Self-adjusting stepped pressure leaching system

Abstract

The invention relates to a self-adjusting stepped pressure leaching system which comprises an ore inlet pipe, a buffer tank, a gas tank, a medicament tank, a first reaction tank, a second reaction tank and a third reaction tank which are sequentially connected in series through pipelines, the agent tank conveys agents to the buffer tank, the second reaction tank and the third reaction tank through the high-pressure agent pump, the ore inlet pipe is communicated with the buffer tank, the buffer tank is communicated with the first reaction tank through the high-pressure ore pulp pump, the air tank is connected with the air compressor, and the air tank is communicated with the first reaction tank through the air inlet pipe. The air inlet pipe extends downwards to the lower part of the first reaction tank. The whole pressure leaching system is in a sealed state, so that the pollution to the surrounding environment is effectively reduced, and the body health of operators is facilitated; air is supplied into the first reaction tank through the air tank, and the air flows into the second reaction tank and the third reaction tank along with the pipeline, so that the reaction time is shortened, the quantity of waste gas is reduced, and the utilization rate of oxygen in the air is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of gold smelting, and in particular to a self-adjusting stepped pressure leaching system. Background Art

[0002] In the gold smelting process, the leaching process is the key process for converting solid gold into liquid gold. The gold-containing raw materials generally require a conversion time of more than or equal to 30 hours in this process. Not only is the conversion speed slow and the equipment occupies a large area, but the process control is also difficult to master, the air utilization rate is low, and a large amount of toxic and harmful gases are generated, which fill the air and endanger the health of operators. Summary of the invention

[0003] In view of the existing technical problems, the present invention provides a self-adjusting stepped pressure leaching system.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: a self-adjusting stepped pressure leaching system, comprising an ore inlet pipe, a buffer tank, a gas tank, a reagent tank, a first reaction tank, a second reaction tank and a third reaction tank, the first reaction tank, the second reaction tank and the third reaction tank are connected in series in sequence through pipelines, the reagent tank transports the reagent to the buffer tank, the second reaction tank and the third reaction tank respectively through a high-pressure reagent pump, the ore inlet pipe is connected to the buffer tank, the buffer tank is connected to the first reaction tank through a high-pressure slurry pump, the gas tank is connected to an air compressor, the gas tank is connected to the first reaction tank through an air inlet pipe, and the air inlet pipe extends downward to the lower part of the first reaction tank.

[0005] On the basis of the above technical solution, the present invention can also be improved as follows:

[0006] Preferably, a lifting assembly is installed in the first reaction tank, the second reaction tank and the third reaction tank, and the lifting assembly includes a lifting cylinder and a mixing cylinder. The lifting cylinder and the mixing cylinder are connected, the lifting cylinder is vertically arranged, the lower end of the mixing cylinder is trumpet-shaped, and a gap for the slurry to pass through is provided between the lower edge of the mixing cylinder and the inner wall of the tank body, and the ore inlet pipe passes through the lifting cylinder and extends downward into the mixing cylinder.

[0007] Preferably, the lifting components are provided in one or more groups.

[0008] Preferably, a hot and cold device is also included, and hot and cold coils are provided in the first reaction tank, the third reaction tank and the third reaction tank, and the hot and cold coils are arranged on the outside of the lifting cylinder. The hot and cold device is connected to the hot and cold coils through a liquid inlet pipe and a liquid discharge pipe.

[0009] Preferably, the first reaction tank is connected to the second reaction tank through an air slurry pipe 1, and the slurry outlet of the air slurry pipe 1 is located in the mixing barrel of the second reaction tank. The second reaction tank is connected to the third reaction tank through an air slurry pipe 2, and the slurry outlet of the air slurry pipe 2 is located in the mixing barrel of the third reaction tank.

[0010] Preferably, the first reaction tank and the second reaction tank are both equipped with sampling devices, the sampling devices comprising a sampling tube and a sampling cup, the sampling tube is connected to the sampling cup, a front-stage sampling valve is installed between the sampling tube and the sampling cup, and an air release valve and a rear-stage sampling valve are installed on the sampling cup.

[0011] Preferably, the first reaction tank and the second reaction tank are each equipped with two glass windows, and glass wipes are installed on the glass windows. A lighting lamp is installed on the outer side of one of the glass windows through a protective cover, and the lighting lamp is used to illuminate the interior of the first reaction tank and the second reaction tank.

[0012] Preferably, the first reaction tank and the second reaction tank are both installed with a safety valve 1, and an anti-blocking screen is installed at the lower end of the safety valve 1, and the anti-blocking screen is located inside the tank body.

[0013] Preferably, the first reaction tank and the second reaction tank are both installed with a pressure gauge 1, and a wide-mouth valve is installed at the lower end of the pressure gauge 1, and the wide-mouth valve is located inside the tank body.

[0014] Preferably, the third reaction tank is provided with an exhaust port and a detection sampling port, the exhaust port is used to be connected to the harmful gas treatment device, and the detection sampling port is provided with a sealing cover.

[0015] The beneficial effects of the present invention are:

[0016] 1. The entire pressure leaching system is in a sealed state, which effectively reduces the pollution to the surrounding environment and is beneficial to the health of operators;

[0017] 2. The entire pressure leaching reaction system supplies air to the first reaction tank through a gas tank, and the air flows into the second and third reaction tanks along the pipeline, shortening the reaction time. This not only reduces the amount of waste gas, but also effectively improves the utilization rate of oxygen in the air, reduces the amount of carbon dioxide participating in the chemical reaction, and reduces the amount of alkaline agents used.

[0018] 3. In the whole pressure leaching reaction system, the air pressure is between 0.1MPa and 1.6MPa, which can accelerate the chemical reaction rate. Under this pressure, the reagents can more easily enter the solid slurry to participate in the reaction, which is also beneficial to improve the leaching rate.

[0019] 4. The entire pressure leaching reaction system is in a stepped pressure state. The first reaction tank has the highest solid metal content, requires the most cyanide and oxygen, and has the highest air pressure to ensure the reaction effect; the solid metal content entering the second reaction tank is less than that of the first reaction tank, and the oxygen content in the gas transported from the first reaction tank to the second reaction tank decreases. By analogy, as the amount of solid metal decreases, the oxygen content also gradually decreases. By fine-tuning the amount of cyanide, the ratio of cyanide to oxygen is always maintained at about six, in accordance with the law of chemical reaction, to ensure the production of liquid gold.

[0020] 5. There are no moving parts in the entire system, ensuring the reliability of equipment operation.

[0021] 6. Under the condition of achieving the same leaching rate, the leaching system can reduce the number of equipment and the floor space.

[0022] 7. A sampling device is installed on the pressure tank, which makes sampling quick and convenient and improves the convenience of operation.

[0023] 8. By setting up air slurry pipes between the tanks, it is not only a common channel for slurry and pressurized gas, but also can ensure that the foam generated in the tank is discharged to the next level in time, effectively separating and recovering the gold liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the self-adjusting stepped pressure leaching system of the present invention.

[0025] The reference numerals are recorded as follows: 1. Ore inlet pipe; 2. Buffer tank; 3. High-pressure slurry pump; 4. Slurry one-way valve; 5. First reaction tank; 6. Second reaction tank; 7. Glass window; 8. Glass wiper; 9. Third reaction tank; 10. Sampling tube; 11. Air inlet pipe; 12. Fixed flange; 13. Power supply line; 14. Protective cover; 15. Illuminating lamp; 16. Lifting cylinder; 17. Mixing cylinder; 18. Inspection valve; 19. Air slurry pipe 1; 20. Air slurry pipe 2; 21. Exhaust port; 22. Flow meter 1; 23. Air release valve; 24. Sampling cup; 25. Post-stage sampling valve; 26. Pre-stage sampling valve; 27. Anti-blocking screen; 28. Safety valve one; 29. ​​Pressure gauge one; 30. Wide-mouth valve; 31. Chemical one-way valve; 32. Flow meter two; 33. Chemical valve; 34. Compressed gas one-way valve; 35. Compressed gas valve; 36. Safety valve two; 37. Pressure gauge two; 38. Gas tank; 39. Air compressor; 40. High-pressure chemical pump; 41. Flow meter three; 42. Chemical tank; 43. Cold and hot device; 44. Liquid inlet pipe; 45. Liquid discharge pipe; 46. Liquid inlet pipe valve; 47. Liquid discharge pipe valve; 48. Cold and hot coils; 49. Ore discharge port; 50. Detection sampling port; 51. Sealing cover. DETAILED DESCRIPTION

[0026] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0027] like Figure 1 As shown, the present invention discloses a self-adjusting step pressure leaching system, including an inlet pipe 1, a buffer tank 2, a gas tank 38, a reagent tank 42, a first reaction tank 5, a second reaction tank 6 and a third reaction tank 9. The first reaction tank 5, the second reaction tank 6 and the third reaction tank 9 are connected in series in sequence through pipelines. The lower ends of the first reaction tank 5, the second reaction tank 6 and the third reaction tank 9 are all equipped with a check valve 18, which is used to remove the slurry or liquid retained in the tank body during maintenance, so as to facilitate maintenance. The reagent tank 42 transfers cyanide to the reagent tank 42 through a high-pressure reagent pump 40. The chemical reagents are transported to the buffer tank 2, the second reaction tank 6 and the third reaction tank 9 respectively. A flow meter 41 is installed on the pipeline between the high-pressure reagent pump 40 and the buffer tank 2 to measure the flow of the reagents and ensure the subsequent reaction efficiency of the reagents and the slurry. The ore inlet pipe 1 is connected to the buffer tank 2. The ore inlet pipe 1 is used to transport the previously processed ore to the buffer tank 2. The slurry and the reagents are mixed in the buffer tank 2. The buffer tank 2 is connected to the first reaction tank 5 through the high-pressure slurry pump 3 to transport the slurry and the reagents to the first reaction tank 5. A slurry check valve 4 is installed on the ore supply pipe between the high-pressure slurry pump 3 and the first reaction tank 5 to prevent the slurry in the first reaction tank 5 from returning to the buffer tank 2 due to the pressure after the high-pressure slurry pump 3 stops running. The gas tank 38 is connected to the air compressor 39. The gas tank 38 is installed with a safety valve 2 36 and a pressure gauge 2 37. The gas tank 38 is connected to the first reaction tank 5 through the air inlet pipe 11. The air inlet pipe 11 is installed on the first reaction tank 5 through a fixed flange 12. A compressed gas check valve 13 is installed on the air inlet pipe 11. Valve 34 and compressed gas valve 35, the compressed gas one-way valve 34 is used to prevent the gas or slurry in the first reaction tank 5 from flowing back due to abnormal air supply, and the compressed gas valve 35 is used to control the on and off of the compressed gas for easy maintenance. The air inlet pipe 11 extends downward to the lower part of the first reaction tank 5, so that the pressure of the first reaction tank 5 is maintained between 0.1MPa-1.6MPa, thereby improving the mixing effect of air and slurry, providing sufficient oxygen, so that cyanide and gold form a soluble complex, and improving the leaching rate of gold.

[0028] In this embodiment, specifically, the first reaction tank 5, the second reaction tank 6 and the third reaction tank 9 are all equipped with lifting components, and the lifting components are provided with one or more groups, and the lifting components include a lifting cylinder 16 and a mixing cylinder 17, and the lifting cylinder 16 and the mixing cylinder 17 are connected, and the lifting cylinder 16 is arranged vertically, and the lower end of the mixing cylinder 17 is trumpet-shaped, and a gap for the slurry to pass through is provided between the lower edge of the mixing cylinder 17 and the inner wall of the tank body, and the gap is 20cm-40cm, so as to ensure the normal flow of the slurry, and the ore inlet pipe 1 passes through the lifting cylinder 16 and extends downward into the mixing cylinder 17. The slurry is made to circulate up and down in the tank body, the contact area between the slurry and the reagent and the air is increased, and the leaching rate of gold is increased.

[0029] The outer wall of the lifting cylinder 16 is fixed to the inner wall of the tank body through a bracket, and the mixing cylinder 17 is connected to the lifting cylinder 16 . The opening angle of the lower end of the mixing cylinder 17 is 45°-60°, which is convenient for the slurry to enter the mixing cylinder 17 .

[0030] In this embodiment, specifically, the first reaction tank 5 is connected to the second reaction tank 6 through the air slurry pipe 19, and the slurry outlet of the air slurry pipe 19 is located in the mixing barrel 17 of the second reaction tank 6, so that the slurry output from the first reaction tank 5 is fully mixed with the slurry in the second reaction tank 6, reducing the probability of the slurry not reacting in the second reaction tank 6 and directly entering the third reaction tank 9, thereby ensuring the leaching rate of gold. The high-pressure reagent pump 40 is connected to the air slurry pipe 19 through the conveying pipeline to ensure that the reagent and the slurry are mixed in advance, which is conducive to the stability of the reagent concentration. The conveying pipeline is equipped with a reagent one-way valve 31, a flow meter 2 32 and a reagent valve 33, wherein the flow meter 2 32 can withstand the pressure in the first reaction tank 5 to ensure that it can work normally; the second reaction tank 6 is connected to the third reaction tank 9 through the air slurry pipe 20, and the slurry outlet of the air slurry pipe 20 is located in the mixing barrel 17 of the third reaction tank 9, so that the slurry output from the second reaction tank 6 is fully mixed with the slurry in the third reaction tank 9, reducing the probability of the slurry being directly discharged without reacting in the third reaction tank 9, thereby ensuring the leaching rate of gold. The high-pressure reagent pump 40 is connected to the third reaction tank 9 through the conveying pipeline, and the flow meter 1 22 is installed on the conveying pipeline. The third reaction tank 9 is the final stage of the reaction, and the requirement for the reagent concentration in the slurry is relatively low. The conveying pipeline is set on the third reaction tank 9 for easy installation.

[0031] Furthermore, regulating valves are installed on both the air slurry pipe 19 and the air slurry pipe 20 to control the pressure in the previous stage reaction tank. When the amount of air and slurry input into the reaction tank remains unchanged, reducing the opening of the regulating valve will increase the pressure in the previous stage reaction tank, and vice versa, the pressure will decrease, thereby ensuring that the pressure in the reaction tank is within a normal range and ensuring safety during use.

[0032] In this embodiment, the first reaction tank 5 and the second reaction tank 6 are both equipped with a sampling device, which includes a sampling tube 10 and a sampling cup 24. The sampling tube 10 is connected to the sampling cup 24. The sampling tube 10 is trumpet-shaped to prevent clogging. The taken out slurry is stored in the sampling cup 24. A front-stage sampling valve 26 is installed between the sampling tube 10 and the sampling cup 24. The sampling cup 24 is equipped with a vent valve 23 and a rear-stage sampling valve 25. The vent valve 23 is used to remove the gas in the sampling cup 24 and is used in conjunction with the front-stage sampling valve 26. The sampling process is as follows: open the front-stage sampling valve 26, slowly open the vent valve 23, and discharge the gas in the sampling tube 10. Due to the pressure in the reaction tank, the slurry in the tank will flow along the sampling tube 10 into the sampling cup 24. The slurry is deposited to the bottom of the sampling cup 24 due to gravity. Close the front-stage sampling valve 26, open the rear-stage sampling valve 25, and after releasing the slurry, close the rear-stage sampling valve 25 and the vent valve 23, and the sampling is completed. By sampling the slurry, it is possible to timely understand whether the reaction conditions of gold are normal and whether the speed is in the optimal state, so as to facilitate timely adjustment of process parameters.

[0033] Furthermore, the sampling port at the end of the sampling tube 10 is positioned lower than the positions of the air slurry ports of the air slurry tube 1 19 and the air slurry tube 2 20, to ensure that the slurry in the tank can be obtained even when there is no ore supply, thereby ensuring that the slurry can be normally tested.

[0034] In this embodiment, specifically, two glass windows 7 are installed on the first reaction tank 5 and the second reaction tank 6. The glass windows 7 are made of high-strength transparent glass, such as tempered glass. Glass wipers 8 are installed on the glass windows 7. The glass wipers 8 are strong magnetic glass wipers. Two glass wipers 8 are installed, which are respectively placed on the inner and outer sides of the glass window 7 to clean the mineral dirt splashed in the tank and the dust on the outer side of the glass to improve the light transmittance of the glass window 7. The cleaning cloth outside the glass wipers 8 in the tank body is a cleaning cloth resistant to strong alkali and cyanide corrosion, such as polytetrafluoroethylene coated fabric, glass fiber cloth, polypropylene base cleaning cloth, etc. A lighting lamp 15 is installed on the outer side of one of the glass windows 7 through a protective cover 14, and the lighting lamp 15 is used to illuminate the inside of the first reaction tank 5 and the second reaction tank 6. The protective cover 14 is used to protect the lighting lamp 15 from being damaged by external forces. At the same time, it can reduce the outward scattering of part of the light, so that most of the light is concentrated on the reaction tank body, ensuring that the operation inside the tank can be clearly observed through the glass window 7 on the other side. The lighting lamp 15 is electrically connected to the power supply through the power supply line 13. The lighting lamp 15 adopts LED energy-saving lamp, which is highly efficient and energy-saving and has a long service life.

[0035] Furthermore, after removing the glass at the glass window 7, it can be used as an inspection passage to improve the convenience and flexibility of use.

[0036] In this embodiment, specifically, the first reaction tank 5 and the second reaction tank 6 are both equipped with a safety valve 28, and the lower end of the safety valve 28 is equipped with an anti-blocking screen 27, which is located in the tank body. The safety valve 28 can prevent the pressure in the first reaction tank 5 and the second reaction tank 6 from being too high and causing damage to the tank body. When the pressure in the reaction tank exceeds a certain value, the safety valve 28 automatically opens to release the pressure. The anti-blocking screen 27 is a screen with multiple small holes, which can effectively prevent bubbles and debris from entering the safety valve 28, ensuring that the safety valve 28 can work normally.

[0037] In this embodiment, specifically, a pressure gauge 29 is installed on both the first reaction tank 5 and the second reaction tank 6, and a wide-mouth valve 30 is installed at the lower end of the pressure gauge 29, and the wide-mouth valve 30 is located in the tank body. The pressure gauge 29 is used to display the pressure in the reaction tank, and the wide-mouth valve 30 can prevent debris from entering the pressure gauge 29, ensuring that the pressure gauge 29 can work normally.

[0038] The third reaction tank 9 is provided with an exhaust port 21, a discharge port 49 and a detection sampling port 50. The detection sampling port 50 is provided with an openable and closable sealing cover 51. The sealing cover 51 seals the detection sampling port 50 when not sampling, detecting or overhauling to prevent the harmful gas in the tank from overflowing. The exhaust port 21 is used to connect with the harmful gas treatment device to prevent the gas containing toxic substances from diffusing into the air and ensure the health of the operator. The harmful gas treatment device adopts the existing technology. The discharge port 49 is used to transport the slurry to the next process.

[0039] The self-adjusting step pressure leaching system also includes a hot and cold device 43. Hot and cold coils 48 are provided in the first reaction tank 5, the second reaction tank 6 and the third reaction tank 9. The hot and cold coils 48 are made of seamless steel pipes. During normal use, a small part of the ore particles will accumulate on the hot and cold coils 48 to form a cone to protect the hot and cold coils 48. The hot and cold coils 48 in the three reaction tanks are arranged in parallel to facilitate the temperature control of each tank body. The hot and cold coils 48 are arranged on the outside of the lifting cylinder 16. The hot and cold device 43 is connected to the hot and cold coils 48 through the liquid inlet pipe 44 and the liquid discharge pipe 45. The liquid inlet pipe 44 is equipped with a liquid inlet pipe valve 46, and the liquid discharge pipe 45 is equipped with a liquid discharge pipe valve 47, which is used to adjust the liquid inlet amount in the hot and cold coils 48. The hot and cold device 43 is a boiler or a radiator. The hot and cold device 43 is to enable the system to meet the winter use in northern regions or to reach the production conditions of a special mineral. Similarly, in the summer in the south, when the ambient temperature is too high and exceeds the temperature range required for system production, the hot and cold device 43 can use a radiator to effectively control the temperature in the leaching system. By transporting hot water or cooling water to the hot and cold coil 48, the temperature in the tank can be controlled to meet the use requirements in different environments and increase the scope of use.

[0040] The working process of the present invention is as follows:

[0041] The slurry enters the buffer tank 2 from the ore inlet pipe 1, is mixed with the reagent flowing out of the reagent tank 42 in the buffer tank 2, and is transported to the first reaction tank 5 through the high-pressure slurry pump 3. The compressed air provided by the air compressor 39 enters the first reaction tank 5 through the gas tank 38, the compressed gas valve 35, the compressed gas one-way valve 34, and the air inlet pipe 11. After being fully mixed with the slurry in the mixing cylinder 17, the gas-slurry mixture, which is subjected to a large buoyancy, floats in the lifting cylinder 16 and overflows at the upper end of the lifting cylinder 16. At the same time, the overflowed slurry will continue to settle to the bottom of the first reaction tank 5 due to gravity, and then enter the lifting cylinder 16 through the mixing cylinder 17. This cycle of operation ensures that the slurry in the first reaction tank 5 is in a suspended state, thereby ensuring the leaching rate of gold.

[0042] The height of the slurry level in the first reaction tank 5 is determined by the position of the air slurry pipe 19 at the interface of the first reaction tank 5. The amount of slurry discharged can be increased or decreased by adjusting the opening of the regulating valve on the air slurry pipe 19: when the amount of slurry discharged decreases, under the combined effect of the pressure wind of the continuous air supply and the slurry passing through the slurry check valve 4, the slurry supply will be greater than the slurry discharge. At this time, the internal pressure of the first reaction tank 5 will rise. By controlling the regulating valve to adjust the amount of slurry discharged, the pressure requirement can be met and the slurry discharge can be ensured to be smooth. On the contrary, the pressure in the tank will decrease.

[0043] Furthermore, even if the regulating valves of the air slurry pipe 19 and the air slurry pipe 20 are in the fully open state, the pressure in each tank is in the state of: the pressure in the first reaction tank 5 > the pressure in the second reaction tank 6 > the pressure in the third reaction tank 9 > the atmospheric pressure, wherein the air pressure in the first reaction tank 5 is equal to the sum of the pressures in the second reaction tank 6 and the third reaction tank 9, ensuring that the slurry can be transported step by step.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-adjusting step pressure leaching system, characterized in that: The invention comprises a mineral inlet pipe (1), a buffer tank (2), a gas tank (38), a reagent tank (42), a first reaction tank (5), a second reaction tank (6) and a third reaction tank (9); the first reaction tank (5), the second reaction tank (6) and the third reaction tank (9) are connected in series in sequence through pipelines; the reagent tank (42) transports reagents to the buffer tank (2), the second reaction tank (6) and the third reaction tank (9) respectively through a high-pressure reagent pump (40); the mineral inlet pipe (1) is connected to the buffer tank (2); the buffer tank (2) is connected to the first reaction tank (5) through a high-pressure slurry pump (3); the gas tank (38) is connected to an air compressor (39); the gas tank (38) is connected to the first reaction tank (5) through an air inlet pipe (11); and the air inlet pipe (11) extends downward to the lower part of the first reaction tank (5).

2. The self-adjusting step pressure leaching system according to claim 1, characterized in that: The first reaction tank (5), the second reaction tank (6) and the third reaction tank (9) are all equipped with lifting assemblies, and the lifting assemblies include a lifting cylinder (16) and a mixing cylinder (17). The lifting cylinder (16) and the mixing cylinder (17) are connected, the lifting cylinder (16) is vertically arranged, the lower end of the mixing cylinder (17) is trumpet-shaped, and a gap is provided between the lower edge of the mixing cylinder (17) and the inner wall of the tank body for the slurry to pass through, and the ore inlet pipe (1) passes through the lifting cylinder (16) and extends downward into the mixing cylinder (17).

3. The self-adjusting step pressure leaching system according to claim 2, characterized in that: The lifting components are provided in one or more groups.

4. The self-adjusting step pressure leaching system according to claim 1 or 2, characterized in that: It also includes a hot and cold device (43), wherein the first reaction tank (5), the third reaction tank (9) and the third reaction tank (9) are all provided with hot and cold coils (48), wherein the hot and cold coils (48) are arranged on the outside of the lifting cylinder (16), and the hot and cold device (43) is connected to the hot and cold coils (48) via a liquid inlet pipe (44) and a liquid discharge pipe (45).

5. The self-adjusting step pressure leaching system according to claim 1 or 2, characterized in that: The first reaction tank (5) is connected to the second reaction tank (6) via an air slurry pipe (19), and the slurry outlet of the air slurry pipe (19) is located in the mixing cylinder (17) of the second reaction tank (6); the second reaction tank (6) is connected to the third reaction tank (9) via an air slurry pipe (20), and the slurry outlet of the air slurry pipe (20) is located in the mixing cylinder (17) of the third reaction tank (9).

6. The self-adjusting step pressure leaching system according to claim 1, characterized in that: The first reaction tank (5) and the second reaction tank (6) are both equipped with a sampling device, the sampling device comprising a sampling tube (10) and a sampling cup (24), the sampling tube (10) being connected to the sampling cup (24), a front-stage sampling valve (26) being installed between the sampling tube (10) and the sampling cup (24), and a venting valve (23) and a rear-stage sampling valve (25) being installed on the sampling cup (24).

7. The self-adjusting step pressure leaching system according to claim 2, characterized in that: The first reaction tank (5) and the second reaction tank (6) are both provided with two glass windows (7), and glass wipers (8) are provided on the glass windows (7). A lighting lamp (15) is provided on the outer side of one of the glass windows (7) through a protective cover (14), and the lighting lamp (15) is used to illuminate the interior of the first reaction tank (5) and the second reaction tank (6).

8. The self-adjusting step pressure leaching system according to claim 1, characterized in that: The first reaction tank (5) and the second reaction tank (6) are both installed with a safety valve 1 (28), and an anti-blocking screen (27) is installed at the lower end of the safety valve 1 (28), and the anti-blocking screen (27) is located inside the tank body.

9. The self-adjusting step pressure leaching system according to claim 1, characterized in that: The first reaction tank (5) and the second reaction tank (6) are both installed with a pressure gauge (29), and a wide-mouth valve (30) is installed at the lower end of the pressure gauge (29), and the wide-mouth valve (30) is located inside the tank body.

10. The self-adjusting step pressure leaching system according to claim 1, characterized in that: The third reaction tank (9) is provided with an exhaust port (21) and a detection sampling port (50); the exhaust port (21) is used to be connected to a harmful gas treatment device; and the detection sampling port (50) is provided with a sealing cover (51).

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