High-pressure acid leaching system

Abstract

The present application relates to the technical field of high-pressure acid leaching. Provided is a high-pressure acid leaching system, comprising an autoclave, a preheater, a flash tank and an autoclave feed pump. The autoclave is connected to the flash tank, the flash tank is connected to the preheater to introduce a flash gas into the preheater, and the preheater is connected to the autoclave via the autoclave feed pump. High-pressure air is introduced into the autoclave and / or the flash tank. The introduction of the high-pressure air into the autoclave and / or the flash tank enables the flash gas and the high-pressure air to jointly enter the preheater, thereby increasing the internal pressure of the preheater and reducing the temperature of ore slurry at an outlet of the preheater, and thus avoiding or reducing the occurrence of cavitation.

Description

High-pressure acid leaching system

[0001] This application claims priority to Chinese Patent Application No. 202411445772.6, filed on October 16, 2024, entitled "High-Pressure Acid Immersion System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of high-pressure acid leaching technology, and particularly to a high-pressure acid leaching system. Background Technology

[0003] In recent years, the demand for nickel in industrial production has been increasing daily. High-pressure acid leaching of laterite nickel ore has become the mainstream process for extracting nickel from minerals in recent years. In the current operating method, because the slurry in the preheater, flash tank, and pressurized kettle operates at near saturated vapor pressure, the pumps and valves in the system operate under relatively harsh conditions, which can easily lead to cavitation and other phenomena that affect their service life and increase the system's maintenance costs.

[0004] CN117083397A discloses a system and method for controlling Al precipitation during high-pressure acid leaching of laterite nickel ore. The system includes a high-pressure autoclave and subsequent processing equipment. The high-pressure autoclave includes a body, a first addition pipe, a second addition pipe, and a discharge pipe. The subsequent processing equipment is connected to the discharge pipe and includes a flash evaporation mechanism and a leachate storage tank. The flash evaporation mechanism is connected to the discharge pipe, and the leachate storage tank is connected to the flash evaporation mechanism. Further, the flash evaporation mechanism includes a primary flash evaporator, a secondary flash evaporator, and a tertiary flash evaporator, which are connected sequentially. The primary flash evaporator is connected to the discharge pipe.

[0005] The invention application disclosed the Al precipitation control system for the high-pressure acid leaching process of laterite nickel ore, which includes a high-pressure autoclave and a multi-stage flash evaporation mechanism connected to it. However, it did not disclose the structure for recycling the flash gas generated by the multi-stage flash evaporation mechanism or related improvement schemes. Summary of the Invention

[0006] This application is made in view of the aforementioned state of the prior art. The purpose of this application is to provide a high-pressure acid leaching system that can at least partially introduce the flash gas generated by the primary flash tank into the final stage preheater to heat the slurry, and can also introduce high-pressure air into the pressure vessel and / or flash tank to reduce cavitation and extend the service life of the pressure vessel feed pump.

[0007] This application provides a high-pressure acid leaching system, which includes a pressure vessel, a preheater, a flash tank, and a pressure vessel feed pump, wherein...

[0008] The pressurizing vessel is connected to the flash tank, which is connected to the preheater to introduce flash gas into the preheater. The preheater is connected to the pressurizing vessel via a feed pump.

[0009] High-pressure air is introduced into the pressurized vessel and / or the flash tank.

[0010] In at least one possible implementation, the high-pressure acid leaching system includes a first flow control mechanism for regulating the flow rate of the high-pressure air introduced into the pressurized vessel.

[0011] The first flow control mechanism is configured to control the flow rate of the high-pressure air based on the difference between the internal pressure of the pressurizing vessel and the inlet pressure of the flash tank.

[0012] In at least one possible implementation, the first flow control mechanism is configured as follows:

[0013] Multiple consecutive and different difference relationships all correspond to the same flow rate, and the flow rate corresponds to the maximum value among multiple consecutive and different difference relationships;

[0014] Alternatively, each of the different difference relationships corresponds to a different flow rate.

[0015] In at least one possible implementation, the pressurizing vessel includes a first exhaust valve.

[0016] The first flow control mechanism calculates the theoretical pressure inside the pressure vessel based on the internal pressure of the pressurizing vessel and the pressure before the valve of the flash tank.

[0017] The opening degree of the first exhaust valve and / or the flow rate of the high-pressure air introduced into the pressurized vessel are controlled based on the numerical relationship between the theoretical pressure inside the vessel and the measured actual pressure inside the vessel.

[0018] In at least one possible implementation, the theoretical pressure inside the vessel is calculated by summing the difference between the internal pressure of the pressurized vessel and the inlet pressure of the flash tank with the saturated vapor pressure corresponding to the temperature of the pressurized vessel.

[0019] In at least one possible implementation, the numerical relationship includes a difference relationship and / or a ratio relationship.

[0020] In at least one possible implementation, a second flow control mechanism is included for regulating the flow rate of the high-pressure air introduced into the flash tank.

[0021] The second flow control mechanism is configured to control the flow rate of the high-pressure air introduced into the flash tank within a preset range.

[0022] In at least one possible implementation, the flash tank includes a second vent valve, and the theoretical tank pressure is calculated based on the preset range.

[0023] The second flow control mechanism controls the opening of the second exhaust valve and / or the flow rate of the high-pressure air introduced into the flash tank based on the numerical relationship between the theoretical tank pressure and the measured actual tank pressure.

[0024] In at least one possible implementation, the theoretical tank pressure is derived from the sum of the saturated vapor pressure corresponding to the temperature of the flash tank and the pressure corresponding to the preset range.

[0025] In at least one possible implementation, a gas control system is included, the gas control system being configured to adjust the amount of flash vapor in the flash tank entering the preheater according to the temperature of the preheater.

[0026] In at least one possible implementation, the preheater includes at least a primary preheater, a secondary preheater, and a final preheater with sequentially increasing temperatures, and the flash tank includes at least a primary flash tank, a secondary flash tank, and a tertiary flash tank with sequentially decreasing pressures.

[0027] The secondary flash tank is connected to the secondary preheater, the tertiary flash tank is connected to the primary preheater, and the primary flash tank is connected to the final preheater.

[0028] The high-pressure acid leaching system provided in this application can separately introduce high-pressure air into the pressure vessel and / or flash tank, allowing flash gas and high-pressure air to enter the preheater together. This increases the pressure within the preheater (especially the final preheater) and reduces the slurry temperature at the preheater outlet. This, in turn, can avoid or reduce cavitation, extend the service life of the pressure vessel feed pump, enable long-term stable operation of the equipment, and reduce the operation and maintenance costs of the high-pressure acid leaching system. Attached Figure Description

[0029] Figure 1 is a simplified structural diagram of a high-pressure acid leaching system according to one embodiment of this application.

[0030] Explanation of reference numerals in the attached drawings: 10-Pressure vessel; 21-First-stage preheater; 22-Second-stage preheater; 23-Third-stage preheater; 31-First-stage flash tank; 32-Second-stage flash tank; 33-Third-stage flash tank; 41-First-stage feed pump; 42-Second-stage feed pump; 43-Third-stage feed pump; 44-Pressure vessel feed pump. Detailed Implementation

[0031] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaustively describe all possible methods of this application, nor to limit the scope of this application.

[0032] This application provides a high-pressure acid leaching system, which may include a pressure vessel 10, a final-stage preheater, a primary flash tank, and a pressure vessel feed pump 44. Preferably, the high-pressure acid leaching system may include a multi-stage preheater, a multi-stage flash tank, and a multi-stage feed pump to achieve staged heating and flash evaporation of the ore slurry, thereby improving the efficiency and effectiveness of ore slurry treatment. The high-pressure acid leaching system provided in this embodiment is applicable to the high-pressure acid leaching production process of laterite nickel ore; however, it is understood that the application scenarios of this high-pressure acid leaching system are not limited to this. The connection referred to in this application includes direct connection as well as indirect connection via pipes, valves, and other structures.

[0033] Specifically, the multi-stage preheater may include a final-stage preheater connected to the pressurized vessel 10 via pumps, valves, etc. For example, the multi-stage preheater may be a three-stage preheater, namely a first-stage preheater 21, a second-stage preheater 22, and a third-stage preheater 23 (understandably, the third-stage preheater is the final-stage preheater in this example), and the operating temperature of the multi-stage preheater can be increased sequentially. The multi-stage flash tank may include a three-stage flash tank, namely a first-stage flash tank 31, a second-stage flash tank 32, and a third-stage flash tank 33. The steam pressure of the first-stage flash tank 31, the second-stage flash tank 32, and the third-stage flash tank 33 can be decreased sequentially; that is, the first-stage flash tank 31 can be a high-pressure flash tank, the second-stage flash tank 32 can be a medium-pressure flash tank, and the third-stage flash tank 33 can be a low-pressure flash tank (flash evaporation: when high-pressure saturated water enters a relatively low-pressure container, the sudden drop in pressure causes the saturated water to become a portion of saturated water vapor and saturated water at the container pressure). The multi-stage feed pump may include a three-stage feed pump, namely a primary feed pump 41, a secondary feed pump 42, a tertiary feed pump 43, and a pressurized vessel feed pump 44. The primary feed pump 41, the secondary feed pump 42, the tertiary feed pump 43, and the pressurized vessel feed pump 44 may be respectively located upstream of the primary preheater 21, the secondary preheater 22, the tertiary preheater 23, and the pressurized vessel 10.

[0034] It is understandable that the high-pressure acid leaching system may also include a piping system, a valve system, and a control and regulation system.

[0035] The primary preheater 21, secondary preheater 22, and tertiary preheater 23 can be connected sequentially (indirectly via pumps and pipelines). The material (slurry) enters the primary preheater 21, passes through the primary preheater 21, secondary preheater 22, and tertiary preheater 23, and then enters the pressure vessel 10. The pressure vessel 10 can be connected to the primary flash tank 31. The material (slurry) treated in the pressure vessel 10 can be discharged into the primary flash tank 31 via a discharge pipe, and then passes through the primary flash tank 31, secondary flash tank 32, and tertiary flash tank 33 before entering downstream production equipment. The primary flash tank 31 is the first flash tank to receive the slurry; the temperature of the slurry decreases progressively. The temperature of the flash gas generated in the primary flash tank is higher than the temperature of the flash gas generated in the subsequent connected flash tanks (secondary flash tank, tertiary flash tank). A pressure reducing valve can be installed upstream of each flash tank to relatively reduce the pressure inside the flash tank.

[0036] The gas generated in the multi-stage flash tank can be introduced into the multi-stage preheaters to heat the material step by step using flash gas (saturated steam). To achieve a step-by-step increase in material temperature, the preheating temperature of the multi-stage preheaters also needs to increase step by step, that is, the temperature of the final preheater (tertiary preheater) is higher than the preheating temperature of the preceding preheaters (primary preheater, secondary preheater). Furthermore, the final preheater can be connected to the primary flash tank, and the primary preheater can be connected to the final flash tank to match the temperature of the multi-stage flash tank and the multi-stage preheaters. Specifically, as shown in Figure 1, the slurry (exemplarily, laterite nickel ore raw material with added water and other auxiliary agents) can be transported to the primary preheater 21 via the primary feed pump 41, and the steam in the tertiary flash tank 33 can be transported to the primary preheater 21. The steam from the tertiary flash tank 33 can heat the slurry in the primary preheater 21, for example, heating the slurry from room temperature to 95 to 100 degrees Celsius. The slurry in the primary preheater 21 can be pumped to the secondary preheater 22 via the secondary feed pump 42, and the steam in the secondary flash tank 32 can also be pumped to the secondary preheater 22. The steam from the secondary flash tank 32 can further heat the slurry within the secondary preheater 22, for example, to 150 to 155 degrees Celsius. The slurry in the secondary preheater 22 can be pumped to the tertiary preheater 23 via the tertiary feed pump 43, and the steam in the primary flash tank 31 can also be pumped to the tertiary preheater 23. The steam from the primary flash tank 31 can further heat the slurry within the tertiary preheater 23, for example, to 200 to 205 degrees Celsius. It can be understood that the above-described multi-stage flash tank, multi-stage feed pump, and multi-stage preheater connection structure and operating process can effectively meet the heating requirements of the slurry and the need for efficient heat recovery and utilization in the high-pressure acid leaching process.

[0037] The slurry, heated by the three-stage preheater 23, can be pumped into the pressure vessel 10 via the pressure vessel feed pump 44. Concentrated sulfuric acid and steam (high-pressure steam) can be added to the pressure vessel 10 in a certain ratio (e.g., a suitable acid-to-ore ratio, i.e., the mass ratio of the dry weight of the slurry to the acid). The heat generated during the dilution by the concentrated sulfuric acid and steam raises the temperature of the slurry to 245 to 255 degrees Celsius. In one experimental example, the leaching rate of nickel in the slurry within the pressure vessel was greater than 95%, the leaching rate of cobalt was greater than 92%, and most impurities such as iron, silicon, and aluminum remained in the slag.

[0038] It is understandable that the primary preheater 21, secondary preheater 22, tertiary preheater 23, pressurized kettle 10 and primary flash tank 31 are all equipped with exhaust gas discharge structures (e.g., exhaust gas discharge pipes) to discharge the exhaust gas generated during the production process.

[0039] Preferably, the primary feed pump 41, the secondary feed pump 42, and the tertiary feed pump 43 can be centrifugal pumps.

[0040] Preferably, the pressure vessel feed pump 44 can be a diaphragm pump, especially a one-way valve diaphragm pump. It is understood that diaphragm pumps have a simple structure, low cost, and good corrosion resistance, making them suitable for use in slurry transportation processes.

[0041] The high-pressure acid leaching system of this embodiment can introduce high-pressure air into the pressure vessel 10. It can be understood that introducing high-pressure air into the pressure vessel 10 can increase the pressure inside the pressure vessel 10, which can avoid or reduce the flashing phenomenon of the slurry in the pressure vessel and discharge pipe in advance (before entering the flash tank).

[0042] The high-pressure acid leaching system of this embodiment can also introduce high-pressure air into the multi-stage flash tanks, particularly into the first-stage flash tank 31. It is understood that when only the flash gas generated by the first-stage flash tank 31 is introduced into the final preheater (tertiary preheater), the slurry in the final preheater is close to or at saturated vapor pressure. Introducing high-pressure air into the first-stage flash tank 31 ensures that the gas delivered to the tertiary preheater 23 includes both flash gas and high-pressure air (normal temperature high-pressure air), which can increase the pressure within the tertiary preheater 23 to some extent, reducing the heat exchange efficiency between the first-stage flash tank 31 and the tertiary preheater 23 (i.e., reducing the effect of the flash gas in raising the slurry temperature to some extent). The aforementioned technical solution of introducing high-pressure air into the primary flash tank 31 can further ensure that the slurry temperature at the outlet of the tertiary preheater is lower than its saturation temperature (under the operating pressure of the tertiary preheater). This, in turn, makes it less likely (to avoid or reduce) cavitation phenomena in the pressure vessel feed pump (especially when it is a diaphragm pump) when the slurry enters the pressure vessel via the pressure vessel feed pump 44, thereby reducing wear and tear on the pressure vessel feed pump and extending its service life. Introducing high-pressure air into the primary flash tank 31 can significantly improve the working environment of the pressure vessel feed pump 44 and valves in the high-pressure acid leaching system, extending their service life, reducing equipment maintenance and replacement frequency, and improving economic efficiency. It is understood that since the pressure vessel is connected to the primary flash tank, introducing high-pressure air only into the pressure vessel 10 can also indirectly introduce high-pressure air into the primary flash tank, achieving the same technical effects.

[0043] During the operation of this high-pressure acid leaching system, high-pressure air can be continuously introduced into the pressurized autoclave and / or flash tank, maintaining the relative stability of the high-pressure air content and pressure within the high-pressure acid leaching system.

[0044] Preferably, the pressure inside the pressure vessel after the introduction of high-pressure air can be 5 to 5.5 MPa (megapascals). The pressure of the high-pressure air introduced into the pressure vessel can be greater than the pressure inside the pressure vessel 10, so that the high-pressure air can be smoothly introduced into the pressure vessel 10. The pressure inside the flash tank after the introduction of high-pressure air can be 2 to 2.2 MPa. The pressure of the high-pressure air introduced into the flash tank (first-stage flash tank) can be greater than the pressure inside the flash tank, so that the high-pressure air can be smoothly introduced into the flash tank. The temperature of the high-pressure air introduced into the pressure vessel and the flash tank can be room temperature. It can be understood that under these pressure and temperature conditions, the aforementioned beneficial effects of introducing high-pressure air into the high-pressure acid leaching system can be well achieved.

[0045] It is understood that the high-pressure air introduced in this embodiment has a different function and effect than the steam (high-pressure steam) introduced into the pressure vessel. High-pressure air and steam can be introduced into the pressure vessel simultaneously or separately.

[0046] The control and regulation system of the high-pressure acid leaching system in this embodiment may include a gas regulation system, which may include valves, and may also include temperature sensors and pressure sensors. Valves can regulate the pressure and flow rate of high-pressure air. Temperature and pressure sensors can monitor the temperature and pressure during the high-pressure air transport process. The gas regulation system can control the amount of flash gas generated by the multi-stage flash tank and / or the amount of high-pressure air introduced into the multi-stage preheater. The flash gas generated by the multi-stage flash tank can be partially or fully (i.e., at least partially) introduced into the multi-stage preheater, and the gas regulation system can control the amount of flash gas introduced into the multi-stage preheater according to actual production needs. It is understood that the gas regulation system can prevent the amount of flash gas introduced into the multi-stage preheater (the heat carried by the flash gas) from being far greater than the amount of flash gas (heat) required by the multi-stage preheater, thereby preventing the slurry at the outlet of the three-stage preheater from approaching saturation (saturated vapor pressure state).

[0047] The gas control system can be configured to adjust the amount of flash gas entering the preheater from the flash tank (including one or more flash tanks) based on the temperature of the preheater (including one or more preheaters), thereby achieving dynamic temperature control within the preheater. Specifically, the gas control system can be configured to adjust the amount of gas entering the preheater from the flash tank connected to each preheater based on the temperature of that preheater.

[0048] The high-pressure acid leaching system may also include a first flow control mechanism, which can be used to regulate the flow rate of high-pressure air introduced into the pressure vessel 10. Further, the first flow control mechanism can be configured to control the flow rate of high-pressure air based on the difference between the internal pressure of the pressure vessel 10 and the pre-valve pressure of the flash tank (first-stage flash tank). Here, the pre-valve pressure refers to the pressure value measured at the valve located upstream of the flash tank. Specifically, the pre-valve pressure of the flash tank is the pressure obtained by subtracting the pipeline loss pressure from the internal pressure of the pressure vessel; that is, the difference between the internal pressure of the pressure vessel 10 and the pre-valve pressure of the flash tank (first-stage flash tank) is the pipeline loss pressure. The difference relationship can include the relative magnitude relationship, the numerical difference relationship, the multiple relationship, etc. In other words, the flow rate of high-pressure air can be controlled based on the relative magnitude, the difference range, the multiple range, etc., of the difference between the internal pressure of the pressure vessel 10 and the pre-valve pressure of the flash tank (first-stage flash tank).

[0049] The first flow control mechanism can be further configured such that multiple consecutive different differential relationships all correspond to the same flow rate, and the flow rate corresponds to the maximum value among these multiple consecutive different differential relationships. That is, when the differential relationships are within a certain range, the flow rate of the high-pressure air is the same. Alternatively, each different differential relationship corresponds to a different flow rate. In other words, the first flow control mechanism can flexibly regulate the flow rate of the high-pressure air in multiple ways.

[0050] The pressure vessel may also include a first exhaust valve, which calculates the theoretical pressure inside the pressure vessel 10 based on the internal pressure and the pressure before the valve of the flash tank. The opening of the first exhaust valve and / or the flow rate of high-pressure air into the pressure vessel 10 are then controlled based on the numerical relationship between the theoretical pressure and the measured (e.g., measured using a pressure gauge) actual pressure inside the vessel. This method enables secondary control of the high-pressure air flow rate, further improving the accuracy of pressure regulation within the pressure vessel. Here, the numerical relationship may include difference relationships, ratio relationships, etc.

[0051] The specific calculation method for the theoretical pressure inside the vessel is the sum of the difference between the internal pressure of the pressure vessel 10 and the pressure before the valve of the flash tank, plus the saturated vapor pressure corresponding to the temperature of the pressure vessel 10. For example, based on practical experience, the theoretical pressure inside the vessel P = P_vessel_saturation + 0.6 MPa.

[0052] The high-pressure acid leaching system may also include a second flow control mechanism, which can be used to control the flow rate of high-pressure air introduced into the flash tank. It can be set to control the flow rate of high-pressure air introduced into the flash tank within a preset range to maintain a stable flow rate of high-pressure air introduced into the flash tank.

[0053] The flash tank (especially the primary flash tank) may include a second vent valve. A second flow control mechanism can control the opening of the second vent valve and / or the flow rate of high-pressure air entering the flash tank based on the relationship between the theoretical tank pressure and the measured (e.g., measured using a pressure gauge) actual tank pressure. The theoretical tank pressure can be calculated as the sum of the saturated vapor pressure corresponding to the temperature of the flash tank (primary flash tank) and a preset range of high-pressure air flow rate. For example, based on practical experience, the theoretical tank pressure P = Ptank saturation + 0.1–0.2 MPa.

[0054] The first and second flow control mechanisms may include valves, pressure gauges, flow meters, and control units. Furthermore, the gas control mechanism and the second flow control mechanism may share some structural components, particularly those within the flash tank (first-stage flash tank). For example, the gas control mechanism and the second flow control mechanism may share a pressure gauge located within the flash tank.

[0055] This application also provides a method for operating a high-pressure acid leaching system, which can be implemented using the aforementioned high-pressure acid leaching system. The method mainly includes: introducing flash gas generated in a flash tank into a preheater for preheating the ore; adding the preheated slurry to a pressure vessel; introducing the slurry from the pressure vessel into a flash tank (first-stage flash tank) for flash evaporation; and introducing high-pressure air into both the pressure vessel and the flash tank (first-stage flash tank). The specific details and technical effects of this method have been described in detail in the above description of the high-pressure acid leaching system and will not be repeated here.

[0056] The following is a brief description of some of the beneficial effects of the above-described embodiments of this application.

[0057] This application proposes a high-pressure acid leaching system that can at least partially introduce flash gas generated by multi-stage flash tanks into a preheater to preheat the slurry, and the appropriate amount of flash gas introduced can be controlled by a gas regulation system. This application also allows high-pressure air to be separately introduced into the pressurized reactor and flash tanks, which can reduce cavitation, extend the service life of the pressurized reactor feed pump and valves, enable long-term stable operation of the equipment, and reduce the operation and maintenance costs of the high-pressure acid leaching system.

[0058] It is understood that, in this application, when the number of parts or components is not specifically limited, the number can be one or more, where multiple refers to two or more. For cases where the number of parts or components shown in the drawings and / or described in the specification is, for example, two, three, four, etc., this specific number is generally exemplary and not restrictive, and can be understood as multiple, i.e., two or more; however, this does not mean that this application excludes the case of one.

[0059] It should be understood that the above embodiments are merely exemplary and are not intended to limit this application. Those skilled in the art can make various modifications and changes to the above embodiments under the teachings of this application without departing from the scope of this application.

[0060] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high pressure acid leaching system, characterized in that, Includes a pressure vessel (10), a preheater, a flash tank, and a pressure vessel feed pump (44), wherein, The pressurizing vessel (10) is connected to the flash tank, which is connected to the preheater to introduce flash gas into the preheater. The preheater is connected to the pressurizing vessel (10) via the pressurizing vessel feed pump (44). High-pressure air is introduced into the pressurized vessel and / or the flash tank.

2. The high pressure acid leaching system of claim 1, wherein, It includes a first flow control mechanism for regulating the flow rate of the high-pressure air introduced into the pressurizing vessel. The first flow control mechanism is configured to control the flow rate of the high-pressure air based on the difference between the internal pressure of the pressurized vessel (10) and the inlet pressure of the flash tank.

3. The high pressure acid leaching system of claim 2, wherein, The first flow control mechanism is configured as follows: Multiple consecutive and different difference relationships all correspond to the same flow rate, and the flow rate corresponds to the maximum value among multiple consecutive and different difference relationships; Alternatively, each of the different difference relationships corresponds to a different flow rate.

4. The high pressure acid leaching system of claim 3, wherein, The pressurized vessel (10) includes a first exhaust valve. The first flow control mechanism calculates the theoretical pressure inside the pressure vessel based on the internal pressure of the pressure vessel (10) and the pressure before the valve of the flash tank. The opening degree of the first exhaust valve and / or the flow rate of the high-pressure air introduced into the pressurized vessel (10) are controlled according to the numerical relationship between the theoretical pressure inside the vessel and the measured actual pressure inside the vessel.

5. The high pressure acid leaching system of claim 4, wherein, The theoretical pressure inside the vessel is calculated by summing the difference between the internal pressure of the pressurized vessel (10) and the pressure before the valve of the flash tank with the saturated vapor pressure corresponding to the temperature of the pressurized vessel (10).

6. The high pressure acid leaching system of claim 4, wherein, The numerical relationships include difference relationships and / or ratio relationships.

7. The high pressure acid leaching system of claim 1, wherein, It includes a second flow control mechanism for regulating the flow rate of high-pressure air introduced into the flash tank. The second flow control mechanism is configured to control the flow rate of the high-pressure air introduced into the flash tank within a preset range.

8. The high pressure acid leaching system of claim 7, wherein, The flash tank includes a second vent valve, and the theoretical internal pressure of the tank is calculated according to the preset range. The second flow control mechanism controls the opening of the second exhaust valve and / or the flow rate of the high-pressure air introduced into the flash tank based on the numerical relationship between the theoretical tank pressure and the measured actual tank pressure.

9. The high pressure acid leaching system of claim 8, wherein, The theoretical pressure inside the tank is calculated as the sum of the saturated vapor pressure corresponding to the temperature of the flash tank and the pressure corresponding to the preset range.

10. The high pressure acid leaching system of claim 1, wherein, It includes a gas control system, which is configured to adjust the amount of flash vapor in the flash tank entering the preheater according to the temperature of the preheater.

11. The high-pressure acid leaching system according to claim 1, characterized in that, The preheater includes at least a primary preheater (21), a secondary preheater (22), and a final preheater with sequentially increasing temperatures, and the flash tank includes at least a primary flash tank (31), a secondary flash tank (32), and a tertiary flash tank (33) with sequentially decreasing pressures. The secondary flash tank (32) is connected to the secondary preheater (22), the tertiary flash tank (33) is connected to the primary preheater (21), and the primary flash tank is connected to the final preheater.

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