Method and device for full resource utilization of arsenic-containing mercury waste residue

Abstract

The application discloses a method for full-amount resource utilization of arsenic and mercury-containing waste residues, and specifically comprises the following steps: performing alkali leaching treatment on arsenic or arsenic and mercury-containing waste residues at normal temperature and pressure; after solid-liquid separation, adding acid into the filtrate to generate a precipitate at 60 DEG C-90 DEG C; collecting and drying the precipitate to obtain As2O3; after drying treatment of the filter residue, pyrolyzing the filter residue at 300 DEG C-600 DEG C, and condensing and recovering mercury; mixing and crushing the waste residues from which arsenic and mercury have been removed with biomass at a mass ratio of 1:1-1:5, and performing soilization composting treatment; and the device for completing the above method comprises an arsenic recovery unit, a mercury recovery unit and a soilization treatment unit, the method and the device can realize full-amount resource utilization of arsenic and mercury-containing waste residues, are simple to operate, have high treatment efficiency, and have remarkable economic and social benefits.

Description

Technical Field

[0001] This invention belongs to the field of harmless treatment and resource utilization of bulk solid waste, specifically a method and apparatus for the full resource utilization of arsenic and mercury-containing waste residue. Background Technology

[0002] Arsenic and mercury are both highly toxic elements; even small amounts can be fatal. As typical toxic and harmful pollutants, arsenic and mercury, present in nature, enter industrial and agricultural production processes as impurities, leading to the generation of large amounts of polluted waste. Untreated arsenic and mercury-containing waste residue is the most dangerous source of arsenic and mercury pollution. During weathering, large amounts of small particles diffuse into the air, causing serious air pollution problems. Secondly, arsenic and mercury are poorly stable in waste residue. Under the leaching of rainwater, unstable arsenic compounds dissolve into the surface cycle, and arsenic and mercury from the atmosphere and water enter the soil, directly affecting agricultural safety and posing a potential threat.

[0003] Arsenic-containing solid waste mainly comes from smelting waste (such as arsenic-alkali slag and arsenic-containing flue dust), arsenic-containing tailings, sludge from the treatment of arsenic-containing wastewater and waste acid, arsenic-containing waste from the electronics industry, and arsenic-containing anode mud generated during electrolysis. Smelting slag (especially arsenic-alkali slag generated during antimony smelting) has a high arsenic content and causes serious pollution. From the perspective of the entire non-ferrous metallurgical system, arsenic entering the smelter, except for a portion that is directly recovered into white arsenic (such as by directly extracting white arsenic from high-arsenic flue dust), almost all other arsenic-containing intermediate products end up in arsenic-containing waste.

[0004] China accounts for approximately 70% of the nation's arsenic resources. During the mining and beneficiation of arsenic-containing minerals, the smelting of non-ferrous metals, and the production of acid from arsenic-containing ores, arsenic, as a by-product, migrates and transforms along with the mining, beneficiation, and smelting of copper, lead, zinc, tin, and other non-ferrous metals, distributing itself in various smelting products and thus forming arsenic-containing waste from non-ferrous smelting. The treatment methods for arsenic- and mercury-containing waste residue are broadly divided into two types. One method involves stabilizing and solidifying the waste before landfilling, using wet processes such as acid leaching, alkali leaching, or salt leaching to separate arsenic and mercury from the waste residue, followed by further treatment using sulfidation or other harmless treatment methods. The other method is thermal treatment recovery, employing pyrometallurgical processes such as oxidative roasting, reduction roasting, and vacuum roasting to volatilize and recover arsenic and mercury.

[0005] Arsenic and mercury-containing waste residues contain large amounts of arsenic and mercury resources. While solidification and stabilization are simple and effective methods to prevent arsenic pollution, their utilization rate is low, and deep burial and stockpiling result in significant resource waste. Furthermore, under certain conditions, arsenic and mercury residues can be oxidized by bacteria and dissolved in water, leading to secondary pollution. Thermal treatment and recovery have wide applications in the resource utilization of arsenic and mercury-containing waste residues. CN113528846A discloses a method for the resource utilization and treatment of arsenic-containing waste residues, which can effectively remove arsenic while recovering valuable metals. CN115446091A discloses a method for rapid mercury recovery from mercury-containing waste residues, but it does not provide an effective treatment for the waste residues after arsenic and mercury removal. In addition, the soil treatment of organic waste in conjunction with industrial solid waste has become a practically feasible approach. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a method for the full-scale resource utilization of arsenic and mercury-containing waste residue. Specifically, arsenic-containing or arsenic-mercury-containing waste residue is subjected to alkaline leaching treatment at room temperature and pressure. After solid-liquid separation, acid is added to the filtrate and a precipitate is generated at 60℃-90℃. The precipitate is collected and dried to obtain As2O3. After drying the filter residue, it is pyrolyzed at 300-600℃, and the mercury is volatilized and condensed for recovery. The waste residue from which arsenic and mercury have been removed is mixed with biomass at a mass ratio of 1:1 to 1:5, crushed, and then subjected to soil composting treatment.

[0007] The arsenic- and mercury-containing waste residues include smelting waste residues (such as arsenic- and mercury-containing waste residues and arsenic- and mercury-containing flue ash), arsenic- and mercury-containing tailings, sediments from the treatment of arsenic- and mercury-containing wastewater and waste acid, arsenic- and mercury-containing wastes from the electronics industry, and arsenic- and mercury-containing anode mud generated during electrolysis.

[0008] The biomass is selected from wood, straw, bamboo, starch, bark, cellulose, lignin, hemicellulose, protein, chitin, bagasse, sawdust, and rice husk.

[0009] The alkali includes a NaOH solution or a KOH solution with a concentration of 0.5-5 mol / L. The solid-liquid ratio for alkali leaching is 1:5-1:20 (g:mL). The acid used for pickling is a sulfuric acid solution with a concentration of 1-5 mol / L. The alkali includes either NaOH or KOH solution. The solid-liquid ratio for alkali leaching is 1:5-1:20. The alkali leaching temperature is room temperature, and the leaching time is 20-60 min. The acid used for pickling is a sulfuric acid solution with a concentration of 1-5 mol / L, replenished from the acid inlet. The reaction temperature is 60℃-90℃, and the pickling time is 30-60 min, with the temperature raised to the required temperature by a heating plate.

[0010] Another object of the present invention is to provide an apparatus for performing the above-described method, comprising an arsenic recovery unit, a mercury recovery unit, and a soil treatment unit. The arsenic recovery unit includes an alkaline leaching tank, an acid washing and filtration box, a dryer I, and a dryer II. The alkaline leaching tank has a feed inlet and an alkali addition inlet at its upper part, and a stirrer is installed inside. A baffle I is installed at the bottom outlet of the alkaline leaching tank and is connected to the outlet acid washing and filtration box. A primary drive filter belt is installed inside the acid washing and filtration box, and an acid washing tank is located below the primary drive filter belt. A heating plate is installed at the bottom of the acid washing tank, and a secondary drive filter belt is installed on one side of the heating plate at the bottom of the acid washing tank. The baffle II is inclinedly installed on the heating plate. At the junction with the secondary drive filter belt, a filtrate tank is installed below the secondary drive filter belt. The filtrate tank is connected to the acid inlet on the pickling tank via a pump. The primary drive filter belt is connected to dryer I, and the secondary drive filter belt is connected to dryer II. The mercury recovery unit includes a vertical pyrolysis furnace, a waste liquid collection tank, a condenser, a ball mill crusher, and a mercury recovery tank. Dryer I is connected to the inlet of the vertical pyrolysis furnace via material conveying pipe I. The top of the vertical pyrolysis furnace is connected to the inlet of the shell-and-tube condenser via a gas conveying pipe. The mercury collection tank is located at the bottom of the vertical pyrolysis furnace. The vertical pyrolysis furnace is connected to the ball mill crusher via material conveying pipe II.

[0011] The vertical pyrolysis furnace is equipped with temperature and pressure sensors. A heating jacket is installed outside the shell of the vertical pyrolysis furnace. The internal cavity of the vertical pyrolysis furnace is divided into a pyrolysis furnace cavity, a waste liquid collection cavity, and a discharge cavity by a filter screen and a partition. The filter screen is an arc-shaped filter screen with a pyrolysis furnace discharge port at the bottom. A waste liquid outlet is provided at the lower part of the shell of the vertical pyrolysis furnace and the waste liquid outlet is connected to the waste liquid collection cavity. The waste liquid collection tank is located below the waste liquid outlet.

[0012] The transmission speed of the primary transmission filter belt is 0.5-1 m / s, and the transmission speed of the secondary transmission filter belt is 0.1-0.8 m / s.

[0013] Dryer I and Dryer II are horizontal spiral dryers with a drying temperature of 50-120℃.

[0014] The ball mill has a ball-to-material mass ratio of 3:1 to 15:1 and a ball mill speed of 600-800 r / min.

[0015] When the above-mentioned device is used, the arsenic and mercury-containing waste residue is fed into the alkaline leaching tank through the feed inlet above the leaching tank. The stirrer in the tank accelerates the reaction rate. After reacting at room temperature for 20-60 minutes, the lower outlet baffle I is opened to allow the material to flow into the pickling filter box. After solid-liquid separation by the primary drive filter belt, the solid is transported to dryer I and dried at 50-120℃ for 1-10 hours. The filtrate enters the lower pickling tank for heating and reaction to generate As2O3 precipitate. The reaction product is then fed into the secondary drive filter belt on the right side of the pickling tank by opening baffle II. Solid-liquid separation occurs thereafter. The filtrate enters the lower filtrate tank and is pumped back into the pickling tank for recycling. The As2O3 filter residue enters the right dryer II for drying and recycling.

[0016] The dried material in dryer I enters the vertical pyrolysis furnace through material conveying pipe I. Pyrolysis is carried out in the pyrolysis furnace chamber at a high temperature of 300-600℃. The Hg vapor generated by pyrolysis enters the shell-and-tube condenser through the gas conveying pipe above the pyrolysis furnace for condensation and recovery. The generated tar and other waste liquids enter the waste liquid collection chamber through the filter screen and are recovered to the waste liquid collection tank from the waste liquid outlet. The solids enter the discharge chamber from the pyrolysis furnace outlet and are conveyed through material conveying pipe II to the ball mill crusher to be mixed and crushed with biomass, and then subjected to conventional soil composting treatment.

[0017] Advantages and technical effects of this invention:

[0018] 1. The equipment of the present invention consists of three main parts: an arsenic recovery unit, a mercury recovery unit, and a soil pretreatment unit. The main parts are connected in series by pipelines. Each unit uses simple equipment components, and the solutions used in the operation are readily available and inexpensive.

[0019] 2. The technology and equipment of this invention conform to the three principles of "resource utilization, volume reduction, and harmlessness". It plays a role in reducing the volume of large-scale stockpiled waste residue. The toxic and harmful substances such as arsenic and mercury in the waste residue are treated and rendered harmless. Both the toxic and harmful substances and the treated waste residue can be fully utilized, realizing the resource utilization of waste residue.

[0020] 3. The equipment of the present invention has a simple structure and is easy to install, and can be well adapted to both large and small factories;

[0021] 4. The pyrolysis furnace in this invention is equipped with a liquid filter screen, which can effectively separate and recover the tar generated during the pyrolysis process, and prevent the tar from sticking together with the waste residue when it cools down, thus affecting the subsequent processing effect. The equipment has the function of effective separation of solid, gas and liquid, and the recovery effect is good. Attached Figure Description

[0022] Figure 1 This is a structural diagram of the device of the present invention;

[0023] In the diagram: 1-Feed inlet, 2-Alkali leaching tank, 3-Baffle I, 4-Alkali solution addition port, 5-First-stage transmission filter belt, 6-Acid washing filter box, 7-Acid feed inlet, 8-Baffle II, 9-Second-stage transmission filter belt, 10-Acid washing tank, 11-Filtration tank, 12-Pump, 13-Dryer I, 14-Dryer II, 15-Material conveying pipe I, 16-Vertical pyrolysis furnace, 17-Pyrolysis furnace chamber, 18-Heating jacket, 19-Waste liquid collection tank, 20-Temperature and pressure sensor, 21-Gas conveying pipe, 22-Shell-type condenser, 23-Material conveying pipe II, 24-Ball mill crusher, 25-Mercury collection tank, 26-Agitator, 27-Filter screen, 28-Heating plate, 29-Waste liquid outlet, 30-Pyrolysis furnace discharge port, 31-Waste liquid collection chamber, 32-Discharge chamber. Detailed Implementation

[0024] The present invention will be further described in detail below through specific embodiments, but the scope of protection of the present invention is not limited to the content described herein; for example Figure 1As shown, the apparatus used in the following embodiments includes an arsenic recovery unit, a mercury recovery unit, and a soil treatment unit. The arsenic recovery unit includes an alkaline leaching tank 2, an acid washing and filtration box 6, a dryer I 13, and a dryer II 14. The alkaline leaching tank 2 is provided with a feed inlet 1 and an alkali addition inlet 4 at its upper part, and a stirrer 26 is installed inside it. A baffle I 3 is provided at the bottom outlet of the alkaline leaching tank 2, and the outlet is connected to the acid washing and filtration box 6. A primary drive filter belt 5 is installed inside the acid washing and filtration box 6, and an acid washing tank 10 is located below the primary drive filter belt 5. A heating plate 28 is installed at the bottom of the washing tank 10. A secondary drive filter belt 9 is installed on one side of the heating plate at the bottom of the pickling tank 10. A baffle II 8 is inclinedly installed at the junction of the heating plate and the secondary drive filter belt. A filtrate tank 11 is installed below the secondary drive filter belt 9. The filtrate tank 11 is connected to the acid inlet 7 on the pickling tank 10 through a pump 12. The primary drive filter belt 5 is connected to the dryer I 13, and the secondary drive filter belt 9 is connected to the dryer II 14. The mercury recovery unit includes a vertical pyrolysis furnace 16 and a waste liquid collection tank 19. The vertical pyrolysis furnace 16 includes a condenser 22, a ball mill crusher 24, a mercury recovery tank 25, and a shell. A heating jacket 18 is installed outside the shell. The inner cavity of the shell is divided into a pyrolysis furnace chamber 17, a waste liquid collection chamber 31, and a discharge chamber 32 by a filter screen 27 and a partition. The filter screen 27 is an arc-shaped filter screen with a pyrolysis furnace discharge port 30 at the bottom. A waste liquid outlet 29 is provided at the lower part of the shell of the vertical pyrolysis furnace 16, and the waste liquid outlet is connected to the waste liquid collection chamber 31. The waste liquid collection tank 19 is located below the waste liquid outlet 29. A dryer is also included. I13 is connected to the inlet of the vertical pyrolysis furnace 16 through material conveying pipe I15. The top of the vertical pyrolysis furnace 16 is connected to the inlet of the shell-and-tube condenser 22 through gas conveying pipe 21. The mercury collection tank 25 is set at the bottom of the vertical pyrolysis furnace 16. The vertical pyrolysis furnace 16 is connected to the ball mill crusher 24 through material conveying pipe II23. Temperature and pressure sensors 20 are installed inside the vertical pyrolysis furnace. Dryer I and dryer II are horizontal spiral dryers. Spiral conveying rods are installed inside material conveying pipe I and material conveying pipe II. Example

[0025] This embodiment applies the above-mentioned device to the full resource utilization of arsenic-mercury anode mud. Specifically, the arsenic-mercury anode mud, after being dried at low temperature, is fed into a container containing 2 mol / L of alkaline leaching solution through the feed inlet 1 above the alkaline leaching tank 2. In the alkaline leaching tank of NaOH solution, stirrer 26 was turned on and stirred at 300 rpm for 30 min at room temperature. After the reaction, baffle I at the outlet of the alkaline leaching tank was opened to allow the material to flow into the pickling filter tank 6. Solid-liquid separation was achieved through the primary drive filter belt 5 (drive speed 0.5 m / s). The solid was conveyed to dryer I 13 and dried at 100℃ for 1 h. The filtrate entered the lower pickling tank 10 and reacted with a 3 mol / L sulfuric acid solution at 60℃ for 50 min to generate As2O3 precipitate. Baffle II 8 was opened, and the reaction product entered the secondary drive filter belt 14 on the right side of the pickling tank (drive speed 0.6 m / s) for solid-liquid separation. The filtrate entered the lower filtrate tank 11 and was pumped back into the pickling tank for recycling. The As2O3 filter residue was dried and recovered in dryer II on the right side. The As2O3 content in the filter residue was tested and found to be... 75.33%; The dried material in dryer I enters the vertical pyrolysis furnace 16 through material conveying pipe I15, and is pyrolyzed at 350℃ for 2 hours in the pyrolysis furnace chamber. The Hg vapor generated by pyrolysis enters the shell-and-tube condenser 22 through the gas conveying pipe 21 above the pyrolysis furnace for condensation and recovery. The mercury content is 94.50%. The generated tar and other waste liquids enter the waste liquid collection chamber 31 through the filter screen 27 and are recovered to the waste liquid collection tank 19 from the waste liquid outlet 29. The solids enter the discharge chamber 32 from the pyrolysis furnace outlet 30 and are conveyed to the ball mill crusher 24 through material conveying pipe II23 to be mixed and crushed with biomass (the mass ratio of waste residue to biomass is 1:2, the ball milling ratio is 3:1, and the ball mill speed is 800 r / min). Then, conventional soil composting treatment is carried out. The remaining waste residue is mixed with dried corn stalks and crushed in a ball mill crusher for 30 minutes before being used for soil utilization. Example

[0026] This embodiment uses the above-mentioned device to treat arsenic sulfide slag from the wastewater treatment workshop of a copper smelter. The chemical composition of the arsenic sulfide slag was analyzed by ICP and XRD. The main components were: As 37.95%, S 37.65%, Cu 1.47%, and Zn 1.26%. Specifically, the arsenic sulfide slag was fed into a solution of 0.8 mol / L... In the alkaline leaching tank of KOH solution, stirrer 26 was turned on and stirred at 200 rpm for 60 min at room temperature. After the reaction, baffle I at the outlet of the alkaline leaching tank was opened to allow the material to flow into the acid washing filter tank 6. After solid-liquid separation by the primary drive filter belt 5 (drive speed 1 m / s), the solid was transported to dryer I 13 and dried at 80℃ for 5 h. The filtrate then entered the lower acid washing tank 10 and reacted with a 2 mol / L sulfuric acid solution at 90℃ for 30 min to generate As2O3 precipitate. Baffle II 8 was opened and the reaction product entered the secondary drive filter belt 14 on the right side of the acid washing tank (drive speed 0.8 m / s) for solid-liquid separation. The filtrate entered the lower filtrate tank 11 and was pumped back into the acid washing tank for recycling. The As2O3 filter residue was dried in dryer II on the right side and then recycled. The As2O3 content in the As2O3 filter residue was tested and found to be 69.52%, with arsenic content of 49.52%. The removal rate reached 98.03%; the dried material in dryer I entered the vertical pyrolysis furnace 16 through the material conveying pipe I15, and was pyrolyzed at 500℃ for 1 hour in the pyrolysis furnace chamber. The Hg vapor generated by pyrolysis entered the shell-and-tube condenser 22 through the gas conveying pipe 21 above the pyrolysis furnace for condensation and recovery. The mercury content was 95.21%; the generated tar and other waste liquids entered the waste liquid collection chamber 31 through the filter screen 27, and were recovered from the waste liquid outlet 29 to the waste liquid collection tank 19; the solids entered the discharge chamber 32 from the pyrolysis furnace discharge port 30, and were conveyed to the ball mill crusher 24 through the material conveying pipe II23 to be mixed and crushed with biomass (the mass ratio of waste residue to biomass is 1:1, the ball milling ratio is 12:1, and the ball mill speed is 700r / min). Then, conventional soil composting treatment was carried out. The remaining waste residue was mixed with rice husks and crushed in the ball mill crusher for 50 minutes before being used for soil utilization. Example

[0027] This embodiment uses the above-mentioned device to process arsenic- and mercury-containing tailings from the flotation workshop of a metallurgical plant. Specifically, arsenic sulfide slag is fed into the feed inlet 1 above the alkaline leaching tank 2, which contains 5 mol / L... In the alkaline leaching tank of NaOH solution, stirrer 26 was turned on and the reaction was carried out at 220 rpm. After reacting for 50 min at room temperature, baffle I at the outlet of the alkaline leaching tank was opened to allow the material to flow into the pickling filter tank 6. After solid-liquid separation by the primary drive filter belt 5 (drive speed 0.6 m / s), the solid was transported to dryer I 13 and dried at 80℃ for 6 h. The filtrate then entered the pickling tank 10 below and reacted with a 3 mol / L sulfuric acid solution at 80℃ for 50 min to generate As2O3 precipitate. Baffle II 8 was opened and the reaction product entered the secondary drive filter belt 14 on the right side of the pickling tank (drive speed 0.5 m / s) for solid-liquid separation. The filtrate entered the lower filtrate tank 11 and was pumped back into the pickling tank by pump 12 for recycling. The As2O3 filter residue was dried and recycled in dryer II on the right side. The As2O3 content in the As2O3 filter residue was tested and found to be 72.81%. Arsenic removal rate reached 97.7%; the dried material in dryer I entered the vertical pyrolysis furnace 16 through material conveying pipe I15, and was pyrolyzed at 450℃ for 1.5h in the pyrolysis furnace chamber. The Hg vapor generated by pyrolysis entered the shell-and-tube condenser 22 through the gas conveying pipe 21 above the pyrolysis furnace for condensation and recovery. The mercury content was 96.02%; the generated tar and other waste liquids entered the waste liquid collection chamber 31 through the filter screen 27, and were recovered from the waste liquid outlet 29 to the waste liquid collection tank 19; the solids entered the discharge chamber 32 from the pyrolysis furnace discharge port 30, and were conveyed to the ball mill crusher 24 through material conveying pipe II23 to be mixed and crushed with biomass (the mass ratio of waste residue to biomass is 1:5, the ball milling ratio is 10:1, and the ball mill speed is 600r / min). Then, conventional soil composting treatment was carried out. The remaining waste residue was mixed with sugarcane bagasse and crushed in a ball mill crusher for 60min before being used for soil utilization.

Claims

1. A method for the complete resource utilization of arsenic and mercury-containing waste residue, characterized in that: Arsenic-containing or arsenic-mercury-containing waste residue was subjected to alkaline leaching treatment at room temperature and pressure. After solid-liquid separation, acid was added to the filtrate and a precipitate was formed at 60℃-90℃. The precipitate was collected and dried to obtain As2O3. After drying the filter residue, it was pyrolyzed at 300-600℃, and the mercury was volatilized and condensed for recovery. The waste residue from which arsenic and mercury were removed was mixed with biomass at a mass ratio of 1:1-1:5, crushed, and then composted in soil. The apparatus for completing the above method includes an arsenic recovery unit, a mercury recovery unit, and a soil treatment unit. The arsenic recovery unit includes an alkaline leaching tank (2), an acid washing filter box (6), a dryer I (13), and a dryer II (14). The alkaline leaching tank (2) is equipped with a feed inlet (1) and an alkali addition inlet (4) at the top, and a stirrer (26) is installed inside. The bottom outlet of the alkaline leaching tank (2) is equipped with a baffle I (3) and the outlet is connected to the acid washing filter box (6). The acid washing filter box (6) is equipped with a primary drive filter belt (5), and below the primary drive filter belt (5) is... Pickling tank (10), with a heating plate (28) at the bottom of the pickling tank (10), a secondary transmission filter belt (9) on one side of the heating plate at the bottom of the pickling tank (10), baffle II (8) is inclined at the junction of the heating plate and the secondary transmission filter belt, a filtrate tank (11) is provided below the secondary transmission filter belt (9), and the filtrate tank (11) is connected to the acid inlet (7) on the pickling tank (10) through a pump (12); the primary transmission filter belt (5) is connected to the dryer I (13), and the secondary transmission filter belt (9) is connected to the dryer II (14); The mercury recovery unit includes a vertical pyrolysis furnace (16), a waste liquid collection tank (19), a condenser (22), a ball mill crusher, and a mercury collection tank (25). The dryer I (13) is connected to the inlet of the vertical pyrolysis furnace (16) through the material conveying pipe I (15). The top of the vertical pyrolysis furnace (16) is connected to the inlet of the shell-and-tube condenser (22) through the gas conveying pipe (21). The mercury collection tank (25) is located at the bottom of the vertical pyrolysis furnace (16). The vertical pyrolysis furnace (16) is connected to the ball mill crusher (24) through the material conveying pipe II (23). A heating jacket (18) is provided outside the shell of the vertical pyrolysis furnace (16). The internal cavity of the vertical pyrolysis furnace (16) is divided into a pyrolysis furnace cavity (17), a waste liquid collection cavity, and a discharge cavity by a filter screen (27) and a partition. The filter screen (27) is an arc-shaped filter screen and has a pyrolysis furnace discharge port (30) at the bottom. A waste liquid outlet (29) is provided at the lower part of the shell of the vertical pyrolysis furnace (16) and the waste liquid outlet is connected to the waste liquid collection cavity. The waste liquid collection tank (19) is located below the waste liquid outlet (29).

2. The method according to claim 1, characterized in that: Temperature and pressure sensors (20) are installed inside the vertical pyrolysis furnace (16).

3. The method according to claim 1, characterized in that: Dryer I and Dryer II are horizontal spiral dryers.

4. The method according to claim 1, characterized in that: A spiral conveyor rod is installed inside material conveying pipe I and material conveying pipe II.

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