explanation of reference numerals in the attached drawings: 1. Rotary feeding structure; 2. Tubular resistance furnace; 3. Lifting structure; 4. Bellows; 5. Reactor; 6. Quartz tube; 7. Control cabinet; 8. Chlorination reaction chamber; 9. Heating structure; 10. Thermocouple; 11. Speed-increasing tube; 12. Preheating tube; 13. Graphite sealing assembly; 14. Tee; 15. Outer sleeve; 16. Screen plate; 17. Inner sleeve; 18. Fixing sleeve; 19. Upper orifice plate; 20. Sleeve; 21. Lower orifice plate; 22. 23. Base; 24. Graphite felt shielding layer; 25. High-purity graphite rod heating element; 26. Rotating shaft; 27. Flange cover plate; 28. Inspection hole; 29. ​​Feeding hopper shell; 30. Rotating plate; 31. Material holding bucket; 32. Intermediate shaft; 33. Connecting pipe; 34. Porous condenser pipe; 35. First sealing cone pipe; 36. Connecting internal thread; 37. Second sealing cone pipe; 38. First sealing cone head; 39. Connecting external thread; 40. Second sealing cone head; 51. Feed pipe. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Example 1:

[0054] like Figures 1 to 8 As shown, this embodiment provides a high-efficiency chlorination volatilization comprehensive recovery device for electronic waste, including a chlorination reaction chamber 8, a heating system, a vacuum system, an atmosphere control system, and a condensation separation system; the heating system is used to control the temperature of the chlorination reaction chamber 8; the vacuum system is connected to the heating system; the atmosphere control system includes a chlorine gas source and a protective gas source, the chlorine gas source is connected to the chlorination reaction chamber 8, and the protective gas source is connected to the heating system; one end of the condensation separation system is connected to the chlorination reaction chamber 8, and the other end is connected to the tail gas treatment device, and the temperature of the condensation separation system decreases stepwise from one end to the other.

[0055] The pretreated electronic waste is placed into the chlorination reaction chamber 8. A vacuum system is used to evacuate the heating chamber and chlorination reaction chamber 8 to 10 Pa, reducing the oxygen content within them. Then, a three-way valve is opened to supply protective gas to the heating chamber and chlorination reaction chamber 8, further reducing the oxygen content and preventing oxidation of the graphite components in the reactor 5 during heating. An intelligent temperature control heating system is then used to gradually increase the temperature within the chlorination reaction chamber 8. Finally, the three-way valve is switched to supply chlorine gas to the chlorination reaction chamber 8. Utilizing the characteristic that the boiling point of metal chlorides is lower than that of metals, under high temperature conditions, metals react with chlorine gases to form corresponding metal chloride vapors. The metal chloride vapors volatilize and enter the condensation and separation system. Since different types of metal chlorides have different melting points, as the temperature in the condensation system gradually decreases, the metal chloride vapors gradually cool at different locations in the condensation system to form metal chloride crystals. This facilitates the subsequent purification of different types of metal chlorides, thereby reducing the emission of pollutants in subsequent metal purification and achieving the goal of efficient and green recovery and high-value utilization of metal resources.

[0056] Since different types of metal chloride crystals have different densities, a separator can be used for further separation to obtain chloride crystals of a certain metal with higher purity, which will facilitate subsequent metal purification.

[0057] The chlorine gas source can supply chlorine gas or hydrogen chloride gas to the chlorination reaction chamber 8. More specifically, the chlorine gas source supplies a mixture of chlorine and nitrogen gas with a chlorine concentration of 10-30 vol% to the chlorination reaction chamber 8.

[0058] A protective gas source can supply nitrogen or inert gas to the heating system. The pressure of the protective gas source can be higher than that of the nitrogen source to prevent chlorine from leaking into the heating system.

[0059] In a more specific embodiment, the chlorination reaction chamber 8 includes a tee 14, an outer sleeve 15, an inner sleeve 17, and a sleeve 20; the first port of the tee 14 is connected to the feeding structure 1, the second port of the tee 14 is connected to one end of the outer sleeve 15, and the third port of the tee 14 is connected to one end of the condensation separation system; the inner sleeve 17 is disposed inside the outer sleeve 15, and a screen plate 16 is disposed at the end of the inner sleeve 17 facing the feeding structure 1. The mesh diameter of the screen plate 16 is smaller than the particle diameter of the pulverized electronic waste, so that the screen plate 16 can support the electronic waste particles; the other end of the outer sleeve 15 is connected to one end of the sleeve 20; a preheating pipe 12 is disposed inside the sleeve 20, and heat storage material is disposed around the preheating pipe 12 inside the sleeve 20. The heat storage material can be heat storage ceramic particles or graphite particles; one end of the preheating pipe 12 is connected to the atmosphere control system, and the other end is connected to the end of the inner sleeve 17 away from the feeding structure 1.

[0060] The chlorine gas introduced into the preheating pipe 12 is preheated by the heat storage material. When it reaches the inner sleeve 17, it basically reaches the temperature of the metal chlorination reaction. The temperature continues to rise in the inner sleeve 17. When it flows out from the screen plate 16, it reaches the temperature of the metal chlorination reaction.

[0061] The tee 14, outer sleeve 15, inner sleeve 17, and sleeve 20 are all made of isostatic high-purity graphite, which can withstand high temperatures and will not react chemically with chlorine or metals.

[0062] The top of the sleeve 20 is provided with an annular boss along the circumference. The lower end of the outer sleeve 15 is connected to the lower end of the inner sleeve 17 by a tapered structure for limiting connection. The upper hole plate 19 and the outer sleeve 15 are connected by bolts between the 316L stainless steel fixing sleeve 18 and the upper hole plate 19.

[0063] A base 22 is provided at the other end of the sleeve 20. The base 22 is connected to a lifting device, which controls the connection and disconnection of the outer sleeve 15 and the tee 14. More specifically, the second interface of the tee 14 is in contact and sealed with the outer sleeve 15. The inner wall of the second interface of the tee 14 and the outer wall of the outer sleeve 15 are both conical structures. When the lifting structure 3 drives the outer sleeve 15 to rise and the upper end of the outer sleeve 15 contacts the second interface of the tee 14, a conical seal is formed between the second interface of the tee 14 and the outer sleeve 15, isolating the chlorination reaction chamber 8 from the heating chamber. This prevents chlorine gas or metal chloride vapor in the chlorination reaction chamber 8 from leaking into the heating chamber, causing damage to the heating element or loss of metal chloride. The base 22 is made of 316L stainless steel.

[0064] The sleeve 20 is made of 316L stainless steel. The sleeve 20 and the furnace body are sealed with two layers of polytetrafluoroethylene rubber rings to achieve a complete seal of the furnace body. The sleeve 20 is equipped with an upper orifice plate 19 and a lower orifice plate 21. The upper end of the preheating pipe 12 is flush with the upper surface of the upper orifice plate 19, and the lower end of the preheating pipe 12 passes through the lower orifice plate 21 and is connected to the chlorine gas source.

[0065] Multiple shock-absorbing springs are installed between the base 22 and the lifting structure 3 to buffer the force and prevent the lifting structure 3 from applying excessive force to the base 22, thereby causing damage to the graphite tee 14 and the graphite outer sleeve 15.

[0066] The lifting structure 3 can use a cylinder, hydraulic cylinder, or linear motor, or a rotary motor combined with a crank rocker structure to achieve the lifting of the base plate.

[0067] A graphite sealing assembly 13 is also provided between the first interface of the tee 14 and the feeding structure 1. The lower end of the graphite sealing assembly 13 is sealed to the first interface of the tee 14, and the upper end of the graphite sealing assembly 13 is connected to the top flange of the reactor 5 and communicates with the feeding structure 1.

[0068] The upper end of the feed pipe 40 is threadedly fastened to the bottom of the rotary feeder 1. During feeding, the rotary feeder is moved up and down by the lifting structure 3, which in turn drives the lower end of the feed pipe 40 through the tee into the chlorination reaction chamber 8 for feeding. After feeding is completed, the feed pipe 40 is reset by the lifting structure 3. The feed pipe 40 is located inside the stainless steel corrugated pipe 4. The upper end of the corrugated pipe 4 is sealed to the lower end of the rotary feeder 1, and the lower end of the corrugated pipe is sealed to the upper end of the furnace body by flanges and sealing rings.

[0069] The condensation separation system includes a heating structure 9 and a cooling structure arranged sequentially from the graphite tee outlet to the exhaust gas treatment device. The heating structure generates three temperature zones with progressively decreasing temperatures along the axial direction, causing higher-boiling-point metal chlorides to crystallize on the cooling structure within the corresponding high-temperature zone, and lower-boiling-point metal chlorides to crystallize on the cooling structure within the low-temperature zone.

[0070] In a more specific embodiment, the heating structure 9 includes a porous condenser tube 33 and a tubular resistance furnace 2. The porous condenser tube 33 is disposed inside the quartz tube 6 of the tubular resistance furnace 2. One end of the quartz tube 6 is connected to the reaction chamber 8, and the other end is connected to the cooling structure.

[0071] Multiple porous condenser tubes 33 are sequentially connected inside the quartz tube 6. Each porous condenser tube 33 includes multiple through holes arranged along the axial direction of the condenser, and adjacent porous condenser tubes 33 are connected by threads. To ensure that the through holes between adjacent porous condenser tubes 33 can communicate with each other, a connecting cavity is provided at the connection point between the porous condenser tubes 33.

[0072] Specifically, an axial positioning hole is provided at one end of the porous condenser tube 33 along the axial direction, and a connecting chamber is provided between the axial positioning hole and the through hole. The outer wall of the other end of the porous condenser tube 33 is provided with a positioning structure that matches the axial positioning hole along the axial direction. A limiting structure is provided between the positioning structure and the end face of the porous condenser tube 33. The length of the limiting structure is less than the length of the connecting chamber. Thus, after the two porous condenser tubes 33 are connected, a connecting cavity is formed between the limiting structure and the connecting chamber.

[0073] More specifically, the axial positioning hole is a first sealing cone 34, a connecting internal thread 35, and a second sealing cone 36 arranged sequentially along the axial direction at one end of the porous condenser tube 33. The connecting chamber is a first sealing cone 37, a connecting external thread 38, and a second sealing cone 39 arranged sequentially between the smaller diameter end of the cone-shaped hole and the through hole. The first sealing cone 34 and the first sealing cone 37 have the same size, the connecting internal thread 35 matches the connecting external thread 38, and the second sealing cone 36 and the second sealing cone 39 have the same size. Thus, after the two porous condenser tubes 33 are connected, the first sealing cone 34 and the first sealing cone 37 are in contact and sealed, the connecting internal thread 35 and the connecting external thread 38 are threadedly connected, and the second sealing cone 36 and the second sealing cone 39 are in contact and sealed.

[0074] The length of the second sealing cone 36 is greater than the length of the second sealing cone 39. Therefore, after the two porous condenser tubes 33 are connected, a communicating chamber is formed between the inner wall of the second sealing cone 36 and the end face of the second sealing cone 39, ensuring that the through holes on adjacent porous condenser tubes 33 can communicate with each other. An alumina anti-stick coating is applied to the inner wall of the porous condenser tube 33 to prevent cooled metal chlorides from adhering to the through holes.

[0075] An alumina anti-stick coating is applied to the inner wall of the porous condenser tube 33 to prevent metal chlorides from adhering to the through holes after cooling.

[0076] The porous condenser tube 33 is connected to the tee 14 via a connecting pipe 32. One end of the connecting pipe 32 is provided with a flange and is connected to the reactor 5 via a flange. The interface of the tee 14 is detachably connected to the flange. The other end of the connecting pipe 32 is connected to the porous condenser tube 33 via a thread.

[0077] A thermocouple 10 is installed on the connecting pipe 32 to monitor the temperature inside the connecting pipe 32, thereby determining the temperature of the metal chloride mixture flowing out of the reactor 5 and ensuring that the temperature inside the reactor 5 meets the process requirements.

[0078] To increase the flow rate of metal chlorides, a speed-increasing tube 11 is also provided inside the connecting pipe 32. One end of the speed-increasing tube 11 is connected to the inside of the connecting pipe 32 by a thread, and the other end of the speed-increasing tube 11 extends into the tee 14. The speed-increasing tube 11 is used to reduce the inner diameter of the connecting pipe 32, thereby increasing the flow rate of metal chloride vapor when it reaches the porous condenser 33. This allows the metal chloride vapor to maintain flow throughout the condensation and separation system, preventing the metal chloride vapor from staying in the condensation and separation system for too long, which would cause different types of metal chlorides to crystallize at the same location, resulting in a decrease in the purity of the final crystal.

[0079] The cooling structure includes a cooling unit, which can specifically be a liquid nitrogen cryogenic unit. The liquid nitrogen cryogenic unit further cools the metal chloride vapor, causing all the remaining metal chloride vapor to form metal chloride crystals.

[0080] In this specific embodiment, in the condensation separation system, the first stage temperature is controlled at 500-600℃, and this condensation section collects the main metals copper and copper chloride (993℃) from the waste circuit boards; the second stage temperature is controlled at 100-150℃, and this condensation section collects aluminum chloride (178℃) or ferric chloride (316℃), etc.; the third stage temperature is controlled at -20-0℃, and this condensation section collects precious metals (such as palladium chloride, boiling point: 100℃).

[0081] The outer shell of reactor 5 is a double-layer water-cooled stainless steel structure, with the inner layer filled with a graphite felt shielding layer 23, and the interlayer is circulated with water (flow rate 20-30 m³ / h). 3 / g, inlet water temperature ≤25℃), the water flow rate is adjusted by a PID controller to ensure the outer surface temperature ≤50℃; multiple high-purity graphite rod heating elements 24 are arranged inside the graphite felt shielding layer 23, and the heating elements are made of isostatic high-purity graphite. The graphite felt shielding layer 23 serves as insulation material to wrap the high-purity graphite rod heating elements 24. Stainless steel plates are respectively set at the upper and lower ends of the graphite felt shielding layer 23, and the stainless steel plates are welded to the inner wall of the furnace body and furnace door; the two ends of the high-purity graphite rod heating elements 24 have external threads, which are connected in series through graphite connectors with double holes and internal threads to form a series circuit. The entire series graphite heating rod assembly is evenly surrounded around the cylindrical graphite sleeve 20 to provide heat.

[0082] The vacuum system includes a rotary vane vacuum pump and a diffusion pump. Accurate measurement of the vacuum level relies on two core components: a resistance gauge and an ionization gauge. The resistance gauge measures the resistance of a hot filament as a function of temperature; changes in gas pressure affect the heat dissipation rate of the hot filament, thus altering the resistance value. Its measurement range covers 10⁻¹ to 10⁻¹. 5 Pa, suitable for low and rough vacuum environments. The ionization gauge works by using a high-temperature cathode to emit electrons, which collide with gas molecules to generate ionization, and then collecting the resulting ion stream; at 10 Pa... -5 ~10 -1Within the Pa range, the ion current intensity and gas pressure exhibit a linear relationship. The gas pressure can be determined by detecting the magnitude of the ion current, making it commonly used for precise measurements in high vacuum environments. The two gauges work together to achieve effective monitoring of the full-range pressure of the vacuum system.

[0083] The rotary feeding device 1 includes a rotating shaft 25, a flange cover 26, a feeding housing 28, a rotating plate 29, a material storage tank 30, and an intermediate shaft 31. The top of the feeding housing 28 is open, and the flange cover 26 is detachably connected to the top of the feeding housing 28. The rotating shaft 25 is rotatably mounted in the middle of the flange cover 26. The rotating plate 29 is rotatably mounted inside the feeding housing 28, and multiple material storage tanks 30 are arranged around the rotating plate 29. The intermediate shaft 31 is located in the middle of the rotating plate 29 and is connected to the rotating shaft 25. A discharge port is provided at the bottom of the housing 28 of the rotary feeding device 1, and the discharge port is connected to the top of the reaction chamber through an extension pipe. The housing 28 of the rotary feeding device 1 is connected to a lifting device, which controls the height of the housing 28 of the rotary feeding device 1, thereby changing the depth of the extension pipe extending into the reaction chamber. The extension pipe is fitted with a corrugated pipe 4. The upper end of the corrugated pipe 4 is sealed to the ground of the feeding shell 28 through a flange, and the lower end of the corrugated pipe 4 is sealed to the top of the reactor 5 through a flange.

[0084] By disassembling the flange cover 26, multiple material containers 30 are exposed, and crushed circuit boards are added to the material containers 30. One material container 30 corresponding to the discharge port is not added. After addition, the flange cover 26 is reinstalled. When it is necessary to add crushed circuit boards to the chlorination reaction chamber 8, the extension pipe is extended through the feed pipe 40 and the tee 14 via a lifting device to reach above the screen plate 16. By rotating the rotating shaft 25, the intermediate shaft 31 rotates synchronously, driving the rotating plate 29 to rotate, causing the material container 30 containing the crushed circuit boards to rotate to the position opposite the discharge port. The crushed circuit boards in the material container 30 fall onto the screen plate 16 through the discharge port and the extension pipe. After adding material, the lifting device raises the feeding shell 28, so that the lower end of the extension pipe is at the top of the reactor 5.

[0085] A feeding port 27 is also provided on the flange cover plate 26 directly above the discharge port. A high-purity quartz sealing plug is provided on the feeding port 27. When feeding, the sealing plug is opened to observe whether the circuit board in the material container 30 has entered the chlorination reaction chamber 8.

[0086] In this specific embodiment, a control cabinet 7 is also included. The control cabinet 7 is equipped with a control module. The control module is electrically connected to the tubular resistance furnace 2, the lifting structure, the lifting device, the thermocouple 10, the high-purity graphite rod heating element 24, the vacuum system, and the atmosphere control system, respectively.

[0087] The control cabinet 7 is equipped with an LCD screen that is electrically connected to the control module, as well as digital display composite vacuum gauges, thermometers, voltmeters, ammeters, and other instruments, which provide precise temperature control for the entire chlorination furnace.

[0088] This invention utilizes a high-purity graphite heating component, a sealed structure, and an atmosphere control system, achieving a maximum heating temperature of 1700℃, surpassing the 1200℃ temperature limit of traditional quartz tube furnaces. It also solves the problem of chlorine corrosion, ensuring no chlorine leakage and eliminating environmental pollution. Through low-temperature pyrolysis, high-temperature chlorination volatilization, and three-stage condensation and sedimentation separation, it enables the high-value recovery of various metal resources, offering advantages such as low energy consumption, high recovery rate, and environmental friendliness, making it suitable for industrial metal resource recovery.

[0089] Example 2:

[0090] This embodiment provides a method for the efficient chlorination volatilization comprehensive recovery device for electronic waste based on Embodiment 1, mainly including the following steps:

[0091] a. The waste circuit boards are crushed to a particle size of 0.5-2mm, and after magnetic separation to remove ferromagnetic materials, they are placed into the reaction furnace 5;

[0092] b. Evacuate the heating system and reaction chamber 8;

[0093] c. Introduce protective gas into the heating system and reaction chamber 8;

[0094] d. Under a protective atmosphere, the temperature in reaction chamber 8 is increased to 300-500℃ at a rate of 1-10℃ / min and held for 20-60min to remove organic resins and low-boiling-point impurities;

[0095] e. Chlorine gas is introduced into reaction chamber 8 through a chlorine gas source. The introduced chlorine gas is a mixed gas with a chlorine concentration of 10-30 vol%, and the flow rate is 10-20 L / min. The reaction temperature is raised to above 1500℃ using a gradient heating program to obtain metal chloride vapor. The negative pressure in reaction chamber 8 is dynamically controlled between -5 kPa and -20 kPa, and the chlorine gas flow rate is adjusted in real time through a chlorine content monitoring sensor to maintain the chlorine content ≤50 ppm.

[0096] The gradient temperature ramping program is as follows:

[0097] First stage: 600-800℃, heating rate 8℃ / min, chlorine concentration 25-30 vol%.

[0098] Second stage: 800-1250℃, heating rate 5℃ / min, chlorine concentration 20-25 vol%.

[0099] Third stage: 1250-1500℃, heating rate 3℃ / min, chlorine concentration 10-15 vol%.

[0100] f. Metal chloride vapor enters the condensation system for stepwise cooling, and different metal chloride crystals are obtained at different temperature ranges in the condensation system;

[0101] g. Centrifuge and dry the metal chloride crystals;

[0102] h. Exhaust gas treatment: The exhaust gas is passed sequentially through a 3%–5% nitric acid solution and a 3%–5% NaOg solution to remove alkaline or acidic gases from the exhaust gas. Then it enters an activated carbon adsorption device. After adsorption treatment, the content of harmful gases and fine particles in the residual exhaust gas is further significantly reduced.

[0103] Example 3:

[0104] This embodiment provides a method for the efficient chlorination volatilization comprehensive recovery device for electronic waste based on Embodiment 2, mainly including the following steps:

[0105] a. Select a batch of waste circuit boards, sort and screen them to remove obvious impurities such as plastic and rubber. Crush the waste circuit boards to a particle size of 0.5-2mm, and remove ferromagnetic materials by magnetic separation. Place the crushed waste circuit boards (particle size ≤2mm) into a rotary feeder, and then feed them into the reaction furnace 5 in batches.

[0106] b. Evacuate the heating system and reaction chamber 8;

[0107] c. Introduce protective gas into the heating system and reaction chamber 8;

[0108] d. Under N2 atmosphere (flow rate 20-50 L / min), the temperature is increased to 500℃ at 3℃ / min and held at the temperature for 30 min to remove organic resin and low-boiling-point impurities;

[0109] e. Chlorine gas is introduced into reaction chamber 8 through a chlorine gas source. The chlorine gas is a mixture of chlorine and nitrogen with a Cl2 concentration of 10-30 vol%. The temperature is raised to 1500°C according to a set gradient temperature rise program through an intelligent temperature control system. Under this condition, the reaction proceeds for 5-15 minutes, allowing the valuable metals in the waste circuit board to fully react with the chlorine gas to generate metal chlorides.

[0110] f. The metal chloride gas generated in the reaction enters the volatilization enrichment module; in the multi-stage condensation unit, the temperature in the first-stage condensation recovery unit is controlled at 500-600℃, and this condensation section collects metal chlorides with lower boiling points, such as zinc chloride (290℃) or lead chloride (501℃); the temperature in the second-stage condensation recovery unit is controlled at 100-150℃, and this condensation section collects copper chloride (620℃), etc.; the temperature in the third-stage condensation recovery unit is controlled at -20-0℃, and this condensation section collects precious metals, etc.; through precise temperature control, the effective separation and collection of different metal chlorides are achieved.

[0111] g. The exhaust gas generated during the reaction process is passed sequentially through a 5% nitric acid solution and a 3% NaOH solution to remove most of the acidic or alkaline gases in the exhaust gas; then the exhaust gas enters an activated carbon adsorption device, and after adsorption treatment, the content of harmful gases and fine particles in the exhaust gas is greatly reduced, and it is discharged after testing to meet environmental emission standards.

[0112] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0113] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A high-efficiency chlorination volatilization comprehensive recovery device for electronic waste, characterized in that, include: Chlorination reaction chamber (8); A heating system, comprising a heating chamber disposed within a reaction furnace (5), for controlling the temperature of the chlorination reaction chamber (8); A vacuum system, which is connected to both the heating chamber and the chlorination reaction chamber (8); The atmosphere control system includes a chlorine gas source and a protective gas source. The chlorine gas source is connected to the chlorination reaction chamber (8), and the protective gas source is connected to both the heating chamber and the chlorination reaction chamber (8). The condensation separation system has one end connected to the chlorination reaction chamber (8) and the other end connected to the tail gas treatment device. The temperature of the condensation separation system decreases gradually from one end to the other.

2. The high-efficiency chlorination volatilization comprehensive recovery device for electronic waste according to claim 1, characterized in that, The chlorination reaction chamber (8) includes a tee (14), an outer sleeve (15), an inner sleeve (17), and a sleeve (20); The first port of the tee (14) is connected to the feeding structure (1), the second port of the tee (14) is connected to one end of the outer sleeve (15), and the third port of the tee (14) is connected to one end of the condensation separation system. The inner sleeve (17) is disposed inside the outer sleeve (15), and a screen plate (16) is disposed on the inner sleeve (17), the screen plate (16) being located in the middle of the outer sleeve (15); The other end of the outer sleeve (15) is connected to one end of the sleeve (20); A preheating pipe (12) is provided inside the sleeve (20), and a heat storage material is provided inside the sleeve (20) outside the preheating pipe (12); One end of the preheating pipe (12) is connected to the chlorine gas source, and the other end is connected to the inner sleeve (17).

3. The high-efficiency chlorination volatilization comprehensive recovery device for electronic waste according to claim 2, characterized in that, The other end of the sleeve (20) is connected to a lifting device, which controls the connection and separation of the outer sleeve (15) and the tee (14) by changing the height of the sleeve (20).

4. The high-efficiency chlorination volatilization comprehensive recovery device for electronic waste according to claim 2, characterized in that, The condensation separation system includes a segmented heating structure (9) and a cooling structure arranged sequentially from the outlet of the three-way valve (14) to the exhaust gas treatment device.

5. The high-efficiency chlorination volatilization comprehensive recovery device for electronic waste according to claim 4, characterized in that, The heating structure (9) includes a porous condenser tube (33) and a tubular resistance furnace (2). The porous condenser tube (33) is disposed inside the quartz tube (6) of the tubular resistance furnace (2). One end of the quartz tube (6) is connected to the tee (14), and the other end is connected to the cooling structure.

6. The high-efficiency chlorination volatilization comprehensive recovery device for electronic waste according to claim 4, characterized in that, The cooling structure includes a cooling unit.

7. A method for the efficient chlorination and volatilization comprehensive recovery device for electronic waste according to any one of claims 1 to 6, characterized in that, The main steps include: a. Place the pretreated waste circuit boards into the reactor (5); b. Evacuate the heating chamber and chlorination reaction chamber (8) in the heating system; c. Introduce protective gas into the heating chamber and the chlorination reaction chamber (8); d. Under a protective atmosphere, the chlorination reaction chamber (8) is heated to the first temperature and kept at that temperature to remove organic matter from the waste circuit board; e. Chlorine gas is introduced into the chlorination reaction chamber (8) through a chlorine gas source, and the chlorination reaction chamber (8) is heated to a second temperature to obtain metal chloride vapor; f. Metal chloride vapor enters the condensation separation system for step-by-step cooling, and different metal chloride crystals are obtained at different temperature ranges in the condensation separation system.

8. The method of the high-efficiency chlorination volatilization comprehensive recovery device for electronic waste according to claim 7, characterized in that, Step d also includes the following steps: d1. Under a protective atmosphere, the temperature in the chlorination reaction chamber (8) is increased to the first temperature of 300-500℃ at 1-10℃ / min and held for 20-60min to remove organic resin and low-boiling-point impurities.

9. The method of the high-efficiency chlorination volatilization comprehensive recovery device for electronic waste according to claim 7, characterized in that, Step e includes the following steps: e1. The introduced chlorine gas is a mixed gas with a chlorine concentration of 10-30 vol%, and the flow rate is 10-20 L / min. The reaction temperature is raised to a second temperature of 1500℃ or above using a gradient heating program.

10. The method of the high-efficiency chlorination volatilization comprehensive recovery device for electronic waste according to claim 9, characterized in that, In step e1, The negative pressure inside the chlorination reaction chamber (8) is dynamically controlled between -5kPa and -20kPa, and the chlorine flow rate is adjusted in real time by a chlorine content monitoring sensor to maintain a chlorine content ≤50ppm; The gradient temperature ramping program is as follows: First stage: 600-800℃, heating rate 8℃ / min, chlorine concentration 25-30 vol%. Second stage: 800-1250℃, heating rate 5℃ / min, chlorine concentration 20-25 vol%. Third stage: 1250-1500℃, heating rate 3℃ / min, chlorine concentration 10-15 vol%.

Images